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Overview
Comment:Merge the write-ahead-logging changes into the trunk.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: de9ae443cc8eebfb0692dcdac93bde9e4c54199a
User & Date: drh 2010-05-03 14:08:28
Context
2010-05-03
14:32
Use VFS method xCurrentTimeInt64 instead of xCurrentTime when it is available. Provide an implementation of xCurrentTimeInt64 for os_unix.c. check-in: ab77b3ae user: drh tags: trunk
14:08
Merge the write-ahead-logging changes into the trunk. check-in: de9ae443 user: drh tags: trunk
14:05
If the sqlite3_wal_checkpoint() API is passed a NULL pointer in place of a database name, attempt to checkpoint all attached databases. Closed-Leaf check-in: 27a5c09c user: dan tags: wal
2010-04-30
21:03
Avoid assertion faults in queries using indices with redundant columns. Ticket [3dbdcdb14e7f41]. check-in: 946e06cd user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to Makefile.in.

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  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbeblob.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/vdbeInt.h \
  $(TOP)/src/vtab.c \


  $(TOP)/src/walker.c \
  $(TOP)/src/where.c

# Generated source code files
#
SRC += \
  keywordhash.h \
................................................................................

vdbetrace.lo:	$(TOP)/src/vdbetrace.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vdbetrace.c

vtab.lo:	$(TOP)/src/vtab.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vtab.c




walker.lo:	$(TOP)/src/walker.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/walker.c

where.lo:	$(TOP)/src/where.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/where.c

tclsqlite-shell.lo:	$(TOP)/src/tclsqlite.c $(HDR)







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  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbeblob.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/vdbeInt.h \
  $(TOP)/src/vtab.c \
  $(TOP)/src/wal.c \
  $(TOP)/src/wal.h \
  $(TOP)/src/walker.c \
  $(TOP)/src/where.c

# Generated source code files
#
SRC += \
  keywordhash.h \
................................................................................

vdbetrace.lo:	$(TOP)/src/vdbetrace.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vdbetrace.c

vtab.lo:	$(TOP)/src/vtab.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vtab.c

wal.lo:	$(TOP)/src/wal.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/wal.c

walker.lo:	$(TOP)/src/walker.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/walker.c

where.lo:	$(TOP)/src/where.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/where.c

tclsqlite-shell.lo:	$(TOP)/src/tclsqlite.c $(HDR)

Changes to VERSION.

1
3.6.23
|
1
3.7.0

Changes to main.mk.

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         mutex.o mutex_noop.o mutex_os2.o mutex_unix.o mutex_w32.o \
         notify.o opcodes.o os.o os_os2.o os_unix.o os_win.o \
         pager.o parse.o pcache.o pcache1.o pragma.o prepare.o printf.o \
         random.o resolve.o rowset.o rtree.o select.o status.o \
         table.o tokenize.o trigger.o \
         update.o util.o vacuum.o \
         vdbe.o vdbeapi.o vdbeaux.o vdbeblob.o vdbemem.o vdbetrace.o \
         walker.o where.o utf.o vtab.o



# All of the source code files.
#
SRC = \
  $(TOP)/src/alter.c \
................................................................................
  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbeblob.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/vdbeInt.h \
  $(TOP)/src/vtab.c \


  $(TOP)/src/walker.c \
  $(TOP)/src/where.c

# Source code for extensions
#
SRC += \
  $(TOP)/ext/fts1/fts1.c \
................................................................................

#TESTSRC += $(TOP)/ext/fts2/fts2_tokenizer.c
#TESTSRC += $(TOP)/ext/fts3/fts3_tokenizer.c

TESTSRC2 = \
  $(TOP)/src/attach.c $(TOP)/src/backup.c $(TOP)/src/btree.c                   \
  $(TOP)/src/build.c $(TOP)/src/date.c                                         \
  $(TOP)/src/expr.c $(TOP)/src/func.c $(TOP)/src/insert.c $(TOP)/src/mem5.c    \
  $(TOP)/src/os.c                                                              \
  $(TOP)/src/os_os2.c $(TOP)/src/os_unix.c $(TOP)/src/os_win.c                 \
  $(TOP)/src/pager.c $(TOP)/src/pragma.c $(TOP)/src/prepare.c                  \
  $(TOP)/src/printf.c $(TOP)/src/random.c $(TOP)/src/pcache.c                  \
  $(TOP)/src/pcache1.c $(TOP)/src/select.c $(TOP)/src/tokenize.c               \
  $(TOP)/src/utf.c $(TOP)/src/util.c $(TOP)/src/vdbeapi.c $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c $(TOP)/src/vdbemem.c $(TOP)/src/where.c parse.c            \
  $(TOP)/ext/fts3/fts3.c $(TOP)/ext/fts3/fts3_expr.c                           \







|







 







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         mutex.o mutex_noop.o mutex_os2.o mutex_unix.o mutex_w32.o \
         notify.o opcodes.o os.o os_os2.o os_unix.o os_win.o \
         pager.o parse.o pcache.o pcache1.o pragma.o prepare.o printf.o \
         random.o resolve.o rowset.o rtree.o select.o status.o \
         table.o tokenize.o trigger.o \
         update.o util.o vacuum.o \
         vdbe.o vdbeapi.o vdbeaux.o vdbeblob.o vdbemem.o vdbetrace.o \
         wal.o walker.o where.o utf.o vtab.o



# All of the source code files.
#
SRC = \
  $(TOP)/src/alter.c \
................................................................................
  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbeblob.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/vdbeInt.h \
  $(TOP)/src/vtab.c \
  $(TOP)/src/wal.c \
  $(TOP)/src/wal.h \
  $(TOP)/src/walker.c \
  $(TOP)/src/where.c

# Source code for extensions
#
SRC += \
  $(TOP)/ext/fts1/fts1.c \
................................................................................

#TESTSRC += $(TOP)/ext/fts2/fts2_tokenizer.c
#TESTSRC += $(TOP)/ext/fts3/fts3_tokenizer.c

TESTSRC2 = \
  $(TOP)/src/attach.c $(TOP)/src/backup.c $(TOP)/src/btree.c                   \
  $(TOP)/src/build.c $(TOP)/src/date.c                                         \
  $(TOP)/src/expr.c $(TOP)/src/func.c $(TOP)/src/insert.c $(TOP)/src/wal.c     \
  $(TOP)/src/mem5.c $(TOP)/src/os.c                                            \
  $(TOP)/src/os_os2.c $(TOP)/src/os_unix.c $(TOP)/src/os_win.c                 \
  $(TOP)/src/pager.c $(TOP)/src/pragma.c $(TOP)/src/prepare.c                  \
  $(TOP)/src/printf.c $(TOP)/src/random.c $(TOP)/src/pcache.c                  \
  $(TOP)/src/pcache1.c $(TOP)/src/select.c $(TOP)/src/tokenize.c               \
  $(TOP)/src/utf.c $(TOP)/src/util.c $(TOP)/src/vdbeapi.c $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c $(TOP)/src/vdbemem.c $(TOP)/src/where.c parse.c            \
  $(TOP)/ext/fts3/fts3.c $(TOP)/ext/fts3/fts3_expr.c                           \

Changes to src/btree.c.

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    int pageSize;
    int usableSize;
    u8 *page1 = pPage1->aData;
    rc = SQLITE_NOTADB;
    if( memcmp(page1, zMagicHeader, 16)!=0 ){
      goto page1_init_failed;
    }


    if( page1[18]>1 ){
      pBt->readOnly = 1;
    }
    if( page1[19]>1 ){
      goto page1_init_failed;
    }





























    /* The maximum embedded fraction must be exactly 25%.  And the minimum
    ** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.
    ** The original design allowed these amounts to vary, but as of
    ** version 3.6.0, we require them to be fixed.
    */
    if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
................................................................................
  assert( cursorHoldsMutex(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  assert(!pCur->isIncrblobHandle);
  assert(!pCur->aOverflow);
  pCur->isIncrblobHandle = 1;
}
#endif











































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    int pageSize;
    int usableSize;
    u8 *page1 = pPage1->aData;
    rc = SQLITE_NOTADB;
    if( memcmp(page1, zMagicHeader, 16)!=0 ){
      goto page1_init_failed;
    }

#ifdef SQLITE_OMIT_WAL
    if( page1[18]>1 ){
      pBt->readOnly = 1;
    }
    if( page1[19]>1 ){
      goto page1_init_failed;
    }
#else
    if( page1[18]>2 ){
      pBt->readOnly = 1;
    }
    if( page1[19]>2 ){
      goto page1_init_failed;
    }

    /* If the write version is set to 2, this database should be accessed
    ** in WAL mode. If the log is not already open, open it now. Then 
    ** return SQLITE_OK and return without populating BtShared.pPage1.
    ** The caller detects this and calls this function again. This is
    ** required as the version of page 1 currently in the page1 buffer
    ** may not be the latest version - there may be a newer one in the log
    ** file.
    */
    if( page1[19]==2 && pBt->doNotUseWAL==0 ){
      int isOpen = 0;
      rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);
      if( rc!=SQLITE_OK ){
        goto page1_init_failed;
      }else if( isOpen==0 ){
        releasePage(pPage1);
        return SQLITE_OK;
      }
      rc = SQLITE_NOTADB;
    }
#endif

    /* The maximum embedded fraction must be exactly 25%.  And the minimum
    ** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.
    ** The original design allowed these amounts to vary, but as of
    ** version 3.6.0, we require them to be fixed.
    */
    if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
................................................................................
  assert( cursorHoldsMutex(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  assert(!pCur->isIncrblobHandle);
  assert(!pCur->aOverflow);
  pCur->isIncrblobHandle = 1;
}
#endif

/*
** Set both the "read version" (single byte at byte offset 18) and 
** "write version" (single byte at byte offset 19) fields in the database
** header to iVersion.
*/
int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
  BtShared *pBt = pBtree->pBt;
  int rc;                         /* Return code */
 
  assert( pBtree->inTrans==TRANS_NONE );
  assert( iVersion==1 || iVersion==2 );

  /* If setting the version fields to 1, do not automatically open the
  ** WAL connection, even if the version fields are currently set to 2.
  */
  pBt->doNotUseWAL = (iVersion==1);

  rc = sqlite3BtreeBeginTrans(pBtree, 0);
  if( rc==SQLITE_OK ){
    u8 *aData = pBt->pPage1->aData;
    if( aData[18]!=(u8)iVersion || aData[19]!=(u8)iVersion ){
      rc = sqlite3BtreeBeginTrans(pBtree, 2);
      if( rc==SQLITE_OK ){
        rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
        if( rc==SQLITE_OK ){
          aData[18] = (u8)iVersion;
          aData[19] = (u8)iVersion;
        }
      }
    }
  }

  pBt->doNotUseWAL = 0;
  return rc;
}

Changes to src/btree.h.

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char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
struct Pager *sqlite3BtreePager(Btree*);

int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
void sqlite3BtreeCacheOverflow(BtCursor *);
void sqlite3BtreeClearCursor(BtCursor *);



#ifndef NDEBUG
int sqlite3BtreeCursorIsValid(BtCursor*);
#endif

#ifndef SQLITE_OMIT_BTREECOUNT
int sqlite3BtreeCount(BtCursor *, i64 *);







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char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
struct Pager *sqlite3BtreePager(Btree*);

int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
void sqlite3BtreeCacheOverflow(BtCursor *);
void sqlite3BtreeClearCursor(BtCursor *);

int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);

#ifndef NDEBUG
int sqlite3BtreeCursorIsValid(BtCursor*);
#endif

#ifndef SQLITE_OMIT_BTREECOUNT
int sqlite3BtreeCount(BtCursor *, i64 *);

Changes to src/btreeInt.h.

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  u16 pageSize;         /* Total number of bytes on a page */
  u16 usableSize;       /* Number of usable bytes on each page */
  u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
  u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
  u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */
  u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */
  u8 inTransaction;     /* Transaction state */

  int nTransaction;     /* Number of open transactions (read + write) */
  u32 nPage;            /* Number of pages in the database */
  void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
  void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */
  sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */
  Bitvec *pHasContent;  /* Set of pages moved to free-list this transaction */
#ifndef SQLITE_OMIT_SHARED_CACHE







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  u16 pageSize;         /* Total number of bytes on a page */
  u16 usableSize;       /* Number of usable bytes on each page */
  u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
  u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
  u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */
  u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */
  u8 inTransaction;     /* Transaction state */
  u8 doNotUseWAL;       /* If true, do not open write-ahead-log file */
  int nTransaction;     /* Number of open transactions (read + write) */
  u32 nPage;            /* Number of pages in the database */
  void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
  void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */
  sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */
  Bitvec *pHasContent;  /* Set of pages moved to free-list this transaction */
#ifndef SQLITE_OMIT_SHARED_CACHE

Changes to src/main.c.

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  pRet = db->pRollbackArg;
  db->xRollbackCallback = xCallback;
  db->pRollbackArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}









































































































































/*
** This function returns true if main-memory should be used instead of
** a temporary file for transient pager files and statement journals.
** The value returned depends on the value of db->temp_store (runtime
** parameter) and the compile time value of SQLITE_TEMP_STORE. The
** following table describes the relationship between these two values
** and this functions return value.
................................................................................
  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
                          SQLITE_DEFAULT_LOCKING_MODE);
#endif

  /* Enable the lookaside-malloc subsystem */
  setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
                        sqlite3GlobalConfig.nLookaside);



opendb_out:
  if( db ){
    assert( db->mutex!=0 || isThreadsafe==0 || sqlite3GlobalConfig.bFullMutex==0 );
    sqlite3_mutex_leave(db->mutex);
  }
  rc = sqlite3_errcode(db);







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1890
1891
1892
  pRet = db->pRollbackArg;
  db->xRollbackCallback = xCallback;
  db->pRollbackArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}

#ifndef SQLITE_OMIT_WAL
/*
** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
** Return non-zero, indicating to the caller that a checkpoint should be run,
** if the number of frames in the log file is greater than 
** sqlite3.pWalArg cast to an integer (the value configured by
** wal_autocheckpoint()).
*/ 
int sqlite3WalDefaultHook(
  void *p,               /* Argument */
  sqlite3 *db,           /* Connection */
  const char *zNotUsed,  /* Database */
  int nFrame             /* Size of WAL */
){
  UNUSED_PARAMETER(zNotUsed);
  return ( nFrame>=SQLITE_PTR_TO_INT(p));
}
#endif /* SQLITE_OMIT_WAL */

/*
** Configure an sqlite3_wal_hook() callback to automatically checkpoint
** a database after committing a transaction if there are nFrame or
** more frames in the log file. Passing zero or a negative value as the
** nFrame parameter disables automatic checkpoints entirely.
**
** The callback registered by this function replaces any existing callback
** registered using sqlite3_wal_hook(). Likewise, registering a callback
** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
** configured by this function.
*/
int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
#ifndef SQLITE_OMIT_WAL
  sqlite3_mutex_enter(db->mutex);
  if( nFrame>0 ){
    sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
  }else{
    sqlite3_wal_hook(db, 0, 0);
  }
  sqlite3_mutex_leave(db->mutex);
#endif
  return SQLITE_OK;
}

/*
** Register a callback to be invoked each time a transaction is written
** into the write-ahead-log by this database connection.
*/
void *sqlite3_wal_hook(
  sqlite3 *db,                    /* Attach the hook to this db handle */
  int(*xCallback)(void *, sqlite3*, const char*, int),
  void *pArg                      /* First argument passed to xCallback() */
){
#ifndef SQLITE_OMIT_WAL
  void *pRet;
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pWalArg;
  db->xWalCallback = xCallback;
  db->pWalArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
#else
  return 0;
#endif
}


/*
** Checkpoint database zDb. If zDb is NULL, the main database is checkpointed.
*/
int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
#ifdef SQLITE_OMIT_WAL
  return SQLITE_OK;
#else
  int rc;                         /* Return code */
  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */

  sqlite3_mutex_enter(db->mutex);
  if( zDb ){
    iDb = sqlite3FindDbName(db, zDb);
  }
  if( iDb<0 ){
    rc = SQLITE_ERROR;
    sqlite3Error(db, SQLITE_ERROR, "unknown database: %s", zDb);
  }else{
    rc = sqlite3Checkpoint(db, iDb);
    sqlite3Error(db, rc, 0);
  }
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
#endif
}

#ifndef SQLITE_OMIT_WAL
/*
** Run a checkpoint on database iDb. This is a no-op if database iDb is
** not currently open in WAL mode.
**
** If a transaction is open on the database being checkpointed, this 
** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 
** an error occurs while running the checkpoint, an SQLite error code is 
** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
**
** The mutex on database handle db should be held by the caller. The mutex
** associated with the specific b-tree being checkpointed is taken by
** this function while the checkpoint is running.
**
** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
** checkpointed. If an error is encountered it is returned immediately -
** no attempt is made to checkpoint any remaining databases.
*/
int sqlite3Checkpoint(sqlite3 *db, int iDb){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Used to iterate through attached dbs */

  assert( sqlite3_mutex_held(db->mutex) );

  for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
    if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
      Btree *pBt = db->aDb[i].pBt;
      if( pBt ){
        if( sqlite3BtreeIsInReadTrans(pBt) ){
          rc = SQLITE_LOCKED;
        }else{
          sqlite3BtreeEnter(pBt);
          rc = sqlite3PagerCheckpoint(sqlite3BtreePager(pBt));
          sqlite3BtreeLeave(pBt);
        }
      }
    }
  }

  return rc;
}
#endif /* SQLITE_OMIT_WAL */

/*
** This function returns true if main-memory should be used instead of
** a temporary file for transient pager files and statement journals.
** The value returned depends on the value of db->temp_store (runtime
** parameter) and the compile time value of SQLITE_TEMP_STORE. The
** following table describes the relationship between these two values
** and this functions return value.
................................................................................
  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
                          SQLITE_DEFAULT_LOCKING_MODE);
#endif

  /* Enable the lookaside-malloc subsystem */
  setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
                        sqlite3GlobalConfig.nLookaside);

  sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);

opendb_out:
  if( db ){
    assert( db->mutex!=0 || isThreadsafe==0 || sqlite3GlobalConfig.bFullMutex==0 );
    sqlite3_mutex_leave(db->mutex);
  }
  rc = sqlite3_errcode(db);

Changes to src/mutex.c.

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84
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86
  return rc;
}

/*
** Retrieve a pointer to a static mutex or allocate a new dynamic one.
*/
sqlite3_mutex *sqlite3_mutex_alloc(int id){

#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

sqlite3_mutex *sqlite3MutexAlloc(int id){







>







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  return rc;
}

/*
** Retrieve a pointer to a static mutex or allocate a new dynamic one.
*/
sqlite3_mutex *sqlite3_mutex_alloc(int id){
  if( !sqlite3GlobalConfig.bCoreMutex ) return 0;
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

sqlite3_mutex *sqlite3MutexAlloc(int id){

Changes to src/os_common.h.

36
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42

43
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50

51
52
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#define OSTRACE3(X,Y,Z)     if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z)
#define OSTRACE4(X,Y,Z,A)   if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z,A)
#define OSTRACE5(X,Y,Z,A,B) if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z,A,B)
#define OSTRACE6(X,Y,Z,A,B,C) \
    if(sqlite3OSTrace) sqlite3DebugPrintf(X,Y,Z,A,B,C)
#define OSTRACE7(X,Y,Z,A,B,C,D) \
    if(sqlite3OSTrace) sqlite3DebugPrintf(X,Y,Z,A,B,C,D)

#else
#define OSTRACE1(X)
#define OSTRACE2(X,Y)
#define OSTRACE3(X,Y,Z)
#define OSTRACE4(X,Y,Z,A)
#define OSTRACE5(X,Y,Z,A,B)
#define OSTRACE6(X,Y,Z,A,B,C)
#define OSTRACE7(X,Y,Z,A,B,C,D)

#endif

/*
** Macros for performance tracing.  Normally turned off.  Only works
** on i486 hardware.
*/
#ifdef SQLITE_PERFORMANCE_TRACE







>








>







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#define OSTRACE3(X,Y,Z)     if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z)
#define OSTRACE4(X,Y,Z,A)   if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z,A)
#define OSTRACE5(X,Y,Z,A,B) if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z,A,B)
#define OSTRACE6(X,Y,Z,A,B,C) \
    if(sqlite3OSTrace) sqlite3DebugPrintf(X,Y,Z,A,B,C)
#define OSTRACE7(X,Y,Z,A,B,C,D) \
    if(sqlite3OSTrace) sqlite3DebugPrintf(X,Y,Z,A,B,C,D)
#define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
#define OSTRACE1(X)
#define OSTRACE2(X,Y)
#define OSTRACE3(X,Y,Z)
#define OSTRACE4(X,Y,Z,A)
#define OSTRACE5(X,Y,Z,A,B)
#define OSTRACE6(X,Y,Z,A,B,C)
#define OSTRACE7(X,Y,Z,A,B,C,D)
#define OSTRACE(X)
#endif

/*
** Macros for performance tracing.  Normally turned off.  Only works
** on i486 hardware.
*/
#ifdef SQLITE_PERFORMANCE_TRACE

Changes to src/os_os2.c.

1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
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1118
1119
1120
1121
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1124
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    os2DlOpen,         /* xDlOpen */
    os2DlError,        /* xDlError */
    os2DlSym,          /* xDlSym */
    os2DlClose,        /* xDlClose */
    os2Randomness,     /* xRandomness */
    os2Sleep,          /* xSleep */
    os2CurrentTime,    /* xCurrentTime */
    os2GetLastError    /* xGetLastError */
  };
  sqlite3_vfs_register(&os2Vfs, 1);
  initUconvObjects();
  return SQLITE_OK;
}
int sqlite3_os_end(void){
  freeUconvObjects();
  return SQLITE_OK;
}

#endif /* SQLITE_OS_OS2 */







|











1107
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1121
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    os2DlOpen,         /* xDlOpen */
    os2DlError,        /* xDlError */
    os2DlSym,          /* xDlSym */
    os2DlClose,        /* xDlClose */
    os2Randomness,     /* xRandomness */
    os2Sleep,          /* xSleep */
    os2CurrentTime,    /* xCurrentTime */
    os2GetLastError,   /* xGetLastError */
  };
  sqlite3_vfs_register(&os2Vfs, 1);
  initUconvObjects();
  return SQLITE_OK;
}
int sqlite3_os_end(void){
  freeUconvObjects();
  return SQLITE_OK;
}

#endif /* SQLITE_OS_OS2 */

Changes to src/os_unix.c.

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5776
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5778
5779
5780
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5782
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <errno.h>


#if SQLITE_ENABLE_LOCKING_STYLE
# include <sys/ioctl.h>
# if OS_VXWORKS
#  include <semaphore.h>
#  include <limits.h>
# else
................................................................................
    ** reading the database file again, make sure that the
    ** transaction counter was updated if any part of the database
    ** file changed.  If the transaction counter is not updated,
    ** other connections to the same file might not realize that
    ** the file has changed and hence might not know to flush their
    ** cache.  The use of a stale cache can lead to database corruption.
    */

    assert( pFile->inNormalWrite==0
         || pFile->dbUpdate==0
         || pFile->transCntrChng==1 );

    pFile->inNormalWrite = 0;
#endif

    /* downgrading to a shared lock on NFS involves clearing the write lock
    ** before establishing the readlock - to avoid a race condition we downgrade
    ** the lock in 2 blocks, so that part of the range will be covered by a 
    ** write lock until the rest is covered by a read lock:
................................................................................
){
  unixFile *pFile = (unixFile *)id;
  int got;
  assert( id );

  /* If this is a database file (not a journal, master-journal or temp
  ** file), the bytes in the locking range should never be read or written. */

  assert( pFile->pUnused==0
       || offset>=PENDING_BYTE+512
       || offset+amt<=PENDING_BYTE 
  );


  got = seekAndRead(pFile, offset, pBuf, amt);
  if( got==amt ){
    return SQLITE_OK;
  }else if( got<0 ){
    /* lastErrno set by seekAndRead */
    return SQLITE_IOERR_READ;
................................................................................
  unixFile *pFile = (unixFile*)id;
  int wrote = 0;
  assert( id );
  assert( amt>0 );

  /* If this is a database file (not a journal, master-journal or temp
  ** file), the bytes in the locking range should never be read or written. */

  assert( pFile->pUnused==0
       || offset>=PENDING_BYTE+512
       || offset+amt<=PENDING_BYTE 
  );


#ifndef NDEBUG
  /* If we are doing a normal write to a database file (as opposed to
  ** doing a hot-journal rollback or a write to some file other than a
  ** normal database file) then record the fact that the database
  ** has changed.  If the transaction counter is modified, record that
  ** fact too.
................................................................................
static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
  UNUSED_PARAMETER(NotUsed);
  UNUSED_PARAMETER(NotUsed2);
  UNUSED_PARAMETER(NotUsed3);
  return 0;
}















































































































































































































































































































































































































































































































































































































































































































































































































































/*
************************ End of sqlite3_vfs methods ***************************
******************************************************************************/

/******************************************************************************
************************** Begin Proxy Locking ********************************
**
................................................................................
  ** Most finders simply return a pointer to a fixed sqlite3_io_methods
  ** object.  But the "autolockIoFinder" available on MacOSX does a little
  ** more than that; it looks at the filesystem type that hosts the 
  ** database file and tries to choose an locking method appropriate for
  ** that filesystem time.
  */
  #define UNIXVFS(VFSNAME, FINDER) {                        \
    1,                    /* iVersion */                    \
    sizeof(unixFile),     /* szOsFile */                    \
    MAX_PATHNAME,         /* mxPathname */                  \
    0,                    /* pNext */                       \
    VFSNAME,              /* zName */                       \
    (void*)&FINDER,       /* pAppData */                    \
    unixOpen,             /* xOpen */                       \
    unixDelete,           /* xDelete */                     \
................................................................................
    unixDlOpen,           /* xDlOpen */                     \
    unixDlError,          /* xDlError */                    \
    unixDlSym,            /* xDlSym */                      \
    unixDlClose,          /* xDlClose */                    \
    unixRandomness,       /* xRandomness */                 \
    unixSleep,            /* xSleep */                      \
    unixCurrentTime,      /* xCurrentTime */                \
    unixGetLastError      /* xGetLastError */               \








  }

  /*
  ** All default VFSes for unix are contained in the following array.
  **
  ** Note that the sqlite3_vfs.pNext field of the VFS object is modified
  ** by the SQLite core when the VFS is registered.  So the following







>







 







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#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <errno.h>
#include <sys/mman.h>

#if SQLITE_ENABLE_LOCKING_STYLE
# include <sys/ioctl.h>
# if OS_VXWORKS
#  include <semaphore.h>
#  include <limits.h>
# else
................................................................................
    ** reading the database file again, make sure that the
    ** transaction counter was updated if any part of the database
    ** file changed.  If the transaction counter is not updated,
    ** other connections to the same file might not realize that
    ** the file has changed and hence might not know to flush their
    ** cache.  The use of a stale cache can lead to database corruption.
    */
#if 0
    assert( pFile->inNormalWrite==0
         || pFile->dbUpdate==0
         || pFile->transCntrChng==1 );
#endif
    pFile->inNormalWrite = 0;
#endif

    /* downgrading to a shared lock on NFS involves clearing the write lock
    ** before establishing the readlock - to avoid a race condition we downgrade
    ** the lock in 2 blocks, so that part of the range will be covered by a 
    ** write lock until the rest is covered by a read lock:
................................................................................
){
  unixFile *pFile = (unixFile *)id;
  int got;
  assert( id );

  /* If this is a database file (not a journal, master-journal or temp
  ** file), the bytes in the locking range should never be read or written. */
#if 0
  assert( pFile->pUnused==0
       || offset>=PENDING_BYTE+512
       || offset+amt<=PENDING_BYTE 
  );
#endif

  got = seekAndRead(pFile, offset, pBuf, amt);
  if( got==amt ){
    return SQLITE_OK;
  }else if( got<0 ){
    /* lastErrno set by seekAndRead */
    return SQLITE_IOERR_READ;
................................................................................
  unixFile *pFile = (unixFile*)id;
  int wrote = 0;
  assert( id );
  assert( amt>0 );

  /* If this is a database file (not a journal, master-journal or temp
  ** file), the bytes in the locking range should never be read or written. */
#if 0
  assert( pFile->pUnused==0
       || offset>=PENDING_BYTE+512
       || offset+amt<=PENDING_BYTE 
  );
#endif

#ifndef NDEBUG
  /* If we are doing a normal write to a database file (as opposed to
  ** doing a hot-journal rollback or a write to some file other than a
  ** normal database file) then record the fact that the database
  ** has changed.  If the transaction counter is modified, record that
  ** fact too.
................................................................................
static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
  UNUSED_PARAMETER(NotUsed);
  UNUSED_PARAMETER(NotUsed2);
  UNUSED_PARAMETER(NotUsed3);
  return 0;
}

#ifndef SQLITE_OMIT_WAL

/* Forward reference */
typedef struct unixShm unixShm;
typedef struct unixShmFile unixShmFile;

/*
** Object used to represent a single file opened and mmapped to provide
** shared memory.  When multiple threads all reference the same
** log-summary, each thread has its own unixFile object, but they all
** point to a single instance of this object.  In other words, each
** log-summary is opened only once per process.
**
** unixMutexHeld() must be true when creating or destroying
** this object or while reading or writing the following fields:
**
**      nRef
**      pNext 
**
** The following fields are read-only after the object is created:
** 
**      fid
**      zFilename
**
** Either unixShmFile.mutex must be held or unixShmFile.nRef==0 and
** unixMutexHeld() is true when reading or writing any other field
** in this structure.
**
** To avoid deadlocks, mutex and mutexBuf are always released in the
** reverse order that they are acquired.  mutexBuf is always acquired
** first and released last.  This invariant is check by asserting
** sqlite3_mutex_notheld() on mutex whenever mutexBuf is acquired or
** released.
*/
struct unixShmFile {
  struct unixFileId fid;     /* Unique file identifier */
  sqlite3_mutex *mutex;      /* Mutex to access this object */
  sqlite3_mutex *mutexBuf;   /* Mutex to access zBuf[] */
  char *zFilename;           /* Name of the file */
  int h;                     /* Open file descriptor */
  int szMap;                 /* Size of the mapping of file into memory */
  char *pMMapBuf;            /* Where currently mmapped().  NULL if unmapped */
  int nRef;                  /* Number of unixShm objects pointing to this */
  unixShm *pFirst;           /* All unixShm objects pointing to this */
  unixShmFile *pNext;        /* Next in list of all unixShmFile objects */
#ifdef SQLITE_DEBUG
  u8 exclMask;               /* Mask of exclusive locks held */
  u8 sharedMask;             /* Mask of shared locks held */
  u8 nextShmId;              /* Next available unixShm.id value */
#endif
};

/*
** A global array of all unixShmFile objects.
**
** The unixMutexHeld() must be true while reading or writing this list.
*/
static unixShmFile *unixShmFileList = 0;

/*
** Structure used internally by this VFS to record the state of an
** open shared memory connection.
**
** unixShm.pFile->mutex must be held while reading or writing the
** unixShm.pNext and unixShm.locks[] elements.
**
** The unixShm.pFile element is initialized when the object is created
** and is read-only thereafter.
*/
struct unixShm {
  unixShmFile *pFile;        /* The underlying unixShmFile object */
  unixShm *pNext;            /* Next unixShm with the same unixShmFile */
  u8 lockState;              /* Current lock state */
  u8 readLock;               /* Which of the two read-lock states to use */
  u8 hasMutex;               /* True if holding the unixShmFile mutex */
  u8 hasMutexBuf;            /* True if holding pFile->mutexBuf */
  u8 sharedMask;             /* Mask of shared locks held */
  u8 exclMask;               /* Mask of exclusive locks held */
#ifdef SQLITE_DEBUG
  u8 id;                     /* Id of this connection with its unixShmFile */
#endif
};

/*
** Size increment by which shared memory grows
*/
#define SQLITE_UNIX_SHM_INCR  4096

/*
** Constants used for locking
*/
#define UNIX_SHM_BASE      32        /* Byte offset of the first lock byte */
#define UNIX_SHM_MUTEX     0x01      /* Mask for MUTEX lock */
#define UNIX_SHM_DMS       0x04      /* Mask for Dead-Man-Switch lock */
#define UNIX_SHM_A         0x10      /* Mask for region locks... */
#define UNIX_SHM_B         0x20
#define UNIX_SHM_C         0x40
#define UNIX_SHM_D         0x80

#ifdef SQLITE_DEBUG
/*
** Return a pointer to a nul-terminated string in static memory that
** describes a locking mask.  The string is of the form "MSABCD" with
** each character representing a lock.  "M" for MUTEX, "S" for DMS, 
** and "A" through "D" for the region locks.  If a lock is held, the
** letter is shown.  If the lock is not held, the letter is converted
** to ".".
**
** This routine is for debugging purposes only and does not appear
** in a production build.
*/
static const char *unixShmLockString(u8 mask){
  static char zBuf[48];
  static int iBuf = 0;
  char *z;

  z = &zBuf[iBuf];
  iBuf += 8;
  if( iBuf>=sizeof(zBuf) ) iBuf = 0;

  z[0] = (mask & UNIX_SHM_MUTEX) ? 'M' : '.';
  z[1] = (mask & UNIX_SHM_DMS)   ? 'S' : '.';
  z[2] = (mask & UNIX_SHM_A)     ? 'A' : '.';
  z[3] = (mask & UNIX_SHM_B)     ? 'B' : '.';
  z[4] = (mask & UNIX_SHM_C)     ? 'C' : '.';
  z[5] = (mask & UNIX_SHM_D)     ? 'D' : '.';
  z[6] = 0;
  return z;
}
#endif /* SQLITE_DEBUG */

/*
** Apply posix advisory locks for all bytes identified in lockMask.
**
** lockMask might contain multiple bits but all bits are guaranteed
** to be contiguous.
**
** Locks block if the UNIX_SHM_MUTEX bit is set and are non-blocking
** otherwise.
*/
static int unixShmSystemLock(
  unixShmFile *pFile,   /* Apply locks to this open shared-memory segment */
  int lockType,         /* F_UNLCK, F_RDLCK, or F_WRLCK */
  u8 lockMask           /* Which bytes to lock or unlock */
){
  struct flock f;       /* The posix advisory locking structure */
  int lockOp;           /* The opcode for fcntl() */
  int i;                /* Offset into the locking byte range */
  int rc;               /* Result code form fcntl() */
  u8 mask;              /* Mask of bits in lockMask */

  /* Access to the unixShmFile object is serialized by the caller */
  assert( sqlite3_mutex_held(pFile->mutex) || pFile->nRef==0 );

  /* Initialize the locking parameters */
  memset(&f, 0, sizeof(f));
  f.l_type = lockType;
  f.l_whence = SEEK_SET;
  if( (lockMask & UNIX_SHM_MUTEX)!=0 && lockType!=F_UNLCK ){
    lockOp = F_SETLKW;
    OSTRACE(("SHM-LOCK requesting blocking lock\n"));
  }else{
    lockOp = F_SETLK;
  }

  /* Find the first bit in lockMask that is set */
  for(i=0, mask=0x01; mask!=0 && (lockMask&mask)==0; mask <<= 1, i++){}
  assert( mask!=0 );
  f.l_start = i+UNIX_SHM_BASE;
  f.l_len = 1;

  /* Extend the locking range for each additional bit that is set */
  mask <<= 1;
  while( mask!=0 && (lockMask & mask)!=0 ){
    f.l_len++;
    mask <<= 1;
  }

  /* Verify that all bits set in lockMask are contiguous */
  assert( mask==0 || (lockMask & ~(mask | (mask-1)))==0 );

  /* Acquire the system-level lock */
  rc = fcntl(pFile->h, lockOp, &f);
  rc = (rc!=(-1)) ? SQLITE_OK : SQLITE_BUSY;

  /* Update the global lock state and do debug tracing */
#ifdef SQLITE_DEBUG
  OSTRACE(("SHM-LOCK "));
  if( rc==SQLITE_OK ){
    if( lockType==F_UNLCK ){
      OSTRACE(("unlock ok"));
      pFile->exclMask &= ~lockMask;
      pFile->sharedMask &= ~lockMask;
    }else if( lockType==F_RDLCK ){
      OSTRACE(("read-lock ok"));
      pFile->exclMask &= ~lockMask;
      pFile->sharedMask |= lockMask;
    }else{
      assert( lockType==F_WRLCK );
      OSTRACE(("write-lock ok"));
      pFile->exclMask |= lockMask;
      pFile->sharedMask &= ~lockMask;
    }
  }else{
    if( lockType==F_UNLCK ){
      OSTRACE(("unlock failed"));
    }else if( lockType==F_RDLCK ){
      OSTRACE(("read-lock failed"));
    }else{
      assert( lockType==F_WRLCK );
      OSTRACE(("write-lock failed"));
    }
  }
  OSTRACE((" - change requested %s - afterwards %s:%s\n",
           unixShmLockString(lockMask),
           unixShmLockString(pFile->sharedMask),
           unixShmLockString(pFile->exclMask)));
#endif

  return rc;        
}

/*
** For connection p, unlock all of the locks identified by the unlockMask
** parameter.
*/
static int unixShmUnlock(
  unixShmFile *pFile,   /* The underlying shared-memory file */
  unixShm *p,           /* The connection to be unlocked */
  u8 unlockMask         /* Mask of locks to be unlocked */
){
  int rc;      /* Result code */
  unixShm *pX; /* For looping over all sibling connections */
  u8 allMask;  /* Union of locks held by connections other than "p" */

  /* Access to the unixShmFile object is serialized by the caller */
  assert( sqlite3_mutex_held(pFile->mutex) );

  /* Compute locks held by sibling connections */
  allMask = 0;
  for(pX=pFile->pFirst; pX; pX=pX->pNext){
    if( pX==p ) continue;
    assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
    allMask |= pX->sharedMask;
  }

  /* Unlock the system-level locks */
  if( (unlockMask & allMask)!=unlockMask ){
    rc = unixShmSystemLock(pFile, F_UNLCK, unlockMask & ~allMask);
  }else{
    rc = SQLITE_OK;
  }

  /* Undo the local locks */
  if( rc==SQLITE_OK ){
    p->exclMask &= ~unlockMask;
    p->sharedMask &= ~unlockMask;
  } 
  return rc;
}

/*
** Get reader locks for connection p on all locks in the readMask parameter.
*/
static int unixShmSharedLock(
  unixShmFile *pFile,   /* The underlying shared-memory file */
  unixShm *p,           /* The connection to get the shared locks */
  u8 readMask           /* Mask of shared locks to be acquired */
){
  int rc;        /* Result code */
  unixShm *pX;   /* For looping over all sibling connections */
  u8 allShared;  /* Union of locks held by connections other than "p" */

  /* Access to the unixShmFile object is serialized by the caller */
  assert( sqlite3_mutex_held(pFile->mutex) );

  /* Find out which shared locks are already held by sibling connections.
  ** If any sibling already holds an exclusive lock, go ahead and return
  ** SQLITE_BUSY.
  */
  allShared = 0;
  for(pX=pFile->pFirst; pX; pX=pX->pNext){
    if( pX==p ) continue;
    if( (pX->exclMask & readMask)!=0 ) return SQLITE_BUSY;
    allShared |= pX->sharedMask;
  }

  /* Get shared locks at the system level, if necessary */
  if( (~allShared) & readMask ){
    rc = unixShmSystemLock(pFile, F_RDLCK, readMask);
  }else{
    rc = SQLITE_OK;
  }

  /* Get the local shared locks */
  if( rc==SQLITE_OK ){
    p->sharedMask |= readMask;
  }
  return rc;
}

/*
** For connection p, get an exclusive lock on all locks identified in
** the writeMask parameter.
*/
static int unixShmExclusiveLock(
  unixShmFile *pFile,    /* The underlying shared-memory file */
  unixShm *p,            /* The connection to get the exclusive locks */
  u8 writeMask           /* Mask of exclusive locks to be acquired */
){
  int rc;        /* Result code */
  unixShm *pX;   /* For looping over all sibling connections */

  /* Access to the unixShmFile object is serialized by the caller */
  assert( sqlite3_mutex_held(pFile->mutex) );

  /* Make sure no sibling connections hold locks that will block this
  ** lock.  If any do, return SQLITE_BUSY right away.
  */
  for(pX=pFile->pFirst; pX; pX=pX->pNext){
    if( pX==p ) continue;
    if( (pX->exclMask & writeMask)!=0 ) return SQLITE_BUSY;
    if( (pX->sharedMask & writeMask)!=0 ) return SQLITE_BUSY;
  }

  /* Get the exclusive locks at the system level.  Then if successful
  ** also mark the local connection as being locked.
  */
  rc = unixShmSystemLock(pFile, F_WRLCK, writeMask);
  if( rc==SQLITE_OK ){
    p->sharedMask &= ~writeMask;
    p->exclMask |= writeMask;
  }
  return rc;
}

/*
** Purge the unixShmFileList list of all entries with unixShmFile.nRef==0.
**
** This is not a VFS shared-memory method; it is a utility function called
** by VFS shared-memory methods.
*/
static void unixShmPurge(void){
  unixShmFile **pp;
  unixShmFile *p;
  assert( unixMutexHeld() );
  pp = &unixShmFileList;
  while( (p = *pp)!=0 ){
    if( p->nRef==0 ){
      if( p->mutex ) sqlite3_mutex_free(p->mutex);
      if( p->mutexBuf ) sqlite3_mutex_free(p->mutexBuf);
      if( p->h>=0 ) close(p->h);
      *pp = p->pNext;
      sqlite3_free(p);
    }else{
      pp = &p->pNext;
    }
  }
}

/*
** Open a shared-memory area.  This particular implementation uses
** mmapped files.
**
** zName is a filename used to identify the shared-memory area.  The
** implementation does not (and perhaps should not) use this name
** directly, but rather use it as a template for finding an appropriate
** name for the shared-memory storage.  In this implementation, the
** string "-index" is appended to zName and used as the name of the
** mmapped file.
**
** When opening a new shared-memory file, if no other instances of that
** file are currently open, in this process or in other processes, then
** the file must be truncated to zero length or have its header cleared.
*/
static int unixShmOpen(
  sqlite3_vfs *pVfs,    /* The VFS */
  const char *zName,    /* Base name of file to mmap */
  sqlite3_shm **pShm    /* Write the unixShm object created here */
){
  struct unixShm *p = 0;             /* The connection to be opened */
  struct unixShmFile *pFile = 0;     /* The underlying mmapped file */
  int rc;                            /* Result code */
  struct unixFileId fid;             /* Unix file identifier */
  struct unixShmFile *pNew;          /* Newly allocated pFile */
  struct stat sStat;                 /* Result from stat() an fstat() */
  int nName;                         /* Size of zName in bytes */

  /* Allocate space for the new sqlite3_shm object.  Also speculatively
  ** allocate space for a new unixShmFile and filename.
  */
  p = sqlite3_malloc( sizeof(*p) );
  if( p==0 ) return SQLITE_NOMEM;
  memset(p, 0, sizeof(*p));
  nName = strlen(zName);
  pNew = sqlite3_malloc( sizeof(*pFile) + nName + 10 );
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
    goto shm_open_err;
  }
  memset(pNew, 0, sizeof(*pNew));
  pNew->zFilename = (char*)&pNew[1];
  sqlite3_snprintf(nName+10, pNew->zFilename, "%s-index", zName);

  /* Look to see if there is an existing unixShmFile that can be used.
  ** If no matching unixShmFile currently exists, create a new one.
  */
  unixEnterMutex();
  rc = stat(pNew->zFilename, &sStat);
  if( rc==0 ){
    memset(&fid, 0, sizeof(fid));
    fid.dev = sStat.st_dev;
    fid.ino = sStat.st_ino;
    for(pFile = unixShmFileList; pFile; pFile=pFile->pNext){
      if( memcmp(&pFile->fid, &fid, sizeof(fid))==0 ) break;
    }
  }
  if( pFile ){
    sqlite3_free(pNew);
  }else{
    pFile = pNew;
    pNew = 0;
    pFile->h = -1;
    pFile->pNext = unixShmFileList;
    unixShmFileList = pFile;

    pFile->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
    if( pFile->mutex==0 ){
      rc = SQLITE_NOMEM;
      goto shm_open_err;
    }
    pFile->mutexBuf = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
    if( pFile->mutexBuf==0 ){
      rc = SQLITE_NOMEM;
      goto shm_open_err;
    }

    pFile->h = open(pFile->zFilename, O_RDWR|O_CREAT, 0664);
    if( pFile->h<0 ){
      rc = SQLITE_CANTOPEN_BKPT;
      goto shm_open_err;
    }

    rc = fstat(pFile->h, &sStat);
    if( rc ){
      rc = SQLITE_CANTOPEN_BKPT;
      goto shm_open_err;
    }
    pFile->fid.dev = sStat.st_dev;
    pFile->fid.ino = sStat.st_ino;

    /* Check to see if another process is holding the dead-man switch.
    ** If not, truncate the file to zero length. 
    */
    if( unixShmSystemLock(pFile, F_WRLCK, UNIX_SHM_MUTEX) ){
      rc = SQLITE_IOERR_LOCK;
      goto shm_open_err;
    }
    if( unixShmSystemLock(pFile, F_WRLCK, UNIX_SHM_DMS)==SQLITE_OK ){
      if( ftruncate(pFile->h, 0) ){
        rc = SQLITE_IOERR;
      }
    }
    if( rc==SQLITE_OK ){
      rc = unixShmSystemLock(pFile, F_RDLCK, UNIX_SHM_DMS);
    }
    unixShmSystemLock(pFile, F_UNLCK, UNIX_SHM_MUTEX);
    if( rc ) goto shm_open_err;
  }

  /* Make the new connection a child of the unixShmFile */
  p->pFile = pFile;
  p->pNext = pFile->pFirst;
#ifdef SQLITE_DEBUG
  p->id = pFile->nextShmId++;
#endif
  pFile->pFirst = p;
  pFile->nRef++;
  *pShm = (sqlite3_shm*)p;
  unixLeaveMutex();
  return SQLITE_OK;

  /* Jump here on any error */
shm_open_err:
  unixShmPurge();
  sqlite3_free(p);
  sqlite3_free(pFile);
  sqlite3_free(pNew);
  *pShm = 0;
  unixLeaveMutex();
  return rc;
}

/*
** Close a connection to shared-memory.  Delete the underlying 
** storage if deleteFlag is true.
*/
static int unixShmClose(sqlite3_shm *pSharedMem, int deleteFlag){
  unixShm *p;            /* The connection to be closed */
  unixShmFile *pFile;    /* The underlying shared-memory file */
  unixShm **pp;          /* For looping over sibling connections */

  if( pSharedMem==0 ) return SQLITE_OK;
  p = (struct unixShm*)pSharedMem;
  pFile = p->pFile;

  /* Verify that the connection being closed holds no locks */
  assert( p->exclMask==0 );
  assert( p->sharedMask==0 );

  /* Remove connection p from the set of connections associated with pFile */
  sqlite3_mutex_enter(pFile->mutex);
  for(pp=&pFile->pFirst; (*pp)!=p; pp = &(*pp)->pNext){}
  *pp = p->pNext;

  /* Free the connection p */
  sqlite3_free(p);
  sqlite3_mutex_leave(pFile->mutex);

  /* If pFile->nRef has reached 0, then close the underlying
  ** shared-memory file, too */
  unixEnterMutex();
  assert( pFile->nRef>0 );
  pFile->nRef--;
  if( pFile->nRef==0 ){
    if( deleteFlag ) unlink(pFile->zFilename);
    unixShmPurge();
  }
  unixLeaveMutex();

  return SQLITE_OK;
}

/*
** Query and/or changes the size of the underlying storage for
** a shared-memory segment.  The reqSize parameter is the new size
** of the underlying storage, or -1 to do just a query.  The size
** of the underlying storage (after resizing if resizing occurs) is
** written into pNewSize.
**
** This routine does not (necessarily) change the size of the mapping 
** of the underlying storage into memory.  Use xShmGet() to change
** the mapping size.
**
** The reqSize parameter is the minimum size requested.  The implementation
** is free to expand the storage to some larger amount if it chooses.
*/
static int unixShmSize(
  sqlite3_shm *pSharedMem,  /* Pointer returned by unixShmOpen() */
  int reqSize,              /* Requested size.  -1 for query only */
  int *pNewSize             /* Write new size here */
){
  unixShm *p = (unixShm*)pSharedMem;
  unixShmFile *pFile = p->pFile;
  int rc = SQLITE_OK;
  struct stat sStat;

  if( reqSize>=0 ){
    reqSize = (reqSize + SQLITE_UNIX_SHM_INCR - 1)/SQLITE_UNIX_SHM_INCR;
    reqSize *= SQLITE_UNIX_SHM_INCR;
    rc = ftruncate(pFile->h, reqSize);
  }
  if( fstat(pFile->h, &sStat)==0 ){
    *pNewSize = (int)sStat.st_size;
  }else{
    *pNewSize = 0;
    rc = SQLITE_IOERR;
  }
  return rc;
}


/*
** Map the shared storage into memory.  The minimum size of the
** mapping should be reqMapSize if reqMapSize is positive.  If
** reqMapSize is zero or negative, the implementation can choose
** whatever mapping size is convenient.
**
** *ppBuf is made to point to the memory which is a mapping of the
** underlying storage.  A mutex is acquired to prevent other threads
** from running while *ppBuf is in use in order to prevent other threads
** remapping *ppBuf out from under this thread.  The unixShmRelease()
** call will release the mutex.  However, if the lock state is CHECKPOINT,
** the mutex is not acquired because CHECKPOINT will never remap the
** buffer.  RECOVER might remap, though, so CHECKPOINT will acquire
** the mutex if and when it promotes to RECOVER.
**
** RECOVER needs to be atomic.  The same mutex that prevents *ppBuf from
** being remapped also prevents more than one thread from being in
** RECOVER at a time.  But, RECOVER sometimes wants to remap itself.
** To prevent RECOVER from losing its lock while remapping, the
** mutex is not released by unixShmRelease() when in RECOVER.
**
** *pNewMapSize is set to the size of the mapping.
**
** *ppBuf and *pNewMapSize might be NULL and zero if no space has
** yet been allocated to the underlying storage.
*/
static int unixShmGet(
  sqlite3_shm *pSharedMem, /* Pointer returned by unixShmOpen() */
  int reqMapSize,          /* Requested size of mapping. -1 means don't care */
  int *pNewMapSize,        /* Write new size of mapping here */
  void **ppBuf             /* Write mapping buffer origin here */
){
  unixShm *p = (unixShm*)pSharedMem;
  unixShmFile *pFile = p->pFile;
  int rc = SQLITE_OK;

  if( p->lockState!=SQLITE_SHM_CHECKPOINT && p->hasMutexBuf==0 ){
    assert( sqlite3_mutex_notheld(pFile->mutex) );
    sqlite3_mutex_enter(pFile->mutexBuf);
    p->hasMutexBuf = 1;
  }
  sqlite3_mutex_enter(pFile->mutex);
  if( pFile->szMap==0 || reqMapSize>pFile->szMap ){
    int actualSize;
    if( unixShmSize(pSharedMem, -1, &actualSize)==SQLITE_OK
     && reqMapSize<actualSize
    ){
      reqMapSize = actualSize;
    }
    if( pFile->pMMapBuf ){
      munmap(pFile->pMMapBuf, pFile->szMap);
    }
    pFile->pMMapBuf = mmap(0, reqMapSize, PROT_READ|PROT_WRITE, MAP_SHARED,
                           pFile->h, 0);
    pFile->szMap = pFile->pMMapBuf ? reqMapSize : 0;
  }
  *pNewMapSize = pFile->szMap;
  *ppBuf = pFile->pMMapBuf;
  sqlite3_mutex_leave(pFile->mutex);
  return rc;
}

/*
** Release the lock held on the shared memory segment to that other
** threads are free to resize it if necessary.
**
** If the lock is not currently held, this routine is a harmless no-op.
**
** If the shared-memory object is in lock state RECOVER, then we do not
** really want to release the lock, so in that case too, this routine
** is a no-op.
*/
static int unixShmRelease(sqlite3_shm *pSharedMem){
  unixShm *p = (unixShm*)pSharedMem;
  if( p->hasMutexBuf && p->lockState!=SQLITE_SHM_RECOVER ){
    unixShmFile *pFile = p->pFile;
    assert( sqlite3_mutex_notheld(pFile->mutex) );
    sqlite3_mutex_leave(pFile->mutexBuf);
    p->hasMutexBuf = 0;
  }
  return SQLITE_OK;
}

/*
** Symbolic names for LOCK states used for debugging.
*/
#ifdef SQLITE_DEBUG
static const char *azLkName[] = {
  "UNLOCK",
  "READ",
  "READ_FULL",
  "WRITE",
  "PENDING",
  "CHECKPOINT",
  "RECOVER"
};
#endif


/*
** Change the lock state for a shared-memory segment.
*/
static int unixShmLock(
  sqlite3_shm *pSharedMem,   /* Pointer from unixShmOpen() */
  int desiredLock,           /* One of SQLITE_SHM_xxxxx locking states */
  int *pGotLock              /* The lock you actually got */
){
  unixShm *p = (unixShm*)pSharedMem;
  unixShmFile *pFile = p->pFile;
  int rc = SQLITE_PROTOCOL;

  /* Note that SQLITE_SHM_READ_FULL and SQLITE_SHM_PENDING are never
  ** directly requested; they are side effects from requesting
  ** SQLITE_SHM_READ and SQLITE_SHM_CHECKPOINT, respectively.
  */
  assert( desiredLock==SQLITE_SHM_QUERY
       || desiredLock==SQLITE_SHM_UNLOCK
       || desiredLock==SQLITE_SHM_READ
       || desiredLock==SQLITE_SHM_WRITE
       || desiredLock==SQLITE_SHM_CHECKPOINT
       || desiredLock==SQLITE_SHM_RECOVER );

  /* Return directly if this is just a lock state query, or if
  ** the connection is already in the desired locking state.
  */
  if( desiredLock==SQLITE_SHM_QUERY
   || desiredLock==p->lockState
   || (desiredLock==SQLITE_SHM_READ && p->lockState==SQLITE_SHM_READ_FULL)
  ){
    OSTRACE(("SHM-LOCK shmid-%d, pid-%d request %s and got %s\n",
             p->id, getpid(), azLkName[desiredLock], azLkName[p->lockState]));
    if( pGotLock ) *pGotLock = p->lockState;
    return SQLITE_OK;
  }

  OSTRACE(("SHM-LOCK shmid-%d, pid-%d request %s->%s\n",
            p->id, getpid(), azLkName[p->lockState], azLkName[desiredLock]));
  
  if( desiredLock==SQLITE_SHM_RECOVER && !p->hasMutexBuf ){
    assert( sqlite3_mutex_notheld(pFile->mutex) );
    sqlite3_mutex_enter(pFile->mutexBuf);
    p->hasMutexBuf = 1;
  }
  sqlite3_mutex_enter(pFile->mutex);
  switch( desiredLock ){
    case SQLITE_SHM_UNLOCK: {
      assert( p->lockState!=SQLITE_SHM_RECOVER );
      unixShmUnlock(pFile, p, UNIX_SHM_A|UNIX_SHM_B|UNIX_SHM_C|UNIX_SHM_D);
      rc = SQLITE_OK;
      p->lockState = SQLITE_SHM_UNLOCK;
      break;
    }
    case SQLITE_SHM_READ: {
      if( p->lockState==SQLITE_SHM_UNLOCK ){
        int nAttempt;
        rc = SQLITE_BUSY;
        assert( p->lockState==SQLITE_SHM_UNLOCK );
        for(nAttempt=0; nAttempt<5 && rc==SQLITE_BUSY; nAttempt++){
          rc = unixShmSharedLock(pFile, p, UNIX_SHM_A|UNIX_SHM_B);
          if( rc==SQLITE_BUSY ){
            rc = unixShmSharedLock(pFile, p, UNIX_SHM_D);
            if( rc==SQLITE_OK ){
              p->lockState = p->readLock = SQLITE_SHM_READ_FULL;
            }
          }else{
            unixShmUnlock(pFile, p, UNIX_SHM_B);
            p->lockState = p->readLock = SQLITE_SHM_READ;
          }
        }
      }else if( p->lockState==SQLITE_SHM_WRITE ){
        rc = unixShmSharedLock(pFile, p, UNIX_SHM_A);
        unixShmUnlock(pFile, p, UNIX_SHM_C|UNIX_SHM_D);
        p->lockState = p->readLock = SQLITE_SHM_READ;
      }else{
        assert( p->lockState==SQLITE_SHM_RECOVER );
        unixShmUnlock(pFile, p, UNIX_SHM_MUTEX);
        p->lockState = p->readLock;
        rc = SQLITE_OK;
      }
      break;
    }
    case SQLITE_SHM_WRITE: {
      assert( p->lockState==SQLITE_SHM_READ 
              || p->lockState==SQLITE_SHM_READ_FULL );
      rc = unixShmExclusiveLock(pFile, p, UNIX_SHM_C|UNIX_SHM_D);
      if( rc==SQLITE_OK ){
        p->lockState = SQLITE_SHM_WRITE;
      }
      break;
    }
    case SQLITE_SHM_CHECKPOINT: {
      assert( p->lockState==SQLITE_SHM_UNLOCK
           || p->lockState==SQLITE_SHM_PENDING
           || p->lockState==SQLITE_SHM_RECOVER );
      if( p->lockState==SQLITE_SHM_RECOVER ){
        unixShmUnlock(pFile, p, UNIX_SHM_MUTEX);
        p->lockState = SQLITE_SHM_CHECKPOINT;
        rc = SQLITE_OK;
      }
      if( p->lockState==SQLITE_SHM_UNLOCK ){
        rc = unixShmExclusiveLock(pFile, p, UNIX_SHM_B|UNIX_SHM_C);
        if( rc==SQLITE_OK ){
          p->lockState = SQLITE_SHM_PENDING;
        }
      }
      if( p->lockState==SQLITE_SHM_PENDING ){
        rc = unixShmExclusiveLock(pFile, p, UNIX_SHM_A);
        if( rc==SQLITE_OK ){
          p->lockState = SQLITE_SHM_CHECKPOINT;
        }
      }
      break;
    }
    default: {
      assert( desiredLock==SQLITE_SHM_RECOVER );
      assert( p->lockState==SQLITE_SHM_READ
           || p->lockState==SQLITE_SHM_READ_FULL
           || p->lockState==SQLITE_SHM_CHECKPOINT );
      assert( sqlite3_mutex_held(pFile->mutexBuf) );
      rc = unixShmExclusiveLock(pFile, p, UNIX_SHM_MUTEX);
      if( rc==SQLITE_OK ){
        p->lockState = SQLITE_SHM_RECOVER;
      }
      break;
    }
  }
  sqlite3_mutex_leave(pFile->mutex);
  OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %s\n",
           p->id, getpid(), azLkName[p->lockState]));
  if( pGotLock ) *pGotLock = p->lockState;
  return rc;
}

#else
# define unixShmOpen    0
# define unixShmSize    0
# define unixShmGet     0
# define unixShmRelease 0
# define unixShmLock    0
# define unixShmClose   0
#endif /* #ifndef SQLITE_OMIT_WAL */

/*
************************ End of sqlite3_vfs methods ***************************
******************************************************************************/

/******************************************************************************
************************** Begin Proxy Locking ********************************
**
................................................................................
  ** Most finders simply return a pointer to a fixed sqlite3_io_methods
  ** object.  But the "autolockIoFinder" available on MacOSX does a little
  ** more than that; it looks at the filesystem type that hosts the 
  ** database file and tries to choose an locking method appropriate for
  ** that filesystem time.
  */
  #define UNIXVFS(VFSNAME, FINDER) {                        \
    2,                    /* iVersion */                    \
    sizeof(unixFile),     /* szOsFile */                    \
    MAX_PATHNAME,         /* mxPathname */                  \
    0,                    /* pNext */                       \
    VFSNAME,              /* zName */                       \
    (void*)&FINDER,       /* pAppData */                    \
    unixOpen,             /* xOpen */                       \
    unixDelete,           /* xDelete */                     \
................................................................................
    unixDlOpen,           /* xDlOpen */                     \
    unixDlError,          /* xDlError */                    \
    unixDlSym,            /* xDlSym */                      \
    unixDlClose,          /* xDlClose */                    \
    unixRandomness,       /* xRandomness */                 \
    unixSleep,            /* xSleep */                      \
    unixCurrentTime,      /* xCurrentTime */                \
    unixGetLastError,     /* xGetLastError */               \
    unixShmOpen,          /* xShmOpen */                    \
    unixShmSize,          /* xShmSize */                    \
    unixShmGet,           /* xShmGet */                     \
    unixShmRelease,       /* xShmRelease */                 \
    unixShmLock,          /* xShmLock */                    \
    unixShmClose,         /* xShmClose */                   \
    0,                    /* xRename */                     \
    0,                    /* xCurrentTimeInt64 */           \
  }

  /*
  ** All default VFSes for unix are contained in the following array.
  **
  ** Note that the sqlite3_vfs.pNext field of the VFS object is modified
  ** by the SQLite core when the VFS is registered.  So the following

Changes to src/os_win.c.

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    winDlOpen,         /* xDlOpen */
    winDlError,        /* xDlError */
    winDlSym,          /* xDlSym */
    winDlClose,        /* xDlClose */
    winRandomness,     /* xRandomness */
    winSleep,          /* xSleep */
    winCurrentTime,    /* xCurrentTime */
    winGetLastError    /* xGetLastError */
  };

  sqlite3_vfs_register(&winVfs, 1);
  return SQLITE_OK; 
}
int sqlite3_os_end(void){ 
  return SQLITE_OK;
}

#endif /* SQLITE_OS_WIN */







|










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    winDlOpen,         /* xDlOpen */
    winDlError,        /* xDlError */
    winDlSym,          /* xDlSym */
    winDlClose,        /* xDlClose */
    winRandomness,     /* xRandomness */
    winSleep,          /* xSleep */
    winCurrentTime,    /* xCurrentTime */
    winGetLastError,   /* xGetLastError */
  };

  sqlite3_vfs_register(&winVfs, 1);
  return SQLITE_OK; 
}
int sqlite3_os_end(void){ 
  return SQLITE_OK;
}

#endif /* SQLITE_OS_WIN */

Changes to src/pager.c.

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1393
1394

1395
1396
1397
1398
1399
1400
1401
....
1404
1405
1406
1407
1408
1409
1410



1411
1412
1413
1414
1415
1416
1417
1418
....
1515
1516
1517
1518
1519
1520
1521

1522
1523
1524
1525
1526
1527
1528
....
1584
1585
1586
1587
1588
1589
1590



1591

1592
1593
1594
1595
1596
1597
1598
....
1601
1602
1603
1604
1605
1606
1607

1608
1609
1610
1611
1612
1613
1614
....
1665
1666
1667
1668
1669
1670
1671

1672
1673
1674
1675
1676
1677
1678
....
2116
2117
2118
2119
2120
2121
2122



2123
2124
2125
2126
2127
2128
2129
....
2136
2137
2138
2139
2140
2141
2142


























































































































































































































































2143
2144
2145
2146
2147
2148
2149
....
2192
2193
2194
2195
2196
2197
2198




2199
2200
2201
2202
2203
2204
2205

2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
....
2254
2255
2256
2257
2258
2259
2260




2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271

2272
2273
2274
2275
2276
2277
2278
....
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569





2570

2571
2572
2573
2574

2575
2576
2577
2578

2579
2580
2581
2582
2583
2584
2585
....
2693
2694
2695
2696
2697
2698
2699

2700
2701
2702
2703
2704
2705
2706
....
2734
2735
2736
2737
2738
2739
2740


2741
2742
2743
2744






2745
2746
2747
2748
2749
2750
2751
....
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
....
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
....
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
....
2974
2975
2976
2977
2978
2979
2980

2981
2982
2983
2984
2985
2986
2987
....
3062
3063
3064
3065
3066
3067
3068


3069

3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
....
3103
3104
3105
3106
3107
3108
3109










3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177

3178
3179
3180
3181
3182
3183
3184
....
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
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3614
3615
3616
3617
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3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
....
3692
3693
3694
3695
3696
3697
3698


3699
3700
3701
3702
3703
3704
3705
3706
....
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
....
3848
3849
3850
3851
3852
3853
3854





3855
3856
3857
3858
3859
3860
3861
....
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
....
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
....
4220
4221
4222
4223
4224
4225
4226













4227
4228
4229
4230
4231
4232
4233
4234
4235
4236

4237
4238
4239
4240
4241
4242
4243
....
4245
4246
4247
4248
4249
4250
4251

4252
4253
4254
4255
4256
4257
4258
....
4299
4300
4301
4302
4303
4304
4305

4306
4307
4308
4309
4310
4311
4312
....
4314
4315
4316
4317
4318
4319
4320

4321


4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332

4333
4334
4335
4336
4337
4338
4339
....
4706
4707
4708
4709
4710
4711
4712






4713


4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
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4734
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4738
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4751
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4755
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4760
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4771
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4820
4821
4822
4823
4824
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4827
4828
4829
4830
4831
4832
4833
4834
4835

4836
4837
4838
4839
4840
4841
4842
....
4936
4937
4938
4939
4940
4941
4942






4943
4944
4945
4946
4947
4948
4949
4950
....
5077
5078
5079
5080
5081
5082
5083



5084
5085
5086
5087
5088
5089
5090
....
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
....
5431
5432
5433
5434
5435
5436
5437

5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
....
5449
5450
5451
5452
5453
5454
5455

5456
5457





5458

5459
5460
5461
5462
5463
5464
5465
5466
5467
....
5469
5470
5471
5472
5473
5474
5475

5476
5477
5478
5479
5480
5481
5482
....
5496
5497
5498
5499
5500
5501
5502
5503






























































































5504
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"


/*
******************** NOTES ON THE DESIGN OF THE PAGER ************************
**
** Within this comment block, a page is deemed to have been synced
** automatically as soon as it is written when PRAGMA synchronous=OFF.
** Otherwise, the page is not synced until the xSync method of the VFS
................................................................................
typedef struct PagerSavepoint PagerSavepoint;
struct PagerSavepoint {
  i64 iOffset;                 /* Starting offset in main journal */
  i64 iHdrOffset;              /* See above */
  Bitvec *pInSavepoint;        /* Set of pages in this savepoint */
  Pgno nOrig;                  /* Original number of pages in file */
  Pgno iSubRec;                /* Index of first record in sub-journal */

};

/*
** A open page cache is an instance of the following structure.
**
** errCode
**
................................................................................
  void (*xCodecSizeChng)(void*,int,int); /* Notify of page size changes */
  void (*xCodecFree)(void*);             /* Destructor for the codec */
  void *pCodec;               /* First argument to xCodec... methods */
#endif
  char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */
  PCache *pPCache;            /* Pointer to page cache object */
  sqlite3_backup *pBackup;    /* Pointer to list of ongoing backup processes */



};

/*
** The following global variables hold counters used for
** testing purposes only.  These variables do not exist in
** a non-testing build.  These variables are not thread-safe.
*/
................................................................................
      testcase( rc==SQLITE_NOMEM );
      assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
    }
  }
  return rc;
}
















/*
** Unlock the database file. This function is a no-op if the pager
** is in exclusive mode.
**
** If the pager is currently in error state, discard the contents of 
** the cache and reset the Pager structure internal state. If there is
** an open journal-file, then the next time a shared-lock is obtained
** on the pager file (by this or any other process), it will be
** treated as a hot-journal and rolled back.
*/
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    int rc;                      /* Return code */

    /* Always close the journal file when dropping the database lock.
    ** Otherwise, another connection with journal_mode=delete might
    ** delete the file out from under us.
    */
    sqlite3OsClose(pPager->jfd);
    sqlite3BitvecDestroy(pPager->pInJournal);
................................................................................
    ** values stored in Pager.dbSize etc. might become invalid if
    ** this happens.  One can argue that this doesn't need to be cleared
    ** until the change-counter check fails in PagerSharedLock().
    ** Clearing the page size cache here is being conservative.
    */
    pPager->dbSizeValid = 0;




    rc = osUnlock(pPager->fd, NO_LOCK);

    if( rc ){
      pPager->errCode = rc;
    }
    IOTRACE(("UNLOCK %p\n", pPager))

    /* If Pager.errCode is set, the contents of the pager cache cannot be
    ** trusted. Now that the pager file is unlocked, the contents of the
................................................................................
  if( pPager->state<PAGER_RESERVED ){
    return SQLITE_OK;
  }
  releaseAllSavepoints(pPager);

  assert( isOpen(pPager->jfd) || pPager->pInJournal==0 );
  if( isOpen(pPager->jfd) ){


    /* Finalize the journal file. */
    if( sqlite3IsMemJournal(pPager->jfd) ){
      assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY );
      sqlite3OsClose(pPager->jfd);
    }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE ){
      if( pPager->journalOff==0 ){
................................................................................
      pager_error(pPager, rc);
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
    }else{
      /* This branch may be executed with Pager.journalMode==MEMORY if
      ** a hot-journal was just rolled back. In this case the journal
      ** file should be closed and deleted. If this connection writes to
      ** the database file, it will do so using an in-memory journal.  */

      assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 
           || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 

      );
      sqlite3OsClose(pPager->jfd);
      if( !pPager->tempFile ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }

................................................................................
#endif
  }
  sqlite3BitvecDestroy(pPager->pInJournal);
  pPager->pInJournal = 0;
  pPager->nRec = 0;
  sqlite3PcacheCleanAll(pPager->pPCache);




  if( !pPager->exclusiveMode ){
    rc2 = osUnlock(pPager->fd, SHARED_LOCK);
    pPager->state = PAGER_SHARED;
    pPager->changeCountDone = 0;
  }else if( pPager->state==PAGER_SYNCED ){
    pPager->state = PAGER_EXCLUSIVE;
  }
  pPager->setMaster = 0;
................................................................................
  assert( (isMainJrnl&~1)==0 );      /* isMainJrnl is 0 or 1 */
  assert( (isSavepnt&~1)==0 );       /* isSavepnt is 0 or 1 */
  assert( isMainJrnl || pDone );     /* pDone always used on sub-journals */
  assert( isSavepnt || pDone==0 );   /* pDone never used on non-savepoint */

  aData = pPager->pTmpSpace;
  assert( aData );         /* Temp storage must have already been allocated */


  /* Read the page number and page data from the journal or sub-journal
  ** file. Return an error code to the caller if an IO error occurs.
  */
  jfd = isMainJrnl ? pPager->jfd : pPager->sjfd;
  rc = read32bits(jfd, *pOffset, &pgno);
  if( rc!=SQLITE_OK ) return rc;
................................................................................
  ** in the main journal either because the page is not in cache or else
  ** the page is marked as needSync==0.
  **
  ** 2008-04-14:  When attempting to vacuum a corrupt database file, it
  ** is possible to fail a statement on a database that does not yet exist.
  ** Do not attempt to write if database file has never been opened.
  */



  pPg = pager_lookup(pPager, pgno);

  assert( pPg || !MEMDB );
  PAGERTRACE(("PLAYBACK %d page %d hash(%08x) %s\n",
           PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, (u8*)aData),
           (isMainJrnl?"main-journal":"sub-journal")
  ));
  if( isMainJrnl ){
    isSynced = pPager->noSync || (*pOffset <= pPager->journalHdr);
................................................................................
  }
  if( (pPager->state>=PAGER_EXCLUSIVE)
   && isOpen(pPager->fd)
   && isSynced
  ){
    i64 ofst = (pgno-1)*(i64)pPager->pageSize;
    testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );

    rc = sqlite3OsWrite(pPager->fd, (u8*)aData, pPager->pageSize, ofst);
    if( pgno>pPager->dbFileSize ){
      pPager->dbFileSize = pgno;
    }
    if( pPager->pBackup ){
      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM);
      sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);
................................................................................
      ** the PGHDR_NEED_SYNC flag is cleared, if the page is written to
      ** again within this transaction, it will be marked as dirty but
      ** the PGHDR_NEED_SYNC flag will not be set. It could then potentially
      ** be written out into the database file before its journal file
      ** segment is synced. If a crash occurs during or following this,
      ** database corruption may ensue.
      */

      sqlite3PcacheMakeClean(pPg);
    }
#ifdef SQLITE_CHECK_PAGES
    pPg->pageHash = pager_pagehash(pPg);
#endif
    /* If this was page 1, then restore the value of Pager.dbFileVers.
    ** Do this before any decoding. */
................................................................................
    zMaster = pPager->pTmpSpace;
    rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK && pPager->noSync==0 && pPager->state>=PAGER_EXCLUSIVE ){
    rc = sqlite3OsSync(pPager->fd, pPager->sync_flags);
  }



  if( rc==SQLITE_OK ){
    rc = pager_end_transaction(pPager, zMaster[0]!='\0');
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK && zMaster[0] && res ){
    /* If there was a master journal and this routine will return success,
    ** see if it is possible to delete the master journal.
................................................................................
  ** back a journal created by a process with a different sector size
  ** value. Reset it to the correct value for this process.
  */
  setSectorSize(pPager);
  return rc;
}



























































































































































































































































/*
** Playback savepoint pSavepoint. Or, if pSavepoint==NULL, then playback
** the entire master journal file. The case pSavepoint==NULL occurs when 
** a ROLLBACK TO command is invoked on a SAVEPOINT that is a transaction 
** savepoint.
**
** When pSavepoint is not NULL (meaning a non-transaction savepoint is 
................................................................................
    }
  }

  /* Set the database size back to the value it was before the savepoint 
  ** being reverted was opened.
  */
  pPager->dbSize = pSavepoint ? pSavepoint->nOrig : pPager->dbOrigSize;





  /* Use pPager->journalOff as the effective size of the main rollback
  ** journal.  The actual file might be larger than this in
  ** PAGER_JOURNALMODE_TRUNCATE or PAGER_JOURNALMODE_PERSIST.  But anything
  ** past pPager->journalOff is off-limits to us.
  */
  szJ = pPager->journalOff;


  /* Begin by rolling back records from the main journal starting at
  ** PagerSavepoint.iOffset and continuing to the next journal header.
  ** There might be records in the main journal that have a page number
  ** greater than the current database size (pPager->dbSize) but those
  ** will be skipped automatically.  Pages are added to pDone as they
  ** are played back.
  */
  if( pSavepoint ){
    iHdrOff = pSavepoint->iHdrOffset ? pSavepoint->iHdrOffset : szJ;
    pPager->journalOff = pSavepoint->iOffset;
    while( rc==SQLITE_OK && pPager->journalOff<iHdrOff ){
      rc = pager_playback_one_page(pPager, &pPager->journalOff, pDone, 1, 1);
    }
    assert( rc!=SQLITE_DONE );
  }else{
................................................................................
  /* Finally,  rollback pages from the sub-journal.  Page that were
  ** previously rolled back out of the main journal (and are hence in pDone)
  ** will be skipped.  Out-of-range pages are also skipped.
  */
  if( pSavepoint ){
    u32 ii;            /* Loop counter */
    i64 offset = pSavepoint->iSubRec*(4+pPager->pageSize);




    for(ii=pSavepoint->iSubRec; rc==SQLITE_OK && ii<pPager->nSubRec; ii++){
      assert( offset==ii*(4+pPager->pageSize) );
      rc = pager_playback_one_page(pPager, &offset, pDone, 0, 1);
    }
    assert( rc!=SQLITE_DONE );
  }

  sqlite3BitvecDestroy(pDone);
  if( rc==SQLITE_OK ){
    pPager->journalOff = szJ;
  }

  return rc;
}

/*
** Change the maximum number of in-memory pages that are allowed.
*/
void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
................................................................................
** the query attempt returns an IO error, the IO error code is returned
** and *pnPage is left unchanged.
**
** Otherwise, if everything is successful, then SQLITE_OK is returned
** and *pnPage is set to the number of pages in the database.
*/
int sqlite3PagerPagecount(Pager *pPager, int *pnPage){
  Pgno nPage;               /* Value to return via *pnPage */

  /* Determine the number of pages in the file. Store this in nPage. */
  if( pPager->dbSizeValid ){
    nPage = pPager->dbSize;
  }else{
    int rc;                 /* Error returned by OsFileSize() */
    i64 n = 0;              /* File size in bytes returned by OsFileSize() */






    assert( isOpen(pPager->fd) || pPager->tempFile );

    if( isOpen(pPager->fd) && (0 != (rc = sqlite3OsFileSize(pPager->fd, &n))) ){
      pager_error(pPager, rc);
      return rc;
    }

    if( n>0 && n<pPager->pageSize ){
      nPage = 1;
    }else{
      nPage = (Pgno)(n / pPager->pageSize);

    }
    if( pPager->state!=PAGER_UNLOCK ){
      pPager->dbSize = nPage;
      pPager->dbFileSize = nPage;
      pPager->dbSizeValid = 1;
    }
  }
................................................................................
void sqlite3PagerTruncateImage(Pager *pPager, Pgno nPage){
  assert( pPager->dbSizeValid );
  assert( pPager->dbSize>=nPage );
  assert( pPager->state>=PAGER_RESERVED );
  pPager->dbSize = nPage;
  assertTruncateConstraint(pPager);
}


/*
** This function is called before attempting a hot-journal rollback. It
** syncs the journal file to disk, then sets pPager->journalHdr to the
** size of the journal file so that the pager_playback() routine knows
** that the entire journal file has been synced.
**
................................................................................
**
** This function always succeeds. If a transaction is active an attempt
** is made to roll it back. If an error occurs during the rollback 
** a hot journal may be left in the filesystem but no error is returned
** to the caller.
*/
int sqlite3PagerClose(Pager *pPager){


  disable_simulated_io_errors();
  sqlite3BeginBenignMalloc();
  pPager->errCode = 0;
  pPager->exclusiveMode = 0;






  pager_reset(pPager);
  if( MEMDB ){
    pager_unlock(pPager);
  }else{
    /* Set Pager.journalHdr to -1 for the benefit of the pager_playback() 
    ** call which may be made from within pagerUnlockAndRollback(). If it
    ** is not -1, then the unsynced portion of an open journal file may
................................................................................
    pagerUnlockAndRollback(pPager);
  }
  sqlite3EndBenignMalloc();
  enable_simulated_io_errors();
  PAGERTRACE(("CLOSE %d\n", PAGERID(pPager)));
  IOTRACE(("CLOSE %p\n", pPager))
  sqlite3OsClose(pPager->fd);
  sqlite3PageFree(pPager->pTmpSpace);
  sqlite3PcacheClose(pPager->pPCache);

#ifdef SQLITE_HAS_CODEC
  if( pPager->xCodecFree ) pPager->xCodecFree(pPager->pCodec);
#endif

  assert( !pPager->aSavepoint && !pPager->pInJournal );
................................................................................
        ** Variable iNextHdrOffset is set to the offset at which this
        ** problematic header will occur, if it exists. aMagic is used 
        ** as a temporary buffer to inspect the first couple of bytes of
        ** the potential journal header.
        */
        i64 iNextHdrOffset;
        u8 aMagic[8];
	u8 zHeader[sizeof(aJournalMagic)+4];

	memcpy(zHeader, aJournalMagic, sizeof(aJournalMagic));
	put32bits(&zHeader[sizeof(aJournalMagic)], pPager->nRec);

        iNextHdrOffset = journalHdrOffset(pPager);
        rc = sqlite3OsRead(pPager->jfd, aMagic, 8, iNextHdrOffset);
        if( rc==SQLITE_OK && 0==memcmp(aMagic, aJournalMagic, 8) ){
          static const u8 zerobyte = 0;
          rc = sqlite3OsWrite(pPager->jfd, &zerobyte, 1, iNextHdrOffset);
        }
................................................................................
          IOTRACE(("JSYNC %p\n", pPager))
          rc = sqlite3OsSync(pPager->jfd, pPager->sync_flags);
          if( rc!=SQLITE_OK ) return rc;
        }
        IOTRACE(("JHDR %p %lld\n", pPager, pPager->journalHdr));
        rc = sqlite3OsWrite(
            pPager->jfd, zHeader, sizeof(zHeader), pPager->journalHdr
	);
        if( rc!=SQLITE_OK ) return rc;
      }
      if( 0==(iDc&SQLITE_IOCAP_SEQUENTIAL) ){
        PAGERTRACE(("SYNC journal of %d\n", PAGERID(pPager)));
        IOTRACE(("JSYNC %p\n", pPager))
        rc = sqlite3OsSync(pPager->jfd, pPager->sync_flags| 
          (pPager->sync_flags==SQLITE_SYNC_FULL?SQLITE_SYNC_DATAONLY:0)
................................................................................
  **
  ** While the pager is in the RESERVED state, the original database file
  ** is unchanged and we can rollback without having to playback the
  ** journal into the original database file.  Once we transition to
  ** EXCLUSIVE, it means the database file has been changed and any rollback
  ** will require a journal playback.
  */

  assert( pPager->state>=PAGER_RESERVED );
  rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);

  /* If the file is a temp-file has not yet been opened, open it now. It
  ** is not possible for rc to be other than SQLITE_OK if this branch
  ** is taken, as pager_wait_on_lock() is a no-op for temp-files.
  */
................................................................................
    void *pData = pPg->pData;
    i64 offset = pPager->nSubRec*(4+pPager->pageSize);
    char *pData2;

    CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
    PAGERTRACE(("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno));
  


    assert( pageInJournal(pPg) || pPg->pgno>pPager->dbOrigSize );

    rc = write32bits(pPager->sjfd, offset, pPg->pgno);
    if( rc==SQLITE_OK ){
      rc = sqlite3OsWrite(pPager->sjfd, pData2, pPager->pageSize, offset+4);
    }
  }
  if( rc==SQLITE_OK ){
    pPager->nSubRec++;
    assert( pPager->nSavepoint>0 );
    rc = addToSavepointBitvecs(pPager, pPg->pgno);
  }
  return rc;
}


/*
** This function is called by the pcache layer when it has reached some
** soft memory limit. The first argument is a pointer to a Pager object
** (cast as a void*). The pager is always 'purgeable' (not an in-memory
** database). The second argument is a reference to a page that is 
** currently dirty but has no outstanding references. The page
................................................................................
static int pagerStress(void *p, PgHdr *pPg){
  Pager *pPager = (Pager *)p;
  int rc = SQLITE_OK;

  assert( pPg->pPager==pPager );
  assert( pPg->flags&PGHDR_DIRTY );











  /* The doNotSync flag is set by the sqlite3PagerWrite() function while it
  ** is journalling a set of two or more database pages that are stored
  ** on the same disk sector. Syncing the journal is not allowed while
  ** this is happening as it is important that all members of such a
  ** set of pages are synced to disk together. So, if the page this function
  ** is trying to make clean will require a journal sync and the doNotSync
  ** flag is set, return without doing anything. The pcache layer will
  ** just have to go ahead and allocate a new page buffer instead of
  ** reusing pPg.
  **
  ** Similarly, if the pager has already entered the error state, do not
  ** try to write the contents of pPg to disk.
  */
  if( NEVER(pPager->errCode)
   || (pPager->doNotSync && pPg->flags&PGHDR_NEED_SYNC)
  ){
    return SQLITE_OK;
  }

  /* Sync the journal file if required. */
  if( pPg->flags&PGHDR_NEED_SYNC ){
    rc = syncJournal(pPager);
    if( rc==SQLITE_OK && pPager->fullSync && 
      !(pPager->journalMode==PAGER_JOURNALMODE_MEMORY) &&
      !(sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_SAFE_APPEND)
    ){
      pPager->nRec = 0;
      rc = writeJournalHdr(pPager);
    }
  }

  /* If the page number of this page is larger than the current size of
  ** the database image, it may need to be written to the sub-journal.
  ** This is because the call to pager_write_pagelist() below will not
  ** actually write data to the file in this case.
  **
  ** Consider the following sequence of events:
  **
  **   BEGIN;
  **     <journal page X>
  **     <modify page X>
  **     SAVEPOINT sp;
  **       <shrink database file to Y pages>
  **       pagerStress(page X)
  **     ROLLBACK TO sp;
  **
  ** If (X>Y), then when pagerStress is called page X will not be written
  ** out to the database file, but will be dropped from the cache. Then,
  ** following the "ROLLBACK TO sp" statement, reading page X will read
  ** data from the database file. This will be the copy of page X as it
  ** was when the transaction started, not as it was when "SAVEPOINT sp"
  ** was executed.
  **
  ** The solution is to write the current data for page X into the 
  ** sub-journal file now (if it is not already there), so that it will
  ** be restored to its current value when the "ROLLBACK TO sp" is 
  ** executed.
  */
  if( NEVER(
      rc==SQLITE_OK && pPg->pgno>pPager->dbSize && subjRequiresPage(pPg)
  ) ){
    rc = subjournalPage(pPg);
  }

  /* Write the contents of the page out to the database file. */
  if( rc==SQLITE_OK ){
    pPg->pDirty = 0;
    rc = pager_write_pagelist(pPg);

  }

  /* Mark the page as clean. */
  if( rc==SQLITE_OK ){
    PAGERTRACE(("STRESS %d page %d\n", PAGERID(pPager), pPg->pgno));
    sqlite3PcacheMakeClean(pPg);
  }
................................................................................
      }
    }
  }

  return rc;
}

/*
** Read the content for page pPg out of the database file and into 
** pPg->pData. A shared lock or greater must be held on the database
** file before this function is called.
**
** If page 1 is read, then the value of Pager.dbFileVers[] is set to
** the value read from the database file.
**
** If an IO error occurs, then the IO error is returned to the caller.
** Otherwise, SQLITE_OK is returned.
*/
static int readDbPage(PgHdr *pPg){
  Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
  Pgno pgno = pPg->pgno;       /* Page number to read */
  int rc;                      /* Return code */
  i64 iOffset;                 /* Byte offset of file to read from */

  assert( pPager->state>=PAGER_SHARED && !MEMDB );
  assert( isOpen(pPager->fd) );

  if( NEVER(!isOpen(pPager->fd)) ){
    assert( pPager->tempFile );
    memset(pPg->pData, 0, pPager->pageSize);
    return SQLITE_OK;
  }
  iOffset = (pgno-1)*(i64)pPager->pageSize;
  rc = sqlite3OsRead(pPager->fd, pPg->pData, pPager->pageSize, iOffset);
  if( rc==SQLITE_IOERR_SHORT_READ ){
    rc = SQLITE_OK;
  }
  if( pgno==1 ){
    if( rc ){
      /* If the read is unsuccessful, set the dbFileVers[] to something
      ** that will never be a valid file version.  dbFileVers[] is a copy
      ** of bytes 24..39 of the database.  Bytes 28..31 should always be
      ** zero.  Bytes 32..35 and 35..39 should be page numbers which are
      ** never 0xffffffff.  So filling pPager->dbFileVers[] with all 0xff
      ** bytes should suffice.
      **
      ** For an encrypted database, the situation is more complex:  bytes
      ** 24..39 of the database are white noise.  But the probability of
      ** white noising equaling 16 bytes of 0xff is vanishingly small so
      ** we should still be ok.
      */
      memset(pPager->dbFileVers, 0xff, sizeof(pPager->dbFileVers));
    }else{
      u8 *dbFileVers = &((u8*)pPg->pData)[24];
      memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
    }
  }
  CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM);

  PAGER_INCR(sqlite3_pager_readdb_count);
  PAGER_INCR(pPager->nRead);
  IOTRACE(("PGIN %p %d\n", pPager, pgno));
  PAGERTRACE(("FETCH %d page %d hash(%08x)\n",
               PAGERID(pPager), pgno, pager_pagehash(pPg)));

  return rc;
}

/*
** This function is called to obtain a shared lock on the database file.
** It is illegal to call sqlite3PagerAcquire() until after this function
** has been successfully called. If a shared-lock is already held when
** this function is called, it is a no-op.
**
** The following operations are also performed by this function.
................................................................................
    if( isOpen(pPager->jfd) || pPager->zJournal ){
      isErrorReset = 1;
    }
    pPager->errCode = SQLITE_OK;
    pager_reset(pPager);
  }



  if( pPager->state==PAGER_UNLOCK || isErrorReset ){
    sqlite3_vfs * const pVfs = pPager->pVfs;
    int isHotJournal = 0;
    assert( !MEMDB );
    assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
    if( pPager->noReadlock ){
      assert( pPager->readOnly );
      pPager->state = PAGER_SHARED;
................................................................................

      /* Reset the journal status fields to indicates that we have no
      ** rollback journal at this time. */
      pPager->journalStarted = 0;
      pPager->journalOff = 0;
      pPager->setMaster = 0;
      pPager->journalHdr = 0;

      /* Make sure the journal file has been synced to disk. */
 
      /* Playback and delete the journal.  Drop the database write
      ** lock and reacquire the read lock. Purge the cache before
      ** playing back the hot-journal so that we don't end up with
      ** an inconsistent cache.  Sync the hot journal before playing
      ** it back since the process that crashed and left the hot journal
................................................................................
      }

      if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
        pager_reset(pPager);
      }
    }
    assert( pPager->exclusiveMode || pPager->state==PAGER_SHARED );





  }

 failed:
  if( rc!=SQLITE_OK ){
    /* pager_unlock() is a no-op for exclusive mode and in-memory databases. */
    pager_unlock(pPager);
  }
................................................................................
    rc = sqlite3PagerPagecount(pPager, &nMax);
    if( rc!=SQLITE_OK ){
      goto pager_acquire_err;
    }

    if( MEMDB || nMax<(int)pgno || noContent || !isOpen(pPager->fd) ){
      if( pgno>pPager->mxPgno ){
	rc = SQLITE_FULL;
	goto pager_acquire_err;
      }
      if( noContent ){
        /* Failure to set the bits in the InJournal bit-vectors is benign.
        ** It merely means that we might do some extra work to journal a 
        ** page that does not need to be journaled.  Nevertheless, be sure 
        ** to test the case where a malloc error occurs while trying to set 
        ** a bit in a bit vector.
................................................................................
**
** SQLITE_OK is returned if everything goes according to plan. 
** An SQLITE_IOERR_XXX error code is returned if a call to 
** sqlite3OsOpen() fails.
*/
static int openSubJournal(Pager *pPager){
  int rc = SQLITE_OK;
  if( isOpen(pPager->jfd) && !isOpen(pPager->sjfd) ){
    if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY || pPager->subjInMemory ){
      sqlite3MemJournalOpen(pPager->sjfd);
    }else{
      rc = pagerOpentemp(pPager, pPager->sjfd, SQLITE_OPEN_SUBJOURNAL);
    }
  }
  return rc;
................................................................................
  int rc = SQLITE_OK;
  assert( pPager->state!=PAGER_UNLOCK );
  pPager->subjInMemory = (u8)subjInMemory;
  if( pPager->state==PAGER_SHARED ){
    assert( pPager->pInJournal==0 );
    assert( !MEMDB && !pPager->tempFile );














    /* Obtain a RESERVED lock on the database file. If the exFlag parameter
    ** is true, then immediately upgrade this to an EXCLUSIVE lock. The
    ** busy-handler callback can be used when upgrading to the EXCLUSIVE
    ** lock, but not when obtaining the RESERVED lock.
    */
    rc = sqlite3OsLock(pPager->fd, RESERVED_LOCK);
    if( rc==SQLITE_OK ){
      pPager->state = PAGER_RESERVED;
      if( exFlag ){
        rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);

      }
    }

    /* No need to open the journal file at this time.  It will be
    ** opened before it is written to.  If we defer opening the journal,
    ** we might save the work of creating a file if the transaction
    ** ends up being a no-op.
................................................................................
  }else if( isOpen(pPager->jfd) && pPager->journalOff==0 ){
    /* This happens when the pager was in exclusive-access mode the last
    ** time a (read or write) transaction was successfully concluded
    ** by this connection. Instead of deleting the journal file it was 
    ** kept open and either was truncated to 0 bytes or its header was
    ** overwritten with zeros.
    */

    assert( pPager->nRec==0 );
    assert( pPager->dbOrigSize==0 );
    assert( pPager->pInJournal==0 );
    rc = pager_open_journal(pPager);
  }

  PAGERTRACE(("TRANSACTION %d\n", PAGERID(pPager)));
................................................................................
  CHECK_PAGE(pPg);

  /* Mark the page as dirty.  If the page has already been written
  ** to the journal then we can return right away.
  */
  sqlite3PcacheMakeDirty(pPg);
  if( pageInJournal(pPg) && !subjRequiresPage(pPg) ){

    pPager->dbModified = 1;
  }else{

    /* If we get this far, it means that the page needs to be
    ** written to the transaction journal or the ckeckpoint journal
    ** or both.
    **
................................................................................
    ** which means they have acquired the necessary locks but the rollback
    ** journal might not yet be open.
    */
    rc = sqlite3PagerBegin(pPager, 0, pPager->subjInMemory);
    if( rc!=SQLITE_OK ){
      return rc;
    }

    if( !isOpen(pPager->jfd) && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){


      assert( pPager->useJournal );
      rc = pager_open_journal(pPager);
      if( rc!=SQLITE_OK ) return rc;
    }
    pPager->dbModified = 1;
  
    /* The transaction journal now exists and we have a RESERVED or an
    ** EXCLUSIVE lock on the main database file.  Write the current page to
    ** the transaction journal if it is not there already.
    */
    if( !pageInJournal(pPg) && isOpen(pPager->jfd) ){

      if( pPg->pgno<=pPager->dbOrigSize ){
        u32 cksum;
        char *pData2;

        /* We should never write to the journal file the page that
        ** contains the database locks.  The following assert verifies
        ** that we do not. */
................................................................................
  if( MEMDB && pPager->dbModified ){
    /* If this is an in-memory db, or no pages have been written to, or this
    ** function has already been called, it is mostly a no-op.  However, any
    ** backup in progress needs to be restarted.
    */
    sqlite3BackupRestart(pPager->pBackup);
  }else if( pPager->state!=PAGER_SYNCED && pPager->dbModified ){









    /* The following block updates the change-counter. Exactly how it
    ** does this depends on whether or not the atomic-update optimization
    ** was enabled at compile time, and if this transaction meets the 
    ** runtime criteria to use the operation: 
    **
    **    * The file-system supports the atomic-write property for
    **      blocks of size page-size, and 
    **    * This commit is not part of a multi-file transaction, and
    **    * Exactly one page has been modified and store in the journal file.
    **
    ** If the optimization was not enabled at compile time, then the
    ** pager_incr_changecounter() function is called to update the change
    ** counter in 'indirect-mode'. If the optimization is compiled in but
    ** is not applicable to this transaction, call sqlite3JournalCreate()
    ** to make sure the journal file has actually been created, then call
    ** pager_incr_changecounter() to update the change-counter in indirect
    ** mode. 
    **
    ** Otherwise, if the optimization is both enabled and applicable,
    ** then call pager_incr_changecounter() to update the change-counter
    ** in 'direct' mode. In this case the journal file will never be
    ** created for this transaction.
    */
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
    PgHdr *pPg;
    assert( isOpen(pPager->jfd) || pPager->journalMode==PAGER_JOURNALMODE_OFF );
    if( !zMaster && isOpen(pPager->jfd) 
     && pPager->journalOff==jrnlBufferSize(pPager) 
     && pPager->dbSize>=pPager->dbFileSize
     && (0==(pPg = sqlite3PcacheDirtyList(pPager->pPCache)) || 0==pPg->pDirty)
    ){
      /* Update the db file change counter via the direct-write method. The 
      ** following call will modify the in-memory representation of page 1 
      ** to include the updated change counter and then write page 1 
      ** directly to the database file. Because of the atomic-write 
      ** property of the host file-system, this is safe.
      */
      rc = pager_incr_changecounter(pPager, 1);
    }else{
      rc = sqlite3JournalCreate(pPager->jfd);
      if( rc==SQLITE_OK ){
        rc = pager_incr_changecounter(pPager, 0);
      }
    }
#else
    rc = pager_incr_changecounter(pPager, 0);
#endif
    if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

    /* If this transaction has made the database smaller, then all pages
    ** being discarded by the truncation must be written to the journal
    ** file. This can only happen in auto-vacuum mode.
    **
    ** Before reading the pages with page numbers larger than the 
    ** current value of Pager.dbSize, set dbSize back to the value
    ** that it took at the start of the transaction. Otherwise, the
    ** calls to sqlite3PagerGet() return zeroed pages instead of 
    ** reading data from the database file.
    **
    ** When journal_mode==OFF the dbOrigSize is always zero, so this
    ** block never runs if journal_mode=OFF.
    */
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pPager->dbSize<pPager->dbOrigSize 
     && ALWAYS(pPager->journalMode!=PAGER_JOURNALMODE_OFF)
    ){
      Pgno i;                                   /* Iterator variable */
      const Pgno iSkip = PAGER_MJ_PGNO(pPager); /* Pending lock page */
      const Pgno dbSize = pPager->dbSize;       /* Database image size */ 
      pPager->dbSize = pPager->dbOrigSize;
      for( i=dbSize+1; i<=pPager->dbOrigSize; i++ ){
        if( !sqlite3BitvecTest(pPager->pInJournal, i) && i!=iSkip ){
          PgHdr *pPage;             /* Page to journal */
          rc = sqlite3PagerGet(pPager, i, &pPage);
          if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
          rc = sqlite3PagerWrite(pPage);
          sqlite3PagerUnref(pPage);
          if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
        }
      } 
      pPager->dbSize = dbSize;
    }
#endif

    /* Write the master journal name into the journal file. If a master 
    ** journal file name has already been written to the journal file, 
    ** or if zMaster is NULL (no master journal), then this call is a no-op.
    */
    rc = writeMasterJournal(pPager, zMaster);
    if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

    /* Sync the journal file. If the atomic-update optimization is being
    ** used, this call will not create the journal file or perform any
    ** real IO.
    */
    rc = syncJournal(pPager);
    if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

    /* Write all dirty pages to the database file. */
    rc = pager_write_pagelist(sqlite3PcacheDirtyList(pPager->pPCache));
    if( rc!=SQLITE_OK ){
      assert( rc!=SQLITE_IOERR_BLOCKED );
      goto commit_phase_one_exit;
    }
    sqlite3PcacheCleanAll(pPager->pPCache);

    /* If the file on disk is not the same size as the database image,
    ** then use pager_truncate to grow or shrink the file here.
    */
    if( pPager->dbSize!=pPager->dbFileSize ){
      Pgno nNew = pPager->dbSize - (pPager->dbSize==PAGER_MJ_PGNO(pPager));
      assert( pPager->state>=PAGER_EXCLUSIVE );
      rc = pager_truncate(pPager, nNew);
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
    }

    /* Finally, sync the database file. */
    if( !pPager->noSync && !noSync ){
      rc = sqlite3OsSync(pPager->fd, pPager->sync_flags);
    }
    IOTRACE(("DBSYNC %p\n", pPager))


    pPager->state = PAGER_SYNCED;
  }

commit_phase_one_exit:
  return rc;
}

................................................................................
**   the journal file. It needs to be left in the file-system so that
**   some other process can use it to restore the database state (by
**   hot-journal rollback).
*/
int sqlite3PagerRollback(Pager *pPager){
  int rc = SQLITE_OK;                  /* Return code */
  PAGERTRACE(("ROLLBACK %d\n", PAGERID(pPager)));






  if( !pPager->dbModified || !isOpen(pPager->jfd) ){
    rc = pager_end_transaction(pPager, pPager->setMaster);
  }else if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
    if( pPager->state>=PAGER_EXCLUSIVE ){
      pager_playback(pPager, 0);
    }
    rc = pPager->errCode;
  }else{
................................................................................
        aNew[ii].iOffset = JOURNAL_HDR_SZ(pPager);
      }
      aNew[ii].iSubRec = pPager->nSubRec;
      aNew[ii].pInSavepoint = sqlite3BitvecCreate(nPage);
      if( !aNew[ii].pInSavepoint ){
        return SQLITE_NOMEM;
      }



    }

    /* Open the sub-journal, if it is not already opened. */
    rc = openSubJournal(pPager);
    assertTruncateConstraint(pPager);
  }

................................................................................
      }
    }
    /* Else this is a rollback operation, playback the specified savepoint.
    ** If this is a temp-file, it is possible that the journal file has
    ** not yet been opened. In this case there have been no changes to
    ** the database file, so the playback operation can be skipped.
    */
    else if( isOpen(pPager->jfd) ){
      PagerSavepoint *pSavepoint = (nNew==0)?0:&pPager->aSavepoint[nNew-1];
      rc = pagerPlaybackSavepoint(pPager, pSavepoint);
      assert(rc!=SQLITE_DONE);
    }
  
  }
  return rc;
................................................................................
**
**    PAGER_JOURNALMODE_QUERY
**    PAGER_JOURNALMODE_DELETE
**    PAGER_JOURNALMODE_TRUNCATE
**    PAGER_JOURNALMODE_PERSIST
**    PAGER_JOURNALMODE_OFF
**    PAGER_JOURNALMODE_MEMORY

**
** If the parameter is not _QUERY, then the journal_mode is set to the
** value specified if the change is allowed.  The change is disallowed
** for the following reasons:
**
**   *  An in-memory database can only have its journal_mode set to _OFF
**      or _MEMORY.
**
**   *  The journal mode may not be changed while a transaction is active.
**
................................................................................
*/
int sqlite3PagerJournalMode(Pager *pPager, int eMode){
  assert( eMode==PAGER_JOURNALMODE_QUERY
            || eMode==PAGER_JOURNALMODE_DELETE
            || eMode==PAGER_JOURNALMODE_TRUNCATE
            || eMode==PAGER_JOURNALMODE_PERSIST
            || eMode==PAGER_JOURNALMODE_OFF 

            || eMode==PAGER_JOURNALMODE_MEMORY );
  assert( PAGER_JOURNALMODE_QUERY<0 );





  if( eMode>=0

   && (!MEMDB || eMode==PAGER_JOURNALMODE_MEMORY 
              || eMode==PAGER_JOURNALMODE_OFF)
   && !pPager->dbModified
   && (!isOpen(pPager->jfd) || 0==pPager->journalOff)
  ){
    if( isOpen(pPager->jfd) ){
      sqlite3OsClose(pPager->jfd);
    }
    assert( (PAGER_JOURNALMODE_TRUNCATE & 1)==1 );
................................................................................
    assert( (PAGER_JOURNALMODE_DELETE & 1)==0 );
    assert( (PAGER_JOURNALMODE_MEMORY & 1)==0 );
    assert( (PAGER_JOURNALMODE_OFF & 1)==0 );
    if( (pPager->journalMode & 1)==1 && (eMode & 1)==0
         && !pPager->exclusiveMode ){
      sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
    }

    pPager->journalMode = (u8)eMode;
  }
  return (int)pPager->journalMode;
}

/*
** Get/set the size-limit used for persistent journal files.
................................................................................
** in backup.c maintains the content of this variable. This module
** uses it opaquely as an argument to sqlite3BackupRestart() and
** sqlite3BackupUpdate() only.
*/
sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){
  return &pPager->pBackup;
}































































































#endif /* SQLITE_OMIT_DISKIO */







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16
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231
...
395
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405
406
407
408
409
410
411
....
1186
1187
1188
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1190
1191
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1194
1195
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1198
1199
1200
1201
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1213
1214
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1217
1218
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1222
1223
1224
1225
1226
1227
....
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
....
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
....
1410
1411
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1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
....
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
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1442
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1445
1446
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1448
....
1545
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1551
1552
1553
1554
1555
1556
1557
1558
1559
....
1615
1616
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1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
....
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
....
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
....
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
....
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
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2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
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2416
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2419
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2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
....
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
....
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
....
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
....
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
....
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
....
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
....
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
....
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
....
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
....
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402

3403
3404
3405
3406
3407
3408
3409
....
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
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3436
3437
3438
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3450
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3455
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3457
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3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
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3480
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3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505

3506
3507
3508
3509
3510
3511
3512
3513
3514
....
3908
3909
3910
3911
3912
3913
3914





























































3915
3916
3917
3918
3919
3920
3921
....
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
....
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
....
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
....
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
....
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
....
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
....
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
....
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
....
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
....
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
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5047
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5052
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5058
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5066
5067
5068
5069
5070
5071
5072
5073
5074
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5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
....
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
....
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
....
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
....
5745
5746
5747
5748
5749
5750
5751
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** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "wal.h"

/*
******************** NOTES ON THE DESIGN OF THE PAGER ************************
**
** Within this comment block, a page is deemed to have been synced
** automatically as soon as it is written when PRAGMA synchronous=OFF.
** Otherwise, the page is not synced until the xSync method of the VFS
................................................................................
typedef struct PagerSavepoint PagerSavepoint;
struct PagerSavepoint {
  i64 iOffset;                 /* Starting offset in main journal */
  i64 iHdrOffset;              /* See above */
  Bitvec *pInSavepoint;        /* Set of pages in this savepoint */
  Pgno nOrig;                  /* Original number of pages in file */
  Pgno iSubRec;                /* Index of first record in sub-journal */
  u32 iFrame;                  /* Last frame in WAL when savepoint opened */
};

/*
** A open page cache is an instance of the following structure.
**
** errCode
**
................................................................................
  void (*xCodecSizeChng)(void*,int,int); /* Notify of page size changes */
  void (*xCodecFree)(void*);             /* Destructor for the codec */
  void *pCodec;               /* First argument to xCodec... methods */
#endif
  char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */
  PCache *pPCache;            /* Pointer to page cache object */
  sqlite3_backup *pBackup;    /* Pointer to list of ongoing backup processes */
#ifndef SQLITE_OMIT_WAL
  Wal *pWal;                  /* Write-ahead log used by "journal_mode=wal" */
#endif
};

/*
** The following global variables hold counters used for
** testing purposes only.  These variables do not exist in
** a non-testing build.  These variables are not thread-safe.
*/
................................................................................
      testcase( rc==SQLITE_NOMEM );
      assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
    }
  }
  return rc;
}

/*
** Return true if this pager uses a write-ahead log instead of the usual
** rollback journal. Otherwise false.
*/
#ifndef SQLITE_OMIT_WAL
static int pagerUseWal(Pager *pPager){
  return (pPager->pWal!=0);
}
#else
# define pagerUseWal(x) 0
# define pagerRollbackWal(x) 0
# define pagerWalFrames(v,w,x,y,z) 0
# define pagerOpenWalIfPresent(z) SQLITE_OK
#endif

/*
** Unlock the database file. This function is a no-op if the pager
** is in exclusive mode.
**
** If the pager is currently in error state, discard the contents of 
** the cache and reset the Pager structure internal state. If there is
** an open journal-file, then the next time a shared-lock is obtained
** on the pager file (by this or any other process), it will be
** treated as a hot-journal and rolled back.
*/
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    int rc = SQLITE_OK;          /* Return code */

    /* Always close the journal file when dropping the database lock.
    ** Otherwise, another connection with journal_mode=delete might
    ** delete the file out from under us.
    */
    sqlite3OsClose(pPager->jfd);
    sqlite3BitvecDestroy(pPager->pInJournal);
................................................................................
    ** values stored in Pager.dbSize etc. might become invalid if
    ** this happens.  One can argue that this doesn't need to be cleared
    ** until the change-counter check fails in PagerSharedLock().
    ** Clearing the page size cache here is being conservative.
    */
    pPager->dbSizeValid = 0;

    if( pagerUseWal(pPager) ){
      sqlite3WalCloseSnapshot(pPager->pWal);
    }else{
      rc = osUnlock(pPager->fd, NO_LOCK);
    }
    if( rc ){
      pPager->errCode = rc;
    }
    IOTRACE(("UNLOCK %p\n", pPager))

    /* If Pager.errCode is set, the contents of the pager cache cannot be
    ** trusted. Now that the pager file is unlocked, the contents of the
................................................................................
  if( pPager->state<PAGER_RESERVED ){
    return SQLITE_OK;
  }
  releaseAllSavepoints(pPager);

  assert( isOpen(pPager->jfd) || pPager->pInJournal==0 );
  if( isOpen(pPager->jfd) ){
    assert( !pagerUseWal(pPager) );

    /* Finalize the journal file. */
    if( sqlite3IsMemJournal(pPager->jfd) ){
      assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY );
      sqlite3OsClose(pPager->jfd);
    }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE ){
      if( pPager->journalOff==0 ){
................................................................................
      pager_error(pPager, rc);
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
    }else{
      /* This branch may be executed with Pager.journalMode==MEMORY if
      ** a hot-journal was just rolled back. In this case the journal
      ** file should be closed and deleted. If this connection writes to
      ** the database file, it will do so using an in-memory journal. 
      */
      assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 
           || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
           || pPager->journalMode==PAGER_JOURNALMODE_WAL 
      );
      sqlite3OsClose(pPager->jfd);
      if( !pPager->tempFile ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }

................................................................................
#endif
  }
  sqlite3BitvecDestroy(pPager->pInJournal);
  pPager->pInJournal = 0;
  pPager->nRec = 0;
  sqlite3PcacheCleanAll(pPager->pPCache);

  if( pagerUseWal(pPager) ){
    rc2 = sqlite3WalWriteLock(pPager->pWal, 0);
    pPager->state = PAGER_SHARED;
  }else if( !pPager->exclusiveMode ){
    rc2 = osUnlock(pPager->fd, SHARED_LOCK);
    pPager->state = PAGER_SHARED;
    pPager->changeCountDone = 0;
  }else if( pPager->state==PAGER_SYNCED ){
    pPager->state = PAGER_EXCLUSIVE;
  }
  pPager->setMaster = 0;
................................................................................
  assert( (isMainJrnl&~1)==0 );      /* isMainJrnl is 0 or 1 */
  assert( (isSavepnt&~1)==0 );       /* isSavepnt is 0 or 1 */
  assert( isMainJrnl || pDone );     /* pDone always used on sub-journals */
  assert( isSavepnt || pDone==0 );   /* pDone never used on non-savepoint */

  aData = pPager->pTmpSpace;
  assert( aData );         /* Temp storage must have already been allocated */
  assert( pagerUseWal(pPager)==0 || (!isMainJrnl && isSavepnt) );

  /* Read the page number and page data from the journal or sub-journal
  ** file. Return an error code to the caller if an IO error occurs.
  */
  jfd = isMainJrnl ? pPager->jfd : pPager->sjfd;
  rc = read32bits(jfd, *pOffset, &pgno);
  if( rc!=SQLITE_OK ) return rc;
................................................................................
  ** in the main journal either because the page is not in cache or else
  ** the page is marked as needSync==0.
  **
  ** 2008-04-14:  When attempting to vacuum a corrupt database file, it
  ** is possible to fail a statement on a database that does not yet exist.
  ** Do not attempt to write if database file has never been opened.
  */
  if( pagerUseWal(pPager) ){
    pPg = 0;
  }else{
    pPg = pager_lookup(pPager, pgno);
  }
  assert( pPg || !MEMDB );
  PAGERTRACE(("PLAYBACK %d page %d hash(%08x) %s\n",
           PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, (u8*)aData),
           (isMainJrnl?"main-journal":"sub-journal")
  ));
  if( isMainJrnl ){
    isSynced = pPager->noSync || (*pOffset <= pPager->journalHdr);
................................................................................
  }
  if( (pPager->state>=PAGER_EXCLUSIVE)
   && isOpen(pPager->fd)
   && isSynced
  ){
    i64 ofst = (pgno-1)*(i64)pPager->pageSize;
    testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );
    assert( !pagerUseWal(pPager) );
    rc = sqlite3OsWrite(pPager->fd, (u8*)aData, pPager->pageSize, ofst);
    if( pgno>pPager->dbFileSize ){
      pPager->dbFileSize = pgno;
    }
    if( pPager->pBackup ){
      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM);
      sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);
................................................................................
      ** the PGHDR_NEED_SYNC flag is cleared, if the page is written to
      ** again within this transaction, it will be marked as dirty but
      ** the PGHDR_NEED_SYNC flag will not be set. It could then potentially
      ** be written out into the database file before its journal file
      ** segment is synced. If a crash occurs during or following this,
      ** database corruption may ensue.
      */
      assert( !pagerUseWal(pPager) );
      sqlite3PcacheMakeClean(pPg);
    }
#ifdef SQLITE_CHECK_PAGES
    pPg->pageHash = pager_pagehash(pPg);
#endif
    /* If this was page 1, then restore the value of Pager.dbFileVers.
    ** Do this before any decoding. */
................................................................................
    zMaster = pPager->pTmpSpace;
    rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK && pPager->noSync==0 && pPager->state>=PAGER_EXCLUSIVE ){
    rc = sqlite3OsSync(pPager->fd, pPager->sync_flags);
  }
  if( rc==SQLITE_OK && pPager->noSync==0 && pPager->state>=PAGER_EXCLUSIVE ){
    rc = sqlite3OsSync(pPager->fd, pPager->sync_flags);
  }
  if( rc==SQLITE_OK ){
    rc = pager_end_transaction(pPager, zMaster[0]!='\0');
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK && zMaster[0] && res ){
    /* If there was a master journal and this routine will return success,
    ** see if it is possible to delete the master journal.
................................................................................
  ** back a journal created by a process with a different sector size
  ** value. Reset it to the correct value for this process.
  */
  setSectorSize(pPager);
  return rc;
}


/*
** Read the content for page pPg out of the database file and into 
** pPg->pData. A shared lock or greater must be held on the database
** file before this function is called.
**
** If page 1 is read, then the value of Pager.dbFileVers[] is set to
** the value read from the database file.
**
** If an IO error occurs, then the IO error is returned to the caller.
** Otherwise, SQLITE_OK is returned.
*/
static int readDbPage(PgHdr *pPg){
  Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
  Pgno pgno = pPg->pgno;       /* Page number to read */
  int rc = SQLITE_OK;          /* Return code */
  i64 iOffset;                 /* Byte offset of file to read from */
  int isInWal = 0;             /* True if page is in log file */

  assert( pPager->state>=PAGER_SHARED && !MEMDB );
  assert( isOpen(pPager->fd) );

  if( NEVER(!isOpen(pPager->fd)) ){
    assert( pPager->tempFile );
    memset(pPg->pData, 0, pPager->pageSize);
    return SQLITE_OK;
  }

  if( pagerUseWal(pPager) ){
    /* Try to pull the page from the write-ahead log. */
    rc = sqlite3WalRead(pPager->pWal, pgno, &isInWal, pPg->pData);
  }
  if( rc==SQLITE_OK && !isInWal ){
    iOffset = (pgno-1)*(i64)pPager->pageSize;
    rc = sqlite3OsRead(pPager->fd, pPg->pData, pPager->pageSize, iOffset);
    if( rc==SQLITE_IOERR_SHORT_READ ){
      rc = SQLITE_OK;
    }
  }

  if( pgno==1 ){
    if( rc ){
      /* If the read is unsuccessful, set the dbFileVers[] to something
      ** that will never be a valid file version.  dbFileVers[] is a copy
      ** of bytes 24..39 of the database.  Bytes 28..31 should always be
      ** zero.  Bytes 32..35 and 35..39 should be page numbers which are
      ** never 0xffffffff.  So filling pPager->dbFileVers[] with all 0xff
      ** bytes should suffice.
      **
      ** For an encrypted database, the situation is more complex:  bytes
      ** 24..39 of the database are white noise.  But the probability of
      ** white noising equaling 16 bytes of 0xff is vanishingly small so
      ** we should still be ok.
      */
      memset(pPager->dbFileVers, 0xff, sizeof(pPager->dbFileVers));
    }else{
      u8 *dbFileVers = &((u8*)pPg->pData)[24];
      memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
    }
  }
  CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM);

  PAGER_INCR(sqlite3_pager_readdb_count);
  PAGER_INCR(pPager->nRead);
  IOTRACE(("PGIN %p %d\n", pPager, pgno));
  PAGERTRACE(("FETCH %d page %d hash(%08x)\n",
               PAGERID(pPager), pgno, pager_pagehash(pPg)));

  return rc;
}

#ifndef SQLITE_OMIT_WAL
/*
** This function is invoked once for each page that has already been 
** written into the log file when a WAL transaction is rolled back.
** Parameter iPg is the page number of said page. The pCtx argument 
** is actually a pointer to the Pager structure.
**
** If page iPg is present in the cache, and has no outstanding references,
** it is discarded. Otherwise, if there are one or more outstanding
** references, the page content is reloaded from the database. If the
** attempt to reload content from the database is required and fails, 
** return an SQLite error code. Otherwise, SQLITE_OK.
*/
static int pagerUndoCallback(void *pCtx, Pgno iPg){
  int rc = SQLITE_OK;
  Pager *pPager = (Pager *)pCtx;
  PgHdr *pPg;

  pPg = sqlite3PagerLookup(pPager, iPg);
  if( pPg ){
    if( sqlite3PcachePageRefcount(pPg)==1 ){
      sqlite3PcacheDrop(pPg);
    }else{
      rc = readDbPage(pPg);
      if( rc==SQLITE_OK ){
        pPager->xReiniter(pPg);
      }
      sqlite3PagerUnref(pPg);
    }
  }

  /* Normally, if a transaction is rolled back, any backup processes are
  ** updated as data is copied out of the rollback journal and into the
  ** database. This is not generally possible with a WAL database, as
  ** rollback involves simply truncating the log file. Therefore, if one
  ** or more frames have already been written to the log (and therefore 
  ** also copied into the backup databases) as part of this transaction,
  ** the backups must be restarted.
  */
  sqlite3BackupRestart(pPager->pBackup);

  return rc;
}

/*
** This function is called to rollback a transaction on a WAL database.
*/
static int pagerRollbackWal(Pager *pPager){
  int rc;                         /* Return Code */
  PgHdr *pList;                   /* List of dirty pages to revert */

  /* For all pages in the cache that are currently dirty or have already
  ** been written (but not committed) to the log file, do one of the 
  ** following:
  **
  **   + Discard the cached page (if refcount==0), or
  **   + Reload page content from the database (if refcount>0).
  */
  pPager->dbSize = pPager->dbOrigSize;
  rc = sqlite3WalUndo(pPager->pWal, pagerUndoCallback, (void *)pPager);
  pList = sqlite3PcacheDirtyList(pPager->pPCache);
  while( pList && rc==SQLITE_OK ){
    PgHdr *pNext = pList->pDirty;
    rc = pagerUndoCallback((void *)pPager, pList->pgno);
    pList = pNext;
  }

  return rc;
}

/*
** This function is a wrapper around sqlite3WalFrames(). As well as logging
** the contents of the list of pages headed by pList (connected by pDirty),
** this function notifies any active backup processes that the pages have
** changed. 
*/ 
static int pagerWalFrames(
  Pager *pPager,                  /* Pager object */
  PgHdr *pList,                   /* List of frames to log */
  Pgno nTruncate,                 /* Database size after this commit */
  int isCommit,                   /* True if this is a commit */
  int sync_flags                  /* Flags to pass to OsSync() (or 0) */
){
  int rc;                         /* Return code */

  assert( pPager->pWal );
  rc = sqlite3WalFrames(pPager->pWal, 
      pPager->pageSize, pList, nTruncate, isCommit, sync_flags
  );
  if( rc==SQLITE_OK && pPager->pBackup ){
    PgHdr *p;
    for(p=pList; p; p=p->pDirty){
      sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);
    }
  }
  return rc;
}

/*
** Open a WAL snapshot on the log file this pager is connected to.
*/
static int pagerOpenSnapshot(Pager *pPager){
  int rc;                         /* Return code */
  int changed = 0;                /* True if cache must be reset */

  assert( pagerUseWal(pPager) );

  rc = sqlite3WalOpenSnapshot(pPager->pWal, &changed);
  if( rc==SQLITE_OK ){
    int dummy;
    if( changed ){
      pager_reset(pPager);
      assert( pPager->errCode || pPager->dbSizeValid==0 );
    }
    rc = sqlite3PagerPagecount(pPager, &dummy);
  }
  pPager->state = PAGER_SHARED;

  return rc;
}

/*
** Check if the *-wal file that corresponds to the database opened by pPager
** exists. Assuming no error occurs, set *pExists to 1 if the file exists,
** or 0 otherwise and return SQLITE_OK. If an IO or OOM error occurs, return
** an SQLite error code.
*/
static int pagerHasWAL(Pager *pPager, int *pExists){
  int rc;                         /* Return code */

  if( !pPager->tempFile ){
    char *zWal = sqlite3_mprintf("%s-wal", pPager->zFilename);
    if( !zWal ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3OsAccess(pPager->pVfs, zWal, SQLITE_ACCESS_EXISTS, pExists);
      sqlite3_free(zWal);
    }
  }else{
    rc = SQLITE_OK;
    *pExists = 0;
  }
  return rc;
}

/*
** Check if the *-wal file that corresponds to the database opened by pPager
** exists. If it does, open the pager in WAL mode. Otherwise, if no error
** occurs, make sure Pager.journalMode is not set to PAGER_JOURNALMODE_WAL.
** If an IO or OOM error occurs, return an SQLite error code.
**
** If the WAL file is opened, also open a snapshot (read transaction).
**
** The caller must hold a SHARED lock on the database file to call this
** function. Because an EXCLUSIVE lock on the db file is required to delete 
** a WAL, this ensures there is no race condition between the xAccess() 
** below and an xDelete() being executed by some other connection.
*/
static int pagerOpenWalIfPresent(Pager *pPager){
  int rc = SQLITE_OK;
  if( !pPager->tempFile ){
    int isWal;                    /* True if WAL file exists */
    rc = pagerHasWAL(pPager, &isWal);
    if( rc==SQLITE_OK ){
      if( isWal ){
        pager_reset(pPager);
        rc = sqlite3PagerOpenWal(pPager, 0);
        if( rc==SQLITE_OK ){
          rc = pagerOpenSnapshot(pPager);
        }
      }else if( pPager->journalMode==PAGER_JOURNALMODE_WAL ){
        pPager->journalMode = PAGER_JOURNALMODE_DELETE;
      }
    }
  }
  return rc;
}
#endif

/*
** Playback savepoint pSavepoint. Or, if pSavepoint==NULL, then playback
** the entire master journal file. The case pSavepoint==NULL occurs when 
** a ROLLBACK TO command is invoked on a SAVEPOINT that is a transaction 
** savepoint.
**
** When pSavepoint is not NULL (meaning a non-transaction savepoint is 
................................................................................
    }
  }

  /* Set the database size back to the value it was before the savepoint 
  ** being reverted was opened.
  */
  pPager->dbSize = pSavepoint ? pSavepoint->nOrig : pPager->dbOrigSize;

  if( !pSavepoint && pagerUseWal(pPager) ){
    return pagerRollbackWal(pPager);
  }

  /* Use pPager->journalOff as the effective size of the main rollback
  ** journal.  The actual file might be larger than this in
  ** PAGER_JOURNALMODE_TRUNCATE or PAGER_JOURNALMODE_PERSIST.  But anything
  ** past pPager->journalOff is off-limits to us.
  */
  szJ = pPager->journalOff;
  assert( pagerUseWal(pPager)==0 || szJ==0 );

  /* Begin by rolling back records from the main journal starting at
  ** PagerSavepoint.iOffset and continuing to the next journal header.
  ** There might be records in the main journal that have a page number
  ** greater than the current database size (pPager->dbSize) but those
  ** will be skipped automatically.  Pages are added to pDone as they
  ** are played back.
  */
  if( pSavepoint && !pagerUseWal(pPager) ){
    iHdrOff = pSavepoint->iHdrOffset ? pSavepoint->iHdrOffset : szJ;
    pPager->journalOff = pSavepoint->iOffset;
    while( rc==SQLITE_OK && pPager->journalOff<iHdrOff ){
      rc = pager_playback_one_page(pPager, &pPager->journalOff, pDone, 1, 1);
    }
    assert( rc!=SQLITE_DONE );
  }else{
................................................................................
  /* Finally,  rollback pages from the sub-journal.  Page that were
  ** previously rolled back out of the main journal (and are hence in pDone)
  ** will be skipped.  Out-of-range pages are also skipped.
  */
  if( pSavepoint ){
    u32 ii;            /* Loop counter */
    i64 offset = pSavepoint->iSubRec*(4+pPager->pageSize);

    if( pagerUseWal(pPager) ){
      rc = sqlite3WalSavepointUndo(pPager->pWal, pSavepoint->iFrame);
    }
    for(ii=pSavepoint->iSubRec; rc==SQLITE_OK && ii<pPager->nSubRec; ii++){
      assert( offset==ii*(4+pPager->pageSize) );
      rc = pager_playback_one_page(pPager, &offset, pDone, 0, 1);
    }
    assert( rc!=SQLITE_DONE );
  }

  sqlite3BitvecDestroy(pDone);
  if( rc==SQLITE_OK ){
    pPager->journalOff = szJ;
  }

  return rc;
}

/*
** Change the maximum number of in-memory pages that are allowed.
*/
void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
................................................................................
** the query attempt returns an IO error, the IO error code is returned
** and *pnPage is left unchanged.
**
** Otherwise, if everything is successful, then SQLITE_OK is returned
** and *pnPage is set to the number of pages in the database.
*/
int sqlite3PagerPagecount(Pager *pPager, int *pnPage){
  Pgno nPage = 0;           /* Value to return via *pnPage */

  /* Determine the number of pages in the file. Store this in nPage. */
  if( pPager->dbSizeValid ){
    nPage = pPager->dbSize;
  }else{
    int rc;                 /* Error returned by OsFileSize() */
    i64 n = 0;              /* File size in bytes returned by OsFileSize() */

    if( pagerUseWal(pPager) ){
      sqlite3WalDbsize(pPager->pWal, &nPage);
    }

    if( nPage==0 ){
      assert( isOpen(pPager->fd) || pPager->tempFile );
      if( isOpen(pPager->fd) ){
        if( SQLITE_OK!=(rc = sqlite3OsFileSize(pPager->fd, &n)) ){
          pager_error(pPager, rc);
          return rc;
        }
      }
      if( n>0 && n<pPager->pageSize ){
        nPage = 1;
      }else{
        nPage = (Pgno)(n / pPager->pageSize);
      }
    }
    if( pPager->state!=PAGER_UNLOCK ){
      pPager->dbSize = nPage;
      pPager->dbFileSize = nPage;
      pPager->dbSizeValid = 1;
    }
  }
................................................................................
void sqlite3PagerTruncateImage(Pager *pPager, Pgno nPage){
  assert( pPager->dbSizeValid );
  assert( pPager->dbSize>=nPage );
  assert( pPager->state>=PAGER_RESERVED );
  pPager->dbSize = nPage;
  assertTruncateConstraint(pPager);
}


/*
** This function is called before attempting a hot-journal rollback. It
** syncs the journal file to disk, then sets pPager->journalHdr to the
** size of the journal file so that the pager_playback() routine knows
** that the entire journal file has been synced.
**
................................................................................
**
** This function always succeeds. If a transaction is active an attempt
** is made to roll it back. If an error occurs during the rollback 
** a hot journal may be left in the filesystem but no error is returned
** to the caller.
*/
int sqlite3PagerClose(Pager *pPager){
  u8 *pTmp = (u8 *)pPager->pTmpSpace;

  disable_simulated_io_errors();
  sqlite3BeginBenignMalloc();
  pPager->errCode = 0;
  pPager->exclusiveMode = 0;
#ifndef SQLITE_OMIT_WAL
  sqlite3WalClose(pPager->pWal, pPager->fd, 
    (pPager->noSync ? 0 : pPager->sync_flags), pTmp
  );
  pPager->pWal = 0;
#endif
  pager_reset(pPager);
  if( MEMDB ){
    pager_unlock(pPager);
  }else{
    /* Set Pager.journalHdr to -1 for the benefit of the pager_playback() 
    ** call which may be made from within pagerUnlockAndRollback(). If it
    ** is not -1, then the unsynced portion of an open journal file may
................................................................................
    pagerUnlockAndRollback(pPager);
  }
  sqlite3EndBenignMalloc();
  enable_simulated_io_errors();
  PAGERTRACE(("CLOSE %d\n", PAGERID(pPager)));
  IOTRACE(("CLOSE %p\n", pPager))
  sqlite3OsClose(pPager->fd);
  sqlite3PageFree(pTmp);
  sqlite3PcacheClose(pPager->pPCache);

#ifdef SQLITE_HAS_CODEC
  if( pPager->xCodecFree ) pPager->xCodecFree(pPager->pCodec);
#endif

  assert( !pPager->aSavepoint && !pPager->pInJournal );
................................................................................
        ** Variable iNextHdrOffset is set to the offset at which this
        ** problematic header will occur, if it exists. aMagic is used 
        ** as a temporary buffer to inspect the first couple of bytes of
        ** the potential journal header.
        */
        i64 iNextHdrOffset;
        u8 aMagic[8];
        u8 zHeader[sizeof(aJournalMagic)+4];

        memcpy(zHeader, aJournalMagic, sizeof(aJournalMagic));
        put32bits(&zHeader[sizeof(aJournalMagic)], pPager->nRec);

        iNextHdrOffset = journalHdrOffset(pPager);
        rc = sqlite3OsRead(pPager->jfd, aMagic, 8, iNextHdrOffset);
        if( rc==SQLITE_OK && 0==memcmp(aMagic, aJournalMagic, 8) ){
          static const u8 zerobyte = 0;
          rc = sqlite3OsWrite(pPager->jfd, &zerobyte, 1, iNextHdrOffset);
        }
................................................................................
          IOTRACE(("JSYNC %p\n", pPager))
          rc = sqlite3OsSync(pPager->jfd, pPager->sync_flags);
          if( rc!=SQLITE_OK ) return rc;
        }
        IOTRACE(("JHDR %p %lld\n", pPager, pPager->journalHdr));
        rc = sqlite3OsWrite(
            pPager->jfd, zHeader, sizeof(zHeader), pPager->journalHdr
        );
        if( rc!=SQLITE_OK ) return rc;
      }
      if( 0==(iDc&SQLITE_IOCAP_SEQUENTIAL) ){
        PAGERTRACE(("SYNC journal of %d\n", PAGERID(pPager)));
        IOTRACE(("JSYNC %p\n", pPager))
        rc = sqlite3OsSync(pPager->jfd, pPager->sync_flags| 
          (pPager->sync_flags==SQLITE_SYNC_FULL?SQLITE_SYNC_DATAONLY:0)
................................................................................
  **
  ** While the pager is in the RESERVED state, the original database file
  ** is unchanged and we can rollback without having to playback the
  ** journal into the original database file.  Once we transition to
  ** EXCLUSIVE, it means the database file has been changed and any rollback
  ** will require a journal playback.
  */
  assert( !pagerUseWal(pList->pPager) );
  assert( pPager->state>=PAGER_RESERVED );
  rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);

  /* If the file is a temp-file has not yet been opened, open it now. It
  ** is not possible for rc to be other than SQLITE_OK if this branch
  ** is taken, as pager_wait_on_lock() is a no-op for temp-files.
  */
................................................................................
    void *pData = pPg->pData;
    i64 offset = pPager->nSubRec*(4+pPager->pageSize);
    char *pData2;

    CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
    PAGERTRACE(("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno));
  
    assert( pagerUseWal(pPager) 
         || pageInJournal(pPg) 
         || pPg->pgno>pPager->dbOrigSize 
    );
    rc = write32bits(pPager->sjfd, offset, pPg->pgno);
    if( rc==SQLITE_OK ){
      rc = sqlite3OsWrite(pPager->sjfd, pData2, pPager->pageSize, offset+4);
    }
  }
  if( rc==SQLITE_OK ){
    pPager->nSubRec++;
    assert( pPager->nSavepoint>0 );
    rc = addToSavepointBitvecs(pPager, pPg->pgno);
  }
  return rc;
}


/*
** This function is called by the pcache layer when it has reached some
** soft memory limit. The first argument is a pointer to a Pager object
** (cast as a void*). The pager is always 'purgeable' (not an in-memory
** database). The second argument is a reference to a page that is 
** currently dirty but has no outstanding references. The page
................................................................................
static int pagerStress(void *p, PgHdr *pPg){
  Pager *pPager = (Pager *)p;
  int rc = SQLITE_OK;

  assert( pPg->pPager==pPager );
  assert( pPg->flags&PGHDR_DIRTY );

  pPg->pDirty = 0;
  if( pagerUseWal(pPager) ){
    /* Write a single frame for this page to the log. */
    if( subjRequiresPage(pPg) ){ 
      rc = subjournalPage(pPg); 
    }
    if( rc==SQLITE_OK ){
      rc = pagerWalFrames(pPager, pPg, 0, 0, 0);
    }
  }else{
    /* The doNotSync flag is set by the sqlite3PagerWrite() function while it
    ** is journalling a set of two or more database pages that are stored
    ** on the same disk sector. Syncing the journal is not allowed while
    ** this is happening as it is important that all members of such a
    ** set of pages are synced to disk together. So, if the page this function
    ** is trying to make clean will require a journal sync and the doNotSync
    ** flag is set, return without doing anything. The pcache layer will
    ** just have to go ahead and allocate a new page buffer instead of
    ** reusing pPg.
    **
    ** Similarly, if the pager has already entered the error state, do not
    ** try to write the contents of pPg to disk.
    */
    if( NEVER(pPager->errCode)
     || (pPager->doNotSync && pPg->flags&PGHDR_NEED_SYNC)
    ){
      return SQLITE_OK;
    }
  
    /* Sync the journal file if required. */
    if( pPg->flags&PGHDR_NEED_SYNC ){
      rc = syncJournal(pPager);
      if( rc==SQLITE_OK && pPager->fullSync && 
        !(pPager->journalMode==PAGER_JOURNALMODE_MEMORY) &&
        !(sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_SAFE_APPEND)
      ){
        pPager->nRec = 0;
        rc = writeJournalHdr(pPager);
      }
    }
  
    /* If the page number of this page is larger than the current size of
    ** the database image, it may need to be written to the sub-journal.
    ** This is because the call to pager_write_pagelist() below will not
    ** actually write data to the file in this case.
    **
    ** Consider the following sequence of events:
    **
    **   BEGIN;
    **     <journal page X>
    **     <modify page X>
    **     SAVEPOINT sp;
    **       <shrink database file to Y pages>
    **       pagerStress(page X)
    **     ROLLBACK TO sp;
    **
    ** If (X>Y), then when pagerStress is called page X will not be written
    ** out to the database file, but will be dropped from the cache. Then,
    ** following the "ROLLBACK TO sp" statement, reading page X will read
    ** data from the database file. This will be the copy of page X as it
    ** was when the transaction started, not as it was when "SAVEPOINT sp"
    ** was executed.
    **
    ** The solution is to write the current data for page X into the 
    ** sub-journal file now (if it is not already there), so that it will
    ** be restored to its current value when the "ROLLBACK TO sp" is 
    ** executed.
    */
    if( NEVER(
        rc==SQLITE_OK && pPg->pgno>pPager->dbSize && subjRequiresPage(pPg)
    ) ){
      rc = subjournalPage(pPg);
    }
  
    /* Write the contents of the page out to the database file. */
    if( rc==SQLITE_OK ){

      rc = pager_write_pagelist(pPg);
    }
  }

  /* Mark the page as clean. */
  if( rc==SQLITE_OK ){
    PAGERTRACE(("STRESS %d page %d\n", PAGERID(pPager), pPg->pgno));
    sqlite3PcacheMakeClean(pPg);
  }
................................................................................
      }
    }
  }

  return rc;
}






























































/*
** This function is called to obtain a shared lock on the database file.
** It is illegal to call sqlite3PagerAcquire() until after this function
** has been successfully called. If a shared-lock is already held when
** this function is called, it is a no-op.
**
** The following operations are also performed by this function.
................................................................................
    if( isOpen(pPager->jfd) || pPager->zJournal ){
      isErrorReset = 1;
    }
    pPager->errCode = SQLITE_OK;
    pager_reset(pPager);
  }

  if( pagerUseWal(pPager) ){
    rc = pagerOpenSnapshot(pPager);
  }else if( pPager->state==PAGER_UNLOCK || isErrorReset ){
    sqlite3_vfs * const pVfs = pPager->pVfs;
    int isHotJournal = 0;
    assert( !MEMDB );
    assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
    if( pPager->noReadlock ){
      assert( pPager->readOnly );
      pPager->state = PAGER_SHARED;
................................................................................

      /* Reset the journal status fields to indicates that we have no
      ** rollback journal at this time. */
      pPager->journalStarted = 0;
      pPager->journalOff = 0;
      pPager->setMaster = 0;
      pPager->journalHdr = 0;
 
      /* Make sure the journal file has been synced to disk. */
 
      /* Playback and delete the journal.  Drop the database write
      ** lock and reacquire the read lock. Purge the cache before
      ** playing back the hot-journal so that we don't end up with
      ** an inconsistent cache.  Sync the hot journal before playing
      ** it back since the process that crashed and left the hot journal
................................................................................
      }

      if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
        pager_reset(pPager);
      }
    }
    assert( pPager->exclusiveMode || pPager->state==PAGER_SHARED );

    /* If there is a WAL file in the file-system, open this database in WAL
    ** mode. Otherwise, the following function call is a no-op.
    */
    rc = pagerOpenWalIfPresent(pPager);
  }

 failed:
  if( rc!=SQLITE_OK ){
    /* pager_unlock() is a no-op for exclusive mode and in-memory databases. */
    pager_unlock(pPager);
  }
................................................................................
    rc = sqlite3PagerPagecount(pPager, &nMax);
    if( rc!=SQLITE_OK ){
      goto pager_acquire_err;
    }

    if( MEMDB || nMax<(int)pgno || noContent || !isOpen(pPager->fd) ){
      if( pgno>pPager->mxPgno ){
        rc = SQLITE_FULL;
        goto pager_acquire_err;
      }
      if( noContent ){
        /* Failure to set the bits in the InJournal bit-vectors is benign.
        ** It merely means that we might do some extra work to journal a 
        ** page that does not need to be journaled.  Nevertheless, be sure 
        ** to test the case where a malloc error occurs while trying to set 
        ** a bit in a bit vector.
................................................................................
**
** SQLITE_OK is returned if everything goes according to plan. 
** An SQLITE_IOERR_XXX error code is returned if a call to 
** sqlite3OsOpen() fails.
*/
static int openSubJournal(Pager *pPager){
  int rc = SQLITE_OK;
  if( (pagerUseWal(pPager) || isOpen(pPager->jfd)) && !isOpen(pPager->sjfd) ){
    if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY || pPager->subjInMemory ){
      sqlite3MemJournalOpen(pPager->sjfd);
    }else{
      rc = pagerOpentemp(pPager, pPager->sjfd, SQLITE_OPEN_SUBJOURNAL);
    }
  }
  return rc;
................................................................................
  int rc = SQLITE_OK;
  assert( pPager->state!=PAGER_UNLOCK );
  pPager->subjInMemory = (u8)subjInMemory;
  if( pPager->state==PAGER_SHARED ){
    assert( pPager->pInJournal==0 );
    assert( !MEMDB && !pPager->tempFile );

    if( pagerUseWal(pPager) ){
      /* Grab the write lock on the log file. If successful, upgrade to
      ** PAGER_EXCLUSIVE state. Otherwise, return an error code to the caller.
      ** The busy-handler is not invoked if another connection already
      ** holds the write-lock. If possible, the upper layer will call it.
      */
      rc = sqlite3WalWriteLock(pPager->pWal, 1);
      if( rc==SQLITE_OK ){
        pPager->dbOrigSize = pPager->dbSize;
        pPager->state = PAGER_RESERVED;
        pPager->journalOff = 0;
      }
    }else{
      /* Obtain a RESERVED lock on the database file. If the exFlag parameter
      ** is true, then immediately upgrade this to an EXCLUSIVE lock. The
      ** busy-handler callback can be used when upgrading to the EXCLUSIVE
      ** lock, but not when obtaining the RESERVED lock.
      */
      rc = sqlite3OsLock(pPager->fd, RESERVED_LOCK);
      if( rc==SQLITE_OK ){
        pPager->state = PAGER_RESERVED;
        if( exFlag ){
          rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
        }
      }
    }

    /* No need to open the journal file at this time.  It will be
    ** opened before it is written to.  If we defer opening the journal,
    ** we might save the work of creating a file if the transaction
    ** ends up being a no-op.
................................................................................
  }else if( isOpen(pPager->jfd) && pPager->journalOff==0 ){
    /* This happens when the pager was in exclusive-access mode the last
    ** time a (read or write) transaction was successfully concluded
    ** by this connection. Instead of deleting the journal file it was 
    ** kept open and either was truncated to 0 bytes or its header was
    ** overwritten with zeros.
    */
    assert( pagerUseWal(pPager)==0 );
    assert( pPager->nRec==0 );
    assert( pPager->dbOrigSize==0 );
    assert( pPager->pInJournal==0 );
    rc = pager_open_journal(pPager);
  }

  PAGERTRACE(("TRANSACTION %d\n", PAGERID(pPager)));
................................................................................
  CHECK_PAGE(pPg);

  /* Mark the page as dirty.  If the page has already been written
  ** to the journal then we can return right away.
  */
  sqlite3PcacheMakeDirty(pPg);
  if( pageInJournal(pPg) && !subjRequiresPage(pPg) ){
    assert( !pagerUseWal(pPager) );
    pPager->dbModified = 1;
  }else{

    /* If we get this far, it means that the page needs to be
    ** written to the transaction journal or the ckeckpoint journal
    ** or both.
    **
................................................................................
    ** which means they have acquired the necessary locks but the rollback
    ** journal might not yet be open.
    */
    rc = sqlite3PagerBegin(pPager, 0, pPager->subjInMemory);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    if( !isOpen(pPager->jfd) 
     && pPager->journalMode!=PAGER_JOURNALMODE_OFF 
     && !pagerUseWal(pPager)
    ){
      assert( pPager->useJournal );
      rc = pager_open_journal(pPager);
      if( rc!=SQLITE_OK ) return rc;
    }
    pPager->dbModified = 1;
  
    /* The transaction journal now exists and we have a RESERVED or an
    ** EXCLUSIVE lock on the main database file.  Write the current page to
    ** the transaction journal if it is not there already.
    */
    if( !pageInJournal(pPg) && isOpen(pPager->jfd) ){
      assert( !pagerUseWal(pPager) );
      if( pPg->pgno<=pPager->dbOrigSize ){
        u32 cksum;
        char *pData2;

        /* We should never write to the journal file the page that
        ** contains the database locks.  The following assert verifies
        ** that we do not. */
................................................................................
  if( MEMDB && pPager->dbModified ){
    /* If this is an in-memory db, or no pages have been written to, or this
    ** function has already been called, it is mostly a no-op.  However, any
    ** backup in progress needs to be restarted.
    */
    sqlite3BackupRestart(pPager->pBackup);
  }else if( pPager->state!=PAGER_SYNCED && pPager->dbModified ){
    if( pagerUseWal(pPager) ){
      PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
      if( pList ){
        rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1, 
            (pPager->fullSync ? pPager->sync_flags : 0)
        );
      }
      sqlite3PcacheCleanAll(pPager->pPCache);
    }else{
      /* The following block updates the change-counter. Exactly how it
      ** does this depends on whether or not the atomic-update optimization
      ** was enabled at compile time, and if this transaction meets the 
      ** runtime criteria to use the operation: 
      **
      **    * The file-system supports the atomic-write property for
      **      blocks of size page-size, and 
      **    * This commit is not part of a multi-file transaction, and
      **    * Exactly one page has been modified and store in the journal file.
      **
      ** If the optimization was not enabled at compile time, then the
      ** pager_incr_changecounter() function is called to update the change
      ** counter in 'indirect-mode'. If the optimization is compiled in but
      ** is not applicable to this transaction, call sqlite3JournalCreate()
      ** to make sure the journal file has actually been created, then call
      ** pager_incr_changecounter() to update the change-counter in indirect
      ** mode. 
      **
      ** Otherwise, if the optimization is both enabled and applicable,
      ** then call pager_incr_changecounter() to update the change-counter
      ** in 'direct' mode. In this case the journal file will never be
      ** created for this transaction.
      */
  #ifdef SQLITE_ENABLE_ATOMIC_WRITE
      PgHdr *pPg;
      assert( isOpen(pPager->jfd) || pPager->journalMode==PAGER_JOURNALMODE_OFF );
      if( !zMaster && isOpen(pPager->jfd) 
       && pPager->journalOff==jrnlBufferSize(pPager) 
       && pPager->dbSize>=pPager->dbFileSize
       && (0==(pPg = sqlite3PcacheDirtyList(pPager->pPCache)) || 0==pPg->pDirty)
      ){
        /* Update the db file change counter via the direct-write method. The 
        ** following call will modify the in-memory representation of page 1 
        ** to include the updated change counter and then write page 1 
        ** directly to the database file. Because of the atomic-write 
        ** property of the host file-system, this is safe.
        */
        rc = pager_incr_changecounter(pPager, 1);
      }else{
        rc = sqlite3JournalCreate(pPager->jfd);
        if( rc==SQLITE_OK ){
          rc = pager_incr_changecounter(pPager, 0);
        }
      }
  #else
      rc = pager_incr_changecounter(pPager, 0);
  #endif
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
  
      /* If this transaction has made the database smaller, then all pages
      ** being discarded by the truncation must be written to the journal
      ** file. This can only happen in auto-vacuum mode.
      **
      ** Before reading the pages with page numbers larger than the 
      ** current value of Pager.dbSize, set dbSize back to the value
      ** that it took at the start of the transaction. Otherwise, the
      ** calls to sqlite3PagerGet() return zeroed pages instead of 
      ** reading data from the database file.
      **
      ** When journal_mode==OFF the dbOrigSize is always zero, so this
      ** block never runs if journal_mode=OFF.
      */
  #ifndef SQLITE_OMIT_AUTOVACUUM
      if( pPager->dbSize<pPager->dbOrigSize 
       && ALWAYS(pPager->journalMode!=PAGER_JOURNALMODE_OFF)
      ){
        Pgno i;                                   /* Iterator variable */
        const Pgno iSkip = PAGER_MJ_PGNO(pPager); /* Pending lock page */
        const Pgno dbSize = pPager->dbSize;       /* Database image size */ 
        pPager->dbSize = pPager->dbOrigSize;
        for( i=dbSize+1; i<=pPager->dbOrigSize; i++ ){
          if( !sqlite3BitvecTest(pPager->pInJournal, i) && i!=iSkip ){
            PgHdr *pPage;             /* Page to journal */
            rc = sqlite3PagerGet(pPager, i, &pPage);
            if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
            rc = sqlite3PagerWrite(pPage);
            sqlite3PagerUnref(pPage);
            if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
          }
        }
        pPager->dbSize = dbSize;
      } 
  #endif
  
      /* Write the master journal name into the journal file. If a master 
      ** journal file name has already been written to the journal file, 
      ** or if zMaster is NULL (no master journal), then this call is a no-op.
      */
      rc = writeMasterJournal(pPager, zMaster);
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
  
      /* Sync the journal file. If the atomic-update optimization is being
      ** used, this call will not create the journal file or perform any
      ** real IO.
      */
      rc = syncJournal(pPager);
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
  
      /* Write all dirty pages to the database file. */
      rc = pager_write_pagelist(sqlite3PcacheDirtyList(pPager->pPCache));
      if( rc!=SQLITE_OK ){
        assert( rc!=SQLITE_IOERR_BLOCKED );
        goto commit_phase_one_exit;
      }
      sqlite3PcacheCleanAll(pPager->pPCache);
  
      /* If the file on disk is not the same size as the database image,
      ** then use pager_truncate to grow or shrink the file here.
      */
      if( pPager->dbSize!=pPager->dbFileSize ){
        Pgno nNew = pPager->dbSize - (pPager->dbSize==PAGER_MJ_PGNO(pPager));
        assert( pPager->state>=PAGER_EXCLUSIVE );
        rc = pager_truncate(pPager, nNew);
        if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
      }
  
      /* Finally, sync the database file. */
      if( !pPager->noSync && !noSync ){
        rc = sqlite3OsSync(pPager->fd, pPager->sync_flags);
      }
      IOTRACE(("DBSYNC %p\n", pPager))
    }

    pPager->state = PAGER_SYNCED;
  }

commit_phase_one_exit:
  return rc;
}

................................................................................
**   the journal file. It needs to be left in the file-system so that
**   some other process can use it to restore the database state (by
**   hot-journal rollback).
*/
int sqlite3PagerRollback(Pager *pPager){
  int rc = SQLITE_OK;                  /* Return code */
  PAGERTRACE(("ROLLBACK %d\n", PAGERID(pPager)));
  if( pagerUseWal(pPager) ){
    int rc2;

    rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);
    rc2 = pager_end_transaction(pPager, pPager->setMaster);
    if( rc==SQLITE_OK ) rc = rc2;
  }else if( !pPager->dbModified || !isOpen(pPager->jfd) ){
    rc = pager_end_transaction(pPager, pPager->setMaster);
  }else if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
    if( pPager->state>=PAGER_EXCLUSIVE ){
      pager_playback(pPager, 0);
    }
    rc = pPager->errCode;
  }else{
................................................................................
        aNew[ii].iOffset = JOURNAL_HDR_SZ(pPager);
      }
      aNew[ii].iSubRec = pPager->nSubRec;
      aNew[ii].pInSavepoint = sqlite3BitvecCreate(nPage);
      if( !aNew[ii].pInSavepoint ){
        return SQLITE_NOMEM;
      }
      if( pagerUseWal(pPager) ){
        aNew[ii].iFrame = sqlite3WalSavepoint(pPager->pWal);
      }
    }

    /* Open the sub-journal, if it is not already opened. */
    rc = openSubJournal(pPager);
    assertTruncateConstraint(pPager);
  }

................................................................................
      }
    }
    /* Else this is a rollback operation, playback the specified savepoint.
    ** If this is a temp-file, it is possible that the journal file has
    ** not yet been opened. In this case there have been no changes to
    ** the database file, so the playback operation can be skipped.
    */
    else if( pagerUseWal(pPager) || isOpen(pPager->jfd) ){
      PagerSavepoint *pSavepoint = (nNew==0)?0:&pPager->aSavepoint[nNew-1];
      rc = pagerPlaybackSavepoint(pPager, pSavepoint);
      assert(rc!=SQLITE_DONE);
    }
  
  }
  return rc;
................................................................................
**
**    PAGER_JOURNALMODE_QUERY
**    PAGER_JOURNALMODE_DELETE
**    PAGER_JOURNALMODE_TRUNCATE
**    PAGER_JOURNALMODE_PERSIST
**    PAGER_JOURNALMODE_OFF
**    PAGER_JOURNALMODE_MEMORY
**    PAGER_JOURNALMODE_WAL
**
** If the parameter is not _QUERY, then the journal_mode is set to the
** value specified if the change is allowed. The change may be disallowed
** for the following reasons:
**
**   *  An in-memory database can only have its journal_mode set to _OFF
**      or _MEMORY.
**
**   *  The journal mode may not be changed while a transaction is active.
**
................................................................................
*/
int sqlite3PagerJournalMode(Pager *pPager, int eMode){
  assert( eMode==PAGER_JOURNALMODE_QUERY
            || eMode==PAGER_JOURNALMODE_DELETE
            || eMode==PAGER_JOURNALMODE_TRUNCATE
            || eMode==PAGER_JOURNALMODE_PERSIST
            || eMode==PAGER_JOURNALMODE_OFF 
            || eMode==PAGER_JOURNALMODE_WAL 
            || eMode==PAGER_JOURNALMODE_MEMORY );
  assert( PAGER_JOURNALMODE_QUERY<0 );

  if( eMode==PAGER_JOURNALMODE_WAL 
   && pPager->journalMode==PAGER_JOURNALMODE_DELETE
  ){
    pPager->journalMode = PAGER_JOURNALMODE_WAL;
  }else if( eMode>=0
   && (pPager->tempFile==0 || eMode!=PAGER_JOURNALMODE_WAL)
   && (!MEMDB || eMode==PAGER_JOURNALMODE_MEMORY||eMode==PAGER_JOURNALMODE_OFF)

   && !pPager->dbModified
   && (!isOpen(pPager->jfd) || 0==pPager->journalOff)
  ){
    if( isOpen(pPager->jfd) ){
      sqlite3OsClose(pPager->jfd);
    }
    assert( (PAGER_JOURNALMODE_TRUNCATE & 1)==1 );
................................................................................
    assert( (PAGER_JOURNALMODE_DELETE & 1)==0 );
    assert( (PAGER_JOURNALMODE_MEMORY & 1)==0 );
    assert( (PAGER_JOURNALMODE_OFF & 1)==0 );
    if( (pPager->journalMode & 1)==1 && (eMode & 1)==0
         && !pPager->exclusiveMode ){
      sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
    }

    pPager->journalMode = (u8)eMode;
  }
  return (int)pPager->journalMode;
}

/*
** Get/set the size-limit used for persistent journal files.
................................................................................
** in backup.c maintains the content of this variable. This module
** uses it opaquely as an argument to sqlite3BackupRestart() and
** sqlite3BackupUpdate() only.
*/
sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){
  return &pPager->pBackup;
}

#ifndef SQLITE_OMIT_WAL
/*
** This function is called when the user invokes "PRAGMA checkpoint".
*/
int sqlite3PagerCheckpoint(Pager *pPager){
  int rc = SQLITE_OK;
  if( pPager->pWal ){
    u8 *zBuf = (u8 *)pPager->pTmpSpace;
    rc = sqlite3WalCheckpoint(pPager->pWal, pPager->fd, 
        (pPager->noSync ? 0 : pPager->sync_flags),
        zBuf, pPager->xBusyHandler, pPager->pBusyHandlerArg
    );
  }
  return rc;
}

int sqlite3PagerWalCallback(Pager *pPager){
  return sqlite3WalCallback(pPager->pWal);
}

/*
** Open a connection to the write-ahead log file for pager pPager. If
** the log connection is already open, this function is a no-op.
**
** The caller must be holding a SHARED lock on the database file to call
** this function.
*/
int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen){
  int rc = SQLITE_OK;             /* Return code */

  assert( pPager->state>=PAGER_SHARED );
  if( !pPager->pWal ){

    /* Open the connection to the log file. If this operation fails, 
    ** (e.g. due to malloc() failure), unlock the database file and 
    ** return an error code.
    */
    rc = sqlite3WalOpen(pPager->pVfs, pPager->zFilename, &pPager->pWal);
    if( rc==SQLITE_OK ){
      pPager->journalMode = PAGER_JOURNALMODE_WAL;
    }
  }else{
    *pisOpen = 1;
  }

  return rc;
}

/*
** This function is called to close the connection to the log file prior
** to switching from WAL to rollback mode.
**
** Before closing the log file, this function attempts to take an 
** EXCLUSIVE lock on the database file. If this cannot be obtained, an
** error (SQLITE_BUSY) is returned and the log connection is not closed.
** If successful, the EXCLUSIVE lock is not released before returning.
*/
int sqlite3PagerCloseWal(Pager *pPager){
  int rc = SQLITE_OK;

  assert( pPager->journalMode==PAGER_JOURNALMODE_WAL );

  /* If the log file is not already open, but does exist in the file-system,
  ** it may need to be checkpointed before the connection can switch to
  ** rollback mode. Open it now so this can happen.
  */
  if( !pPager->pWal ){
    int logexists = 0;
    rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_SHARED);
    if( rc==SQLITE_OK ){
      rc = pagerHasWAL(pPager, &logexists);
    }
    if( rc==SQLITE_OK && logexists ){
      rc = sqlite3WalOpen(pPager->pVfs, pPager->zFilename, &pPager->pWal);
    }
  }
    
  /* Checkpoint and close the log. Because an EXCLUSIVE lock is held on
  ** the database file, the log and log-summary files will be deleted.
  */
  if( rc==SQLITE_OK && pPager->pWal ){
    rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_EXCLUSIVE);
    if( rc==SQLITE_OK ){
      rc = sqlite3WalClose(pPager->pWal, pPager->fd,
        (pPager->noSync ? 0 : pPager->sync_flags), 
        (u8*)pPager->pTmpSpace
      );
      pPager->pWal = 0;
    }
  }
  return rc;
}
#endif

#endif /* SQLITE_OMIT_DISKIO */

Changes to src/pager.h.

72
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78

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134





135
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*/
#define PAGER_JOURNALMODE_QUERY      -1
#define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
#define PAGER_JOURNALMODE_PERSIST     1   /* Commit by zeroing journal header */
#define PAGER_JOURNALMODE_OFF         2   /* Journal omitted.  */
#define PAGER_JOURNALMODE_TRUNCATE    3   /* Commit by truncating journal */
#define PAGER_JOURNALMODE_MEMORY      4   /* In-memory journal file */


/*
** The remainder of this file contains the declarations of the functions
** that make up the Pager sub-system API. See source code comments for 
** a detailed description of each routine.
*/

................................................................................
int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, int);
int sqlite3PagerSync(Pager *pPager);
int sqlite3PagerCommitPhaseTwo(Pager*);
int sqlite3PagerRollback(Pager*);
int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
int sqlite3PagerSharedLock(Pager *pPager);






/* Functions used to query pager state and configuration. */
u8 sqlite3PagerIsreadonly(Pager*);
int sqlite3PagerRefcount(Pager*);
int sqlite3PagerMemUsed(Pager*);
const char *sqlite3PagerFilename(Pager*);
const sqlite3_vfs *sqlite3PagerVfs(Pager*);







>







 







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72
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143
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147
*/
#define PAGER_JOURNALMODE_QUERY      -1
#define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
#define PAGER_JOURNALMODE_PERSIST     1   /* Commit by zeroing journal header */
#define PAGER_JOURNALMODE_OFF         2   /* Journal omitted.  */
#define PAGER_JOURNALMODE_TRUNCATE    3   /* Commit by truncating journal */
#define PAGER_JOURNALMODE_MEMORY      4   /* In-memory journal file */
#define PAGER_JOURNALMODE_WAL         5   /* Use write-ahead logging */

/*
** The remainder of this file contains the declarations of the functions
** that make up the Pager sub-system API. See source code comments for 
** a detailed description of each routine.
*/

................................................................................
int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, int);
int sqlite3PagerSync(Pager *pPager);
int sqlite3PagerCommitPhaseTwo(Pager*);
int sqlite3PagerRollback(Pager*);
int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
int sqlite3PagerSharedLock(Pager *pPager);

int sqlite3PagerCheckpoint(Pager *pPager);
int sqlite3PagerWalCallback(Pager *pPager);
int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
int sqlite3PagerCloseWal(Pager *pPager);

/* Functions used to query pager state and configuration. */
u8 sqlite3PagerIsreadonly(Pager*);
int sqlite3PagerRefcount(Pager*);
int sqlite3PagerMemUsed(Pager*);
const char *sqlite3PagerFilename(Pager*);
const sqlite3_vfs *sqlite3PagerVfs(Pager*);

Changes to src/pragma.c.

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1381
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1387
    default:          zName = "NO ACTION";  
                      assert( action==OE_None ); break;
  }
  return zName;
}
#endif


























/*
** Process a pragma statement.  
**
** Pragmas are of this form:
**
**      PRAGMA [database.]id [= value]
**
................................................................................
  }else

  /*
  **  PRAGMA [database.]journal_mode
  **  PRAGMA [database.]journal_mode = (delete|persist|off|truncate|memory)
  */
  if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){
    int eMode;
    static char * const azModeName[] = {
      "delete", "persist", "off", "truncate", "memory"
    };

    if( zRight==0 ){
      eMode = PAGER_JOURNALMODE_QUERY;
    }else{

      int n = sqlite3Strlen30(zRight);
      eMode = sizeof(azModeName)/sizeof(azModeName[0]) - 1;

      while( eMode>=0 && sqlite3StrNICmp(zRight, azModeName[eMode], n)!=0 ){

        eMode--;

      }
    }
    if( pId2->n==0 && eMode==PAGER_JOURNALMODE_QUERY ){
      /* Simple "PRAGMA journal_mode;" statement. This is a query for
      ** the current default journal mode (which may be different to
      ** the journal-mode of the main database).
      */
      eMode = db->dfltJournalMode;


    }else{
      Pager *pPager;


      if( pId2->n==0 ){
        /* This indicates that no database name was specified as part
        ** of the PRAGMA command. In this case the journal-mode must be
        ** set on all attached databases, as well as the main db file.
        **
        ** Also, the sqlite3.dfltJournalMode variable is set so that
        ** any subsequently attached databases also use the specified
        ** journal mode.

        */
        int ii;
        assert(pDb==&db->aDb[0]);
        for(ii=1; ii<db->nDb; ii++){



          if( db->aDb[ii].pBt ){
            pPager = sqlite3BtreePager(db->aDb[ii].pBt);
            sqlite3PagerJournalMode(pPager, eMode);


          }
        }
        db->dfltJournalMode = (u8)eMode;
      }
      pPager = sqlite3BtreePager(pDb->pBt);
      eMode = sqlite3PagerJournalMode(pPager, eMode);
    }
    assert( eMode==PAGER_JOURNALMODE_DELETE
              || eMode==PAGER_JOURNALMODE_TRUNCATE
              || eMode==PAGER_JOURNALMODE_PERSIST
              || eMode==PAGER_JOURNALMODE_OFF
              || eMode==PAGER_JOURNALMODE_MEMORY );
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", SQLITE_STATIC);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, 
           azModeName[eMode], P4_STATIC);
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
  }else

  /*
  **  PRAGMA [database.]journal_size_limit
  **  PRAGMA [database.]journal_size_limit=N
  **
................................................................................
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "compile_option", SQLITE_STATIC);
    while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zOpt, 0);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
    }
  }else
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */































#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /*
  ** Report the current state of file logs for all databases
  */
  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
    static const char *const azLockName[] = {







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>







 







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>

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>








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<







 







>
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>







253
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286
287
288
289
290
291
...
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546

547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562

563
564
565
566
567
568
569
570
571
572
573
574

575

576
577
578
579


580
581
582
583

584


585









586
587
588
589
590
591
592
....
1395
1396
1397
1398
1399
1400
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1405
1406
1407
1408
1409
1410
1411
1412
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1414
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1431
1432
1433
1434
1435
1436
1437
1438
    default:          zName = "NO ACTION";  
                      assert( action==OE_None ); break;
  }
  return zName;
}
#endif


/*
** Parameter eMode must be one of the PAGER_JOURNALMODE_XXX constants
** defined in pager.h. This function returns the associated lowercase
** journal-mode name.
*/
const char *sqlite3JournalModename(int eMode){
  static char * const azModeName[] = {
    "delete", "persist", "off", "truncate", "memory"
#ifndef SQLITE_OMIT_WAL
     , "wal"
#endif
  };
  assert( PAGER_JOURNALMODE_DELETE==0 );
  assert( PAGER_JOURNALMODE_PERSIST==1 );
  assert( PAGER_JOURNALMODE_OFF==2 );
  assert( PAGER_JOURNALMODE_TRUNCATE==3 );
  assert( PAGER_JOURNALMODE_MEMORY==4 );
  assert( PAGER_JOURNALMODE_WAL==5 );
  assert( eMode>=0 && eMode<=ArraySize(azModeName) );

  if( eMode==ArraySize(azModeName) ) return 0;
  return azModeName[eMode];
}

/*
** Process a pragma statement.  
**
** Pragmas are of this form:
**
**      PRAGMA [database.]id [= value]
**
................................................................................
  }else

  /*
  **  PRAGMA [database.]journal_mode
  **  PRAGMA [database.]journal_mode = (delete|persist|off|truncate|memory)
  */
  if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){
    int eMode;                    /* One of the PAGER_JOURNALMODE_XXX symbols */

    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", SQLITE_STATIC);

    if( zRight==0 ){
      eMode = PAGER_JOURNALMODE_QUERY;
    }else{
      const char *zMode;
      int n = sqlite3Strlen30(zRight);

      for(eMode=0; (zMode = sqlite3JournalModename(eMode)); eMode++){
        if( sqlite3StrNICmp(zRight, zMode, n)==0 ) break;
      }
      if( !zMode ){
        eMode = PAGER_JOURNALMODE_QUERY;
      }
    }
    if( pId2->n==0 && eMode==PAGER_JOURNALMODE_QUERY ){
      /* Simple "PRAGMA journal_mode;" statement. This is a query for
      ** the current default journal mode (which may be different to
      ** the journal-mode of the main database).
      */
      eMode = db->dfltJournalMode;
      sqlite3VdbeAddOp2(v, OP_String8, 0, 1);
      sqlite3VdbeChangeP4(v, -1, sqlite3JournalModename(eMode), P4_STATIC);
    }else{

      int ii;

      if( pId2->n==0 && eMode!=PAGER_JOURNALMODE_WAL ){
        /* This indicates that no database name was specified as part
        ** of the PRAGMA command. In this case the journal-mode must be
        ** set on all attached databases, as well as the main db file.
        **
        ** Also, the sqlite3.dfltJournalMode variable is set so that
        ** any subsequently attached databases also use the specified
        ** journal mode. Except, the default journal mode is never set
        ** to WAL.
        */

        db->dfltJournalMode = (u8)eMode;

      }

      for(ii=db->nDb-1; ii>=0; ii--){
        if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){


          sqlite3VdbeUsesBtree(v, ii);
          sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
        }
      }

    }












    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
  }else

  /*
  **  PRAGMA [database.]journal_size_limit
  **  PRAGMA [database.]journal_size_limit=N
  **
................................................................................
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "compile_option", SQLITE_STATIC);
    while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zOpt, 0);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
    }
  }else
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

#ifndef SQLITE_OMIT_WAL
  /*
  **   PRAGMA [database.]wal_checkpoint
  **
  ** Checkpoint the database.
  */
  if( sqlite3StrICmp(zLeft, "wal_checkpoint")==0 ){
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeAddOp3(v, OP_Checkpoint, iDb, 0, 0);
  }else

  /*
  **   PRAGMA wal_autocheckpoint
  **   PRAGMA wal_autocheckpoint = N
  **
  ** Configure a database connection to automatically checkpoint a database
  ** after accumulating N frames in the log. Or query for the current value
  ** of N.
  */
  if( sqlite3StrICmp(zLeft, "wal_autocheckpoint")==0 ){
    if( zRight ){
      int nAuto = atoi(zRight);
      sqlite3_wal_autocheckpoint(db, nAuto);
    }
    returnSingleInt(pParse, "wal_autocheckpoint", 
       db->xWalCallback==sqlite3WalDefaultHook ? 
           SQLITE_PTR_TO_INT(db->pWalArg) : 0);
  }else
#endif

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /*
  ** Report the current state of file logs for all databases
  */
  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
    static const char *const azLockName[] = {

Changes to src/sqlite.h.in.

814
815
816
817
818
819
820

821
822
823
824
825
826
827
828
829
...
834
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836
837
838
839
840














841
842

843
844
845
846
847
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849
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855
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866
867
868
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5724
5725
5726
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5728












































5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
** the actual number of bytes of randomness obtained.
** The xSleep() method causes the calling thread to sleep for at
** least the number of microseconds given.  The xCurrentTime()
** method returns a Julian Day Number for the current date and time.
**
*/
typedef struct sqlite3_vfs sqlite3_vfs;

struct sqlite3_vfs {
  int iVersion;            /* Structure version number */
  int szOsFile;            /* Size of subclassed sqlite3_file */
  int mxPathname;          /* Maximum file pathname length */
  sqlite3_vfs *pNext;      /* Next registered VFS */
  const char *zName;       /* Name of this virtual file system */
  void *pAppData;          /* Pointer to application-specific data */
  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
               int flags, int *pOutFlags);
................................................................................
  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
  void (*xDlClose)(sqlite3_vfs*, void*);
  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
  int (*xSleep)(sqlite3_vfs*, int microseconds);
  int (*xCurrentTime)(sqlite3_vfs*, double*);
  int (*xGetLastError)(sqlite3_vfs*, int, char *);














  /* New fields may be appended in figure versions.  The iVersion
  ** value will increment whenever this happens. */

};

/*
** CAPI3REF: Flags for the xAccess VFS method
**
** These integer constants can be used as the third parameter to
** the xAccess method of an [sqlite3_vfs] object.  They determine
................................................................................
** With SQLITE_ACCESS_READ, the xAccess method
** checks whether the file is readable.
*/
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1
#define SQLITE_ACCESS_READ      2



















/*
** CAPI3REF: Initialize The SQLite Library
**
** ^The sqlite3_initialize() routine initializes the
** SQLite library.  ^The sqlite3_shutdown() routine
** deallocates any resources that were allocated by sqlite3_initialize().
** These routines are designed to aid in process initialization and
................................................................................
** will not use dynamically allocated memory.  The log message is stored in
** a fixed-length buffer on the stack.  If the log message is longer than
** a few hundred characters, it will be truncated to the length of the
** buffer.
*/
void sqlite3_log(int iErrCode, const char *zFormat, ...);













































/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif







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814
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...
835
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841
842
843
844
845
846
847
848
849
850
851
852
853
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857
858
859
860
861
862
863
864
865
...
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
....
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
** the actual number of bytes of randomness obtained.
** The xSleep() method causes the calling thread to sleep for at
** least the number of microseconds given.  The xCurrentTime()
** method returns a Julian Day Number for the current date and time.
**
*/
typedef struct sqlite3_vfs sqlite3_vfs;
typedef struct sqlite3_shm sqlite3_shm;
struct sqlite3_vfs {
  int iVersion;            /* Structure version number (currently 2) */
  int szOsFile;            /* Size of subclassed sqlite3_file */
  int mxPathname;          /* Maximum file pathname length */
  sqlite3_vfs *pNext;      /* Next registered VFS */
  const char *zName;       /* Name of this virtual file system */
  void *pAppData;          /* Pointer to application-specific data */
  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
               int flags, int *pOutFlags);
................................................................................
  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
  void (*xDlClose)(sqlite3_vfs*, void*);
  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
  int (*xSleep)(sqlite3_vfs*, int microseconds);
  int (*xCurrentTime)(sqlite3_vfs*, double*);
  int (*xGetLastError)(sqlite3_vfs*, int, char *);
  /*
  ** The methods above are in version 1 of the sqlite_vfs object
  ** definition.  Those that follow are added in version 2 or later
  */
  int (*xShmOpen)(sqlite3_vfs*, const char *zName, sqlite3_shm**);
  int (*xShmSize)(sqlite3_shm*, int reqSize, int *pNewSize);
  int (*xShmGet)(sqlite3_shm*, int reqMapSize, int *pMapSize, void**);
  int (*xShmRelease)(sqlite3_shm*);
  int (*xShmLock)(sqlite3_shm*, int desiredLock, int *gotLock);
  int (*xShmClose)(sqlite3_shm*, int deleteFlag);
  int (*xRename)(sqlite3_vfs*, const char *zOld, const char *zNew, int dirSync);
  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
  /*
  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
  ** New fields may be appended in figure versions.  The iVersion
  ** value will increment whenever this happens. 
  */
};

/*
** CAPI3REF: Flags for the xAccess VFS method
**
** These integer constants can be used as the third parameter to
** the xAccess method of an [sqlite3_vfs] object.  They determine
................................................................................
** With SQLITE_ACCESS_READ, the xAccess method
** checks whether the file is readable.
*/
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1
#define SQLITE_ACCESS_READ      2

/*
** CAPI3REF: Flags for the xShmLock VFS method
**
** These integer constants define the various locking states that
** an sqlite3_shm object can be in.  The SQLITE_SHM_QUERY integer
** is not a valid data - it is a constant pasted to the 
** sqlite3_vfs.xShmLock() method for querying the current lock
** state.
*/
#define SQLITE_SHM_UNLOCK       0
#define SQLITE_SHM_READ         1
#define SQLITE_SHM_READ_FULL    2
#define SQLITE_SHM_WRITE        3
#define SQLITE_SHM_PENDING      4
#define SQLITE_SHM_CHECKPOINT   5
#define SQLITE_SHM_RECOVER      6
#define SQLITE_SHM_QUERY        (-1)

/*
** CAPI3REF: Initialize The SQLite Library
**
** ^The sqlite3_initialize() routine initializes the
** SQLite library.  ^The sqlite3_shutdown() routine
** deallocates any resources that were allocated by sqlite3_initialize().
** These routines are designed to aid in process initialization and
................................................................................
** will not use dynamically allocated memory.  The log message is stored in
** a fixed-length buffer on the stack.  If the log message is longer than
** a few hundred characters, it will be truncated to the length of the
** buffer.
*/
void sqlite3_log(int iErrCode, const char *zFormat, ...);

/*
** CAPI3REF: Write-Ahead Log Commit Hook
**
** The [sqlite3_wal_hook()] function is used to register a callback that
** will be invoked each time a database connection commits data to a
** write-ahead-log (i.e. whenever a transaction is committed in
** journal_mode=WAL mode). 
**
** The callback is invoked by SQLite after the commit has taken place and 
** the associated write-lock on the database released, so the implementation 
** may read, write or checkpoint the database as required.
**
** The first parameter passed to the callback function when it is invoked
** is a copy of the third parameter passed to sqlite3_wal_hook() when
** registering the callback. The second is a copy of the database handle.
** The third parameter is the name of the database that was written to -
** either "main" or the name of an ATTACHed database. The fourth parameter
** is the number of pages currently in the log file, including those that
** were just committed.
**
** If an invocation of the callback function returns non-zero, then a
** checkpoint is automatically run on the database. If zero is returned,
** no special action is taken.
**
** A single database handle may have at most a single log callback 
** registered at one time. Calling [sqlite3_wal_hook()] replaces any
** previously registered log callback. 
*/
void *sqlite3_wal_hook(
  sqlite3*, 
  int(*)(void *,sqlite3*,const char*,int),
  void*
);

/*
** CAPI3REF: Configure an auto-checkpoint
*/
int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);

/*
** CAPI3REF: Checkpoint a database
*/
int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);

/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif

Changes to src/sqliteInt.h.

819
820
821
822
823
824
825




826
827
828
829
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831
832
....
2989
2990
2991
2992
2993
2994
2995



2996
2997
2998
2999
3000
3001
3002
  void *pProfileArg;                        /* Argument to profile function */
  void *pCommitArg;                 /* Argument to xCommitCallback() */   
  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
  void *pRollbackArg;               /* Argument to xRollbackCallback() */   
  void (*xRollbackCallback)(void*); /* Invoked at every commit. */
  void *pUpdateArg;
  void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);




  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
  void *pCollNeededArg;
  sqlite3_value *pErr;          /* Most recent error message */
  char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
  char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
  union {
................................................................................
int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
int sqlite3Reprepare(Vdbe*);
void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
int sqlite3TempInMemory(const sqlite3*);
VTable *sqlite3GetVTable(sqlite3*, Table*);




/* Declarations for functions in fkey.c. All of these are replaced by
** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
** key functionality is available. If OMIT_TRIGGER is defined but
** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
** this case foreign keys are parsed, but no other functionality is 
** provided (enforcement of FK constraints requires the triggers sub-system).







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819
820
821
822
823
824
825
826
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831
832
833
834
835
836
....
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
  void *pProfileArg;                        /* Argument to profile function */
  void *pCommitArg;                 /* Argument to xCommitCallback() */   
  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
  void *pRollbackArg;               /* Argument to xRollbackCallback() */   
  void (*xRollbackCallback)(void*); /* Invoked at every commit. */
  void *pUpdateArg;
  void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
#ifndef SQLITE_OMIT_WAL
  int (*xWalCallback)(void *, sqlite3 *, const char *, int);
  void *pWalArg;
#endif
  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
  void *pCollNeededArg;
  sqlite3_value *pErr;          /* Most recent error message */
  char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
  char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
  union {
................................................................................
int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
int sqlite3Reprepare(Vdbe*);
void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
int sqlite3TempInMemory(const sqlite3*);
VTable *sqlite3GetVTable(sqlite3*, Table*);
const char *sqlite3JournalModename(int);
int sqlite3Checkpoint(sqlite3*, int);
int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);

/* Declarations for functions in fkey.c. All of these are replaced by
** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
** key functionality is available. If OMIT_TRIGGER is defined but
** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
** this case foreign keys are parsed, but no other functionality is 
** provided (enforcement of FK constraints requires the triggers sub-system).

Changes to src/sqliteLimit.h.

104
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107
108
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110








111
112
113
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115
116
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#ifndef SQLITE_DEFAULT_CACHE_SIZE
# define SQLITE_DEFAULT_CACHE_SIZE  2000
#endif
#ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE
# define SQLITE_DEFAULT_TEMP_CACHE_SIZE  500
#endif









/*
** The maximum number of attached databases.  This must be between 0
** and 30.  The upper bound on 30 is because a 32-bit integer bitmap
** is used internally to track attached databases.
*/
#ifndef SQLITE_MAX_ATTACHED
# define SQLITE_MAX_ATTACHED 10







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104
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#ifndef SQLITE_DEFAULT_CACHE_SIZE
# define SQLITE_DEFAULT_CACHE_SIZE  2000
#endif
#ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE
# define SQLITE_DEFAULT_TEMP_CACHE_SIZE  500
#endif

/*
** The default number of frames to accumulate in the log file before
** checkpointing the database in WAL mode.
*/
#ifndef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT
# define SQLITE_DEFAULT_WAL_AUTOCHECKPOINT  1000
#endif

/*
** The maximum number of attached databases.  This must be between 0
** and 30.  The upper bound on 30 is because a 32-bit integer bitmap
** is used internally to track attached databases.
*/
#ifndef SQLITE_MAX_ATTACHED
# define SQLITE_MAX_ATTACHED 10

Changes to src/tclsqlite.c.

119
120
121
122
123
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125

126
127
128
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130
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132
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481
482
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2745
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....
2763
2764
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2767
2768
2769

2770
2771
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2775
2776
  char *zProgress;           /* The progress callback routine */
  char *zAuth;               /* The authorization callback routine */
  int disableAuth;           /* Disable the authorizer if it exists */
  char *zNull;               /* Text to substitute for an SQL NULL value */
  SqlFunc *pFunc;            /* List of SQL functions */
  Tcl_Obj *pUpdateHook;      /* Update hook script (if any) */
  Tcl_Obj *pRollbackHook;    /* Rollback hook script (if any) */

  Tcl_Obj *pUnlockNotify;    /* Unlock notify script (if any) */
  SqlCollate *pCollate;      /* List of SQL collation functions */
  int rc;                    /* Return code of most recent sqlite3_exec() */
  Tcl_Obj *pCollateNeeded;   /* Collation needed script */
  SqlPreparedStmt *stmtList; /* List of prepared statements*/
  SqlPreparedStmt *stmtLast; /* Last statement in the list */
  int maxStmt;               /* The next maximum number of stmtList */
................................................................................
  }
  if( pDb->pUpdateHook ){
    Tcl_DecrRefCount(pDb->pUpdateHook);
  }
  if( pDb->pRollbackHook ){
    Tcl_DecrRefCount(pDb->pRollbackHook);
  }



  if( pDb->pCollateNeeded ){
    Tcl_DecrRefCount(pDb->pCollateNeeded);
  }
  Tcl_Free((char*)pDb);
}

/*
................................................................................
static void DbRollbackHandler(void *clientData){
  SqliteDb *pDb = (SqliteDb*)clientData;
  assert(pDb->pRollbackHook);
  if( TCL_OK!=Tcl_EvalObjEx(pDb->interp, pDb->pRollbackHook, 0) ){
    Tcl_BackgroundError(pDb->interp);
  }
}



























#if defined(SQLITE_TEST) && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
static void setTestUnlockNotifyVars(Tcl_Interp *interp, int iArg, int nArg){
  char zBuf[64];
  sprintf(zBuf, "%d", iArg);
  Tcl_SetVar(interp, "sqlite_unlock_notify_arg", zBuf, TCL_GLOBAL_ONLY);
  sprintf(zBuf, "%d", nArg);
................................................................................
    "errorcode",          "eval",              "exists",
    "function",           "incrblob",          "interrupt",
    "last_insert_rowid",  "nullvalue",         "onecolumn",
    "profile",            "progress",          "rekey",
    "restore",            "rollback_hook",     "status",
    "timeout",            "total_changes",     "trace",
    "transaction",        "unlock_notify",     "update_hook",
    "version",            0                    
  };
  enum DB_enum {
    DB_AUTHORIZER,        DB_BACKUP,           DB_BUSY,
    DB_CACHE,             DB_CHANGES,          DB_CLOSE,
    DB_COLLATE,           DB_COLLATION_NEEDED, DB_COMMIT_HOOK,
    DB_COMPLETE,          DB_COPY,             DB_ENABLE_LOAD_EXTENSION,
    DB_ERRORCODE,         DB_EVAL,             DB_EXISTS,
    DB_FUNCTION,          DB_INCRBLOB,         DB_INTERRUPT,
    DB_LAST_INSERT_ROWID, DB_NULLVALUE,        DB_ONECOLUMN,
    DB_PROFILE,           DB_PROGRESS,         DB_REKEY,
    DB_RESTORE,           DB_ROLLBACK_HOOK,    DB_STATUS,
    DB_TIMEOUT,           DB_TOTAL_CHANGES,    DB_TRACE,
    DB_TRANSACTION,       DB_UNLOCK_NOTIFY,    DB_UPDATE_HOOK,
    DB_VERSION,
  };
  /* don't leave trailing commas on DB_enum, it confuses the AIX xlc compiler */

  if( objc<2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
    return TCL_ERROR;
  }
................................................................................
      }
    }
#endif
    break;
  }

  /*

  **    $db update_hook ?script?
  **    $db rollback_hook ?script?
  */

  case DB_UPDATE_HOOK: 
  case DB_ROLLBACK_HOOK: {

    /* set ppHook to point at pUpdateHook or pRollbackHook, depending on 
    ** whether [$db update_hook] or [$db rollback_hook] was invoked.
    */
    Tcl_Obj **ppHook; 
    if( choice==DB_UPDATE_HOOK ){
      ppHook = &pDb->pUpdateHook;


    }else{
      ppHook = &pDb->pRollbackHook;
    }

    if( objc!=2 && objc!=3 ){
       Tcl_WrongNumArgs(interp, 2, objv, "?SCRIPT?");
       return TCL_ERROR;
................................................................................
        *ppHook = objv[2];
        Tcl_IncrRefCount(*ppHook);
      }
    }

    sqlite3_update_hook(pDb->db, (pDb->pUpdateHook?DbUpdateHandler:0), pDb);
    sqlite3_rollback_hook(pDb->db,(pDb->pRollbackHook?DbRollbackHandler:0),pDb);


    break;
  }

  /*    $db version
  **
  ** Return the version string for this database.







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....
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....
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
  char *zProgress;           /* The progress callback routine */
  char *zAuth;               /* The authorization callback routine */
  int disableAuth;           /* Disable the authorizer if it exists */
  char *zNull;               /* Text to substitute for an SQL NULL value */
  SqlFunc *pFunc;            /* List of SQL functions */
  Tcl_Obj *pUpdateHook;      /* Update hook script (if any) */
  Tcl_Obj *pRollbackHook;    /* Rollback hook script (if any) */
  Tcl_Obj *pLogHook;         /* WAL hook script (if any) */
  Tcl_Obj *pUnlockNotify;    /* Unlock notify script (if any) */
  SqlCollate *pCollate;      /* List of SQL collation functions */
  int rc;                    /* Return code of most recent sqlite3_exec() */
  Tcl_Obj *pCollateNeeded;   /* Collation needed script */
  SqlPreparedStmt *stmtList; /* List of prepared statements*/
  SqlPreparedStmt *stmtLast; /* Last statement in the list */
  int maxStmt;               /* The next maximum number of stmtList */
................................................................................
  }
  if( pDb->pUpdateHook ){
    Tcl_DecrRefCount(pDb->pUpdateHook);
  }
  if( pDb->pRollbackHook ){
    Tcl_DecrRefCount(pDb->pRollbackHook);
  }
  if( pDb->pLogHook ){
    Tcl_DecrRefCount(pDb->pLogHook);
  }
  if( pDb->pCollateNeeded ){
    Tcl_DecrRefCount(pDb->pCollateNeeded);
  }
  Tcl_Free((char*)pDb);
}

/*
................................................................................
static void DbRollbackHandler(void *clientData){
  SqliteDb *pDb = (SqliteDb*)clientData;
  assert(pDb->pRollbackHook);
  if( TCL_OK!=Tcl_EvalObjEx(pDb->interp, pDb->pRollbackHook, 0) ){
    Tcl_BackgroundError(pDb->interp);
  }
}

static int DbLogHandler(
  void *clientData, 
  sqlite3 *db, 
  const char *zDb, 
  int nEntry
){
  int ret = 0;
  Tcl_Obj *p;
  SqliteDb *pDb = (SqliteDb*)clientData;
  Tcl_Interp *interp = pDb->interp;
  assert(pDb->pLogHook);

  p = Tcl_DuplicateObj(pDb->pLogHook);
  Tcl_IncrRefCount(p);
  Tcl_ListObjAppendElement(interp, p, Tcl_NewStringObj(zDb, -1));
  Tcl_ListObjAppendElement(interp, p, Tcl_NewIntObj(nEntry));
  if( TCL_OK!=Tcl_EvalObjEx(interp, p, 0) 
   || TCL_OK!=Tcl_GetIntFromObj(interp, Tcl_GetObjResult(interp), &ret)
  ){
    Tcl_BackgroundError(interp);
  }
  Tcl_DecrRefCount(p);

  return ret;
}

#if defined(SQLITE_TEST) && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
static void setTestUnlockNotifyVars(Tcl_Interp *interp, int iArg, int nArg){
  char zBuf[64];
  sprintf(zBuf, "%d", iArg);
  Tcl_SetVar(interp, "sqlite_unlock_notify_arg", zBuf, TCL_GLOBAL_ONLY);
  sprintf(zBuf, "%d", nArg);
................................................................................
    "errorcode",          "eval",              "exists",
    "function",           "incrblob",          "interrupt",
    "last_insert_rowid",  "nullvalue",         "onecolumn",
    "profile",            "progress",          "rekey",
    "restore",            "rollback_hook",     "status",
    "timeout",            "total_changes",     "trace",
    "transaction",        "unlock_notify",     "update_hook",
    "version",            "wal_hook",          0
  };
  enum DB_enum {
    DB_AUTHORIZER,        DB_BACKUP,           DB_BUSY,
    DB_CACHE,             DB_CHANGES,          DB_CLOSE,
    DB_COLLATE,           DB_COLLATION_NEEDED, DB_COMMIT_HOOK,
    DB_COMPLETE,          DB_COPY,             DB_ENABLE_LOAD_EXTENSION,
    DB_ERRORCODE,         DB_EVAL,             DB_EXISTS,
    DB_FUNCTION,          DB_INCRBLOB,         DB_INTERRUPT,
    DB_LAST_INSERT_ROWID, DB_NULLVALUE,        DB_ONECOLUMN,
    DB_PROFILE,           DB_PROGRESS,         DB_REKEY,
    DB_RESTORE,           DB_ROLLBACK_HOOK,    DB_STATUS,
    DB_TIMEOUT,           DB_TOTAL_CHANGES,    DB_TRACE,
    DB_TRANSACTION,       DB_UNLOCK_NOTIFY,    DB_UPDATE_HOOK,
    DB_VERSION,           DB_WAL_HOOK
  };
  /* don't leave trailing commas on DB_enum, it confuses the AIX xlc compiler */

  if( objc<2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
    return TCL_ERROR;
  }
................................................................................
      }
    }
#endif
    break;
  }

  /*
  **    $db wal_hook ?script?
  **    $db update_hook ?script?
  **    $db rollback_hook ?script?
  */
  case DB_WAL_HOOK: 
  case DB_UPDATE_HOOK: 
  case DB_ROLLBACK_HOOK: {

    /* set ppHook to point at pUpdateHook or pRollbackHook, depending on 
    ** whether [$db update_hook] or [$db rollback_hook] was invoked.
    */
    Tcl_Obj **ppHook; 
    if( choice==DB_UPDATE_HOOK ){
      ppHook = &pDb->pUpdateHook;
    }else if( choice==DB_WAL_HOOK ){
      ppHook = &pDb->pLogHook;
    }else{
      ppHook = &pDb->pRollbackHook;
    }

    if( objc!=2 && objc!=3 ){
       Tcl_WrongNumArgs(interp, 2, objv, "?SCRIPT?");
       return TCL_ERROR;
................................................................................
        *ppHook = objv[2];
        Tcl_IncrRefCount(*ppHook);
      }
    }

    sqlite3_update_hook(pDb->db, (pDb->pUpdateHook?DbUpdateHandler:0), pDb);
    sqlite3_rollback_hook(pDb->db,(pDb->pRollbackHook?DbRollbackHandler:0),pDb);
    sqlite3_wal_hook(pDb->db,(pDb->pLogHook?DbLogHandler:0),pDb);

    break;
  }

  /*    $db version
  **
  ** Return the version string for this database.

Changes to src/test1.c.

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4866
4867
4868
4869
4870





























4871
4872
4873
4874
4875
4876
4877
....
5085
5086
5087
5088
5089
5090
5091

5092
5093
5094
5095
5096
5097
5098
  }
  rc = sqlite3_unlock_notify(db, test_unlock_notify_cb, (void *)interp);
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
  return TCL_OK;
}
#endif































/*
**     tcl_objproc COMMANDNAME ARGS...
**
** Run a TCL command using its objProc interface.  Throw an error if
** the command has no objProc interface.
*/
................................................................................
     { "sqlite3_blob_read",  test_blob_read, 0  },
     { "sqlite3_blob_write", test_blob_write, 0  },
#endif
     { "pcache_stats",       test_pcache_stats, 0  },
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
     { "sqlite3_unlock_notify", test_unlock_notify, 0  },
#endif

  };
  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;
  extern int sqlite3_like_count;
  extern int sqlite3_xferopt_count;







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4864
4865
4866
4867
4868
4869
4870
4871
4872
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4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
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4888
4889
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4898
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....
5114
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5117
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  }
  rc = sqlite3_unlock_notify(db, test_unlock_notify_cb, (void *)interp);
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
  return TCL_OK;
}
#endif

/*
** tclcmd:  sqlite3_wal_checkpoint db ?NAME?
*/
static int test_wal_checkpoint(
  ClientData clientData, /* Unused */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  char *zDb = 0;
  sqlite3 *db;
  int rc;

  if( objc!=3 && objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB ?NAME?");
    return TCL_ERROR;
  }

  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  if( objc==3 ){
    zDb = Tcl_GetString(objv[2]);
  }
  rc = sqlite3_wal_checkpoint(db, zDb);
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
  return TCL_OK;
}


/*
**     tcl_objproc COMMANDNAME ARGS...
**
** Run a TCL command using its objProc interface.  Throw an error if
** the command has no objProc interface.
*/
................................................................................
     { "sqlite3_blob_read",  test_blob_read, 0  },
     { "sqlite3_blob_write", test_blob_write, 0  },
#endif
     { "pcache_stats",       test_pcache_stats, 0  },
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
     { "sqlite3_unlock_notify", test_unlock_notify, 0  },
#endif
     { "sqlite3_wal_checkpoint", test_wal_checkpoint, 0  },
  };
  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;
  extern int sqlite3_like_count;
  extern int sqlite3_xferopt_count;

Changes to src/test6.c.

777
778
779
780
781
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783
784
785
786
787
788
789
790
791
    cfFullPathname,       /* xFullPathname */
    cfDlOpen,             /* xDlOpen */
    cfDlError,            /* xDlError */
    cfDlSym,              /* xDlSym */
    cfDlClose,            /* xDlClose */
    cfRandomness,         /* xRandomness */
    cfSleep,              /* xSleep */
    cfCurrentTime         /* xCurrentTime */
  };

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "ENABLE");
    return TCL_ERROR;
  }








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    cfFullPathname,       /* xFullPathname */
    cfDlOpen,             /* xDlOpen */
    cfDlError,            /* xDlError */
    cfDlSym,              /* xDlSym */
    cfDlClose,            /* xDlClose */
    cfRandomness,         /* xRandomness */
    cfSleep,              /* xSleep */
    cfCurrentTime,        /* xCurrentTime */
  };

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "ENABLE");
    return TCL_ERROR;
  }

Changes to src/test_config.c.

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503
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#endif

#ifdef SQLITE_OMIT_VIRTUALTABLE
  Tcl_SetVar2(interp, "sqlite_options", "vtab", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "vtab", "1", TCL_GLOBAL_ONLY);
#endif







#ifdef SQLITE_OMIT_WSD
  Tcl_SetVar2(interp, "sqlite_options", "wsd", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "wsd", "1", TCL_GLOBAL_ONLY);
#endif








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494
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#endif

#ifdef SQLITE_OMIT_VIRTUALTABLE
  Tcl_SetVar2(interp, "sqlite_options", "vtab", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "vtab", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_WAL
  Tcl_SetVar2(interp, "sqlite_options", "wal", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "wal", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_WSD
  Tcl_SetVar2(interp, "sqlite_options", "wsd", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "wsd", "1", TCL_GLOBAL_ONLY);
#endif

Changes to src/test_demovfs.c.

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629
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    demoFullPathname,             /* xFullPathname */
    demoDlOpen,                   /* xDlOpen */
    demoDlError,                  /* xDlError */
    demoDlSym,                    /* xDlSym */
    demoDlClose,                  /* xDlClose */
    demoRandomness,               /* xRandomness */
    demoSleep,                    /* xSleep */
    demoCurrentTime               /* xCurrentTime */
  };
  return &demovfs;
}

#endif /* !defined(SQLITE_TEST) || defined(SQLITE_OS_UNIX) */









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    demoFullPathname,             /* xFullPathname */
    demoDlOpen,                   /* xDlOpen */
    demoDlError,                  /* xDlError */
    demoDlSym,                    /* xDlSym */
    demoDlClose,                  /* xDlClose */
    demoRandomness,               /* xRandomness */
    demoSleep,                    /* xSleep */
    demoCurrentTime,              /* xCurrentTime */
  };
  return &demovfs;
}

#endif /* !defined(SQLITE_TEST) || defined(SQLITE_OS_UNIX) */


Changes to src/test_devsym.c.

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static void (*devsymDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void);
static void devsymDlClose(sqlite3_vfs*, void*);
#endif /* SQLITE_OMIT_LOAD_EXTENSION */
static int devsymRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int devsymSleep(sqlite3_vfs*, int microseconds);
static int devsymCurrentTime(sqlite3_vfs*, double*);








static sqlite3_vfs devsym_vfs = {
  1,                     /* iVersion */
  sizeof(devsym_file),      /* szOsFile */
  DEVSYM_MAX_PATHNAME,      /* mxPathname */
  0,                     /* pNext */
  DEVSYM_VFS_NAME,          /* zName */
  0,                     /* pAppData */
  devsymOpen,               /* xOpen */
  devsymDelete,             /* xDelete */
................................................................................
  0,                        /* xDlOpen */
  0,                        /* xDlError */
  0,                        /* xDlSym */
  0,                        /* xDlClose */
#endif /* SQLITE_OMIT_LOAD_EXTENSION */
  devsymRandomness,         /* xRandomness */
  devsymSleep,              /* xSleep */
  devsymCurrentTime         /* xCurrentTime */









};

static sqlite3_io_methods devsym_io_methods = {
  1,                            /* iVersion */
  devsymClose,                      /* xClose */
  devsymRead,                       /* xRead */
  devsymWrite,                      /* xWrite */
................................................................................
/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int devsymCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return sqlite3OsCurrentTime(g.pVfs, pTimeOut);
}






























/*
** This procedure registers the devsym vfs with SQLite. If the argument is
** true, the devsym vfs becomes the new default vfs. It is the only publicly
** available function in this file.
*/
void devsym_register(int iDeviceChar, int iSectorSize){
  if( g.pVfs==0 ){
    g.pVfs = sqlite3_vfs_find(0);
    devsym_vfs.szOsFile += g.pVfs->szOsFile;






    sqlite3_vfs_register(&devsym_vfs, 0);
  }
  if( iDeviceChar>=0 ){
    g.iDeviceChar = iDeviceChar;
  }else{
    g.iDeviceChar = 0;
  }







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345
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402
static void (*devsymDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void);
static void devsymDlClose(sqlite3_vfs*, void*);
#endif /* SQLITE_OMIT_LOAD_EXTENSION */
static int devsymRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int devsymSleep(sqlite3_vfs*, int microseconds);
static int devsymCurrentTime(sqlite3_vfs*, double*);

static int devsymShmOpen(sqlite3_vfs *, const char *, sqlite3_shm **);
static int devsymShmSize(sqlite3_shm *, int , int *);
static int devsymShmGet(sqlite3_shm *, int , int *, void **);
static int devsymShmRelease(sqlite3_shm *);
static int devsymShmLock(sqlite3_shm *, int , int *);
static int devsymShmClose(sqlite3_shm *, int);

static sqlite3_vfs devsym_vfs = {
  2,                     /* iVersion */
  sizeof(devsym_file),      /* szOsFile */
  DEVSYM_MAX_PATHNAME,      /* mxPathname */
  0,                     /* pNext */
  DEVSYM_VFS_NAME,          /* zName */
  0,                     /* pAppData */
  devsymOpen,               /* xOpen */
  devsymDelete,             /* xDelete */
................................................................................
  0,                        /* xDlOpen */
  0,                        /* xDlError */
  0,                        /* xDlSym */
  0,                        /* xDlClose */
#endif /* SQLITE_OMIT_LOAD_EXTENSION */
  devsymRandomness,         /* xRandomness */
  devsymSleep,              /* xSleep */
  devsymCurrentTime,        /* xCurrentTime */
  0,                        /* xGetLastError */
  devsymShmOpen,
  devsymShmSize,
  devsymShmGet,
  devsymShmRelease,
  devsymShmLock,
  devsymShmClose,
  0,
  0,
};

static sqlite3_io_methods devsym_io_methods = {
  1,                            /* iVersion */
  devsymClose,                      /* xClose */
  devsymRead,                       /* xRead */
  devsymWrite,                      /* xWrite */
................................................................................
/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int devsymCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return sqlite3OsCurrentTime(g.pVfs, pTimeOut);
}


static int devsymShmOpen(
  sqlite3_vfs *pVfs, 
  const char *zName, 
  sqlite3_shm **pp
){
  return g.pVfs->xShmOpen(g.pVfs, zName, pp);
}
static int devsymShmSize(sqlite3_shm *p, int reqSize, int *pNewSize){
  return g.pVfs->xShmSize(p, reqSize, pNewSize);
}
static int devsymShmGet(
  sqlite3_shm *p, 
  int reqMapSize, 
  int *pMapSize, 
  void **pp
){
  return g.pVfs->xShmGet(p, reqMapSize, pMapSize, pp);
}
static int devsymShmRelease(sqlite3_shm *p){
  return g.pVfs->xShmRelease(p);
}
static int devsymShmLock(sqlite3_shm *p, int desiredLock, int *gotLock){
  return g.pVfs->xShmLock(p, desiredLock, gotLock);
}
static int devsymShmClose(sqlite3_shm *p, int deleteFlag){
  return g.pVfs->xShmClose(p, deleteFlag);
}

/*
** This procedure registers the devsym vfs with SQLite. If the argument is
** true, the devsym vfs becomes the new default vfs. It is the only publicly
** available function in this file.
*/
void devsym_register(int iDeviceChar, int iSectorSize){
  if( g.pVfs==0 ){
    g.pVfs = sqlite3_vfs_find(0);
    devsym_vfs.szOsFile += g.pVfs->szOsFile;
    devsym_vfs.xShmOpen = (g.pVfs->xShmOpen ? devsymShmOpen : 0);
    devsym_vfs.xShmSize = (g.pVfs->xShmSize ? devsymShmSize : 0);
    devsym_vfs.xShmGet = (g.pVfs->xShmGet ? devsymShmGet : 0);
    devsym_vfs.xShmRelease = (g.pVfs->xShmRelease ? devsymShmRelease : 0);
    devsym_vfs.xShmLock = (g.pVfs->xShmLock ? devsymShmLock : 0);
    devsym_vfs.xShmClose = (g.pVfs->xShmClose ? devsymShmClose : 0);
    sqlite3_vfs_register(&devsym_vfs, 0);
  }
  if( iDeviceChar>=0 ){
    g.iDeviceChar = iDeviceChar;
  }else{
    g.iDeviceChar = 0;
  }

Changes to src/test_journal.c.

175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
  jtFullPathname,                /* xFullPathname */
  jtDlOpen,                      /* xDlOpen */
  jtDlError,                     /* xDlError */
  jtDlSym,                       /* xDlSym */
  jtDlClose,                     /* xDlClose */
  jtRandomness,                  /* xRandomness */
  jtSleep,                       /* xSleep */
  jtCurrentTime                  /* xCurrentTime */
};

static sqlite3_io_methods jt_io_methods = {
  1,                             /* iVersion */
  jtClose,                       /* xClose */
  jtRead,                        /* xRead */
  jtWrite,                       /* xWrite */







|







175
176
177
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179
180
181
182
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184
185
186
187
188
189
  jtFullPathname,                /* xFullPathname */
  jtDlOpen,                      /* xDlOpen */
  jtDlError,                     /* xDlError */
  jtDlSym,                       /* xDlSym */
  jtDlClose,                     /* xDlClose */
  jtRandomness,                  /* xRandomness */
  jtSleep,                       /* xSleep */
  jtCurrentTime,                 /* xCurrentTime */
};

static sqlite3_io_methods jt_io_methods = {
  1,                             /* iVersion */
  jtClose,                       /* xClose */
  jtRead,                        /* xRead */
  jtWrite,                       /* xWrite */

Changes to src/test_onefile.c.

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195
196
197
198
199
200
201







202
203
204
205
206
207
208
    fsFullPathname,                             /* xFullPathname */
    fsDlOpen,                                   /* xDlOpen */
    fsDlError,                                  /* xDlError */
    fsDlSym,                                    /* xDlSym */
    fsDlClose,                                  /* xDlClose */
    fsRandomness,                               /* xRandomness */
    fsSleep,                                    /* xSleep */
    fsCurrentTime                               /* xCurrentTime */







  }, 
  0,                                            /* pFileList */
  0                                             /* pParent */
};

static sqlite3_io_methods fs_io_methods = {
  1,                            /* iVersion */







|
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>







194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
    fsFullPathname,                             /* xFullPathname */
    fsDlOpen,                                   /* xDlOpen */
    fsDlError,                                  /* xDlError */
    fsDlSym,                                    /* xDlSym */
    fsDlClose,                                  /* xDlClose */
    fsRandomness,                               /* xRandomness */
    fsSleep,                                    /* xSleep */
    fsCurrentTime,                              /* xCurrentTime */
    0,                                          /* xShmOpen */
    0,                                          /* xShmSize */
    0,                                          /* xShmLock */
    0,                                          /* xShmClose */
    0,                                          /* xShmDelete */
    0,                                          /* xRename */
    0                                           /* xCurrentTimeInt64 */
  }, 
  0,                                            /* pFileList */
  0                                             /* pParent */
};

static sqlite3_io_methods fs_io_methods = {
  1,                            /* iVersion */

Changes to src/test_osinst.c.

199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
  instFullPathname,       /* xFullPathname */
  instDlOpen,             /* xDlOpen */
  instDlError,            /* xDlError */
  instDlSym,              /* xDlSym */
  instDlClose,            /* xDlClose */
  instRandomness,         /* xRandomness */
  instSleep,              /* xSleep */
  instCurrentTime         /* xCurrentTime */
};

static sqlite3_io_methods inst_io_methods = {
  1,                            /* iVersion */
  instClose,                      /* xClose */
  instRead,                       /* xRead */
  instWrite,                      /* xWrite */







|







199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
  instFullPathname,       /* xFullPathname */
  instDlOpen,             /* xDlOpen */
  instDlError,            /* xDlError */
  instDlSym,              /* xDlSym */
  instDlClose,            /* xDlClose */
  instRandomness,         /* xRandomness */
  instSleep,              /* xSleep */
  instCurrentTime,        /* xCurrentTime */
};

static sqlite3_io_methods inst_io_methods = {
  1,                            /* iVersion */
  instClose,                      /* xClose */
  instRead,                       /* xRead */
  instWrite,                      /* xWrite */

Changes to src/test_thread.c.

54
55
56
57
58
59
60

61
62
63
64
65
66
67
...
120
121
122
123
124
125
126

127
128
129
130
131
132
133
static Tcl_ObjCmdProc sqlthread_proc;
static Tcl_ObjCmdProc clock_seconds_proc;
#if defined(SQLITE_OS_UNIX) && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
static Tcl_ObjCmdProc blocking_step_proc;
static Tcl_ObjCmdProc blocking_prepare_v2_proc;
#endif
int Sqlitetest1_Init(Tcl_Interp *);


/* Functions from test1.c */
void *sqlite3TestTextToPtr(const char *);
const char *sqlite3TestErrorName(int);
int getDbPointer(Tcl_Interp *, const char *, sqlite3 **);
int sqlite3TestMakePointerStr(Tcl_Interp *, char *, void *);
int sqlite3TestErrCode(Tcl_Interp *, sqlite3 *, int);
................................................................................
  Tcl_CreateObjCommand(interp, 
      "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0);
  Tcl_CreateObjCommand(interp, 
      "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0);
#endif
  Sqlitetest1_Init(interp);
  Sqlitetest_mutex_Init(interp);


  rc = Tcl_Eval(interp, p->zScript);
  pRes = Tcl_GetObjResult(interp);
  pList = Tcl_NewObj();
  Tcl_IncrRefCount(pList);
  Tcl_IncrRefCount(pRes);








>







 







>







54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
...
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
static Tcl_ObjCmdProc sqlthread_proc;
static Tcl_ObjCmdProc clock_seconds_proc;
#if defined(SQLITE_OS_UNIX) && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
static Tcl_ObjCmdProc blocking_step_proc;
static Tcl_ObjCmdProc blocking_prepare_v2_proc;
#endif
int Sqlitetest1_Init(Tcl_Interp *);
int Sqlite3_Init(Tcl_Interp *);

/* Functions from test1.c */
void *sqlite3TestTextToPtr(const char *);
const char *sqlite3TestErrorName(int);
int getDbPointer(Tcl_Interp *, const char *, sqlite3 **);
int sqlite3TestMakePointerStr(Tcl_Interp *, char *, void *);
int sqlite3TestErrCode(Tcl_Interp *, sqlite3 *, int);
................................................................................
  Tcl_CreateObjCommand(interp, 
      "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0);
  Tcl_CreateObjCommand(interp, 
      "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0);
#endif
  Sqlitetest1_Init(interp);
  Sqlitetest_mutex_Init(interp);
  Sqlite3_Init(interp);

  rc = Tcl_Eval(interp, p->zScript);
  pRes = Tcl_GetObjResult(interp);
  pList = Tcl_NewObj();
  Tcl_IncrRefCount(pList);
  Tcl_IncrRefCount(pRes);

Changes to src/vdbe.c.

5182
5183
5184
5185
5186
5187
5188










































































































5189
5190
5191
5192
5193
5194
5195
  UPDATE_MAX_BLOBSIZE(pMem);
  if( sqlite3VdbeMemTooBig(pMem) ){
    goto too_big;
  }
  break;
}












































































































#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
/* Opcode: Vacuum * * * * *
**
** Vacuum the entire database.  This opcode will cause other virtual
** machines to be created and run.  It may not be called from within
** a transaction.







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5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
  UPDATE_MAX_BLOBSIZE(pMem);
  if( sqlite3VdbeMemTooBig(pMem) ){
    goto too_big;
  }
  break;
}

#ifndef SQLITE_OMIT_WAL
/* Opcode: Checkpoint P1 * * * *
**
** Checkpoint database P1. This is a no-op if P1 is not currently in
** WAL mode.
*/
case OP_Checkpoint: {
  rc = sqlite3Checkpoint(db, pOp->p1);
  break;
};  
#endif

/* Opcode: JournalMode P1 P2 P3 * *
**
** Change the journal mode of database P1 to P3. P3 must be one of the
** PAGER_JOURNALMODE_XXX values. If changing between the various rollback
** modes (delete, truncate, persist, off and memory), this is a simple
** operation. No IO is required.
**
** If changing into or out of WAL mode the procedure is more complicated.
**
** Write a string containing the final journal-mode to register P2.
*/
case OP_JournalMode: {    /* out2-prerelease */
  Btree *pBt;                     /* Btree to change journal mode of */
  Pager *pPager;                  /* Pager associated with pBt */
  int eNew;                       /* New journal mode */
  int eOld;                       /* The old journal mode */
  const sqlite3_vfs *pVfs;        /* The VFS of pPager */
  const char *zFilename;          /* Name of database file for pPager */

  eNew = pOp->p3;
  assert( eNew==PAGER_JOURNALMODE_DELETE 
       || eNew==PAGER_JOURNALMODE_TRUNCATE 
       || eNew==PAGER_JOURNALMODE_PERSIST 
       || eNew==PAGER_JOURNALMODE_OFF
       || eNew==PAGER_JOURNALMODE_MEMORY
       || eNew==PAGER_JOURNALMODE_WAL
       || eNew==PAGER_JOURNALMODE_QUERY
  );
  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( (p->btreeMask & (1<<pOp->p1))!=0 );

  pBt = db->aDb[pOp->p1].pBt;
  pPager = sqlite3BtreePager(pBt);

#ifndef SQLITE_OMIT_WAL
  zFilename = sqlite3PagerFilename(pPager);
  pVfs = sqlite3PagerVfs(pPager);

  /* Do not allow a transition to journal_mode=WAL for a database
  ** in temporary storage or if the VFS does not support xShmOpen.
  */
  if( eNew==PAGER_JOURNALMODE_WAL
   && (zFilename[0]==0                               /* Temp file */
         || pVfs->iVersion<2 || pVfs->xShmOpen==0)   /* No xShmOpen support */
  ){
    eNew = PAGER_JOURNALMODE_QUERY;
  }

  if( eNew!=PAGER_JOURNALMODE_QUERY ){
    eOld = sqlite3PagerJournalMode(pPager, PAGER_JOURNALMODE_QUERY);
    if( (eNew!=eOld)
     && (eOld==PAGER_JOURNALMODE_WAL || eNew==PAGER_JOURNALMODE_WAL)
    ){
      if( !db->autoCommit || db->activeVdbeCnt>1 ){
        rc = SQLITE_ERROR;
        sqlite3SetString(&p->zErrMsg, db, 
            "cannot change %s wal mode from within a transaction",
            (eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
        );
      }else{
  
        if( eOld==PAGER_JOURNALMODE_WAL ){
          /* If leaving WAL mode, close the log file. If successful, the call
          ** to PagerCloseWal() checkpoints and deletes the write-ahead-log 
          ** file. An EXCLUSIVE lock may still be held on the database file 
          ** after a successful return. 
          */
          rc = sqlite3PagerCloseWal(pPager);
          if( rc!=SQLITE_OK ) goto abort_due_to_error;
          sqlite3PagerJournalMode(pPager, eNew);
        }else{
          sqlite3PagerJournalMode(pPager, PAGER_JOURNALMODE_DELETE);
        }
  
        /* Open a transaction on the database file. Regardless of the journal
        ** mode, this transaction always uses a rollback journal.
        */
        assert( sqlite3BtreeIsInTrans(pBt)==0 );
        rc = sqlite3BtreeSetVersion(pBt, (eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));
        if( rc!=SQLITE_OK ) goto abort_due_to_error;
      }
    }
  }
#endif /* ifndef SQLITE_OMIT_WAL */

  eNew = sqlite3PagerJournalMode(pPager, eNew);
  pOut = &aMem[pOp->p2];
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = (char *)sqlite3JournalModename(eNew);
  pOut->n = sqlite3Strlen30(pOut->z);
  pOut->enc = SQLITE_UTF8;
  sqlite3VdbeChangeEncoding(pOut, encoding);
  break;
};  

#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
/* Opcode: Vacuum * * * * *
**
** Vacuum the entire database.  This opcode will cause other virtual
** machines to be created and run.  It may not be called from within
** a transaction.

Changes to src/vdbeapi.c.

301
302
303
304
305
306
307























308
309
310
311
312
313
314
...
382
383
384
385
386
387
388








389
390
391
392
393
394
395
/* An SQLITE_NOMEM error. */
void sqlite3_result_error_nomem(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetNull(&pCtx->s);
  pCtx->isError = SQLITE_NOMEM;
  pCtx->s.db->mallocFailed = 1;
}
























/*
** Execute the statement pStmt, either until a row of data is ready, the
** statement is completely executed or an error occurs.
**
** This routine implements the bulk of the logic behind the sqlite_step()
** API.  The only thing omitted is the automatic recompile if a 
................................................................................

    sqlite3OsCurrentTime(db->pVfs, &rNow);
    elapseTime = (u64)((rNow - (int)rNow)*3600.0*24.0*1000000000.0);
    elapseTime -= p->startTime;
    db->xProfile(db->pProfileArg, p->zSql, elapseTime);
  }
#endif









  db->errCode = rc;
  if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
    p->rc = SQLITE_NOMEM;
  }
end_of_step:
  /* At this point local variable rc holds the value that should be 







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>







 







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301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
...
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
/* An SQLITE_NOMEM error. */
void sqlite3_result_error_nomem(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetNull(&pCtx->s);
  pCtx->isError = SQLITE_NOMEM;
  pCtx->s.db->mallocFailed = 1;
}

/*
** This function is called after a transaction has been committed. It 
** invokes callbacks registered with sqlite3_wal_hook() as required.
*/
static int doWalCallbacks(sqlite3 *db){
  int rc = SQLITE_OK;
#ifndef SQLITE_OMIT_WAL
  int i;
  for(i=0; i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      int nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
      if( db->xWalCallback && nEntry>0 && rc==SQLITE_OK
       && db->xWalCallback(db->pWalArg, db, db->aDb[i].zName, nEntry)
      ){
        rc = sqlite3Checkpoint(db, i);
      }
    }
  }
#endif
  return rc;
}

/*
** Execute the statement pStmt, either until a row of data is ready, the
** statement is completely executed or an error occurs.
**
** This routine implements the bulk of the logic behind the sqlite_step()
** API.  The only thing omitted is the automatic recompile if a 
................................................................................

    sqlite3OsCurrentTime(db->pVfs, &rNow);
    elapseTime = (u64)((rNow - (int)rNow)*3600.0*24.0*1000000000.0);
    elapseTime -= p->startTime;
    db->xProfile(db->pProfileArg, p->zSql, elapseTime);
  }
#endif

  if( rc==SQLITE_DONE ){
    assert( p->rc==SQLITE_OK );
    p->rc = doWalCallbacks(db);
    if( p->rc!=SQLITE_OK ){
      rc = SQLITE_ERROR;
    }
  }

  db->errCode = rc;
  if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
    p->rc = SQLITE_NOMEM;
  }
end_of_step:
  /* At this point local variable rc holds the value that should be 

Added src/wal.c.









































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
** 2010 February 1
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains the implementation of a write-ahead log file used in 
** "journal_mode=wal" mode.
*/
#ifndef SQLITE_OMIT_WAL

#include "wal.h"


/*
** WRITE-AHEAD LOG (WAL) FILE FORMAT
**
** A wal file consists of a header followed by zero or more "frames".
** The header is 12 bytes in size and consists of the following three
** big-endian 32-bit unsigned integer values:
**
**     0: Database page size,
**     4: Randomly selected salt value 1,
**     8: Randomly selected salt value 2.
**
** Immediately following the header are zero or more frames. Each
** frame itself consists of a 16-byte header followed by a <page-size> bytes
** of page data. The header is broken into 4 big-endian 32-bit unsigned 
** integer values, as follows:
**
**     0: Page number.
**     4: For commit records, the size of the database image in pages 
**        after the commit. For all other records, zero.
**     8: Checksum value 1.
**    12: Checksum value 2.
*/

/* 
** WAL-INDEX FILE FORMAT
**
** The wal-index file consists of a 32-byte header region, followed by an 
** 8-byte region that contains no useful data (used to apply byte-range locks
** to), followed by the data region. 
**
** The contents of both the header and data region are specified in terms
** of 1, 2 and 4 byte unsigned integers. All integers are stored in 
** machine-endian order.  The wal-index is not a persistent file and
** so it does not need to be portable across archtectures.
**
** A wal-index file is essentially a shadow-pager map. It contains a
** mapping from database page number to the set of locations in the wal
** file that contain versions of the database page. When a database 
** client needs to read a page of data, it first queries the wal-index
** file to determine if the required version of the page is stored in
** the wal. If so, the page is read from the wal. If not, the page is
** read from the database file.
**
** Whenever a transaction is appended to the wal or a checkpoint transfers
** data from the wal into the database file, the wal-index is 
** updated accordingly.
**
** The fields in the wal-index file header are described in the comment 
** directly above the definition of struct WalIndexHdr (see below). 
** Immediately following the fields in the WalIndexHdr structure is
** an 8 byte checksum based on the contents of the header. This field is
** not the same as the iCheck1 and iCheck2 fields of the WalIndexHdr.
*/

/* Object declarations */
typedef struct WalIndexHdr WalIndexHdr;
typedef struct WalIterator WalIterator;


/*
** The following object stores a copy of the wal-index header.
**
** Member variables iCheck1 and iCheck2 contain the checksum for the
** last frame written to the wal, or 2 and 3 respectively if the log 
** is currently empty.
*/
struct WalIndexHdr {
  u32 iChange;                    /* Counter incremented each transaction */
  u32 pgsz;                       /* Database page size in bytes */
  u32 iLastPg;                    /* Address of last valid frame in log */
  u32 nPage;                      /* Size of database in pages */
  u32 iCheck1;                    /* Checkpoint value 1 */
  u32 iCheck2;                    /* Checkpoint value 2 */
};

/* Size of serialized WalIndexHdr object. */
#define WALINDEX_HDR_NFIELD (sizeof(WalIndexHdr) / sizeof(u32))

/* A block of 16 bytes beginning at WALINDEX_LOCK_OFFSET is reserved
** for locks. Since some systems only feature mandatory file-locks, we
** do not read or write data from the region of the file on which locks
** are applied.
*/
#define WALINDEX_LOCK_OFFSET   ((sizeof(WalIndexHdr))+2*sizeof(u32))
#define WALINDEX_LOCK_RESERVED 8

/* Size of header before each frame in wal */
#define WAL_FRAME_HDRSIZE 16

/* Size of write ahead log header */
#define WAL_HDRSIZE 12

/*
** Return the offset of frame iFrame in the write-ahead log file, 
** assuming a database page size of pgsz bytes. The offset returned
** is to the start of the write-ahead log frame-header.
*/
#define walFrameOffset(iFrame, pgsz) (                               \
  WAL_HDRSIZE + ((iFrame)-1)*((pgsz)+WAL_FRAME_HDRSIZE)        \
)

/*
** An open write-ahead log file is represented by an instance of the
** following object.
*/
struct Wal {
  sqlite3_vfs *pVfs;         /* The VFS used to create pFd */
  sqlite3_file *pFd;         /* File handle for WAL file */
  u32 iCallback;             /* Value to pass to log callback (or 0) */
  sqlite3_shm *pWIndex;      /* The open wal-index file */
  int szWIndex;              /* Size of the wal-index that is mapped in mem */
  u32 *pWiData;              /* Pointer to wal-index content in memory */
  u8 lockState;              /* SQLITE_SHM_xxxx constant showing lock state */
  u8 readerType;             /* SQLITE_SHM_READ or SQLITE_SHM_READ_FULL */
  WalIndexHdr hdr;           /* Wal-index for current snapshot */
  char *zName;               /* Name of underlying storage */
};


/*
** This structure is used to implement an iterator that iterates through
** all frames in the log in database page order. Where two or more frames
** correspond to the same database page, the iterator visits only the 
** frame most recently written to the log.
**
** The internals of this structure are only accessed by:
**
**   walIteratorInit() - Create a new iterator,
**   walIteratorNext() - Step an iterator,
**   walIteratorFree() - Free an iterator.
**
** This functionality is used by the checkpoint code (see walCheckpoint()).
*/
struct WalIterator {
  int nSegment;                   /* Size of WalIterator.aSegment[] array */
  int nFinal;                     /* Elements in segment nSegment-1 */
  struct WalSegment {
    int iNext;                    /* Next aIndex index */
    u8 *aIndex;                   /* Pointer to index array */
    u32 *aDbPage;                 /* Pointer to db page array */
  } aSegment[1];
};


/*
** Generate an 8 byte checksum based on the data in array aByte[] and the
** initial values of aCksum[0] and aCksum[1]. The checksum is written into
** aCksum[] before returning.
**
** The range of bytes to checksum is treated as an array of 32-bit 
** little-endian unsigned integers. For each integer X in the array, from
** start to finish, do the following:
**
**   aCksum[0] += X;
**   aCksum[1] += aCksum[0];
**
** For the calculation above, use 64-bit unsigned accumulators. Before
** returning, truncate the values to 32-bits as follows: 
**
**   aCksum[0] = (u32)(aCksum[0] + (aCksum[0]>>24));
**   aCksum[1] = (u32)(aCksum[1] + (aCksum[1]>>24));
*/
static void walChecksumBytes(u8 *aByte, int nByte, u32 *aCksum){
  u64 sum1 = aCksum[0];
  u64 sum2 = aCksum[1];
  u32 *a32 = (u32 *)aByte;
  u32 *aEnd = (u32 *)&aByte[nByte];

  assert( (nByte&0x00000003)==0 );

  if( SQLITE_LITTLEENDIAN ){
#ifdef SQLITE_DEBUG
    u8 *a = (u8 *)a32;
    assert( *a32==(a[0] + (a[1]<<8) + (a[2]<<16) + (a[3]<<24)) );
#endif
    do {
      sum1 += *a32;
      sum2 += sum1;
    } while( ++a32<aEnd );
  }else{
    do {
      u8 *a = (u8*)a32;
      sum1 += a[0] + (a[1]<<8) + (a[2]<<16) + (a[3]<<24);
      sum2 += sum1;
    } while( ++a32<aEnd );
  }

  aCksum[0] = sum1 + (sum1>>24);
  aCksum[1] = sum2 + (sum2>>24);
}

/*
** Attempt to change the lock status.
**
** When changing the lock status to SQLITE_SHM_READ, store the
** type of reader lock (either SQLITE_SHM_READ or SQLITE_SHM_READ_FULL)
** in pWal->readerType.
*/
static int walSetLock(Wal *pWal, int desiredStatus){
  int rc, got;
  if( pWal->lockState==desiredStatus ) return SQLITE_OK;
  rc = pWal->pVfs->xShmLock(pWal->pWIndex, desiredStatus, &got);
  pWal->lockState = got;
  if( got==SQLITE_SHM_READ_FULL || got==SQLITE_SHM_READ ){
    pWal->readerType = got;
    pWal->lockState = SQLITE_SHM_READ;
  }
  return rc;
}

/*
** Update the header of the wal-index file.
*/
static void walIndexWriteHdr(Wal *pWal, WalIndexHdr *pHdr){
  u32 *aHdr = pWal->pWiData;                   /* Write header here */
  u32 *aCksum = &aHdr[WALINDEX_HDR_NFIELD];    /* Write header cksum here */

  assert( WALINDEX_HDR_NFIELD==sizeof(WalIndexHdr)/4 );
  assert( aHdr!=0 );
  memcpy(aHdr, pHdr, sizeof(WalIndexHdr));
  aCksum[0] = aCksum[1] = 1;
  walChecksumBytes((u8 *)aHdr, sizeof(WalIndexHdr), aCksum);
}

/*
** This function encodes a single frame header and writes it to a buffer
** supplied by the caller. A frame-header is made up of a series of 
** 4-byte big-endian integers, as follows:
**
**     0: Database page size in bytes.
**     4: Page number.
**     8: New database size (for commit frames, otherwise zero).
**    12: Frame checksum 1.
**    16: Frame checksum 2.
*/
static void walEncodeFrame(
  u32 *aCksum,                    /* IN/OUT: Checksum values */
  u32 iPage,                      /* Database page number for frame */
  u32 nTruncate,                  /* New db size (or 0 for non-commit frames) */
  int nData,                      /* Database page size (size of aData[]) */
  u8 *aData,                      /* Pointer to page data (for checksum) */
  u8 *aFrame                      /* OUT: Write encoded frame here */
){
  assert( WAL_FRAME_HDRSIZE==16 );

  sqlite3Put4byte(&aFrame[0], iPage);
  sqlite3Put4byte(&aFrame[4], nTruncate);

  walChecksumBytes(aFrame, 8, aCksum);
  walChecksumBytes(aData, nData, aCksum);

  sqlite3Put4byte(&aFrame[8], aCksum[0]);
  sqlite3Put4byte(&aFrame[12], aCksum[1]);
}

/*
** Return 1 and populate *piPage, *pnTruncate and aCksum if the 
** frame checksum looks Ok. Otherwise return 0.
*/
static int walDecodeFrame(
  u32 *aCksum,                    /* IN/OUT: Checksum values */
  u32 *piPage,                    /* OUT: Database page number for frame */
  u32 *pnTruncate,                /* OUT: New db size (or 0 if not commit) */
  int nData,                      /* Database page size (size of aData[]) */
  u8 *aData,                      /* Pointer to page data (for checksum) */
  u8 *aFrame                      /* Frame data */
){
  assert( WAL_FRAME_HDRSIZE==16 );

  walChecksumBytes(aFrame, 8, aCksum);
  walChecksumBytes(aData, nData, aCksum);

  if( aCksum[0]!=sqlite3Get4byte(&aFrame[8]) 
   || aCksum[1]!=sqlite3Get4byte(&aFrame[12]) 
  ){
    /* Checksum failed. */
    return 0;
  }

  *piPage = sqlite3Get4byte(&aFrame[0]);
  *pnTruncate = sqlite3Get4byte(&aFrame[4]);
  return 1;
}

static void walMergesort8(
  Pgno *aContent,                 /* Pages in wal */
  u8 *aBuffer,                    /* Buffer of at least *pnList items to use */
  u8 *aList,                      /* IN/OUT: List to sort */
  int *pnList                     /* IN/OUT: Number of elements in aList[] */
){
  int nList = *pnList;
  if( nList>1 ){
    int nLeft = nList / 2;        /* Elements in left list */
    int nRight = nList - nLeft;   /* Elements in right list */
    u8 *aLeft = aList;            /* Left list */
    u8 *aRight = &aList[nLeft];   /* Right list */
    int iLeft = 0;                /* Current index in aLeft */
    int iRight = 0;               /* Current index in aright */
    int iOut = 0;                 /* Current index in output buffer */

    /* TODO: Change to non-recursive version. */
    walMergesort8(aContent, aBuffer, aLeft, &nLeft);
    walMergesort8(aContent, aBuffer, aRight, &nRight);

    while( iRight<nRight || iLeft<nLeft ){
      u8 logpage;
      Pgno dbpage;

      if( (iLeft<nLeft) 
       && (iRight>=nRight || aContent[aLeft[iLeft]]<aContent[aRight[iRight]])
      ){
        logpage = aLeft[iLeft++];
      }else{
        logpage = aRight[iRight++];
      }
      dbpage = aContent[logpage];

      aBuffer[iOut++] = logpage;
      if( iLeft<nLeft && aContent[aLeft[iLeft]]==dbpage ) iLeft++;

      assert( iLeft>=nLeft || aContent[aLeft[iLeft]]>dbpage );
      assert( iRight>=nRight || aContent[aRight[iRight]]>dbpage );
    }
    memcpy(aList, aBuffer, sizeof(aList[0])*iOut);
    *pnList = iOut;
  }

#ifdef SQLITE_DEBUG
  {
    int i;
    for(i=1; i<*pnList; i++){
      assert( aContent[aList[i]] > aContent[aList[i-1]] );
    }
  }
#endif
}


/*
** Return the index in the WalIndex.aData array that corresponds to 
** frame iFrame. The wal-index file consists of a header, followed by
** alternating "map" and "index" blocks.
*/
static int walIndexEntry(u32 iFrame){
  return (
      (WALINDEX_LOCK_OFFSET+WALINDEX_LOCK_RESERVED)/sizeof(u32)
    + (((iFrame-1)>>8)<<6)        /* Indexes that occur before iFrame */
    + iFrame-1                    /* Db page numbers that occur before iFrame */
  );
}

/*
** Release our reference to the wal-index memory map, if we are holding
** it.
*/
static void walIndexUnmap(Wal *pWal){
  if( pWal->pWiData ){
    pWal->pVfs->xShmRelease(pWal->pWIndex);
    pWal->pWiData = 0;
  }
}

/*
** Map the wal-index file into memory if it isn't already. 
**
** The reqSize parameter is the minimum required size of the mapping.
** A value of -1 means "don't care".  The reqSize parameter is ignored
** if the mapping is already held.
*/
static int walIndexMap(Wal *pWal, int reqSize){
  int rc = SQLITE_OK;
  if( pWal->pWiData==0 ){
    rc = pWal->pVfs->xShmGet(pWal->pWIndex, reqSize, &pWal->szWIndex,
                             (void**)(char*)&pWal->pWiData);
    if( rc==SQLITE_OK && pWal->pWiData==0 ){
      /* Make sure pWal->pWiData is not NULL while we are holding the
      ** lock on the mapping. */
      assert( pWal->szWIndex==0 );
      pWal->pWiData = &pWal->iCallback;
    }
  }
  return rc;
}

/*
** Remap the wal-index so that the mapping covers the full size
** of the underlying file.
**
** If enlargeTo is non-negative, then increase the size of the underlying
** storage to be at least as big as enlargeTo before remapping.
*/
static int walIndexRemap(Wal *pWal, int enlargeTo){
  int rc;
  int sz;
  rc = pWal->pVfs->xShmSize(pWal->pWIndex, enlargeTo, &sz);
  if( rc==SQLITE_OK && sz>pWal->szWIndex ){
    walIndexUnmap(pWal);
    rc = walIndexMap(pWal, sz);
  }
  return rc;
}

/*
** Increment by which to increase the wal-index file size.
*/
#define WALINDEX_MMAP_INCREMENT (64*1024)

/*
** Set an entry in the wal-index map to map log frame iFrame to db 
** page iPage. Values are always appended to the wal-index (i.e. the
** value of iFrame is always exactly one more than the value passed to
** the previous call), but that restriction is not enforced or asserted
** here.
*/
static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
  u32 iSlot = walIndexEntry(iFrame);
  
  walIndexMap(pWal, -1);
  while( ((iSlot+128)*sizeof(u32))>=pWal->szWIndex ){
    int rc;
    int nByte = pWal->szWIndex + WALINDEX_MMAP_INCREMENT;

    /* Enlarge the storage, then remap it. */
    rc = walIndexRemap(pWal, nByte);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }

  /* Set the wal-index entry itself */
  pWal->pWiData[iSlot] = iPage;

  /* If the frame number is a multiple of 256 (frames are numbered starting
  ** at 1), build an index of the most recently added 256 frames.
  */
  if( (iFrame&0x000000FF)==0 ){
    int i;                        /* Iterator used while initializing aIndex */
    u32 *aFrame;                  /* Pointer to array of 256 frames */
    int nIndex;                   /* Number of entries in index */
    u8 *aIndex;                   /* 256 bytes to build index in */
    u8 *aTmp;                     /* Scratch space to use while sorting */

    aFrame = &pWal->pWiData[iSlot-255];
    aIndex = (u8 *)&pWal->pWiData[iSlot+1];
    aTmp = &aIndex[256];

    nIndex = 256;
    for(i=0; i<256; i++) aIndex[i] = (u8)i;
    walMergesort8(aFrame, aTmp, aIndex, &nIndex);
    memset(&aIndex[nIndex], aIndex[nIndex-1], 256-nIndex);
  }

  return SQLITE_OK;
}


/*
** Recover the wal-index by reading the write-ahead log file. 
** The caller must hold RECOVER lock on the wal-index file.
*/
static int walIndexRecover(Wal *pWal){
  int rc;                         /* Return Code */
  i64 nSize;                      /* Size of log file */
  WalIndexHdr hdr;              /* Recovered wal-index header */

  assert( pWal->lockState==SQLITE_SHM_RECOVER );
  memset(&hdr, 0, sizeof(hdr));

  rc = sqlite3OsFileSize(pWal->pFd, &nSize);
  if( rc!=SQLITE_OK ){
    return rc;
  }

  if( nSize>WAL_FRAME_HDRSIZE ){
    u8 aBuf[WAL_FRAME_HDRSIZE];   /* Buffer to load first frame header into */
    u8 *aFrame = 0;               /* Malloc'd buffer to load entire frame */
    int nFrame;                   /* Number of bytes at aFrame */
    u8 *aData;                    /* Pointer to data part of aFrame buffer */
    int iFrame;                   /* Index of last frame read */
    i64 iOffset;                  /* Next offset to read from log file */
    int nPgsz;                    /* Page size according to the log */
    u32 aCksum[2];                /* Running checksum */

    /* Read in the first frame header in the file (to determine the 
    ** database page size).
    */
    rc = sqlite3OsRead(pWal->pFd, aBuf, WAL_HDRSIZE, 0);
    if( rc!=SQLITE_OK ){
      return rc;
    }

    /* If the database page size is not a power of two, or is greater than
    ** SQLITE_MAX_PAGE_SIZE, conclude that the log file contains no valid data.
    */
    nPgsz = sqlite3Get4byte(&aBuf[0]);
    if( nPgsz&(nPgsz-1) || nPgsz>SQLITE_MAX_PAGE_SIZE || nPgsz<512 ){
      goto finished;
    }
    aCksum[0] = sqlite3Get4byte(&aBuf[4]);
    aCksum[1] = sqlite3Get4byte(&aBuf[8]);

    /* Malloc a buffer to read frames into. */
    nFrame = nPgsz + WAL_FRAME_HDRSIZE;
    aFrame = (u8 *)sqlite3_malloc(nFrame);
    if( !aFrame ){
      return SQLITE_NOMEM;
    }
    aData = &aFrame[WAL_FRAME_HDRSIZE];

    /* Read all frames from the log file. */
    iFrame = 0;
    for(iOffset=WAL_HDRSIZE; (iOffset+nFrame)<=nSize; iOffset+=nFrame){
      u32 pgno;                   /* Database page number for frame */
      u32 nTruncate;              /* dbsize field from frame header */
      int isValid;                /* True if this frame is valid */

      /* Read and decode the next log frame. */
      rc = sqlite3OsRead(pWal->pFd, aFrame, nFrame, iOffset);
      if( rc!=SQLITE_OK ) break;
      isValid = walDecodeFrame(aCksum, &pgno, &nTruncate, nPgsz, aData, aFrame);
      if( !isValid ) break;
      walIndexAppend(pWal, ++iFrame, pgno);

      /* If nTruncate is non-zero, this is a commit record. */
      if( nTruncate ){
        hdr.iCheck1 = aCksum[0];
        hdr.iCheck2 = aCksum[1];
        hdr.iLastPg = iFrame;
        hdr.nPage = nTruncate;
        hdr.pgsz = nPgsz;
      }
    }

    sqlite3_free(aFrame);
  }else{
    hdr.iCheck1 = 2;
    hdr.iCheck2 = 3;
  }

finished:
  walIndexWriteHdr(pWal, &hdr);
  return rc;
}

/* 
** Open a connection to the log file associated with database zDb. The
** database file does not actually have to exist. zDb is used only to
** figure out the name of the log file to open. If the log file does not 
** exist it is created by this call.
**
** A SHARED lock should be held on the database file when this function
** is called. The purpose of this SHARED lock is to prevent any other
** client from unlinking the log or wal-index file. If another process
** were to do this just after this client opened one of these files, the
** system would be badly broken.
*/
int sqlite3WalOpen(
  sqlite3_vfs *pVfs,              /* vfs module to open wal and wal-index */
  const char *zDb,                /* Name of database file */
  Wal **ppWal                     /* OUT: Allocated Wal handle */
){
  int rc = SQLITE_OK;             /* Return Code */
  Wal *pRet;                      /* Object to allocate and return */
  int flags;                      /* Flags passed to OsOpen() */
  char *zWal = 0;                 /* Path to WAL file */
  int nWal;                       /* Length of zWal in bytes */

  assert( zDb );
  if( pVfs->xShmOpen==0 ) return SQLITE_CANTOPEN_BKPT;

  /* Allocate an instance of struct Wal to return. */
  *ppWal = 0;
  nWal = strlen(zDb);
  pRet = (Wal*)sqlite3MallocZero(sizeof(Wal) + pVfs->szOsFile + nWal+5);
  if( !pRet ) goto wal_open_out;
  pRet->pVfs = pVfs;
  pRet->pFd = (sqlite3_file *)&pRet[1];
  pRet->zName = zWal = pVfs->szOsFile + (char*)pRet->pFd;
  sqlite3_snprintf(nWal+5, zWal, "%s-wal", zDb);
  rc = pVfs->xShmOpen(pVfs, zWal, &pRet->pWIndex);
  if( rc ) goto wal_open_out;

  /* Open file handle on the write-ahead log file. */
  flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_MAIN_JOURNAL);
  rc = sqlite3OsOpen(pVfs, zWal, pRet->pFd, flags, &flags);

wal_open_out:
  if( rc!=SQLITE_OK ){
    if( pRet ){
      pVfs->xShmClose(pRet->pWIndex, 0);
      sqlite3OsClose(pRet->pFd);
      sqlite3_free(pRet);
    }
  }
  *ppWal = pRet;
  return rc;
}

static int walIteratorNext(
  WalIterator *p,               /* Iterator */
  u32 *piPage,                  /* OUT: Next db page to write */
  u32 *piFrame                  /* OUT: Wal frame to read from */
){
  u32 iMin = *piPage;
  u32 iRet = 0xFFFFFFFF;
  int i;
  int nBlock = p->nFinal;

  for(i=p->nSegment-1; i>=0; i--){
    struct WalSegment *pSegment = &p->aSegment[i];
    while( pSegment->iNext<nBlock ){
      u32 iPg = pSegment->aDbPage[pSegment->aIndex[pSegment->iNext]];
      if( iPg>iMin ){
        if( iPg<iRet ){
          iRet = iPg;
          *piFrame = i*256 + 1 + pSegment->aIndex[pSegment->iNext];
        }
        break;
      }
      pSegment->iNext++;
    }

    nBlock = 256;
  }

  *piPage = iRet;
  return (iRet==0xFFFFFFFF);
}

static WalIterator *walIteratorInit(Wal *pWal){
  u32 *aData;                     /* Content of the wal-index file */
  WalIterator *p;                 /* Return value */
  int nSegment;                   /* Number of segments to merge */
  u32 iLast;                      /* Last frame in log */
  int nByte;                      /* Number of bytes to allocate */
  int i;                          /* Iterator variable */
  int nFinal;                     /* Number of unindexed entries */
  struct WalSegment *pFinal;      /* Final (unindexed) segment */
  u8 *aTmp;                       /* Temp space used by merge-sort */

  walIndexMap(pWal, -1);
  aData = pWal->pWiData;
  iLast = pWal->hdr.iLastPg;
  nSegment = (iLast >> 8) + 1;
  nFinal = (iLast & 0x000000FF);

  nByte = sizeof(WalIterator) + (nSegment-1)*sizeof(struct WalSegment) + 512;
  p = (WalIterator *)sqlite3_malloc(nByte);
  if( p ){
    memset(p, 0, nByte);
    p->nSegment = nSegment;
    p->nFinal = nFinal;
  }

  for(i=0; i<nSegment-1; i++){
    p->aSegment[i].aDbPage = &aData[walIndexEntry(i*256+1)];
    p->aSegment[i].aIndex = (u8 *)&aData[walIndexEntry(i*256+1)+256];
  }
  pFinal = &p->aSegment[nSegment-1];

  pFinal->aDbPage = &aData[walIndexEntry((nSegment-1)*256+1)];
  pFinal->aIndex = (u8 *)&pFinal[1];
  aTmp = &pFinal->aIndex[256];
  for(i=0; i<nFinal; i++){
    pFinal->aIndex[i] = i;
  }
  walMergesort8(pFinal->aDbPage, aTmp, pFinal->aIndex, &nFinal);
  p->nFinal = nFinal;

  return p;
}

/* 
** Free a log iterator allocated by walIteratorInit().
*/
static void walIteratorFree(WalIterator *p){
  sqlite3_free(p);
}

/*
** Checkpoint the contents of the log file.
*/
static int walCheckpoint(
  Wal *pWal,                      /* Wal connection */
  sqlite3_file *pFd,              /* File descriptor open on db file */
  int sync_flags,                 /* Flags for OsSync() (or 0) */
  u8 *zBuf                        /* Temporary buffer to use */
){
  int rc;                         /* Return code */
  int pgsz = pWal->hdr.pgsz;      /* Database page-size */
  WalIterator *pIter = 0;         /* Wal iterator context */
  u32 iDbpage = 0;                /* Next database page to write */
  u32 iFrame = 0;                 /* Wal frame containing data for iDbpage */

  if( pWal->hdr.iLastPg==0 ){
    return SQLITE_OK;
  }

  /* Allocate the iterator */
  pIter = walIteratorInit(pWal);
  if( !pIter ) return SQLITE_NOMEM;

  /* Sync the log file to disk */
  if( sync_flags ){
    rc = sqlite3OsSync(pWal->pFd, sync_flags);
    if( rc!=SQLITE_OK ) goto out;
  }

  /* Iterate through the contents of the log, copying data to the db file. */
  while( 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
    rc = sqlite3OsRead(pWal->pFd, zBuf, pgsz, 
        walFrameOffset(iFrame, pgsz) + WAL_FRAME_HDRSIZE
    );
    if( rc!=SQLITE_OK ) goto out;
    rc = sqlite3OsWrite(pFd, zBuf, pgsz, (iDbpage-1)*pgsz);
    if( rc!=SQLITE_OK ) goto out;
  }

  /* Truncate the database file */
  rc = sqlite3OsTruncate(pFd, ((i64)pWal->hdr.nPage*(i64)pgsz));
  if( rc!=SQLITE_OK ) goto out;

  /* Sync the database file. If successful, update the wal-index. */
  if( sync_flags ){
    rc = sqlite3OsSync(pFd, sync_flags);
    if( rc!=SQLITE_OK ) goto out;
  }
  pWal->hdr.iLastPg = 0;
  pWal->hdr.iCheck1 = 2;
  pWal->hdr.iCheck2 = 3;
  walIndexWriteHdr(pWal, &pWal->hdr);

  /* TODO: If a crash occurs and the current log is copied into the 
  ** database there is no problem. However, if a crash occurs while
  ** writing the next transaction into the start of the log, such that:
  **
  **   * The first transaction currently in the log is left intact, but
  **   * The second (or subsequent) transaction is damaged,
  **
  ** then the database could become corrupt.
  **
  ** The easiest thing to do would be to write and sync a dummy header
  ** into the log at this point. Unfortunately, that turns out to be
  ** an unwelcome performance hit. Alternatives are...
  */
#if 0 
  memset(zBuf, 0, WAL_FRAME_HDRSIZE);
  rc = sqlite3OsWrite(pWal->pFd, zBuf, WAL_FRAME_HDRSIZE, 0);
  if( rc!=SQLITE_OK ) goto out;
  rc = sqlite3OsSync(pWal->pFd, pWal->sync_flags);
#endif

 out:
  walIteratorFree(pIter);
  return rc;
}

/*
** Close a connection to a log file.
*/
int sqlite3WalClose(
  Wal *pWal,                      /* Wal to close */
  sqlite3_file *pFd,              /* Database file */
  int sync_flags,                 /* Flags to pass to OsSync() (or 0) */
  u8 *zBuf                        /* Buffer of at least page-size bytes */
){
  int rc = SQLITE_OK;
  if( pWal ){
    int isDelete = 0;             /* True to unlink wal and wal-index files */

    /* If an EXCLUSIVE lock can be obtained on the database file (using the
    ** ordinary, rollback-mode locking methods, this guarantees that the
    ** connection associated with this log file is the only connection to
    ** the database. In this case checkpoint the database and unlink both
    ** the wal and wal-index files.
    **
    ** The EXCLUSIVE lock is not released before returning.
    */
    rc = sqlite3OsLock(pFd, SQLITE_LOCK_EXCLUSIVE);
    if( rc==SQLITE_OK ){
      rc = walCheckpoint(pWal, pFd, sync_flags, zBuf);
      if( rc==SQLITE_OK ){
        isDelete = 1;
      }
      walIndexUnmap(pWal);
    }

    pWal->pVfs->xShmClose(pWal->pWIndex, isDelete);
    sqlite3OsClose(pWal->pFd);
    if( isDelete ){
      sqlite3OsDelete(pWal->pVfs, pWal->zName, 0);
    }
    sqlite3_free(pWal);
  }
  return rc;
}

/*
** Try to read the wal-index header. Attempt to verify the header
** checksum. If the checksum can be verified, copy the wal-index
** header into structure pWal->hdr. If the contents of pWal->hdr are
** modified by this and pChanged is not NULL, set *pChanged to 1. 
** Otherwise leave *pChanged unmodified.
**
** If the checksum cannot be verified return SQLITE_ERROR.
*/
int walIndexTryHdr(Wal *pWal, int *pChanged){
  u32 aCksum[2] = {1, 1};
  u32 aHdr[WALINDEX_HDR_NFIELD+2];

  if( pWal->szWIndex==0 ){
    int rc;
    rc = walIndexRemap(pWal, WALINDEX_MMAP_INCREMENT);
    if( rc ) return rc;
  }

  /* Read the header. The caller may or may not have locked the wal-index
  ** file, meaning it is possible that an inconsistent snapshot is read
  ** from the file. If this happens, return SQLITE_ERROR. The caller will
  ** retry. Or, if the caller has already locked the file and the header
  ** still looks inconsistent, it will run recovery.
  **
  ** FIX-ME:  It is no longer possible to have not locked the wal-index.
  */
  memcpy(aHdr, pWal->pWiData, sizeof(aHdr));
  walChecksumBytes((u8*)aHdr, sizeof(u32)*WALINDEX_HDR_NFIELD, aCksum);
  if( aCksum[0]!=aHdr[WALINDEX_HDR_NFIELD]
   || aCksum[1]!=aHdr[WALINDEX_HDR_NFIELD+1]
  ){
    return SQLITE_ERROR;
  }

  if( memcmp(&pWal->hdr, aHdr, sizeof(WalIndexHdr)) ){
    if( pChanged ){
      *pChanged = 1;
    }
    memcpy(&pWal->hdr, aHdr, sizeof(WalIndexHdr));
  }
  return SQLITE_OK;
}

/*
** Read the wal-index header from the wal-index file into structure 
** pWal->hdr. If attempting to verify the header checksum fails, try
** to recover the log before returning.
**
** If the wal-index header is successfully read, return SQLITE_OK. 
** Otherwise an SQLite error code.
*/
static int walIndexReadHdr(Wal *pWal, int *pChanged){
  int rc;

  assert( pWal->lockState>=SQLITE_SHM_READ );
  walIndexMap(pWal, -1);

  /* First try to read the header without a lock. Verify the checksum
  ** before returning. This will almost always work.  
  */
  if( SQLITE_OK==walIndexTryHdr(pWal, pChanged) ){
    return SQLITE_OK;
  }

  /* If the first attempt to read the header failed, lock the wal-index
  ** file and try again. If the header checksum verification fails this
  ** time as well, run log recovery.
  */
  if( SQLITE_OK==(rc = walSetLock(pWal, SQLITE_SHM_RECOVER)) ){
    if( SQLITE_OK!=walIndexTryHdr(pWal, pChanged) ){
      if( pChanged ){
        *pChanged = 1;
      }
      rc = walIndexRecover(pWal);
      if( rc==SQLITE_OK ){
        rc = walIndexTryHdr(pWal, 0);
      }
    }
    walSetLock(pWal, SQLITE_SHM_READ);
  }

  return rc;
}

/*
** Lock a snapshot.
**
** If this call obtains a new read-lock and the database contents have been
** modified since the most recent call to WalCloseSnapshot() on this Wal
** connection, then *pChanged is set to 1 before returning. Otherwise, it 
** is left unmodified. This is used by the pager layer to determine whether 
** or not any cached pages may be safely reused.
*/
int sqlite3WalOpenSnapshot(Wal *pWal, int *pChanged){
  int rc;

  rc = walSetLock(pWal, SQLITE_SHM_READ);
  if( rc==SQLITE_OK ){
    pWal->lockState = SQLITE_SHM_READ;

    rc = walIndexReadHdr(pWal, pChanged);
    if( rc!=SQLITE_OK ){
      /* An error occured while attempting log recovery. */
      sqlite3WalCloseSnapshot(pWal);
    }else{
      /* Check if the mapping needs to grow. */
      if( pWal->hdr.iLastPg 
       && walIndexEntry(pWal->hdr.iLastPg)*sizeof(u32)>=pWal->szWIndex
      ){
         walIndexRemap(pWal, -1);
      }
    }
  }

  walIndexUnmap(pWal);
  return rc;
}

/*
** Unlock the current snapshot.
*/
void sqlite3WalCloseSnapshot(Wal *pWal){
  if( pWal->lockState!=SQLITE_SHM_UNLOCK ){
    assert( pWal->lockState==SQLITE_SHM_READ );
    walSetLock(pWal, SQLITE_SHM_UNLOCK);
  }
}

/*
** Read a page from the log, if it is present. 
*/
int sqlite3WalRead(Wal *pWal, Pgno pgno, int *pInWal, u8 *pOut){
  u32 iRead = 0;
  u32 *aData; 
  int iFrame = (pWal->hdr.iLastPg & 0xFFFFFF00);

  assert( pWal->lockState==SQLITE_SHM_READ||pWal->lockState==SQLITE_SHM_WRITE );
  walIndexMap(pWal, -1);

  /* Do a linear search of the unindexed block of page-numbers (if any) 
  ** at the end of the wal-index. An alternative to this would be to
  ** build an index in private memory each time a read transaction is
  ** opened on a new snapshot.
  */
  aData = pWal->pWiData;
  if( pWal->hdr.iLastPg ){
    u32 *pi = &aData[walIndexEntry(pWal->hdr.iLastPg)];
    u32 *piStop = pi - (pWal->hdr.iLastPg & 0xFF);
    while( *pi!=pgno && pi!=piStop ) pi--;
    if( pi!=piStop ){
      iRead = (pi-piStop) + iFrame;
    }
  }
  assert( iRead==0 || aData[walIndexEntry(iRead)]==pgno );

  while( iRead==0 && iFrame>0 ){
    int iLow = 0;
    int iHigh = 255;
    u32 *aFrame;
    u8 *aIndex;

    iFrame -= 256;
    aFrame = &aData[walIndexEntry(iFrame+1)];
    aIndex = (u8 *)&aFrame[256];

    while( iLow<=iHigh ){
      int iTest = (iLow+iHigh)>>1;
      u32 iPg = aFrame[aIndex[iTest]];

      if( iPg==pgno ){
        iRead = iFrame + 1 + aIndex[iTest];
        break;
      }
      else if( iPg<pgno ){
        iLow = iTest+1;
      }else{
        iHigh = iTest-1;
      }
    }
  }
  assert( iRead==0 || aData[walIndexEntry(iRead)]==pgno );
  walIndexUnmap(pWal);

  /* If iRead is non-zero, then it is the log frame number that contains the
  ** required page. Read and return data from the log file.
  */
  if( iRead ){
    i64 iOffset = walFrameOffset(iRead, pWal->hdr.pgsz) + WAL_FRAME_HDRSIZE;
    *pInWal = 1;
    return sqlite3OsRead(pWal->pFd, pOut, pWal->hdr.pgsz, iOffset);
  }

  *pInWal = 0;
  return SQLITE_OK;
}


/* 
** Set *pPgno to the size of the database file (or zero, if unknown).
*/
void sqlite3WalDbsize(Wal *pWal, Pgno *pPgno){
  assert( pWal->lockState==SQLITE_SHM_READ
       || pWal->lockState==SQLITE_SHM_WRITE );
  *pPgno = pWal->hdr.nPage;
}

/* 
** This function returns SQLITE_OK if the caller may write to the database.
** Otherwise, if the caller is operating on a snapshot that has already
** been overwritten by another writer, SQLITE_BUSY is returned.
*/
int sqlite3WalWriteLock(Wal *pWal, int op){
  int rc;
  if( op ){
    assert( pWal->lockState == SQLITE_SHM_READ );
    rc = walSetLock(pWal, SQLITE_SHM_WRITE);

    /* If this connection is not reading the most recent database snapshot,
    ** it is not possible to write to the database. In this case release
    ** the write locks and return SQLITE_BUSY.
    */
    if( rc==SQLITE_OK ){
      rc = walIndexMap(pWal, -1);
      if( rc==SQLITE_OK
       && memcmp(&pWal->hdr, pWal->pWiData, sizeof(WalIndexHdr))
      ){
        rc = SQLITE_BUSY;
      }
      walIndexUnmap(pWal);
      if( rc!=SQLITE_OK ){
        walSetLock(pWal, SQLITE_SHM_READ);
      }
    }
  }else if( pWal->lockState==SQLITE_SHM_WRITE ){
    rc = walSetLock(pWal, SQLITE_SHM_READ);
  }
  return rc;
}

/*
** The Wal object passed to this function must be holding the write-lock.
**
** If any data has been written (but not committed) to the log file, this
** function moves the write-pointer back to the start of the transaction.
**
** Additionally, the callback function is invoked for each frame written
** to the log since the start of the transaction. If the callback returns
** other than SQLITE_OK, it is not invoked again and the error code is
** returned to the caller.
**
** Otherwise, if the callback function does not return an error, this
** function returns SQLITE_OK.
*/
int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx){
  int rc = SQLITE_OK;
  Pgno iMax = pWal->hdr.iLastPg;
  Pgno iFrame;

  assert( pWal->lockState==SQLITE_SHM_WRITE );
  walIndexReadHdr(pWal, 0);
  for(iFrame=pWal->hdr.iLastPg+1; iFrame<=iMax && rc==SQLITE_OK; iFrame++){
    rc = xUndo(pUndoCtx, pWal->pWiData[walIndexEntry(iFrame)]);
  }
  walIndexUnmap(pWal);
  return rc;
}

/* Return an integer that records the current (uncommitted) write
** position in the WAL
*/
u32 sqlite3WalSavepoint(Wal *pWal){
  assert( pWal->lockState==SQLITE_SHM_WRITE );
  return pWal->hdr.iLastPg;
}

/* Move the write position of the WAL back to iFrame.  Called in
** response to a ROLLBACK TO command.
*/
int sqlite3WalSavepointUndo(Wal *pWal, u32 iFrame){
  int rc = SQLITE_OK;
  u8 aCksum[8];
  assert( pWal->lockState==SQLITE_SHM_WRITE );

  pWal->hdr.iLastPg = iFrame;
  if( iFrame>0 ){
    i64 iOffset = walFrameOffset(iFrame, pWal->hdr.pgsz) + sizeof(u32)*2;
    rc = sqlite3OsRead(pWal->pFd, aCksum, sizeof(aCksum), iOffset);
    pWal->hdr.iCheck1 = sqlite3Get4byte(&aCksum[0]);
    pWal->hdr.iCheck2 = sqlite3Get4byte(&aCksum[4]);
  }

  return rc;
}

/* 
** Write a set of frames to the log. The caller must hold the write-lock
** on the log file (obtained using sqlite3WalWriteLock()).
*/
int sqlite3WalFrames(
  Wal *pWal,                      /* Wal handle to write to */
  int nPgsz,                      /* Database page-size in bytes */
  PgHdr *pList,                   /* List of dirty pages to write */
  Pgno nTruncate,                 /* Database size after this commit */
  int isCommit,                   /* True if this is a commit */
  int sync_flags                  /* Flags to pass to OsSync() (or 0) */
){
  int rc;                         /* Used to catch return codes */
  u32 iFrame;                     /* Next frame address */
  u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-header in */
  PgHdr *p;                       /* Iterator to run through pList with. */
  u32 aCksum[2];                  /* Checksums */
  PgHdr *pLast;                   /* Last frame in list */
  int nLast = 0;                  /* Number of extra copies of last page */

  assert( WAL_FRAME_HDRSIZE==(4 * 2 + 2*sizeof(u32)) );
  assert( pList );
  assert( pWal->lockState==SQLITE_SHM_WRITE );
  assert( pWal->pWiData==0 );

  /* If this is the first frame written into the log, write the log 
  ** header to the start of the log file. See comments at the top of
  ** this file for a description of the log-header format.
  */
  assert( WAL_FRAME_HDRSIZE>=WAL_HDRSIZE );
  iFrame = pWal->hdr.iLastPg;
  if( iFrame==0 ){
    sqlite3Put4byte(aFrame, nPgsz);
    sqlite3_randomness(8, &aFrame[4]);
    pWal->hdr.iCheck1 = sqlite3Get4byte(&aFrame[4]);
    pWal->hdr.iCheck2 = sqlite3Get4byte(&aFrame[8]);
    rc = sqlite3OsWrite(pWal->pFd, aFrame, WAL_HDRSIZE, 0);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }

  aCksum[0] = pWal->hdr.iCheck1;
  aCksum[1] = pWal->hdr.iCheck2;

  /* Write the log file. */
  for(p=pList; p; p=p->pDirty){
    u32 nDbsize;                  /* Db-size field for frame header */
    i64 iOffset;                  /* Write offset in log file */

    iOffset = walFrameOffset(++iFrame, nPgsz);
    
    /* Populate and write the frame header */
    nDbsize = (isCommit && p->pDirty==0) ? nTruncate : 0;
    walEncodeFrame(aCksum, p->pgno, nDbsize, nPgsz, p->pData, aFrame);
    rc = sqlite3OsWrite(pWal->pFd, aFrame, sizeof(aFrame), iOffset);
    if( rc!=SQLITE_OK ){
      return rc;
    }

    /* Write the page data */
    rc = sqlite3OsWrite(pWal->pFd, p->pData, nPgsz, iOffset + sizeof(aFrame));
    if( rc!=SQLITE_OK ){
      return rc;
    }
    pLast = p;
  }

  /* Sync the log file if the 'isSync' flag was specified. */
  if( sync_flags ){
    i64 iSegment = sqlite3OsSectorSize(pWal->pFd);
    i64 iOffset = walFrameOffset(iFrame+1, nPgsz);

    assert( isCommit );

    if( iSegment<SQLITE_DEFAULT_SECTOR_SIZE ){
      iSegment = SQLITE_DEFAULT_SECTOR_SIZE;
    }
    iSegment = (((iOffset+iSegment-1)/iSegment) * iSegment);
    while( iOffset<iSegment ){
      walEncodeFrame(aCksum,pLast->pgno,nTruncate,nPgsz,pLast->pData,aFrame);
      rc = sqlite3OsWrite(pWal->pFd, aFrame, sizeof(aFrame), iOffset);
      if( rc!=SQLITE_OK ){
        return rc;
      }

      iOffset += WAL_FRAME_HDRSIZE;
      rc = sqlite3OsWrite(pWal->pFd, pLast->pData, nPgsz, iOffset); 
      if( rc!=SQLITE_OK ){
        return rc;
      }
      nLast++;
      iOffset += nPgsz;
    }

    rc = sqlite3OsSync(pWal->pFd, sync_flags);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }
  assert( pWal->pWiData==0 );

  /* Append data to the log summary. It is not necessary to lock the 
  ** wal-index to do this as the RESERVED lock held on the db file
  ** guarantees that there are no other writers, and no data that may
  ** be in use by existing readers is being overwritten.
  */
  iFrame = pWal->hdr.iLastPg;
  for(p=pList; p; p=p->pDirty){
    iFrame++;
    walIndexAppend(pWal, iFrame, p->pgno);
  }
  while( nLast>0 ){
    iFrame++;
    nLast--;
    walIndexAppend(pWal, iFrame, pLast->pgno);
  }

  /* Update the private copy of the header. */
  pWal->hdr.pgsz = nPgsz;
  pWal->hdr.iLastPg = iFrame;
  if( isCommit ){
    pWal->hdr.iChange++;
    pWal->hdr.nPage = nTruncate;
  }
  pWal->hdr.iCheck1 = aCksum[0];
  pWal->hdr.iCheck2 = aCksum[1];

  /* If this is a commit, update the wal-index header too. */
  if( isCommit ){
    walIndexWriteHdr(pWal, &pWal->hdr);
    pWal->iCallback = iFrame;
  }
  walIndexUnmap(pWal);

  return rc;
}

/* 
** Checkpoint the database:
**
**   1. Acquire a CHECKPOINT lock
**   2. Copy the contents of the log into the database file.
**   3. Zero the wal-index header (so new readers will ignore the log).
**   4. Drop the CHECKPOINT lock.
*/
int sqlite3WalCheckpoint(
  Wal *pWal,                      /* Wal connection */
  sqlite3_file *pFd,              /* File descriptor open on db file */
  int sync_flags,                 /* Flags to sync db file with (or 0) */
  u8 *zBuf,                       /* Temporary buffer to use */
  int (*xBusyHandler)(void *),    /* Pointer to busy-handler function */
  void *pBusyHandlerArg           /* Argument to pass to xBusyHandler */
){
  int rc;                         /* Return code */
  int isChanged = 0;              /* True if a new wal-index header is loaded */

  assert( pWal->lockState==SQLITE_SHM_UNLOCK );
  assert( pWal->pWiData==0 );

  /* Get the CHECKPOINT lock */
  do {
    rc = walSetLock(pWal, SQLITE_SHM_CHECKPOINT);
  }while( rc==SQLITE_BUSY && xBusyHandler(pBusyHandlerArg) );
  if( rc!=SQLITE_OK ){
    walSetLock(pWal, SQLITE_SHM_UNLOCK);
    return rc;
  }

  /* Copy data from the log to the database file. */
  rc = walIndexReadHdr(pWal, &isChanged);
  if( rc==SQLITE_OK ){
    rc = walCheckpoint(pWal, pFd, sync_flags, zBuf);
  }
  if( isChanged ){
    /* If a new wal-index header was loaded before the checkpoint was 
    ** performed, then the pager-cache associated with log pWal is now
    ** out of date. So zero the cached wal-index header to ensure that
    ** next time the pager opens a snapshot on this database it knows that
    ** the cache needs to be reset.
    */
    memset(&pWal->hdr, 0, sizeof(WalIndexHdr));
  }

  /* Release the locks. */
  walIndexUnmap(pWal);
  walSetLock(pWal, SQLITE_SHM_UNLOCK);
  return rc;
}

/* Return the value to pass to a sqlite3_wal_hook callback, the
** number of frames in the WAL at the point of the last commit since
** sqlite3WalCallback() was called.  If no commits have occurred since
** the last call, then return 0.
*/
int sqlite3WalCallback(Wal *pWal){
  u32 ret = 0;
  if( pWal ){
    ret = pWal->iCallback;
    pWal->iCallback = 0;
  }
  return (int)ret;
}
#endif /* #ifndef SQLITE_OMIT_WAL */

Added src/wal.h.







































































































































































































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/*
** 2010 February 1
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface to the write-ahead logging 
** system. Refer to the comments below and the header comment attached to 
** the implementation of each function in log.c for further details.
*/

#ifndef _WAL_H_
#define _WAL_H_

#include "sqliteInt.h"

#ifdef SQLITE_OMIT_WAL
# define sqlite3WalOpen(x,y,z)             0
# define sqlite3WalClose(w,x,y,z)          0
# define sqlite3WalOpenSnapshot(y,z)       0
# define sqlite3WalCloseSnapshot(z) 
# define sqlite3WalRead(w,x,y,z)           0
# define sqlite3WalDbsize(y,z)
# define sqlite3WalWriteLock(y,z)          0
# define sqlite3WalUndo(x,y,z)             0
# define sqlite3WalSavepoint(z)            0
# define sqlite3WalSavepointUndo(y,z)      0
# define sqlite3WalFrames(u,v,w,x,y,z)     0
# define sqlite3WalCheckpoint(u,v,w,x,y,z) 0
# define sqlite3WalCallback(z)             0
#else

/* Connection to a write-ahead log (WAL) file. 
** There is one object of this type for each pager. 
*/
typedef struct Wal Wal;

/* Open and close a connection to a write-ahead log. */
int sqlite3WalOpen(sqlite3_vfs*, const char *zDb, Wal **ppWal);
int sqlite3WalClose(Wal *pWal, sqlite3_file *pFd, int sync_flags, u8 *zBuf);

/* Used by readers to open (lock) and close (unlock) a snapshot.  A 
** snapshot is like a read-transaction.  It is the state of the database
** at an instant in time.  sqlite3WalOpenSnapshot gets a read lock and
** preserves the current state even if the other threads or processes
** write to or checkpoint the WAL.  sqlite3WalCloseSnapshot() closes the
** transaction and releases the lock.
*/
int sqlite3WalOpenSnapshot(Wal *pWal, int *);
void sqlite3WalCloseSnapshot(Wal *pWal);

/* Read a page from the write-ahead log, if it is present. */
int sqlite3WalRead(Wal *pWal, Pgno pgno, int *pInWal, u8 *pOut);

/* Return the size of the database as it existed at the beginning
** of the snapshot */
void sqlite3WalDbsize(Wal *pWal, Pgno *pPgno);

/* Obtain or release the WRITER lock. */
int sqlite3WalWriteLock(Wal *pWal, int op);

/* Undo any frames written (but not committed) to the log */
int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx);

/* Return an integer that records the current (uncommitted) write
** position in the WAL */
u32 sqlite3WalSavepoint(Wal *pWal);

/* Move the write position of the WAL back to iFrame.  Called in
** response to a ROLLBACK TO command. */
int sqlite3WalSavepointUndo(Wal *pWal, u32 iFrame);

/* Write a frame or frames to the log. */
int sqlite3WalFrames(Wal *pWal, int, PgHdr *, Pgno, int, int);

/* Copy pages from the log to the database file */ 
int sqlite3WalCheckpoint(
  Wal *pWal,                      /* Write-ahead log connection */
  sqlite3_file *pFd,              /* File descriptor open on db file */
  int sync_flags,                 /* Flags to sync db file with (or 0) */
  u8 *zBuf,                       /* Temporary buffer to use */
  int (*xBusyHandler)(void *),    /* Pointer to busy-handler function */
  void *pBusyHandlerArg           /* Argument to pass to xBusyHandler */
);

/* Return the value to pass to a sqlite3_wal_hook callback, the
** number of frames in the WAL at the point of the last commit since
** sqlite3WalCallback() was called.  If no commits have occurred since
** the last call, then return 0.
*/
int sqlite3WalCallback(Wal *pWal);

#endif /* ifndef SQLITE_OMIT_WAL */
#endif /* _WAL_H_ */

Changes to test/avtrans.test.

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set testdir [file dirname $argv0]
source $testdir/tester.tcl


# Create several tables to work with.
#
do_test avtrans-1.0 {


  execsql {
    PRAGMA auto_vacuum=ON;
    CREATE TABLE one(a int PRIMARY KEY, b text);
    INSERT INTO one VALUES(1,'one');
    INSERT INTO one VALUES(2,'two');
    INSERT INTO one VALUES(3,'three');
    SELECT b FROM one ORDER BY a;
  }
} {one two three}
................................................................................
  sqlite3 altdb test.db
  execsql {SELECT b FROM one ORDER BY a} altdb
} {one two three}
do_test avtrans-1.10 {
  execsql {SELECT b FROM two ORDER BY a} altdb
} {I V X}
integrity_check avtrans-1.11


# Basic transactions
#
do_test avtrans-2.1 {
  set v [catch {execsql {BEGIN}} msg]
  lappend v $msg
} {0 {}}
................................................................................
    BEGIN;
    SELECT a FROM one ORDER BY a;
    SELECT a FROM two ORDER BY a;
    END;
  }
} {1 2 3 1 5 10}
integrity_check avtrans-2.11


# Check the locking behavior
#
sqlite3_soft_heap_limit 0
do_test avtrans-3.1 {
  execsql {
    BEGIN;
................................................................................
        } [expr {$i%2==0}]
      } else {
        do_test avtrans-9.$i.5-$cnt {
           expr {$sqlite_fullsync_count==0}
        } {1}
      }
    }

  }
  set ::pager_old_format 0
}
integrity_check avtrans-10.1

   
finish_test







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set testdir [file dirname $argv0]
source $testdir/tester.tcl


# Create several tables to work with.
#
do_test avtrans-1.0 {
  execsql { PRAGMA auto_vacuum=ON }
  wal_set_journal_mode
  execsql { 

    CREATE TABLE one(a int PRIMARY KEY, b text);
    INSERT INTO one VALUES(1,'one');
    INSERT INTO one VALUES(2,'two');
    INSERT INTO one VALUES(3,'three');
    SELECT b FROM one ORDER BY a;
  }
} {one two three}
................................................................................
  sqlite3 altdb test.db
  execsql {SELECT b FROM one ORDER BY a} altdb
} {one two three}
do_test avtrans-1.10 {
  execsql {SELECT b FROM two ORDER BY a} altdb
} {I V X}
integrity_check avtrans-1.11
wal_check_journal_mode avtrans-1.12

# Basic transactions
#
do_test avtrans-2.1 {
  set v [catch {execsql {BEGIN}} msg]
  lappend v $msg
} {0 {}}
................................................................................
    BEGIN;
    SELECT a FROM one ORDER BY a;
    SELECT a FROM two ORDER BY a;
    END;
  }
} {1 2 3 1 5 10}
integrity_check avtrans-2.11
wal_check_journal_mode avtrans-2.12

# Check the locking behavior
#
sqlite3_soft_heap_limit 0
do_test avtrans-3.1 {
  execsql {
    BEGIN;
................................................................................
        } [expr {$i%2==0}]
      } else {
        do_test avtrans-9.$i.5-$cnt {
           expr {$sqlite_fullsync_count==0}
        } {1}
      }
    }
    wal_check_journal_mode avtrans-9.$i-6.$cnt
  }
  set ::pager_old_format 0
}
integrity_check avtrans-10.1
wal_check_journal_mode avtrans-10.2
   
finish_test

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#
# backup-7.*: Test SQLITE_BUSY and SQLITE_LOCKED errors.
#
# backup-8.*: Test multiple simultaneous backup operations.
#
# backup-9.*: Test that passing a negative argument to backup_step() is
#             interpreted as "copy the whole file".


#

proc data_checksum {db file} { $db one "SELECT md5sum(a, b) FROM ${file}.t1" }
proc test_contents {name db1 file1 db2 file2} {
  $db2 eval {select * from sqlite_master}
  $db1 eval {select * from sqlite_master}
  set checksum [data_checksum $db2 $file2]
................................................................................
#
#   1) Backing up file-to-file. The writer writes via an external pager.
#   2) Backing up file-to-file. The writer writes via the same pager as
#      is used by the backup operation.
#   3) Backing up memory-to-file. 
#
set iTest 0

foreach {writer file} {db test.db db3 test.db db :memory:} {
  incr iTest
  catch { file delete bak.db }
  sqlite3 db2 bak.db
  catch { file delete $file }
  sqlite3 db $file
  sqlite3 db3 $file
................................................................................
  } {ok}

  db2 close
  db3 close
}



# Test that if the database is written to via the same database handle being
# used as the source by a backup operation:
#
#   10.1.*: If the db is in-memory, the backup is restarted.
#   10.2.*: If the db is a file, the backup is not restarted.
#
db close







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#
# backup-7.*: Test SQLITE_BUSY and SQLITE_LOCKED errors.
#
# backup-8.*: Test multiple simultaneous backup operations.
#
# backup-9.*: Test that passing a negative argument to backup_step() is
#             interpreted as "copy the whole file".
# 
# backup-10.*: Test writing the source database mid backup.
#

proc data_checksum {db file} { $db one "SELECT md5sum(a, b) FROM ${file}.t1" }
proc test_contents {name db1 file1 db2 file2} {
  $db2 eval {select * from sqlite_master}
  $db1 eval {select * from sqlite_master}
  set checksum [data_checksum $db2 $file2]
................................................................................
#
#   1) Backing up file-to-file. The writer writes via an external pager.
#   2) Backing up file-to-file. The writer writes via the same pager as
#      is used by the backup operation.
#   3) Backing up memory-to-file. 
#
set iTest 0
file delete -force bak.db-wal
foreach {writer file} {db test.db db3 test.db db :memory:} {
  incr iTest
  catch { file delete bak.db }
  sqlite3 db2 bak.db
  catch { file delete $file }
  sqlite3 db $file
  sqlite3 db3 $file
................................................................................
  } {ok}

  db2 close
  db3 close
}


#-----------------------------------------------------------------------
# Test that if the database is written to via the same database handle being
# used as the source by a backup operation:
#
#   10.1.*: If the db is in-memory, the backup is restarted.
#   10.2.*: If the db is a file, the backup is not restarted.
#
db close

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# Corrupt the file header in various ways and make sure the corruption
# is detected when opening the database file.
#
db close
file copy -force test.db test.db-template



do_test corruptA-2.1 {
  file copy -force test.db-template test.db
  hexio_write test.db 19 02   ;# the read format number
  sqlite3 db test.db
  catchsql {SELECT * FROM t1}  
} {1 {file is encrypted or is not a database}}
 
do_test corruptA-2.2 {
  db close
  file copy -force test.db-template test.db







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# Corrupt the file header in various ways and make sure the corruption
# is detected when opening the database file.
#
db close
file copy -force test.db test.db-template

set unreadable_version 02
ifcapable wal { set unreadable_version 03 }
do_test corruptA-2.1 {
  file copy -force test.db-template test.db
  hexio_write test.db 19 $unreadable_version   ;# the read format number
  sqlite3 db test.db
  catchsql {SELECT * FROM t1}  
} {1 {file is encrypted or is not a database}}
 
do_test corruptA-2.2 {
  db close
  file copy -force test.db-template test.db

Changes to test/lock2.test.

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# focus of this script is database locks between competing processes.
#
# $Id: lock2.test,v 1.11 2009/05/01 10:55:34 danielk1977 Exp $


set testdir [file dirname $argv0]
source $testdir/tester.tcl


# Launch another testfixture process to be controlled by this one. A
# channel name is returned that may be passed as the first argument to proc
# 'testfixture' to execute a command. The child testfixture process is shut
# down by closing the channel.
proc launch_testfixture {} {
  set prg [info nameofexec]
  if {$prg eq ""} {
    set prg [file join . testfixture]
  }
  set chan [open "|$prg tf_main.tcl" r+]
  fconfigure $chan -buffering line
  return $chan
}

# Execute a command in a child testfixture process, connected by two-way
# channel $chan. Return the result of the command, or an error message.
proc testfixture {chan cmd} {
  puts $chan $cmd
  puts $chan OVER
  set r ""
  while { 1 } {
    set line [gets $chan]
    if { $line == "OVER" } { 
      return $r
    }
    if {[eof $chan]} {
      return "ERROR: Child process hung up"
    }
    append r $line
  }
}

# Write the main loop for the child testfixture processes into file
# tf_main.tcl. The parent (this script) interacts with the child processes
# via a two way pipe. The parent writes a script to the stdin of the child
# process, followed by the word "OVER" on a line of its own. The child
# process evaluates the script and writes the results to stdout, followed
# by an "OVER" of its own.
set f [open tf_main.tcl w]
puts $f {
  set l [open log w]
  set script ""
  while {![eof stdin]} {
    flush stdout
    set line [gets stdin]
    puts $l "READ $line"
    if { $line == "OVER" } {
      catch {eval $script} result
      puts $result
      puts $l "WRITE $result"
      puts OVER
      puts $l "WRITE OVER"
      flush stdout
      set script ""
    } else {
      append script $line
      append script " ; "
    }
  }
  close $l
}
close $f

# Simple locking test case:
#
# lock2-1.1: Connect a second process to the database.
# lock2-1.2: Establish a RESERVED lock with this process.
# lock2-1.3: Get a SHARED lock with the second process.
# lock2-1.4: Try for a RESERVED lock with process 2. This fails.
................................................................................
# lock2-1.6: Release the SHARED lock held by the second process. 
# lock2-1.7: Attempt to reaquire a SHARED lock with the second process.
#            this fails due to the PENDING lock.
# lock2-1.8: Ensure the first process can now upgrade to EXCLUSIVE.
#
do_test lock2-1.1 {
  set ::tf1 [launch_testfixture]
  testfixture $::tf1 "sqlite3_test_control_pending_byte $::sqlite_pending_byte"
  testfixture $::tf1 {
    sqlite3 db test.db -key xyzzy
    db eval {select * from sqlite_master}
  }
} {}
do_test lock2-1.1.1 {
  execsql {pragma lock_status}







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# focus of this script is database locks between competing processes.
#
# $Id: lock2.test,v 1.11 2009/05/01 10:55:34 danielk1977 Exp $


set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
































































# Simple locking test case:
#
# lock2-1.1: Connect a second process to the database.
# lock2-1.2: Establish a RESERVED lock with this process.
# lock2-1.3: Get a SHARED lock with the second process.
# lock2-1.4: Try for a RESERVED lock with process 2. This fails.
................................................................................
# lock2-1.6: Release the SHARED lock held by the second process. 
# lock2-1.7: Attempt to reaquire a SHARED lock with the second process.
#            this fails due to the PENDING lock.
# lock2-1.8: Ensure the first process can now upgrade to EXCLUSIVE.
#
do_test lock2-1.1 {
  set ::tf1 [launch_testfixture]

  testfixture $::tf1 {
    sqlite3 db test.db -key xyzzy
    db eval {select * from sqlite_master}
  }
} {}
do_test lock2-1.1.1 {
  execsql {pragma lock_status}

Added test/lock_common.tcl.







































































































































































































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# 2010 April 14
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file contains code used by several different test scripts. The
# code in this file allows testfixture to control another process (or
# processes) to test locking.
#

# Launch another testfixture process to be controlled by this one. A
# channel name is returned that may be passed as the first argument to proc
# 'testfixture' to execute a command. The child testfixture process is shut
# down by closing the channel.
proc launch_testfixture {} {
  set prg [info nameofexec]
  if {$prg eq ""} {
    set prg [file join . testfixture]
  }
  set chan [open "|$prg tf_main.tcl" r+]
  fconfigure $chan -buffering line
  testfixture $chan "sqlite3_test_control_pending_byte $::sqlite_pending_byte"
  return $chan
}

# Execute a command in a child testfixture process, connected by two-way
# channel $chan. Return the result of the command, or an error message.
proc testfixture {chan cmd} {
  puts $chan $cmd
  puts $chan OVER
  set r ""
  while { 1 } {
    set line [gets $chan]
    if { $line == "OVER" } { 
      return $r
    }
    if {[eof $chan]} {
      return "ERROR: Child process hung up"
    }
    append r $line
  }
}

proc testfixture_nb_cb {varname chan} {
  set line [gets $chan]
  if { $line == "OVER" } {
    set $varname $::tfnb($chan)
    unset ::tfnb($chan)
    close $chan
  } else {
    append ::tfnb($chan) $line
  }
}

proc testfixture_nb {varname cmd} {
  set chan [launch_testfixture]
  set ::tfnb($chan) ""
  fconfigure $chan -blocking 0 -buffering none
  puts $chan $cmd
  puts $chan OVER
  fileevent $chan readable [list testfixture_nb_cb $varname $chan]
  return ""
}

# Write the main loop for the child testfixture processes into file
# tf_main.tcl. The parent (this script) interacts with the child processes
# via a two way pipe. The parent writes a script to the stdin of the child
# process, followed by the word "OVER" on a line of its own. The child
# process evaluates the script and writes the results to stdout, followed
# by an "OVER" of its own.
set f [open tf_main.tcl w]
puts $f {
  set l [open log w]
  set script ""
  while {![eof stdin]} {
    flush stdout
    set line [gets stdin]
    puts $l "READ $line"
    if { $line == "OVER" } {
      set rc [catch {eval $script} result]
      puts $result
      puts $l "WRITE $result"
      puts OVER
      puts $l "WRITE OVER"
      flush stdout
      set script ""
    } else {
      append script $line
      append script "\n"
    }
  }
  close $l
}
close $f

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  } -shutdown {
    unregister_demovfs
  } -include {
    insert.test   insert2.test  insert3.test rollback.test 
    select1.test  select2.test  select3.test
  }
}












# End of tests
#############################################################################

if {$::perm::testmode eq "targets"} { puts "" ; exit }

# Restore the [sqlite3] command.







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  } -shutdown {
    unregister_demovfs
  } -include {
    insert.test   insert2.test  insert3.test rollback.test 
    select1.test  select2.test  select3.test
  }
}

run_tests "wal" -description {
  Run tests with journal_mode=WAL
} -initialize {
  set ::savepoint6_iterations 100
} -shutdown {
  unset -nocomplain ::savepoint6_iterations
} -include {
  savepoint.test     savepoint2.test     savepoint6.test
  trans.test         avtrans.test
}

# End of tests
#############################################################################

if {$::perm::testmode eq "targets"} { puts "" ; exit }

# Restore the [sqlite3] command.

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  incrvacuum_ioerr.test
  autovacuum_crash.test
  btree8.test
  shared_err.test
  vtab_err.test
  veryquick.test
  mallocAll.test




}

if {[sqlite3 -has-codec]} {
  # lappend EXCLUDE \
  #  conflict.test
}








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  incrvacuum_ioerr.test
  autovacuum_crash.test
  btree8.test
  shared_err.test
  vtab_err.test
  veryquick.test
  mallocAll.test

  walslow.test
  walcrash.test
  walthread.test
}

if {[sqlite3 -has-codec]} {
  # lappend EXCLUDE \
  #  conflict.test
}

Changes to test/rdonly.test.

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  execsql {
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(1);
    SELECT * FROM t1;
  }
} {1}

# Changes the write version from 1 to 2.  Verify that the database
# can be read but not written.
#
do_test rdonly-1.2 {
  db close
  hexio_get_int [hexio_read test.db 18 1]
} 1
do_test rdonly-1.3 {
  hexio_write test.db 18 02
  sqlite3 db test.db
  execsql {
    SELECT * FROM t1;
  }
} {1}
do_test rdonly-1.4 {
  catchsql {
................................................................................
} {0 {1 2}}

# Now, after connection [db] has loaded the database schema, modify the
# write-version of the file (and the change-counter, so that the 
# write-version is reloaded). This way, SQLite does not discover that
# the database is read-only until after it is locked.
#


do_test rdonly-1.6 {
  hexio_write test.db 18 02              ; # write-version
  hexio_write test.db 24 11223344        ; # change-counter
  catchsql {
    INSERT INTO t1 VALUES(2);
  }
} {1 {attempt to write a readonly database}}

finish_test







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  execsql {
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(1);
    SELECT * FROM t1;
  }
} {1}

# Changes the write version from 1 to 3.  Verify that the database
# can be read but not written.
#
do_test rdonly-1.2 {
  db close
  hexio_get_int [hexio_read test.db 18 1]
} 1
do_test rdonly-1.3 {
  hexio_write test.db 18 03
  sqlite3 db test.db
  execsql {
    SELECT * FROM t1;
  }
} {1}
do_test rdonly-1.4 {
  catchsql {
................................................................................
} {0 {1 2}}

# Now, after connection [db] has loaded the database schema, modify the
# write-version of the file (and the change-counter, so that the 
# write-version is reloaded). This way, SQLite does not discover that
# the database is read-only until after it is locked.
#
set ro_version 02
ifcapable wal { set ro_version 03 }
do_test rdonly-1.6 {
  hexio_write test.db 18 $ro_version     ; # write-version
  hexio_write test.db 24 11223344        ; # change-counter
  catchsql {
    INSERT INTO t1 VALUES(2);
  }
} {1 {attempt to write a readonly database}}

finish_test

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#***********************************************************************
#
# $Id: savepoint.test,v 1.13 2009/07/18 08:30:45 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl


#----------------------------------------------------------------------
# The following tests - savepoint-1.* - test that the SAVEPOINT, RELEASE
# and ROLLBACK TO comands are correctly parsed, and that the auto-commit
# flag is correctly set and unset as a result.
#
do_test savepoint-1.1 {

  execsql {
    SAVEPOINT sp1;
    RELEASE sp1;
  }
} {}
do_test savepoint-1.2 {
  execsql {
................................................................................
    SAVEPOINT sp1;
    ROLLBACK TO sp1;
  }
} {}
do_test savepoint-1.6 {
  execsql COMMIT
} {}


#------------------------------------------------------------------------
# These tests - savepoint-2.* - test rollbacks and releases of savepoints
# with a very simple data set.
# 

do_test savepoint-2.1 {
................................................................................
} {1 2 3 a b c d e f}
do_test savepoint-2.11 {
  execsql {
    ROLLBACK;
  }
  execsql { SELECT * FROM t1 }
} {}


#------------------------------------------------------------------------
# This block of tests - savepoint-3.* - test that when a transaction
# savepoint is rolled back, locks are not released from database files.
# And that when a transaction savepoint is released, they are released.
# 




do_test savepoint-3.1 {
  execsql { SAVEPOINT "transaction" }
  execsql { PRAGMA lock_status }
} {main unlocked temp closed}

do_test savepoint-3.2 {
  execsql { INSERT INTO t1 VALUES(1, 2, 3) }
  execsql { PRAGMA lock_status }
} {main reserved temp closed}

do_test savepoint-3.3 {
  execsql { ROLLBACK TO "transaction" }
  execsql { PRAGMA lock_status }
} {main reserved temp closed}

do_test savepoint-3.4 {
  execsql { INSERT INTO t1 VALUES(1, 2, 3) }
  execsql { PRAGMA lock_status }
} {main reserved temp closed}

do_test savepoint-3.5 {
  execsql { RELEASE "transaction" }
  execsql { PRAGMA lock_status }
} {main unlocked temp closed}


#------------------------------------------------------------------------
# Test that savepoints that include schema modifications are handled
# correctly. Test cases savepoint-4.*.
# 
do_test savepoint-4.1 {
  execsql {
................................................................................
    INSERT INTO t3 VALUES('value');
  }
  execsql {SELECT * FROM t3}
} {value}
do_test savepoint-4.8 {
  execsql COMMIT
} {}


#------------------------------------------------------------------------
# Test some logic errors to do with the savepoint feature.
# 

ifcapable incrblob {
  do_test savepoint-5.1.1 {
................................................................................
    catchsql {release def}
  } {1 {cannot release savepoint - SQL statements in progress}}
  do_test savepoint-5.3.5 {
    close $fd
    execsql {release abc}
  } {}
  












  do_test savepoint-5.4.1 {
    execsql {
      SAVEPOINT main;
      INSERT INTO blobs VALUES('another blob');
    }
  } {}
  do_test savepoint-5.4.2 {
    sqlite3 db2 test.db
    execsql { BEGIN ; SELECT * FROM blobs } db2






    catchsql { RELEASE main }
  } {1 {database is locked}}
  do_test savepoint-5.4.3 {
    db2 close
    catchsql { RELEASE main }
  } {0 {}}

  do_test savepoint-5.4.4 {
    execsql { SELECT x FROM blobs WHERE rowid = 2 }
  } {{another blob}}



}


#-------------------------------------------------------------------------
# The following tests, savepoint-6.*, test an incr-vacuum inside of a
# couple of nested savepoints.
#
ifcapable {autovacuum && pragma} {
  db close
  file delete -force test.db
  sqlite3 db test.db

  do_test savepoint-6.1 {


    execsql { 
      PRAGMA auto_vacuum = incremental;
      CREATE TABLE t1(a, b, c);
      CREATE INDEX i1 ON t1(a, b);
      BEGIN;
      INSERT INTO t1 VALUES(randstr(10,400),randstr(10,400),randstr(10,400));
    }
    set r "randstr(10,400)"
    for {set ii 0} {$ii < 10} {incr ii} {
................................................................................
            PRAGMA incr_vacuum;
        ROLLBACK TO one;
      COMMIT;
    }
  } {}

  integrity_check savepoint-6.4


}

#-------------------------------------------------------------------------
# The following tests, savepoint-7.*, attempt to break the logic 
# surrounding savepoints by growing and shrinking the database file.
#
db close
file delete -force test.db
sqlite3 db test.db

do_test savepoint-7.1 {


  execsql {
    PRAGMA auto_vacuum = incremental;
    PRAGMA cache_size = 10;
    BEGIN;
    CREATE TABLE t1(a PRIMARY KEY, b);
      INSERT INTO t1(a) VALUES('alligator');
      INSERT INTO t1(a) VALUES('angelfish');
      INSERT INTO t1(a) VALUES('ant');
      INSERT INTO t1(a) VALUES('antelope');
................................................................................
        SAVEPOINT two;
          INSERT INTO t2 SELECT a, b FROM t1;
        ROLLBACK TO two;
    COMMIT;
  }
  execsql { PRAGMA integrity_check }
} {ok}


do_test savepoint-7.4.1 {
  db close
  file delete -force test.db
  sqlite3 db test.db


  execsql {
    PRAGMA auto_vacuum = incremental;
    CREATE TABLE t1(a, b, PRIMARY KEY(a, b));
    INSERT INTO t1 VALUES(randstr(1000,1000), randstr(1000,1000));
    BEGIN;
      DELETE FROM t1;
      SAVEPOINT one;
      PRAGMA incremental_vacuum;
      ROLLBACK TO one;
................................................................................
  }
} {ok}
do_test savepoint-7.5.2 {
  execsql {
    DROP TABLE t5;
  }
} {}


# Test oddly named and quoted savepoints.
#
do_test savepoint-8-1 {
  execsql { SAVEPOINT "save1" }
  execsql { RELEASE save1 }
} {}
................................................................................
# The lock state of the TEMP database can vary if SQLITE_TEMP_STORE=3
# And the following set of tests is only really interested in the status
# of the aux1 and aux2 locks.  So record the current lock status of
# TEMP for use in the answers.
set templockstate [lindex [db eval {PRAGMA lock_status}] 3]



do_test savepoint-10.2.1 {
  file delete -force test3.db
  file delete -force test2.db
  execsql {
    ATTACH 'test2.db' AS aux1;
    ATTACH 'test3.db' AS aux2;
    DROP TABLE t1;
    CREATE TABLE main.t1(x, y);
    CREATE TABLE aux1.t2(x, y);
    CREATE TABLE aux2.t3(x, y);
    SELECT name FROM sqlite_master 
      UNION ALL
    SELECT name FROM aux1.sqlite_master 
      UNION ALL
    SELECT name FROM aux2.sqlite_master;
  }
} {t1 t2 t3}
do_test savepoint-10.2.2 {
  execsql { PRAGMA lock_status }
} [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]

do_test savepoint-10.2.3 {
  execsql {
    SAVEPOINT one;
    INSERT INTO t1 VALUES(1, 2);
    PRAGMA lock_status;
  }
} [list main reserved temp $templockstate aux1 unlocked aux2 unlocked]
do_test savepoint-10.2.4 {
  execsql {
    INSERT INTO t3 VALUES(3, 4);
    PRAGMA lock_status;
  }
} [list main reserved temp $templockstate aux1 unlocked aux2 reserved]
do_test savepoint-10.2.5 {
  execsql {
    SAVEPOINT two;
    INSERT INTO t2 VALUES(5, 6);
    PRAGMA lock_status;
  }
} [list main reserved temp $templockstate aux1 reserved aux2 reserved]
do_test savepoint-10.2.6 {
  execsql { SELECT * FROM t2 }
} {5 6}
do_test savepoint-10.2.7 {
  execsql { ROLLBACK TO two }
  execsql { SELECT * FROM t2 }
} {}
do_test savepoint-10.2.8 {
  execsql { PRAGMA lock_status }
} [list main reserved temp $templockstate aux1 reserved aux2 reserved]
do_test savepoint-10.2.9 {
  execsql { SELECT 'a', * FROM t1 UNION ALL SELECT 'b', * FROM t3 }
} {a 1 2 b 3 4}
do_test savepoint-10.2.9 {
  execsql {
    INSERT INTO t2 VALUES(5, 6);
    RELEASE one;
  }
  execsql { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 5 6 3 4}
do_test savepoint-10.2.9 {
  execsql { PRAGMA lock_status }
} [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]

do_test savepoint-10.2.10 {
  execsql { 
    SAVEPOINT one;
      INSERT INTO t1 VALUES('a', 'b');
      SAVEPOINT two;
        INSERT INTO t2 VALUES('c', 'd');
        SAVEPOINT three;
          INSERT INTO t3 VALUES('e', 'f');
  }
  execsql { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 a b 5 6 c d 3 4 e f}
do_test savepoint-10.2.11 {
  execsql { ROLLBACK TO two }
  execsql { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 a b 5 6 3 4}
do_test savepoint-10.2.12 {
  execsql { 
    INSERT INTO t3 VALUES('g', 'h');
    ROLLBACK TO two;
  }
  execsql { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 a b 5 6 3 4}
do_test savepoint-10.2.13 {
  execsql { ROLLBACK }
  execsql { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 5 6 3 4}
do_test savepoint-10.2.14 {
  execsql { PRAGMA lock_status }
} [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]


#-------------------------------------------------------------------------
# The following tests - savepoint-11.* - test the interaction of 
# savepoints and creating or dropping tables and indexes in 
# auto-vacuum mode.
# 
do_test savepoint-11.1 {
  db close
  file delete -force test.db
  sqlite3 db test.db


  execsql {
    PRAGMA auto_vacuum = full;
    CREATE TABLE t1(a, b, UNIQUE(a, b));
    INSERT INTO t1 VALUES(1, randstr(1000,1000));
    INSERT INTO t1 VALUES(2, randstr(1000,1000));
  }
} {}
do_test savepoint-11.2 {
  execsql {
................................................................................
    CREATE TABLE t3(a, b, UNIQUE(a, b));
    ROLLBACK TO one;
  }
} {}
integrity_check savepoint-11.7
do_test savepoint-11.8 {
  execsql { ROLLBACK }

  file size test.db
} {8192}


do_test savepoint-11.9 {
  execsql {
    DROP TABLE IF EXISTS t1;
    DROP TABLE IF EXISTS t2;
    DROP TABLE IF EXISTS t3;
  }
................................................................................
} {1 2 3 4}
do_test savepoint-11.11 {
  execsql COMMIT
} {}
do_test savepoint-11.12 {
  execsql {SELECT * FROM t2}
} {1 2 3 4}


#-------------------------------------------------------------------------
# The following tests - savepoint-12.* - test the interaction of 
# savepoints and "ON CONFLICT ROLLBACK" clauses.
# 
do_test savepoint-12.1 {
  execsql {
................................................................................
} {1 {column a is not unique}}
do_test savepoint-12.3 {
  sqlite3_get_autocommit db
} {1}
do_test savepoint-12.4 {
  execsql { SAVEPOINT one }
} {}


#-------------------------------------------------------------------------
# The following tests - savepoint-13.* - test the interaction of 
# savepoints and "journal_mode = off".
# 

do_test savepoint-13.1 {
  db close
  catch {file delete -force test.db}
  sqlite3 db test.db
  execsql {
    BEGIN;
      CREATE TABLE t1(a PRIMARY KEY, b);
      INSERT INTO t1 VALUES(1, 2);
    COMMIT;
    PRAGMA journal_mode = off;
  }
} {off}
do_test savepoint-13.2 {
  execsql {
    BEGIN;
    INSERT INTO t1 VALUES(3, 4);
    INSERT INTO t1 SELECT a+4,b+4  FROM t1;
    COMMIT;
  }
} {}
do_test savepoint-13.3 {
  execsql {
    BEGIN;
      INSERT INTO t1 VALUES(9, 10);
      SAVEPOINT s1;
        INSERT INTO t1 VALUES(11, 12);
    COMMIT;
  }
} {}
do_test savepoint-13.4 {
  execsql {
    BEGIN;
      INSERT INTO t1 VALUES(13, 14);
      SAVEPOINT s1;
        INSERT INTO t1 VALUES(15, 16);
      ROLLBACK TO s1;
    ROLLBACK;
    SELECT * FROM t1;
  }
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16}


finish_test







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#***********************************************************************
#
# $Id: savepoint.test,v 1.13 2009/07/18 08:30:45 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl


#----------------------------------------------------------------------
# The following tests - savepoint-1.* - test that the SAVEPOINT, RELEASE
# and ROLLBACK TO comands are correctly parsed, and that the auto-commit
# flag is correctly set and unset as a result.
#
do_test savepoint-1.1 {
  wal_set_journal_mode
  execsql {
    SAVEPOINT sp1;
    RELEASE sp1;
  }
} {}
do_test savepoint-1.2 {
  execsql {
................................................................................
    SAVEPOINT sp1;
    ROLLBACK TO sp1;
  }
} {}
do_test savepoint-1.6 {
  execsql COMMIT
} {}
wal_check_journal_mode savepoint-1.7

#------------------------------------------------------------------------
# These tests - savepoint-2.* - test rollbacks and releases of savepoints
# with a very simple data set.
# 

do_test savepoint-2.1 {
................................................................................
} {1 2 3 a b c d e f}
do_test savepoint-2.11 {
  execsql {
    ROLLBACK;
  }
  execsql { SELECT * FROM t1 }
} {}
wal_check_journal_mode savepoint-2.12

#------------------------------------------------------------------------
# This block of tests - savepoint-3.* - test that when a transaction
# savepoint is rolled back, locks are not released from database files.
# And that when a transaction savepoint is released, they are released.
#
# These tests do not work in WAL mode. WAL mode does not take RESERVED
# locks on the database file.
# 
if {[wal_is_wal_mode]==0} {
  do_test savepoint-3.1 {
    execsql { SAVEPOINT "transaction" }
    execsql { PRAGMA lock_status }
  } {main unlocked temp closed}
  
  do_test savepoint-3.2 {
    execsql { INSERT INTO t1 VALUES(1, 2, 3) }
    execsql { PRAGMA lock_status }
  } {main reserved temp closed}
  
  do_test savepoint-3.3 {
    execsql { ROLLBACK TO "transaction" }
    execsql { PRAGMA lock_status }
  } {main reserved temp closed}
  
  do_test savepoint-3.4 {
    execsql { INSERT INTO t1 VALUES(1, 2, 3) }
    execsql { PRAGMA lock_status }
  } {main reserved temp closed}
  
  do_test savepoint-3.5 {
    execsql { RELEASE "transaction" }
    execsql { PRAGMA lock_status }
  } {main unlocked temp closed}
}

#------------------------------------------------------------------------
# Test that savepoints that include schema modifications are handled
# correctly. Test cases savepoint-4.*.
# 
do_test savepoint-4.1 {
  execsql {
................................................................................
    INSERT INTO t3 VALUES('value');
  }
  execsql {SELECT * FROM t3}
} {value}
do_test savepoint-4.8 {
  execsql COMMIT
} {}
wal_check_journal_mode savepoint-4.9

#------------------------------------------------------------------------
# Test some logic errors to do with the savepoint feature.
# 

ifcapable incrblob {
  do_test savepoint-5.1.1 {
................................................................................
    catchsql {release def}
  } {1 {cannot release savepoint - SQL statements in progress}}
  do_test savepoint-5.3.5 {
    close $fd
    execsql {release abc}
  } {}
  
  # Rollback mode:
  #
  #   Open a savepoint transaction and insert a row into the database. Then,
  #   using a second database handle, open a read-only transaction on the
  #   database file. Check that the savepoint transaction cannot be committed
  #   until after the read-only transaction has been closed.
  #
  # WAL mode:
  # 
  #   As above, except that the savepoint transaction can be successfully
  #   committed before the read-only transaction has been closed.
  #
  do_test savepoint-5.4.1 {
    execsql {
      SAVEPOINT main;
      INSERT INTO blobs VALUES('another blob');
    }
  } {}
  do_test savepoint-5.4.2 {
    sqlite3 db2 test.db
    execsql { BEGIN ; SELECT count(*) FROM blobs } db2
  } {1}
  if {[wal_is_wal_mode]} {
    do_test savepoint-5.4.3 { catchsql "RELEASE main" } {0 {}}
    do_test savepoint-5.4.4 { db2 close               } {}
  } else {
    do_test savepoint-5.4.3 {
      catchsql { RELEASE main }
    } {1 {database is locked}}
    do_test savepoint-5.4.4 {
      db2 close
      catchsql { RELEASE main }
    } {0 {}}
  }
  do_test savepoint-5.4.5 {
    execsql { SELECT x FROM blobs WHERE rowid = 2 }
  } {{another blob}}
  do_test savepoint-5.4.6 {
    execsql { SELECT count(*) FROM blobs }
  } {2}
}
wal_check_journal_mode savepoint-5.5

#-------------------------------------------------------------------------
# The following tests, savepoint-6.*, test an incr-vacuum inside of a
# couple of nested savepoints.
#
ifcapable {autovacuum && pragma} {
  db close
  file delete -force test.db
  sqlite3 db test.db

  do_test savepoint-6.1 {
    execsql { PRAGMA auto_vacuum = incremental }
    wal_set_journal_mode
    execsql {

      CREATE TABLE t1(a, b, c);
      CREATE INDEX i1 ON t1(a, b);
      BEGIN;
      INSERT INTO t1 VALUES(randstr(10,400),randstr(10,400),randstr(10,400));
    }
    set r "randstr(10,400)"
    for {set ii 0} {$ii < 10} {incr ii} {
................................................................................
            PRAGMA incr_vacuum;
        ROLLBACK TO one;
      COMMIT;
    }
  } {}

  integrity_check savepoint-6.4

  wal_check_journal_mode savepoint-6.5
}

#-------------------------------------------------------------------------
# The following tests, savepoint-7.*, attempt to break the logic 
# surrounding savepoints by growing and shrinking the database file.
#
db close
file delete -force test.db
sqlite3 db test.db

do_test savepoint-7.1 {
  execsql { PRAGMA auto_vacuum = incremental }
  wal_set_journal_mode
  execsql {

    PRAGMA cache_size = 10;
    BEGIN;
    CREATE TABLE t1(a PRIMARY KEY, b);
      INSERT INTO t1(a) VALUES('alligator');
      INSERT INTO t1(a) VALUES('angelfish');
      INSERT INTO t1(a) VALUES('ant');
      INSERT INTO t1(a) VALUES('antelope');
................................................................................
        SAVEPOINT two;
          INSERT INTO t2 SELECT a, b FROM t1;
        ROLLBACK TO two;
    COMMIT;
  }
  execsql { PRAGMA integrity_check }
} {ok}
wal_check_journal_mode savepoint-7.3.3

do_test savepoint-7.4.1 {
  db close
  file delete -force test.db
  sqlite3 db test.db
  execsql { PRAGMA auto_vacuum = incremental }
  wal_set_journal_mode
  execsql {

    CREATE TABLE t1(a, b, PRIMARY KEY(a, b));
    INSERT INTO t1 VALUES(randstr(1000,1000), randstr(1000,1000));
    BEGIN;
      DELETE FROM t1;
      SAVEPOINT one;
      PRAGMA incremental_vacuum;
      ROLLBACK TO one;
................................................................................
  }
} {ok}
do_test savepoint-7.5.2 {
  execsql {
    DROP TABLE t5;
  }
} {}
wal_check_journal_mode savepoint-7.5.3

# Test oddly named and quoted savepoints.
#
do_test savepoint-8-1 {
  execsql { SAVEPOINT "save1" }
  execsql { RELEASE save1 }
} {}
................................................................................
# The lock state of the TEMP database can vary if SQLITE_TEMP_STORE=3
# And the following set of tests is only really interested in the status
# of the aux1 and aux2 locks.  So record the current lock status of
# TEMP for use in the answers.
set templockstate [lindex [db eval {PRAGMA lock_status}] 3]


if {[wal_is_wal_mode]==0} {
  do_test savepoint-10.2.1 {
    file delete -force test3.db
    file delete -force test2.db
    execsql {
      ATTACH 'test2.db' AS aux1;
      ATTACH 'test3.db' AS aux2;
      DROP TABLE t1;
      CREATE TABLE main.t1(x, y);
      CREATE TABLE aux1.t2(x, y);
      CREATE TABLE aux2.t3(x, y);
      SELECT name FROM sqlite_master 
        UNION ALL
      SELECT name FROM aux1.sqlite_master 
        UNION ALL
      SELECT name FROM aux2.sqlite_master;
    }
  } {t1 t2 t3}
  do_test savepoint-10.2.2 {
    execsql { PRAGMA lock_status }
  } [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]
  
  do_test savepoint-10.2.3 {
    execsql {
      SAVEPOINT one;
      INSERT INTO t1 VALUES(1, 2);
      PRAGMA lock_status;
    }
  } [list main reserved temp $templockstate aux1 unlocked aux2 unlocked]
  do_test savepoint-10.2.4 {
    execsql {
      INSERT INTO t3 VALUES(3, 4);
      PRAGMA lock_status;
    }
  } [list main reserved temp $templockstate aux1 unlocked aux2 reserved]
  do_test savepoint-10.2.5 {
    execsql {
      SAVEPOINT two;
      INSERT INTO t2 VALUES(5, 6);
      PRAGMA lock_status;
    }
  } [list main reserved temp $templockstate aux1 reserved aux2 reserved]
  do_test savepoint-10.2.6 {
    execsql { SELECT * FROM t2 }
  } {5 6}
  do_test savepoint-10.2.7 {
    execsql { ROLLBACK TO two }
    execsql { SELECT * FROM t2 }
  } {}
  do_test savepoint-10.2.8 {
    execsql { PRAGMA lock_status }
  } [list main reserved temp $templockstate aux1 reserved aux2 reserved]
  do_test savepoint-10.2.9 {
    execsql { SELECT 'a', * FROM t1 UNION ALL SELECT 'b', * FROM t3 }
  } {a 1 2 b 3 4}
  do_test savepoint-10.2.9 {
    execsql {
      INSERT INTO t2 VALUES(5, 6);
      RELEASE one;
    }
    execsql { 
      SELECT * FROM t1;
      SELECT * FROM t2;
      SELECT * FROM t3;
    }
  } {1 2 5 6 3 4}
  do_test savepoint-10.2.9 {
    execsql { PRAGMA lock_status }
  } [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]
  
  do_test savepoint-10.2.10 {
    execsql { 
      SAVEPOINT one;
        INSERT INTO t1 VALUES('a', 'b');
        SAVEPOINT two;
          INSERT INTO t2 VALUES('c', 'd');
          SAVEPOINT three;
            INSERT INTO t3 VALUES('e', 'f');
    }
    execsql { 
      SELECT * FROM t1;
      SELECT * FROM t2;
      SELECT * FROM t3;
    }
  } {1 2 a b 5 6 c d 3 4 e f}
  do_test savepoint-10.2.11 {
    execsql { ROLLBACK TO two }
    execsql { 
      SELECT * FROM t1;
      SELECT * FROM t2;
      SELECT * FROM t3;
    }
  } {1 2 a b 5 6 3 4}
  do_test savepoint-10.2.12 {
    execsql { 
      INSERT INTO t3 VALUES('g', 'h');
      ROLLBACK TO two;
    }
    execsql { 
      SELECT * FROM t1;
      SELECT * FROM t2;
      SELECT * FROM t3;
    }
  } {1 2 a b 5 6 3 4}
  do_test savepoint-10.2.13 {
    execsql { ROLLBACK }
    execsql { 
      SELECT * FROM t1;
      SELECT * FROM t2;
      SELECT * FROM t3;
    }
  } {1 2 5 6 3 4}
  do_test savepoint-10.2.14 {
    execsql { PRAGMA lock_status }
  } [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]
}

#-------------------------------------------------------------------------
# The following tests - savepoint-11.* - test the interaction of 
# savepoints and creating or dropping tables and indexes in 
# auto-vacuum mode.
# 
do_test savepoint-11.1 {
  db close
  file delete -force test.db
  sqlite3 db test.db
  execsql { PRAGMA auto_vacuum = full; }
  wal_set_journal_mode
  execsql {

    CREATE TABLE t1(a, b, UNIQUE(a, b));
    INSERT INTO t1 VALUES(1, randstr(1000,1000));
    INSERT INTO t1 VALUES(2, randstr(1000,1000));
  }
} {}
do_test savepoint-11.2 {
  execsql {
................................................................................
    CREATE TABLE t3(a, b, UNIQUE(a, b));
    ROLLBACK TO one;
  }
} {}
integrity_check savepoint-11.7
do_test savepoint-11.8 {
  execsql { ROLLBACK }
  execsql { PRAGMA wal_checkpoint }
  file size test.db
} {8192}


do_test savepoint-11.9 {
  execsql {
    DROP TABLE IF EXISTS t1;
    DROP TABLE IF EXISTS t2;
    DROP TABLE IF EXISTS t3;
  }
................................................................................
} {1 2 3 4}
do_test savepoint-11.11 {
  execsql COMMIT
} {}
do_test savepoint-11.12 {
  execsql {SELECT * FROM t2}
} {1 2 3 4}
wal_check_journal_mode savepoint-11.13

#-------------------------------------------------------------------------
# The following tests - savepoint-12.* - test the interaction of 
# savepoints and "ON CONFLICT ROLLBACK" clauses.
# 
do_test savepoint-12.1 {
  execsql {
................................................................................
} {1 {column a is not unique}}
do_test savepoint-12.3 {
  sqlite3_get_autocommit db
} {1}
do_test savepoint-12.4 {
  execsql { SAVEPOINT one }
} {}
wal_check_journal_mode savepoint-12.5

#-------------------------------------------------------------------------
# The following tests - savepoint-13.* - test the interaction of 
# savepoints and "journal_mode = off".
# 
if {[wal_is_wal_mode]==0} {
  do_test savepoint-13.1 {
    db close
    catch {file delete -force test.db}
    sqlite3 db test.db
    execsql {
      BEGIN;
        CREATE TABLE t1(a PRIMARY KEY, b);
        INSERT INTO t1 VALUES(1, 2);
      COMMIT;
      PRAGMA journal_mode = off;
    }
  } {off}
  do_test savepoint-13.2 {
    execsql {
      BEGIN;
      INSERT INTO t1 VALUES(3, 4);
      INSERT INTO t1 SELECT a+4,b+4  FROM t1;
      COMMIT;
    }
  } {}
  do_test savepoint-13.3 {
    execsql {
      BEGIN;
        INSERT INTO t1 VALUES(9, 10);
        SAVEPOINT s1;
          INSERT INTO t1 VALUES(11, 12);
      COMMIT;
    }
  } {}
  do_test savepoint-13.4 {
    execsql {
      BEGIN;
        INSERT INTO t1 VALUES(13, 14);
        SAVEPOINT s1;
          INSERT INTO t1 VALUES(15, 16);
        ROLLBACK TO s1;
      ROLLBACK;
      SELECT * FROM t1;
    }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16}
}

finish_test

Changes to test/savepoint2.test.

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#
#***********************************************************************
#
# $Id: savepoint2.test,v 1.5 2009/06/05 17:09:12 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl


# Tests in this file are quite similar to those run by trans.test and
# avtrans.test.
#

proc signature {} {
  return [db eval {SELECT count(*), md5sum(x) FROM t3}]
}

do_test savepoint2-1 {

  execsql {
    PRAGMA cache_size=10;
    BEGIN;
    CREATE TABLE t3(x TEXT);
    INSERT INTO t3 VALUES(randstr(10,400));
    INSERT INTO t3 VALUES(randstr(10,400));
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
................................................................................
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    COMMIT;
    SELECT count(*) FROM t3;
  }
} {1024}


unset -nocomplain ::sig
unset -nocomplain SQL

set iterations 20

set SQL(1) {
................................................................................
  #
  do_test savepoint2-$ii.6 {
    execsql $SQL(4)
    execsql COMMIT
    sqlite3_get_autocommit db
  } {1}
  integrity_check savepoint2-$ii.6.1



}

unset -nocomplain ::sig
unset -nocomplain SQL

finish_test







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#
#***********************************************************************
#
# $Id: savepoint2.test,v 1.5 2009/06/05 17:09:12 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl


# Tests in this file are quite similar to those run by trans.test and
# avtrans.test.
#

proc signature {} {
  return [db eval {SELECT count(*), md5sum(x) FROM t3}]
}

do_test savepoint2-1 {
  wal_set_journal_mode
  execsql {
    PRAGMA cache_size=10;
    BEGIN;
    CREATE TABLE t3(x TEXT);
    INSERT INTO t3 VALUES(randstr(10,400));
    INSERT INTO t3 VALUES(randstr(10,400));
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
................................................................................
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    COMMIT;
    SELECT count(*) FROM t3;
  }
} {1024}
wal_check_journal_mode savepoint2-1.1

unset -nocomplain ::sig
unset -nocomplain SQL

set iterations 20

set SQL(1) {
................................................................................
  #
  do_test savepoint2-$ii.6 {
    execsql $SQL(4)
    execsql COMMIT
    sqlite3_get_autocommit db
  } {1}
  integrity_check savepoint2-$ii.6.1

  # Check that the connection is still running in WAL mode.
  wal_check_journal_mode savepoint2-$ii.7
}

unset -nocomplain ::sig
unset -nocomplain SQL

finish_test

Changes to test/savepoint6.test.

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set DATABASE_SCHEMA {
    PRAGMA auto_vacuum = incremental;
    CREATE TABLE t1(x, y);
    CREATE UNIQUE INDEX i1 ON t1(x);
    CREATE INDEX i2 ON t1(y);
}





#--------------------------------------------------------------------------
# In memory database state.
#
# ::lSavepoint is a list containing one entry for each active savepoint. The
# first entry in the list corresponds to the most recently opened savepoint.
# Each entry consists of two elements:
................................................................................
  execsql {SELECT count(*) FROM t1}
} {44}

foreach zSetup [list {
  set testname normal
  sqlite3 db test.db
} {

  set testname tempdb
  sqlite3 db ""
} {
  if {[catch {set ::permutations_test_prefix} z] == 0 && $z eq "journaltest"} {
    continue
  }
  set testname nosync
................................................................................
  sql { PRAGMA cache_size = 10 }
}] {

  unset -nocomplain ::lSavepoint
  unset -nocomplain ::aEntry

  catch { db close }
  file delete -force test.db
  eval $zSetup
  sql $DATABASE_SCHEMA



  do_test savepoint6-$testname.setup {
    savepoint one
    insert_rows [random_integers 100 1000]
    release one
    checkdb
  } {ok}
  
  for {set i 0} {$i < 1000} {incr i} {
    do_test savepoint6-$testname.$i.1 {
      savepoint_op
      checkdb
    } {ok}
  
    do_test savepoint6-$testname.$i.2 {
      database_op
      database_op
      checkdb
    } {ok}
  }


}

unset -nocomplain ::lSavepoint
unset -nocomplain ::aEntry

finish_test







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set DATABASE_SCHEMA {
    PRAGMA auto_vacuum = incremental;
    CREATE TABLE t1(x, y);
    CREATE UNIQUE INDEX i1 ON t1(x);
    CREATE INDEX i2 ON t1(y);
}

if {0==[info exists ::savepoint6_iterations]} {
  set ::savepoint6_iterations 1000
}

#--------------------------------------------------------------------------
# In memory database state.
#
# ::lSavepoint is a list containing one entry for each active savepoint. The
# first entry in the list corresponds to the most recently opened savepoint.
# Each entry consists of two elements:
................................................................................
  execsql {SELECT count(*) FROM t1}
} {44}

foreach zSetup [list {
  set testname normal
  sqlite3 db test.db
} {
  if {[wal_is_wal_mode]} continue
  set testname tempdb
  sqlite3 db ""
} {
  if {[catch {set ::permutations_test_prefix} z] == 0 && $z eq "journaltest"} {
    continue
  }
  set testname nosync
................................................................................
  sql { PRAGMA cache_size = 10 }
}] {

  unset -nocomplain ::lSavepoint
  unset -nocomplain ::aEntry

  catch { db close }
  file delete -force test.db test.db-wal test.db-journal
  eval $zSetup
  sql $DATABASE_SCHEMA

  wal_set_journal_mode

  do_test savepoint6-$testname.setup {
    savepoint one
    insert_rows [random_integers 100 1000]
    release one
    checkdb
  } {ok}
  
  for {set i 0} {$i < $::savepoint6_iterations} {incr i} {
    do_test savepoint6-$testname.$i.1 {
      savepoint_op
      checkdb
    } {ok}
  
    do_test savepoint6-$testname.$i.2 {
      database_op
      database_op
      checkdb
    } {ok}
  }

  wal_check_journal_mode savepoint6-$testname.walok
}

unset -nocomplain ::lSavepoint
unset -nocomplain ::aEntry

finish_test

Changes to test/tclsqlite.test.

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  set v [catch {sqlite3 bogus} msg]
  regsub {really_sqlite3} $msg {sqlite3} msg
  lappend v $msg
} [list 1 "wrong # args: should be \"$r\""]
do_test tcl-1.2 {
  set v [catch {db bogus} msg]
  lappend v $msg
} {1 {bad option "bogus": must be authorizer, backup, busy, cache, changes, close, collate, collation_needed, commit_hook, complete, copy, enable_load_extension, errorcode, eval, exists, function, incrblob, interrupt, last_insert_rowid, nullvalue, onecolumn, profile, progress, rekey, restore, rollback_hook, status, timeout, total_changes, trace, transaction, unlock_notify, update_hook, or version}}
do_test tcl-1.2.1 {
  set v [catch {db cache bogus} msg]
  lappend v $msg
} {1 {bad option "bogus": must be flush or size}}
do_test tcl-1.2.2 {
  set v [catch {db cache} msg]
  lappend v $msg







|







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  set v [catch {sqlite3 bogus} msg]
  regsub {really_sqlite3} $msg {sqlite3} msg
  lappend v $msg
} [list 1 "wrong # args: should be \"$r\""]
do_test tcl-1.2 {
  set v [catch {db bogus} msg]
  lappend v $msg
} {1 {bad option "bogus": must be authorizer, backup, busy, cache, changes, close, collate, collation_needed, commit_hook, complete, copy, enable_load_extension, errorcode, eval, exists, function, incrblob, interrupt, last_insert_rowid, nullvalue, onecolumn, profile, progress, rekey, restore, rollback_hook, status, timeout, total_changes, trace, transaction, unlock_notify, update_hook, version, or wal_hook}}
do_test tcl-1.2.1 {
  set v [catch {db cache bogus} msg]
  lappend v $msg
} {1 {bad option "bogus": must be flush or size}}
do_test tcl-1.2.2 {
  set v [catch {db cache} msg]
  lappend v $msg

Changes to test/tester.tcl.

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  }
}

proc reset_db {} {
  catch {db close}
  file delete -force test.db
  file delete -force test.db-journal

  sqlite3 db ./test.db
  set ::DB [sqlite3_connection_pointer db]
  if {[info exists ::SETUP_SQL]} {
    db eval $::SETUP_SQL
  }
}
reset_db
................................................................................
      $db eval "DROP $type $t"
    }
  }
  ifcapable trigger&&foreignkey {
    $db eval "PRAGMA foreign_keys = $pk"
  }
}






































# If the library is compiled with the SQLITE_DEFAULT_AUTOVACUUM macro set
# to non-zero, then set the global variable $AUTOVACUUM to 1.
set AUTOVACUUM $sqlite_options(default_autovacuum)

source $testdir/thread_common.tcl







>







 







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  }
}

proc reset_db {} {
  catch {db close}
  file delete -force test.db
  file delete -force test.db-journal
  file delete -force test.db-wal
  sqlite3 db ./test.db
  set ::DB [sqlite3_connection_pointer db]
  if {[info exists ::SETUP_SQL]} {
    db eval $::SETUP_SQL
  }
}
reset_db
................................................................................
      $db eval "DROP $type $t"
    }
  }
  ifcapable trigger&&foreignkey {
    $db eval "PRAGMA foreign_keys = $pk"
  }
}

#-------------------------------------------------------------------------
# If a test script is executed with global variable 
# $::permutations_test_prefix set to "wal", then the tests are run
# in WAL mode. Otherwise, they should be run in rollback mode. The 
# following Tcl procs are used to make this less intrusive:
#
#   wal_set_journal_mode ?DB?
#
#     If running a WAL test, execute "PRAGMA journal_mode = wal" using
#     connection handle DB. Otherwise, this command is a no-op.
#
#   wal_check_journal_mode TESTNAME ?DB?
#
#     If running a WAL test, execute a tests case that fails if the main
#     database for connection handle DB is not currently a WAL database.
#     Otherwise (if not running a WAL permutation) this is a no-op.
#
#   wal_is_wal_mode
#   
#     Returns true if this test should be run in WAL mode. False otherwise.
# 
proc wal_is_wal_mode {} {
  expr { [catch {set ::permutations_test_prefix} v]==0 && $v == "wal" }
}
proc wal_set_journal_mode {{db db}} {
  if { [wal_is_wal_mode] } {
    $db eval "PRAGMA journal_mode = WAL"
  }
}
proc wal_check_journal_mode {testname {db db}} {
  if { [wal_is_wal_mode] } {
    $db eval { SELECT * FROM sqlite_master }
    do_test $testname [list $db eval "PRAGMA main.journal_mode"] {wal}
  }
}


# If the library is compiled with the SQLITE_DEFAULT_AUTOVACUUM macro set
# to non-zero, then set the global variable $AUTOVACUUM to 1.
set AUTOVACUUM $sqlite_options(default_autovacuum)

source $testdir/thread_common.tcl

Changes to test/thread_common.tcl.

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    if {$res ne $result} {
      error "$name failed: expected \"$result\" got \"$res\""
    }
  }
}

proc thread_spawn {varname args} {
  sqlthread spawn $varname [join $args ;]
}

# Return true if this build can run the multi-threaded tests.
#
proc run_thread_tests {{print_warning 0}} {
  ifcapable !mutex { 
    set zProblem "SQLite build is not threadsafe"







|







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    if {$res ne $result} {
      error "$name failed: expected \"$result\" got \"$res\""
    }
  }
}

proc thread_spawn {varname args} {
  sqlthread spawn $varname [join $args {;}]
}

# Return true if this build can run the multi-threaded tests.
#
proc run_thread_tests {{print_warning 0}} {
  ifcapable !mutex { 
    set zProblem "SQLite build is not threadsafe"

Changes to test/trans.test.

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set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Create several tables to work with.
#

do_test trans-1.0 {
  execsql {
    CREATE TABLE one(a int PRIMARY KEY, b text);
    INSERT INTO one VALUES(1,'one');
    INSERT INTO one VALUES(2,'two');
    INSERT INTO one VALUES(3,'three');
    SELECT b FROM one ORDER BY a;
................................................................................
  sqlite3 altdb test.db
  execsql {SELECT b FROM one ORDER BY a} altdb
} {one two three}
do_test trans-1.10 {
  execsql {SELECT b FROM two ORDER BY a} altdb
} {I V X}
integrity_check trans-1.11


# Basic transactions
#
do_test trans-2.1 {
  set v [catch {execsql {BEGIN}} msg]
  lappend v $msg
} {0 {}}
................................................................................
    BEGIN;
    SELECT a FROM one ORDER BY a;
    SELECT a FROM two ORDER BY a;
    END;
  }
} {1 2 3 1 5 10}
integrity_check trans-2.11


# Check the locking behavior
#
do_test trans-3.1 {
  execsql {
    BEGIN;
    UPDATE one SET a = 0 WHERE 0;
................................................................................
do_test trans-3.14 {
  set v [catch {execsql {
    SELECT a FROM one ORDER BY a;
  } db} msg]
  lappend v $msg
} {0 {1 2 3 4}}
integrity_check trans-3.15


do_test trans-4.1 {
  set v [catch {execsql {
    COMMIT;
  } db} msg]
  lappend v $msg
} {1 {cannot commit - no transaction is active}}
................................................................................
do_test trans-4.11 {
  set v [catch {execsql {
    SELECT a FROM one ORDER BY a;
  } altdb} msg]
  lappend v $msg
} {0 {1 2 3 4}}
integrity_check trans-4.12


do_test trans-4.98 {
  altdb close
  execsql {
    DROP TABLE one;
    DROP TABLE two;
  }
} {}
................................................................................
    }
  } $checksum
}
do_test trans-7.14 {
  execsql {SELECT md5sum(type,name,tbl_name,rootpage,sql) FROM sqlite_master}
} $checksum2
integrity_check trans-7.15


# Arrange for another process to begin modifying the database but abort
# and die in the middle of the modification.  Then have this process read
# the database.  This process should detect the journal file and roll it
# back.  Verify that this happens correctly.
#
set fd [open test.tcl w]
................................................................................
  catch {exec [info nameofexec] test.tcl}
  execsql {SELECT md5sum(x,y,z) FROM t2}
} $checksum
do_test trans-8.5 {
  execsql {SELECT md5sum(type,name,tbl_name,rootpage,sql) FROM sqlite_master}
} $checksum2
integrity_check trans-8.6


# In the following sequence of tests, compute the MD5 sum of the content
# of a table, make lots of modifications to that table, then do a rollback.
# Verify that after the rollback, the MD5 checksum is unchanged.
#
do_test trans-9.1 {
  execsql {
................................................................................
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    COMMIT;
    SELECT count(*) FROM t3;
  }
} {1024}


# The following procedure computes a "signature" for table "t3".  If
# T3 changes in any way, the signature should change.  
#
# This is used to test ROLLBACK.  We gather a signature for t3, then
# make lots of changes to t3, then rollback and take another signature.
# The two signatures should be the same.
................................................................................
      } else {
        do_test trans-9.$i.5-$cnt {
          expr {$sqlite_fullsync_count==0}
        } {1}
      }
    }
  }


  set ::pager_old_format 0
}
   
finish_test







>







 







>







 







>







 







>







 







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>







 







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set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Create several tables to work with.
#
wal_set_journal_mode
do_test trans-1.0 {
  execsql {
    CREATE TABLE one(a int PRIMARY KEY, b text);
    INSERT INTO one VALUES(1,'one');
    INSERT INTO one VALUES(2,'two');
    INSERT INTO one VALUES(3,'three');
    SELECT b FROM one ORDER BY a;
................................................................................
  sqlite3 altdb test.db
  execsql {SELECT b FROM one ORDER BY a} altdb
} {one two three}
do_test trans-1.10 {
  execsql {SELECT b FROM two ORDER BY a} altdb
} {I V X}
integrity_check trans-1.11
wal_check_journal_mode trans-1.12

# Basic transactions
#
do_test trans-2.1 {
  set v [catch {execsql {BEGIN}} msg]
  lappend v $msg
} {0 {}}
................................................................................
    BEGIN;
    SELECT a FROM one ORDER BY a;
    SELECT a FROM two ORDER BY a;
    END;
  }
} {1 2 3 1 5 10}
integrity_check trans-2.11
wal_check_journal_mode trans-2.12

# Check the locking behavior
#
do_test trans-3.1 {
  execsql {
    BEGIN;
    UPDATE one SET a = 0 WHERE 0;
................................................................................
do_test trans-3.14 {
  set v [catch {execsql {
    SELECT a FROM one ORDER BY a;
  } db} msg]
  lappend v $msg
} {0 {1 2 3 4}}
integrity_check trans-3.15
wal_check_journal_mode trans-3.16

do_test trans-4.1 {
  set v [catch {execsql {
    COMMIT;
  } db} msg]
  lappend v $msg
} {1 {cannot commit - no transaction is active}}
................................................................................
do_test trans-4.11 {
  set v [catch {execsql {
    SELECT a FROM one ORDER BY a;
  } altdb} msg]
  lappend v $msg
} {0 {1 2 3 4}}
integrity_check trans-4.12
wal_check_journal_mode trans-4.13
wal_check_journal_mode trans-4.14 altdb
do_test trans-4.98 {
  altdb close
  execsql {
    DROP TABLE one;
    DROP TABLE two;
  }
} {}
................................................................................
    }
  } $checksum
}
do_test trans-7.14 {
  execsql {SELECT md5sum(type,name,tbl_name,rootpage,sql) FROM sqlite_master}
} $checksum2
integrity_check trans-7.15
wal_check_journal_mode trans-7.16

# Arrange for another process to begin modifying the database but abort
# and die in the middle of the modification.  Then have this process read
# the database.  This process should detect the journal file and roll it
# back.  Verify that this happens correctly.
#
set fd [open test.tcl w]
................................................................................
  catch {exec [info nameofexec] test.tcl}
  execsql {SELECT md5sum(x,y,z) FROM t2}
} $checksum
do_test trans-8.5 {
  execsql {SELECT md5sum(type,name,tbl_name,rootpage,sql) FROM sqlite_master}
} $checksum2
integrity_check trans-8.6
wal_check_journal_mode trans-8.7

# In the following sequence of tests, compute the MD5 sum of the content
# of a table, make lots of modifications to that table, then do a rollback.
# Verify that after the rollback, the MD5 checksum is unchanged.
#
do_test trans-9.1 {
  execsql {
................................................................................
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    COMMIT;
    SELECT count(*) FROM t3;
  }
} {1024}
wal_check_journal_mode trans-9.1.1

# The following procedure computes a "signature" for table "t3".  If
# T3 changes in any way, the signature should change.  
#
# This is used to test ROLLBACK.  We gather a signature for t3, then
# make lots of changes to t3, then rollback and take another signature.
# The two signatures should be the same.
................................................................................
      } else {
        do_test trans-9.$i.5-$cnt {
          expr {$sqlite_fullsync_count==0}
        } {1}
      }
    }
  }

  wal_check_journal_mode trans-9.$i.6-$cnt
  set ::pager_old_format 0
}
   
finish_test

Added test/wal.test.



























































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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# 2010 April 13
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl

ifcapable !wal {finish_test ; return }

proc reopen_db {} {
  catch { db close }
  file delete -force test.db test.db-wal test.db-wal-summary
  sqlite3_wal db test.db
}

set ::blobcnt 0
proc blob {nByte} {
  incr ::blobcnt
  return [string range [string repeat "${::blobcnt}x" $nByte] 1 $nByte]
}

proc sqlite3_wal {args} {
  eval sqlite3 $args
  [lindex $args 0] eval { PRAGMA page_size = 1024 }
  [lindex $args 0] eval { PRAGMA journal_mode = wal }
  [lindex $args 0] eval { PRAGMA synchronous = normal }
  [lindex $args 0] function blob blob
}

proc log_file_size {nFrame pgsz} {
  expr {12 + ($pgsz+16)*$nFrame}
}

proc log_deleted {logfile} {
  return [expr [file exists $logfile]==0]
}

#
# These are 'warm-body' tests used while developing the WAL code. They
# serve to prove that a few really simple cases work:
#
# wal-1.*: Read and write the database.
# wal-2.*: Test MVCC with one reader, one writer.
# wal-3.*: Test transaction rollback.
# wal-4.*: Test savepoint/statement rollback.
# wal-5.*: Test the temp database.
# wal-6.*: Test creating databases with different page sizes.
#

do_test wal-0.1 {
  execsql { PRAGMA synchronous = normal }
  execsql { PRAGMA journal_mode = wal }
} {wal}
do_test wal-0.2 {
  file size test.db
} {1024}

do_test wal-1.0 {
  execsql { 
    BEGIN;
    CREATE TABLE t1(a, b); 
  }
  list [file exists test.db-journal] \
       [file exists test.db-wal]     \
       [file size test.db]
} {0 1 1024}
do_test wal-1.1 {
  execsql COMMIT
  list [file exists test.db-journal] [file exists test.db-wal]
} {0 1}
do_test wal-1.2 {
  # There are now two pages in the log.
  file size test.db-wal
} [log_file_size 2 1024]

do_test wal-1.3 {
  execsql { SELECT * FROM sqlite_master }
} {table t1 t1 2 {CREATE TABLE t1(a, b)}}

do_test wal-1.4 {
  execsql { INSERT INTO t1 VALUES(1, 2) }
  execsql { INSERT INTO t1 VALUES(3, 4) }
  execsql { INSERT INTO t1 VALUES(5, 6) }
  execsql { INSERT INTO t1 VALUES(7, 8) }
  execsql { INSERT INTO t1 VALUES(9, 10) }
} {}

do_test wal-1.5 {
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.1 {
  sqlite3_wal db2 ./test.db
  execsql { BEGIN; SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.2 {
  execsql { INSERT INTO t1 VALUES(11, 12) }
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10 11 12}

do_test wal-2.3 {
  execsql { SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.4 {
  execsql { INSERT INTO t1 VALUES(13, 14) }
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}

do_test wal-2.5 {
  execsql { SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.6 {
  execsql { COMMIT; SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}

do_test wal-3.1 {
  execsql { BEGIN; DELETE FROM t1 }
  execsql { SELECT * FROM t1 }
} {}
do_test wal-3.2 {
  execsql { SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
do_test wal-3.3 {
  execsql { ROLLBACK }
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
db2 close

#-------------------------------------------------------------------------
# The following tests, wal-4.*, test that savepoints work with WAL 
# databases.
#
do_test wal-4.1 {
  execsql {
    DELETE FROM t1;
    BEGIN;
      INSERT INTO t1 VALUES('a', 'b');
      SAVEPOINT sp;
        INSERT INTO t1 VALUES('c', 'd');
        SELECT * FROM t1;
  }
} {a b c d}
do_test wal-4.2 {
  execsql {
      ROLLBACK TO sp;
      SELECT * FROM t1;
  }
} {a b}
do_test wal-4.3 {
  execsql {
    COMMIT;
    SELECT * FROM t1;
  }
} {a b}

do_test wal-4.4.1 {
  db close
  sqlite3 db test.db
  db func blob blob
  list [execsql { SELECT * FROM t1 }] [file size test.db-wal]
} {{a b} 0}
do_test wal-4.4.2 {
  execsql { PRAGMA cache_size = 10 }
  execsql {
    CREATE TABLE t2(a, b);
    INSERT INTO t2 VALUES(blob(400), blob(400));
    SAVEPOINT tr;
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  2 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  4 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  8 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 16 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 32 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  2 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  4 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  8 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 16 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 32 */
      SELECT count(*) FROM t2;
  }
} {32}
do_test wal-4.4.3 {
  execsql { ROLLBACK TO tr }
} {}
do_test wal-4.4.4 {
  set logsize [file size test.db-wal]
  execsql {
      INSERT INTO t1 VALUES('x', 'y');
    RELEASE tr;
  }
  expr { $logsize == [file size test.db-wal] }
} {1}
do_test wal-4.4.5 {
  execsql { SELECT count(*) FROM t2 }
} {1}
do_test wal-4.4.6 {
  file copy -force test.db test2.db
  file copy -force test.db-wal test2.db-wal
  sqlite3 db2 test2.db
  execsql { SELECT count(*) FROM t2 ; SELECT count(*) FROM t1 } db2
} {1 2}
do_test wal-4.4.7 {
  execsql { PRAGMA integrity_check } db2
} {ok}
db2 close

do_test wal-4.5.1 {
  reopen_db
  db func blob blob
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES('a', 'b');
  }
  sqlite3 db test.db
  db func blob blob
  list [execsql { SELECT * FROM t1 }] [file size test.db-wal]
} {{a b} 0}
do_test wal-4.5.2 {
  execsql { PRAGMA cache_size = 10 }
  execsql {
    CREATE TABLE t2(a, b);
    BEGIN;
    INSERT INTO t2 VALUES(blob(400), blob(400));
    SAVEPOINT tr;
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  2 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  4 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  8 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 16 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 32 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  2 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  4 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  8 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 16 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 32 */
      SELECT count(*) FROM t2;
  }
} {32}
do_test wal-4.5.3 {
  execsql { ROLLBACK TO tr }
} {}
do_test wal-4.5.4 {
  set logsize [file size test.db-wal]
  execsql {
      INSERT INTO t1 VALUES('x', 'y');
    RELEASE tr;
    COMMIT;
  }
  expr { $logsize == [file size test.db-wal] }
} {1}
do_test wal-4.5.5 {
  execsql { SELECT count(*) FROM t2 ; SELECT count(*) FROM t1 }
} {1 2}
do_test wal-4.5.6 {
  file copy -force test.db test2.db
  file copy -force test.db-wal test2.db-wal
  sqlite3 db2 test2.db
  execsql { SELECT count(*) FROM t2 ; SELECT count(*) FROM t1 } db2
} {1 2}
do_test wal-4.5.7 {
  execsql { PRAGMA integrity_check } db2
} {ok}
db2 close


reopen_db
do_test wal-5.1 {
  execsql {
    CREATE TEMP TABLE t2(a, b);
    INSERT INTO t2 VALUES(1, 2);
  }
} {}
do_test wal-5.2 {
  execsql {
    BEGIN;
      INSERT INTO t2 VALUES(3, 4);
      SELECT * FROM t2;
  }
} {1 2 3 4}
do_test wal-5.3 {
  execsql {
    ROLLBACK;
    SELECT * FROM t2;
  }
} {1 2}
do_test wal-5.4 {
  execsql {
    CREATE TEMP TABLE t3(x UNIQUE);
    BEGIN;
      INSERT INTO t2 VALUES(3, 4);
      INSERT INTO t3 VALUES('abc');
  }
  catchsql { INSERT INTO t3 VALUES('abc') }
} {1 {column x is not unique}}
do_test wal-5.5 {
  execsql {
    COMMIT;
    SELECT * FROM t2;
  }
} {1 2 3 4}
db close

foreach sector {512 4096} {
  sqlite3_simulate_device -sectorsize $sector
  foreach pgsz {512 1024 2048 4096} {
    file delete -force test.db test.db-wal
    do_test wal-6.$sector.$pgsz.1 {
      sqlite3 db test.db -vfs devsym
      execsql "
        PRAGMA page_size = $pgsz;
        PRAGMA journal_mode = wal;
      "
      execsql "
        CREATE TABLE t1(a, b);
        INSERT INTO t1 VALUES(1, 2);
      "
      db close
      file size test.db
    } [expr $pgsz*2]
  
    do_test wal-6.$sector.$pgsz.2 {
      log_deleted test.db-wal
    } {1}
  }
}

do_test wal-7.1 {
  file delete -force test.db test.db-wal
  sqlite3_wal db test.db
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  }
  list [file size test.db] [file size test.db-wal]
} [list 1024 [log_file_size 3 1024]]
do_test wal-7.2 {
  execsql { PRAGMA wal_checkpoint }
  list [file size test.db] [file size test.db-wal]
} [list 2048 [log_file_size 3 1024]]

# Execute some transactions in auto-vacuum mode to test database file
# truncation.
#
do_test wal-8.1 {
  reopen_db
  catch { db close }
  file delete -force test.db test.db-wal

  sqlite3 db test.db
  db function blob blob
  execsql {
    PRAGMA auto_vacuum = 1;
    PRAGMA journal_mode = wal;
    PRAGMA auto_vacuum;
  }
} {wal 1}
do_test wal-8.2 {
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  4 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  8 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 16 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 32 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 64 */
    PRAGMA wal_checkpoint;
  }
  file size test.db
} [expr 68*1024]
do_test wal-8.3 {
  execsql { 
    DELETE FROM t1 WHERE rowid<54;
    PRAGMA wal_checkpoint;
  }
  file size test.db
} [expr 14*1024]

# Run some "warm-body" tests to ensure that log-summary files with more
# than 256 entries (log summaries that contain index blocks) work Ok.
#
do_test wal-9.1 {
  reopen_db
  execsql {
    CREATE TABLE t1(x PRIMARY KEY);
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  4 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  8 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 16 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 32 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 64 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 128 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 256 */
  }
  file size test.db
} 1024
do_test wal-9.2 {
  sqlite3_wal db2 test.db
  execsql {PRAGMA integrity_check } db2
} {ok}

do_test wal-9.3 {
  file delete -force test2.db test2.db-wal
  file copy test.db test2.db
  file copy test.db-wal test2.db-wal
  sqlite3_wal db3 test2.db 
  execsql {PRAGMA integrity_check } db3
} {ok}
db3 close

do_test wal-9.4 {
  execsql { PRAGMA wal_checkpoint }
  db2 close
  sqlite3_wal db2 test.db
  execsql {PRAGMA integrity_check } db2
} {ok}

foreach handle {db db2 db3} { catch { $handle close } }
unset handle

#-------------------------------------------------------------------------
# The following block of tests - wal-10.* - test that the WAL locking 
# scheme works in simple cases. This block of tests is run twice. Once
# using multiple connections in the address space of the current process,
# and once with all connections except one running in external processes.
#
foreach code [list {
  set ::code2_chan [launch_testfixture]
  set ::code3_chan [launch_testfixture]
  proc code2 {tcl} { testfixture $::code2_chan $tcl }
  proc code3 {tcl} { testfixture $::code3_chan $tcl }
  set tn 1
} {
  proc code2 {tcl} { uplevel #0 $tcl }
  proc code3 {tcl} { uplevel #0 $tcl }
  set tn 2
}] {

  eval $code
  reopen_db

  # Open connections [db2] and [db3]. Depending on which iteration this
  # is, the connections may be created in this interpreter, or in 
  # interpreters running in other OS processes. As such, the [db2] and [db3]
  # commands should only be accessed within [code2] and [code3] blocks,
  # respectively.
  #
  code2 { sqlite3 db2 test.db ; db2 eval { PRAGMA journal_mode = WAL } }
  code3 { sqlite3 db3 test.db ; db3 eval { PRAGMA journal_mode = WAL } }

  # Shorthand commands. Execute SQL using database connection [db2] or 
  # [db3]. Return the results.
  #
  proc sql2 {sql} { code2 [list db2 eval $sql] }
  proc sql3 {sql} { code3 [list db3 eval $sql] }

  # Initialize the database schema and contents.
  #
  do_test wal-10.$tn.1 {
    execsql {
      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
      SELECT * FROM t1;
    }
  } {1 2}

  # Open a transaction and write to the database using [db]. Check that [db2]
  # is still able to read the snapshot before the transaction was opened.
  #
  do_test wal-10.$tn.2 {
    execsql { BEGIN; INSERT INTO t1 VALUES(3, 4); }
    sql2 {SELECT * FROM t1}
  } {1 2}

  # Have [db] commit the transaction. Check that [db2] is now seeing the 
  # new, updated snapshot.
  #
  do_test wal-10.$tn.3 {
    execsql { COMMIT }
    sql2 {SELECT * FROM t1}
  } {1 2 3 4}

  # Have [db2] open a read transaction. Then write to the db via [db]. Check
  # that [db2] is still seeing the original snapshot. Then read with [db3].
  # [db3] should see the newly committed data.
  #
  do_test wal-10.$tn.4 {
    sql2 { BEGIN ; SELECT * FROM t1}
  } {1 2 3 4}
  do_test wal-10.$tn.5 {
    execsql { INSERT INTO t1 VALUES(5, 6); }
    sql2 {SELECT * FROM t1}
  } {1 2 3 4}
  do_test wal-10.$tn.6 {
    sql3 {SELECT * FROM t1}
  } {1 2 3 4 5 6}
  do_test wal-10.$tn.7 {
    sql2 COMMIT
  } {}

  # Have [db2] open a write transaction. Then attempt to write to the 
  # database via [db]. This should fail (writer lock cannot be obtained).
  #
  # Then open a read-transaction with [db]. Commit the [db2] transaction
  # to disk. Verify that [db] still cannot write to the database (because
  # it is reading an old snapshot).
  #
  # Close the current [db] transaction. Open a new one. [db] can now write
  # to the database (as it is not locked and [db] is reading the latest
  # snapshot).
  #
  do_test wal-10.$tn.7 {
    sql2 { BEGIN; INSERT INTO t1 VALUES(7, 8) ; }
    catchsql { INSERT INTO t1 VALUES(9, 10) }
  } {1 {database is locked}}
  do_test wal-10.$tn.8 {
    execsql { BEGIN ; SELECT * FROM t1 }
  } {1 2 3 4 5 6}
  do_test wal-10.$tn.9 {
    sql2 COMMIT
    catchsql { INSERT INTO t1 VALUES(9, 10) }
  } {1 {database is locked}}
  do_test wal-10.$tn.10 {
    execsql { COMMIT; BEGIN; INSERT INTO t1 VALUES(9, 10); COMMIT; }
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10}

  # Open a read transaction with [db2]. Check that this prevents [db] from
  # checkpointing the database. But not from writing to it.
  #
  do_test wal-10.$tn.11 {
    sql2 { BEGIN; SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10}
  do_test wal-10.$tn.12 {
    catchsql { PRAGMA wal_checkpoint } 
  } {1 {database is locked}}
  do_test wal-10.$tn.13 {
    execsql { INSERT INTO t1 VALUES(11, 12) }
    sql2 {SELECT * FROM t1}
  } {1 2 3 4 5 6 7 8 9 10}

  # Connection [db2] is holding a lock on a snapshot, preventing [db] from
  # checkpointing the database. Add a busy-handler to [db]. If [db2] completes
  # its transaction from within the busy-handler, [db] is able to complete
  # the checkpoint operation.
  #
  proc busyhandler x {
    if {$x==4} { sql2 COMMIT }
    if {$x<5} { return 0 }
    return 1
  }
  db busy busyhandler
  do_test wal-10.$tn.14 {
    execsql { PRAGMA wal_checkpoint } 
  } {}

  # Similar to the test above. Except this time, a new read transaction is
  # started (db3) while the checkpointer is waiting for an old one (db2) to 
  # finish. The checkpointer can finish, but any subsequent write operations 
  # must wait until after db3 has closed the read transaction, as db3 is a
  # "region D" writer.
  #
  db busy {}
  do_test wal-10.$tn.15 {
    sql2 { BEGIN; SELECT * FROM t1; }
  } {1 2 3 4 5 6 7 8 9 10 11 12}
  do_test wal-10.$tn.16 {
    catchsql { PRAGMA wal_checkpoint } 
  } {1 {database is locked}}
  proc busyhandler x {
    if {$x==3} { sql3 { BEGIN; SELECT * FROM t1 } }
    if {$x==4} { sql2 COMMIT }
    if {$x<5}  { return 0 }
    return 1
  }
  db busy busyhandler
  do_test wal-10.$tn.17 {
    execsql { PRAGMA wal_checkpoint } 
  } {}
  do_test wal-10.$tn.18 {
    sql3 { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12}
  do_test wal-10.$tn.19 {
    catchsql { INSERT INTO t1 VALUES(13, 14) }
  } {1 {database is locked}}
  do_test wal-10.$tn.20 {
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12}
  do_test wal-10.$tn.21 {
    sql3 COMMIT
  } {}
  do_test wal-10.$tn.22 {
    execsql { INSERT INTO t1 VALUES(13, 14) }
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14}

  # Set [db3] up as a "region D" reader again. Then upgrade it to a writer
  # and back down to a reader. Then, check that a checkpoint is not possible
  # (as [db3] still has a snapshot locked).
  #
  do_test wal-10.$tn.23 {
    execsql { PRAGMA wal_checkpoint }
  } {}
  do_test wal-10.$tn.24 {
    sql2 { BEGIN; SELECT * FROM t1; }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
  do_test wal-10.$tn.25 {
    execsql { PRAGMA wal_checkpoint }
  } {}
  do_test wal-10.$tn.26 {
    catchsql { INSERT INTO t1 VALUES(15, 16) }
  } {1 {database is locked}}
  do_test wal-10.$tn.27 {
    sql3 { INSERT INTO t1 VALUES(15, 16) }
  } {}
  do_test wal-10.$tn.28 {
    code3 {
      set ::STMT [sqlite3_prepare db3 "SELECT * FROM t1" -1 TAIL]
      sqlite3_step $::STMT
    }
    sql3 COMMIT
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16}
  db busy {}
  do_test wal-10.$tn.29 {
    execsql { INSERT INTO t1 VALUES(17, 18) }
    catchsql { PRAGMA wal_checkpoint }
  } {1 {database is locked}}
  do_test wal-10.$tn.30 {
    code3 { sqlite3_finalize $::STMT }
    execsql { PRAGMA wal_checkpoint }
  } {}

  # At one point, if a reader failed to upgrade to a writer because it
  # was reading an old snapshot, the write-locks were not being released.
  # Test that this bug has been fixed.
  #
  do_test wal-10.$tn.31 {
    execsql { BEGIN ; SELECT * FROM t1 }
    sql2 { INSERT INTO t1 VALUES(19, 20) }
    catchsql { INSERT INTO t1 VALUES(21, 22) }
  } {1 {database is locked}}
  do_test wal-10.$tn.32 {
    # This statement would fail when the bug was present.
    sql2 { INSERT INTO t1 VALUES(21, 22) }
  } {}
  do_test wal-10.$tn.33 {
    execsql { SELECT * FROM t1 ; COMMIT }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18}
  do_test wal-10.$tn.34 {
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22}

  # Test that if a checkpointer cannot obtain the required locks, it
  # releases all locks before returning a busy error.
  #
  do_test wal-10.$tn.35 {
    execsql { 
      DELETE FROM t1;
      INSERT INTO t1 VALUES('a', 'b');
      INSERT INTO t1 VALUES('c', 'd');
    }
    sql2 {
      BEGIN;
        SELECT * FROM t1;
    }
  } {a b c d}
  proc busyhandler x { return 1 }
  db busy busyhandler
  do_test wal-10.$tn.36 {
    catchsql { PRAGMA wal_checkpoint }
  } {1 {database is locked}}
  do_test wal-10.$tn.36 {
    sql3 { INSERT INTO t1 VALUES('e', 'f') }
    sql2 { SELECT * FROM t1 }
  } {a b c d}
  do_test wal-10.$tn.37 {
    sql2 COMMIT
    execsql { PRAGMA wal_checkpoint }
  } {}

  catch { db close }
  catch { code2 { db2 close } }
  catch { code3 { db3 close } }
  catch { close $::code2_chan }
  catch { close $::code3_chan }
}

#-------------------------------------------------------------------------
# This block of tests, wal-11.*, test that nothing goes terribly wrong
# if frames must be written to the log file before a transaction is
# committed (in order to free up memory).
#
do_test wal-11.1 {
  reopen_db
  execsql {
    PRAGMA cache_size = 10;
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x PRIMARY KEY);
  }
  list [expr [file size test.db]/1024] [expr [file size test.db-wal]/1044]
} {1 3}
do_test wal-11.2 {
  execsql { PRAGMA wal_checkpoint }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [log_file_size 3 1024]]
do_test wal-11.3 {
  execsql { INSERT INTO t1 VALUES( blob(900) ) }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [log_file_size 4 1024]]

do_test wal-11.4 {
  execsql { 
    BEGIN;
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 2
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 4
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 8
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 16
  }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [log_file_size 32 1024]]
do_test wal-11.5 {
  execsql { 
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {16 ok}
do_test wal-11.6 {
  execsql COMMIT
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [log_file_size 41 1024]]
do_test wal-11.7 {
  execsql { 
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {16 ok}
do_test wal-11.8 {
  execsql { PRAGMA wal_checkpoint }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [log_file_size 41 1024]]
do_test wal-11.9 {
  db close
  list [expr [file size test.db]/1024] [log_deleted test.db-wal]
} {37 1}
sqlite3_wal db test.db
do_test wal-11.10 {
  execsql {
    PRAGMA cache_size = 10;
    BEGIN;
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 32
      SELECT count(*) FROM t1;
  }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [log_file_size 37 1024]]
do_test wal-11.11 {
  execsql {
      SELECT count(*) FROM t1;
    ROLLBACK;
    SELECT count(*) FROM t1;
  }
} {32 16}
do_test wal-11.12 {
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [log_file_size 37 1024]]
do_test wal-11.13 {
  execsql {
    INSERT INTO t1 VALUES( blob(900) );
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {17 ok}
do_test wal-11.14 {
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [log_file_size 37 1024]]


#-------------------------------------------------------------------------
# This block of tests, wal-12.*, tests the fix for a problem that 
# could occur if a log that is a prefix of an older log is written 
# into a reused log file.
#
reopen_db
do_test wal-12.1 {
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x, y);
    CREATE TABLE t2(x, y);
    INSERT INTO t1 VALUES('A', 1);
  }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 1 [log_file_size 5 1024]]
do_test wal-12.2 {
  db close
  sqlite3 db test.db
  execsql {
    PRAGMA synchronous = normal;
    UPDATE t1 SET y = 0 WHERE x = 'A';
  }
  list [expr [file size test.db]/1024] [expr [file size test.db-wal]/1044]
} {3 1}
do_test wal-12.3 {
  execsql { INSERT INTO t2 VALUES('B', 1) }
  list [expr [file size test.db]/1024] [expr [file size test.db-wal]/1044]
} {3 2}
do_test wal-12.4 {
  file copy -force test.db test2.db
  file copy -force test.db-wal test2.db-wal
  sqlite3_wal db2 test2.db
  execsql { SELECT * FROM t2 } db2
} {B 1}
db2 close
do_test wal-12.5 {
  execsql {
    PRAGMA wal_checkpoint;
    UPDATE t2 SET y = 2 WHERE x = 'B'; 
    PRAGMA wal_checkpoint;
    UPDATE t1 SET y = 1 WHERE x = 'A';
    PRAGMA wal_checkpoint;
    UPDATE t1 SET y = 0 WHERE x = 'A';
    SELECT * FROM t2;
  }
} {B 2}
do_test wal-12.6 {
  file copy -force test.db test2.db
  file copy -force test.db-wal test2.db-wal
  sqlite3_wal db2 test2.db
  execsql { SELECT * FROM t2 } db2
} {B 2}
db2 close
db close

#-------------------------------------------------------------------------
# Test large log summaries.
#
do_test wal-13.1.1 {
  list [file exists test.db] [file exists test.db-wal]
} {1 0}
do_test wal-13.1.2 {
  set fd [open test.db-wal w]
  seek $fd [expr 200*1024*1024]
  puts $fd ""
  close $fd
  sqlite3 db test.db
  execsql { SELECT * FROM t2 }
} {B 2}
do_test wal-13.1.3 {
  db close
  file exists test.db-wal
} {0}
do_test wal-13.1.4 {
  sqlite3 db test.db
  execsql { SELECT count(*) FROM t2 }
} {1}
do_test wal-13.1.5 {
  for {set i 0} {$i < 6} {incr i} {
    execsql { INSERT INTO t2 SELECT randomblob(400), randomblob(400) FROM t2 }
  }
  execsql { SELECT count(*) FROM t2 }
} [expr int(pow(2, 6))]
do_test wal-13.1.6 {
  file size test.db-wal
} [log_file_size 80 1024]

foreach code [list {
  set tn 2
  proc buddy {tcl} { uplevel #0 $tcl }
} {
  set tn 3
  set ::buddy [launch_testfixture]
  proc buddy {tcl} { testfixture $::buddy $tcl }
}] {

  eval $code
  reopen_db

  do_test wal-13.$tn.0 {
    buddy { sqlite3 db2 test.db }
    execsql {
      PRAGMA journal_mode = WAL;
      CREATE TABLE t1(x);
      INSERT INTO t1 SELECT randomblob(400);
    }
    execsql { SELECT count(*) FROM t1 }
  } {1}

  for {set ii 1} {$ii<16} {incr ii} {
    do_test wal-13.$tn.$ii.a {
      buddy { db2 eval { INSERT INTO t1 SELECT randomblob(400) FROM t1 } }
      buddy { db2 eval { SELECT count(*) FROM t1 } }
    } [expr (1<<$ii)]
    do_test wal-13.$tn.$ii.b {
      db eval { SELECT count(*) FROM t1 }
    } [expr (1<<$ii)]
    do_test wal-13.$tn.$ii.c {
      db eval { SELECT count(*) FROM t1 }
    } [expr (1<<$ii)]
    do_test wal-13.$tn.$ii.d {
      db eval { PRAGMA integrity_check }
    } {ok}
  }

  catch { db2 close }
  catch { close $::buddy }
  db close
}

#-------------------------------------------------------------------------
# Check a fun corruption case has been fixed.
#
# The problem was that after performing a checkpoint using a connection
# that had an out-of-date pager-cache, the next time the connection was
# used it did not realize the cache was out-of-date and proceeded to
# operate with an inconsistent cache. Leading to corruption.
#

catch { db close }
catch { db2 close }
catch { db3 close }
file delete -force test.db test.db-wal
sqlite3 db test.db
sqlite3 db2 test.db

do_test wal-14 {
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a PRIMARY KEY, b);
    INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
    INSERT INTO t1 SELECT randomblob(10), randomblob(100) FROM t1;
    INSERT INTO t1 SELECT randomblob(10), randomblob(100) FROM t1;
    INSERT INTO t1 SELECT randomblob(10), randomblob(100) FROM t1;
  }

  db2 eval { 
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
  }

  # After executing the "PRAGMA wal_checkpoint", connection [db] was being
  # left with an inconsistent cache. Running the CREATE INDEX statement
  # in this state led to database corruption.
  catchsql { 
    PRAGMA wal_checkpoint;
    CREATE INDEX i1 on t1(b);
  }
   
  db2 eval { PRAGMA integrity_check }
} {ok}

catch { db close }
catch { db2 close }

#-------------------------------------------------------------------------
# The following block of tests - wal-15.* - focus on testing the 
# implementation of the sqlite3_wal_checkpoint() interface.
#
file delete -force test.db test.db-wal
sqlite3 db test.db
do_test wal-15.1 {
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = WAL;
  }
  execsql {
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  }
} {}

# Test that an error is returned if the database name is not recognized
#
do_test wal-15.2.1 {
  sqlite3_wal_checkpoint db aux
} {SQLITE_ERROR}
do_test wal-15.2.2 {
  sqlite3_errcode db
} {SQLITE_ERROR}
do_test wal-15.2.3 {
  sqlite3_errmsg db
} {unknown database: aux}

# Test that an error is returned if an attempt is made to checkpoint
# if a transaction is open on the database.
#
do_test wal-15.3.1 {
  execsql {
    BEGIN;
    INSERT INTO t1 VALUES(3, 4);
  }
  sqlite3_wal_checkpoint db main
} {SQLITE_LOCKED}
do_test wal-15.3.2 {
  sqlite3_errcode db
} {SQLITE_LOCKED}
do_test wal-15.3.3 {
  sqlite3_errmsg db
} {database table is locked}

# Also test that an error is returned if the db cannot be checkpointed
# because of locks held by another connection.
#
sqlite3 db2 test.db
do_test wal-15.4.1 {
  execsql {
    BEGIN;
    SELECT * FROM t1;
  } db2
} {1 2}
do_test wal-15.4.2 {
  execsql { COMMIT }
  sqlite3_wal_checkpoint db
} {SQLITE_BUSY}
do_test wal-15.4.3 {
  sqlite3_errmsg db
} {database is locked}

# After [db2] drops its lock, [db] may checkpoint the db.
#
do_test wal-15.4.4 {
  execsql { COMMIT } db2
  sqlite3_wal_checkpoint db
} {SQLITE_OK}
do_test wal-15.4.5 {
  sqlite3_errmsg db
} {not an error}
do_test wal-15.4.6 {
  file size test.db
} [expr 1024*2]

catch { db2 close }
catch { db close }
finish_test


Added test/walbak.test.





















































































































































































































































































































































































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# 2010 April 22
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !wal {finish_test ; return }

proc log_file_size {nFrame pgsz} {
  expr {12 + ($pgsz+16)*$nFrame}
}

# Test organization:
# 
#   walback-1.*: Simple tests.
#   walback-2.*: Test backups when the source db is modified mid-backup.
#

# Make sure a simple backup from a WAL database works.
#
do_test walbak-1.0 {
  execsql { 
    PRAGMA synchronous = NORMAL;
    PRAGMA page_size = 1024;
    PRAGMA auto_vacuum = 0;
    PRAGMA journal_mode = wal;
    BEGIN;
      CREATE TABLE t1(a PRIMARY KEY, b);
      INSERT INTO t1 VALUES('I', 'one');
    COMMIT;
  }
} {wal}
do_test walbak-1.1 {
  file delete -force bak.db bak.db-journal bak.db-wal
  db backup bak.db
  file size bak.db
} [expr 3*1024]
do_test walbak-1.2 {
  sqlite3 db2 bak.db
  execsql { 
    SELECT * FROM t1;
    PRAGMA main.journal_mode;
  } db2
} {I one wal}
do_test walbak-1.3 {
  execsql { PRAGMA integrity_check } db2
} {ok}
db2 close

# Try a VACUUM on a WAL database.
#
do_test walbak-1.4 {
  execsql { 
    VACUUM;
    PRAGMA main.journal_mode;
  }
} {wal}
do_test walbak-1.5 {
  list [file size test.db] [file size test.db-wal]
} [list 1024 [log_file_size 6 1024]]
do_test walbak-1.6 {
  execsql { PRAGMA wal_checkpoint }
  list [file size test.db] [file size test.db-wal]
} [list [expr 3*1024] [log_file_size 6 1024]]
do_test walbak-1.7 {
  execsql { 
    CREATE TABLE t2(a, b);
    INSERT INTO t2 SELECT * FROM t1;
    DROP TABLE t1;
  }
  list [file size test.db] [file size test.db-wal]
} [list [expr 3*1024] [log_file_size 6 1024]]
do_test walbak-1.8 {
  execsql { VACUUM }
  list [file size test.db] [file size test.db-wal]
} [list [expr 3*1024] [log_file_size 8 1024]]
do_test walbak-1.9 {
  execsql { PRAGMA wal_checkpoint }
  list [file size test.db] [file size test.db-wal]
} [list [expr 2*1024] [log_file_size 8 1024]]

#-------------------------------------------------------------------------
# Backups when the source db is modified mid-backup.
#
proc sig {{db db}} {
  $db eval { 
    PRAGMA integrity_check;
    SELECT md5sum(a, b) FROM t1; 
  }
}
db close
file delete test.db
sqlite3 db test.db
do_test walbak-2.1 {
  execsql { PRAGMA journal_mode = WAL }
  execsql {
    CREATE TABLE t1(a PRIMARY KEY, b);
    BEGIN;
      INSERT INTO t1 VALUES(randomblob(500), randomblob(500));
      INSERT INTO t1 SELECT randomblob(500), randomblob(500) FROM t1; /*  2 */
      INSERT INTO t1 SELECT randomblob(500), randomblob(500) FROM t1; /*  4 */
      INSERT INTO t1 SELECT randomblob(500), randomblob(500) FROM t1; /*  8 */
      INSERT INTO t1 SELECT randomblob(500), randomblob(500) FROM t1; /* 16 */
      INSERT INTO t1 SELECT randomblob(500), randomblob(500) FROM t1; /* 32 */
      INSERT INTO t1 SELECT randomblob(500), randomblob(500) FROM t1; /* 64 */
    COMMIT;
  }
} {}
do_test walbak-2.2 {
  db backup abc.db
  sqlite3 db2 abc.db
  string compare [sig db] [sig db2]
} {0}

do_test walbak-2.3 {
  sqlite3_backup B db2 main db main
  B step 50
  execsql { UPDATE t1 SET b = randomblob(500) }
  list [B step 1000] [B finish]
} {SQLITE_DONE SQLITE_OK}
do_test walbak-2.4 {
  string compare [sig db] [sig db2]
} {0}

do_test walbak-2.5 {
  db close
  sqlite3 db test.db
  execsql { PRAGMA cache_size = 10 }
  sqlite3_backup B db2 main db main
  B step 50
  execsql {
    BEGIN;
      UPDATE t1 SET b = randomblob(500);
  }
  expr [file size test.db-wal] > 10*1024
} {1}
do_test walbak-2.6 {
  B step 1000
} {SQLITE_BUSY}
do_test walbak-2.7 {
  execsql COMMIT
  list [B step 1000] [B finish]
} {SQLITE_DONE SQLITE_OK}
do_test walbak-2.8 {
  string compare [sig db] [sig db2]
} {0}

do_test walbak-2.9 {
  db close
  sqlite3 db test.db
  execsql { PRAGMA cache_size = 10 }
  sqlite3_backup B db2 main db main
  B step 50
  execsql {
    BEGIN;
      UPDATE t1 SET b = randomblob(500);
  }
  expr [file size test.db-wal] > 10*1024
} {1}
do_test walbak-2.10 {
  B step 1000
} {SQLITE_BUSY}
do_test walbak-2.11 {
  execsql ROLLBACK
set sigB [sig db]
  list [B step 1000] [B finish]
} {SQLITE_DONE SQLITE_OK}
do_test walbak-2.12 {
  string compare [sig db] [sig db2]
} {0}
db2 close

finish_test

Added test/walcrash.test.

















































































































































































































































































































































































































































































































































































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# 2010 February 8
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library when
# recovering a database following a simulated system failure in 
# "PRAGMA journal_mode=WAL" mode.
#

#
# These are 'warm-body' tests of database recovery used while developing 
# the WAL code. They serve to prove that a few really simple cases work:
#
# walcrash-1.*: Recover a database.
# walcrash-2.*: Recover a database where the failed transaction spanned more
#               than one page.
# walcrash-3.*: Recover multiple databases where the failed transaction 
#               was a multi-file transaction.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable !wal {finish_test ; return }

db close

set seed 0
set REPEATS 100

# walcrash-1.*
#
for {set i 1} {$i < $REPEATS} {incr i} {
  file delete -force test.db test.db-wal
  do_test walcrash-1.$i.1 {
    crashsql -delay 4 -file test.db-wal -seed [incr seed] {
      PRAGMA journal_mode = WAL;
      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 1);
      INSERT INTO t1 VALUES(2, 3);
      INSERT INTO t1 VALUES(3, 6);
    }
  } {1 {child process exited abnormally}}
  do_test walcrash-1.$i.2 {
    sqlite3 db test.db
    execsql { SELECT sum(a)==max(b) FROM t1 }
  } {1}
  integrity_check walcrash-1.$i.3
  db close
  
  do_test walcrash-1.$i.4 {
    crashsql -delay 2 -file test.db-wal -seed [incr seed] {
      INSERT INTO t1 VALUES(4, (SELECT sum(a) FROM t1) + 4);
      INSERT INTO t1 VALUES(5, (SELECT sum(a) FROM t1) + 5);
    }
  } {1 {child process exited abnormally}}
  do_test walcrash-1.$i.5 {
    sqlite3 db test.db
    execsql { SELECT sum(a)==max(b) FROM t1 }
  } {1}
  integrity_check walcrash-1.$i.6
  do_test walcrash-1.$i.5 {
    execsql { PRAGMA main.journal_mode }
  } {wal}
  db close
}

# walcrash-2.*
#
for {set i 1} {$i < $REPEATS} {incr i} {
  file delete -force test.db test.db-wal
  do_test walcrash-2.$i.1 {
    crashsql -delay 4 -file test.db-wal -seed [incr seed] {
      PRAGMA journal_mode = WAL;
      CREATE TABLE t1(a PRIMARY KEY, b);
      INSERT INTO t1 VALUES(1, 2);
      INSERT INTO t1 VALUES(3, 4);
      INSERT INTO t1 VALUES(5, 9);
    }
  } {1 {child process exited abnormally}}
  do_test walcrash-2.$i.2 {
    sqlite3 db test.db
    execsql { SELECT sum(a)==max(b) FROM t1 }
  } {1}
  integrity_check walcrash-2.$i.3
  db close
  
  do_test walcrash-2.$i.4 {
    crashsql -delay 2 -file test.db-wal -seed [incr seed] {
      INSERT INTO t1 VALUES(6, (SELECT sum(a) FROM t1) + 6);
      INSERT INTO t1 VALUES(7, (SELECT sum(a) FROM t1) + 7);
    }
  } {1 {child process exited abnormally}}
  do_test walcrash-2.$i.5 {
    sqlite3 db test.db
    execsql { SELECT sum(a)==max(b) FROM t1 }
  } {1}
  integrity_check walcrash-2.$i.6
  do_test walcrash-2.$i.6 {
    execsql { PRAGMA main.journal_mode }
  } {wal}
  db close
}

# walcrash-3.*
#
# for {set i 1} {$i < $REPEATS} {incr i} {
#   file delete -force test.db test.db-wal
#   file delete -force test2.db test2.db-wal
# 
#   do_test walcrash-3.$i.1 {
#     crashsql -delay 2 -file test2.db-wal -seed [incr seed] {
#       PRAGMA journal_mode = WAL;
#       ATTACH 'test2.db' AS aux;
#       CREATE TABLE t1(a PRIMARY KEY, b);
#       CREATE TABLE aux.t2(a PRIMARY KEY, b);
#       BEGIN;
#         INSERT INTO t1 VALUES(1, 2);
#         INSERT INTO t2 VALUES(1, 2);
#       COMMIT;
#     }
#   } {1 {child process exited abnormally}}
# 
#   do_test walcrash-3.$i.2 {
#     sqlite3_wal db test.db
#     execsql { 
#       ATTACH 'test2.db' AS aux;
#       SELECT * FROM t1 EXCEPT SELECT * FROM t2;
#     }
#   } {}
#   do_test walcrash-3.$i.3 { execsql { PRAGMA main.integrity_check } } {ok}
#   do_test walcrash-3.$i.4 { execsql { PRAGMA aux.integrity_check  } } {ok}
# 
#   db close
# }

# walcrash-4.*
#
for {set i 1} {$i < $REPEATS} {incr i} {
  file delete -force test.db test.db-wal
  file delete -force test2.db test2.db-wal

  do_test walcrash-4.$i.1 {
    crashsql -delay 3 -file test.db-wal -seed [incr seed] -blocksize 4096 {
      PRAGMA journal_mode = WAL;
      PRAGMA page_size = 1024;
      CREATE TABLE t1(a PRIMARY KEY, b);
      INSERT INTO t1 VALUES(1, 2);
      INSERT INTO t1 VALUES(3, 4);
    }
  } {1 {child process exited abnormally}}

  do_test walcrash-4.$i.2 {
    sqlite3 db test.db
    execsql { 
      SELECT * FROM t1 WHERE a = 1;
    }
  } {1 2}
  do_test walcrash-4.$i.3 { execsql { PRAGMA main.integrity_check } } {ok}
  do_test walcrash-4.$i.4 { execsql { PRAGMA main.journal_mode } } {wal}

  db close
}

# walcrash-5.*
#
for {set i 1} {$i < $REPEATS} {incr i} {
  file delete -force test.db test.db-wal
  file delete -force test2.db test2.db-wal

  do_test walcrash-5.$i.1 {
    crashsql -delay 11 -file test.db-wal -seed [incr seed] -blocksize 4096 {
      PRAGMA journal_mode = WAL;
      PRAGMA page_size = 1024;
      BEGIN;
        CREATE TABLE t1(x PRIMARY KEY);
        INSERT INTO t1 VALUES(randomblob(900));
        INSERT INTO t1 VALUES(randomblob(900));
        INSERT INTO t1 SELECT randomblob(900) FROM t1;           /* 4 */
      COMMIT;
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 8 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 12 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 16 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 20 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 24 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 28 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 32 */

      PRAGMA wal_checkpoint;
      INSERT INTO t1 VALUES(randomblob(900));
      INSERT INTO t1 VALUES(randomblob(900));
      INSERT INTO t1 VALUES(randomblob(900));
    }
  } {1 {child process exited abnormally}}

  do_test walcrash-5.$i.2 {
    sqlite3 db test.db
    execsql { SELECT count(*)==33 OR count(*)==34 FROM t1 WHERE x != 1 }
  } {1}
  do_test walcrash-5.$i.3 { execsql { PRAGMA main.integrity_check } } {ok}
  do_test walcrash-5.$i.4 { execsql { PRAGMA main.journal_mode } } {wal}

  db close
}

# walcrash-6.*
#
for {set i 1} {$i < $REPEATS} {incr i} {
  file delete -force test.db test.db-wal
  file delete -force test2.db test2.db-wal

  do_test walcrash-6.$i.1 {
    crashsql -delay 12 -file test.db-wal -seed [incr seed] -blocksize 512 {
      PRAGMA journal_mode = WAL;
      PRAGMA page_size = 1024;
      BEGIN;
        CREATE TABLE t1(x PRIMARY KEY);
        INSERT INTO t1 VALUES(randomblob(900));
        INSERT INTO t1 VALUES(randomblob(900));
        INSERT INTO t1 SELECT randomblob(900) FROM t1;           /* 4 */
      COMMIT;
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 8 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 12 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 16 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 20 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 24 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 28 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1 LIMIT 4;   /* 32 */

      PRAGMA wal_checkpoint;
      INSERT INTO t1 VALUES(randomblob(900));
      INSERT INTO t1 VALUES(randomblob(900));
      INSERT INTO t1 VALUES(randomblob(900));
    }
  } {1 {child process exited abnormally}}

  do_test walcrash-6.$i.2 {
    sqlite3 db test.db
    execsql { SELECT count(*)==34 OR count(*)==35 FROM t1 WHERE x != 1 }
  } {1}
  do_test walcrash-6.$i.3 { execsql { PRAGMA main.integrity_check } } {ok}
  do_test walcrash-6.$i.4 { execsql { PRAGMA main.journal_mode } } {wal}

  db close
}

for {set i 1} {$i < $REPEATS} {incr i} {
  file delete -force test.db test.db-wal

  do_test walcrash-7.$i.1 {
    crashsql -delay 3 -file test.db -seed [incr seed] -blocksize 512 {
      PRAGMA journal_mode = wal;
      BEGIN;
        CREATE TABLE t1(a, b);
        INSERT INTO t1 VALUES(1, 2);
      COMMIT;
      PRAGMA wal_checkpoint;
      CREATE INDEX i1 ON t1(a);
      PRAGMA wal_checkpoint;
    }
  } {1 {child process exited abnormally}}

  do_test walcrash-7.$i.2 {
    sqlite3 db test.db
    execsql { SELECT b FROM t1 WHERE a = 1 }
  } {2}
  do_test walcrash-7.$i.3 { execsql { PRAGMA main.integrity_check } } {ok}
  do_test walcrash-7.$i.4 { execsql { PRAGMA main.journal_mode } } {wal}

  db close
}

finish_test

Added test/walhook.test.































































































































































































































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# 2010 April 19
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode.
# 
# More specifically, this file contains regression tests for the 
# sqlite3_wal_hook() mechanism, including the sqlite3_wal_autocheckpoint()
# and "PRAGMA wal_autocheckpoint" convenience interfaces.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !wal {finish_test ; return }

proc log_file_size {nFrame pgsz} {
  expr {12 + ($pgsz+16)*$nFrame}
}

set ::wal_hook [list]
proc wal_hook {zDb nEntry} {
  lappend ::wal_hook $zDb $nEntry
  return 0
}
db wal_hook wal_hook

do_test walhook-1.1 {
  execsql { 
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = wal;
    PRAGMA synchronous = normal;
    CREATE TABLE t1(i PRIMARY KEY, j);
  }
  set ::wal_hook
} {main 3}

do_test walhook-1.2 {
  set ::wal_hook [list]
  execsql { INSERT INTO t1 VALUES(1, 'one') }
  set ::wal_hook
} {main 5}
do_test walhook-1.3 {
  proc wal_hook {args} { return 1 }
  execsql { INSERT INTO t1 VALUES(2, 'two') }
  file size test.db
} [expr 3*1024]
do_test walhook-1.4 {
  proc wal_hook {zDb nEntry} { 
    execsql { PRAGMA wal_checkpoint }
    return 0
  }
  execsql { CREATE TABLE t2(a, b) }
  file size test.db
} [expr 4*1024]

do_test walhook-1.5 {
  sqlite3 db2 test.db
  proc wal_hook {zDb nEntry} {
    execsql { PRAGMA wal_checkpoint } db2
    return 0
  }
  execsql { CREATE TABLE t3(a PRIMARY KEY, b) }
  file size test.db
} [expr 6*1024]

db2 close
db close
sqlite3 db test.db
do_test walhook-2.1 {
  execsql { PRAGMA synchronous = NORMAL }
  execsql { PRAGMA wal_autocheckpoint }
} {1000}
do_test walhook-2.2 {
  execsql { PRAGMA wal_autocheckpoint = 10}
} {10}
do_test walhook-2.3 {
  execsql { PRAGMA wal_autocheckpoint }
} {10}

#
# The database connection is configured with "PRAGMA wal_autocheckpoint = 10".
# Check that transactions are written to the log file until it contains at
# least 10 frames, then the database is checkpointed. Subsequent transactions
# are written into the start of the log file.
#
foreach {tn sql dbpages logpages} {
  4 "CREATE TABLE t4(x PRIMARY KEY, y)"   6   3
  5 "INSERT INTO t4 VALUES(1, 'one')"     6   5
  6 "INSERT INTO t4 VALUES(2, 'two')"     6   7
  7 "INSERT INTO t4 VALUES(3, 'three')"   6   9
  8 "INSERT INTO t4 VALUES(4, 'four')"    8  11
  9 "INSERT INTO t4 VALUES(5, 'five')"    8  11
} {
  do_test walhook-2.$tn {
    execsql $sql
    list [file size test.db] [file size test.db-wal]
  } [list [expr $dbpages*1024] [log_file_size $logpages 1024]]
}

catch { db2 close }
catch { db close }
finish_test

Added test/walmode.test.











































































































































































































































































































































































































































































































































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# 2010 April 19
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If the library was compiled without WAL support, check that the 
# "PRAGMA journal_mode=WAL" treats "WAL" as an unrecognized mode.
#
ifcapable !wal {

  do_test walmode-0.1 {
    execsql { PRAGMA journal_mode = wal }
  } {delete}
  do_test walmode-0.2 {
    execsql { PRAGMA main.journal_mode = wal }
  } {delete}
  do_test walmode-0.3 {
    execsql { PRAGMA main.journal_mode }
  } {delete}

  finish_test
  return
}

do_test walmode-1.1 {
  set sqlite_sync_count 0
  execsql { PRAGMA page_size = 1024 }
  execsql { PRAGMA journal_mode = wal }
} {wal}
do_test walmode-1.2 {
  file size test.db
} {1024}
do_test walmode-1.3 {
  set sqlite_sync_count
} {4}
do_test walmode-1.4 {
  file exists test.db-wal
} {0}
do_test walmode-1.5 {
  execsql { CREATE TABLE t1(a, b) }
  file size test.db
} {1024}
do_test walmode-1.6 {
  file exists test.db-wal
} {1}
do_test walmode-1.7 {
  db close
  file exists test.db-wal
} {0}

# There is now a database file with the read and write versions set to 2
# in the file system. This file should default to WAL mode.
#
do_test walmode-2.1 {
  sqlite3 db test.db
  file exists test.db-wal
} {0}
do_test walmode-2.2 {
  execsql { SELECT * FROM sqlite_master }
  file exists test.db-wal
} {1}
do_test walmode-2.3 {
  db close
  file exists test.db-wal
} {0}

# If the first statement executed is "PRAGMA journal_mode = wal", and
# the file is already configured for WAL (read and write versions set
# to 2), then there should be no need to write the database. The 
# statement should cause the client to connect to the log file.
#
set sqlite_sync_count 0
do_test walmode-3.1 {
  sqlite3 db test.db
  execsql { PRAGMA journal_mode = wal }
} {wal}
do_test walmode-3.2 {
  list $sqlite_sync_count [file exists test.db-wal] [file size test.db-wal]
} {0 1 0}

# Test that changing back to journal_mode=persist works.
#
do_test walmode-4.1 {
  execsql { INSERT INTO t1 VALUES(1, 2) }
  execsql { PRAGMA journal_mode = persist }
} {persist}
do_test walmode-4.2 {
  list [file exists test.db-journal] [file exists test.db-wal]
} {1 0}
do_test walmode-4.3 {
  execsql { SELECT * FROM t1 }
} {1 2}
do_test walmode-4.4 {
  db close
  sqlite3 db test.db
  execsql { SELECT * FROM t1 }
} {1 2}
do_test walmode-4.5 {
  list [file exists test.db-journal] [file exists test.db-wal]
} {1 0}

# Test that nothing goes wrong if a connection is prevented from changing
# from WAL to rollback mode because a second connection has the database
# open. Or from rollback to WAL.
#
do_test walmode-4.1 {
  sqlite3 db2 test.db
  execsql { PRAGMA main.journal_mode } db2
} {delete}
do_test walmode-4.2 {
  execsql { PRAGMA main.journal_mode = wal } db
} {wal}
do_test walmode-4.3 {
  execsql { SELECT * FROM t1 } db2
} {1 2}
do_test walmode-4.4 {
  catchsql { PRAGMA journal_mode = delete } db
} {1 {database is locked}}
do_test walmode-4.5 {
  execsql { PRAGMA main.journal_mode } db
} {wal}
do_test walmode-4.6 {
  db2 close
  execsql { PRAGMA journal_mode = delete } db
} {delete}
do_test walmode-4.7 {
  execsql { PRAGMA main.journal_mode } db
} {delete}
do_test walmode-4.8 {
  list [file exists test.db-journal] [file exists test.db-wal]
} {0 0}
do_test walmode-4.9 {
  sqlite3 db2 test.db
  execsql {
    BEGIN;
      SELECT * FROM t1;
  } db2
} {1 2}
do_test walmode-4.11 {
  execsql { PRAGMA main.journal_mode } db
} {delete}
do_test walmode-4.10 {
  catchsql { PRAGMA main.journal_mode = wal } db
} {1 {database is locked}}
do_test walmode-4.11 {
  execsql { PRAGMA main.journal_mode } db
} {delete}
catch { db close }
catch { db2 close }

# Test that it is not possible to change a temporary or in-memory database
# to WAL mode. WAL mode is for persistent file-backed databases only.
#
#   walmode-5.1.*: Try to set journal_mode=WAL on [sqlite3 db :memory:] database.
#   walmode-5.2.*: Try to set journal_mode=WAL on [sqlite3 db ""] database.
#   walmode-5.3.*: Try to set temp.journal_mode=WAL.
#
do_test walmode-5.1.1 {
  sqlite3 db :memory:
  execsql { PRAGMA main.journal_mode }
} {memory}
breakpoint
do_test walmode-5.1.2 {
  execsql { PRAGMA main.journal_mode = wal }
} {memory}
do_test walmode-5.1.3 {
  execsql {
    BEGIN;
      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
    COMMIT;
    SELECT * FROM t1;
    PRAGMA main.journal_mode;
  }
} {1 2 memory}
do_test walmode-5.1.4 {
  execsql { PRAGMA main.journal_mode = wal }
} {memory}
do_test walmode-5.1.5 {
  execsql { 
    INSERT INTO t1 VALUES(3, 4);
    SELECT * FROM t1;
    PRAGMA main.journal_mode;
  }
} {1 2 3 4 memory}

do_test walmode-5.2.1 {
  sqlite3 db ""
  execsql { PRAGMA main.journal_mode }
} {delete}
do_test walmode-5.2.2 {
  execsql { PRAGMA main.journal_mode = wal }
} {delete}
do_test walmode-5.2.3 {
  execsql {
    BEGIN;
      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
    COMMIT;
    SELECT * FROM t1;
    PRAGMA main.journal_mode;
  }
} {1 2 delete}
do_test walmode-5.2.4 {
  execsql { PRAGMA main.journal_mode = wal }
} {delete}
do_test walmode-5.2.5 {
  execsql { 
    INSERT INTO t1 VALUES(3, 4);
    SELECT * FROM t1;
    PRAGMA main.journal_mode;
  }
} {1 2 3 4 delete}

if {$TEMP_STORE>=2} {
  set tempJrnlMode memory
} else {
  set tempJrnlMode delete
}
do_test walmode-5.3.1 {
  sqlite3 db test.db
  execsql { PRAGMA temp.journal_mode }
} $tempJrnlMode
do_test walmode-5.3.2 {
  execsql { PRAGMA temp.journal_mode = wal }
} $tempJrnlMode
do_test walmode-5.3.3 {
  execsql {
    BEGIN;
      CREATE TEMP TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
    COMMIT;
    SELECT * FROM t1;
    PRAGMA temp.journal_mode;
  }
} [list 1 2 $tempJrnlMode]
do_test walmode-5.3.4 {
  execsql { PRAGMA temp.journal_mode = wal }
} $tempJrnlMode
do_test walmode-5.3.5 {
  execsql { 
    INSERT INTO t1 VALUES(3, 4);
    SELECT * FROM t1;
    PRAGMA temp.journal_mode;
  }
} [list 1 2 3 4 $tempJrnlMode]

finish_test

Added test/walslow.test.



















































































































































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# 2010 March 17
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode. The tests in this file use 
# brute force methods, so may take a while to run.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !wal {finish_test ; return }

proc reopen_db {} {
  catch { db close }
  file delete -force test.db test.db-wal
  sqlite3 db test.db
  execsql { PRAGMA journal_mode = wal }
}

db close
save_prng_state
for {set seed 1} {$seed<10} {incr seed} {
  expr srand($seed)
  restore_prng_state
  reopen_db
  do_test walslow-1.seed=$seed.0 {
    execsql { CREATE TABLE t1(a, b) }
    execsql { CREATE INDEX i1 ON t1(a) }
    execsql { CREATE INDEX i2 ON t1(b) }
  } {}

  for {set iTest 1} {$iTest < 100} {incr iTest} {

    do_test walslow-1.seed=$seed.$iTest.1 {
      set w [expr int(rand()*2000)]
      set x [expr int(rand()*2000)]
      execsql { INSERT INTO t1 VALUES(randomblob($w), randomblob($x)) }
      execsql { PRAGMA integrity_check }
    } {ok}

    do_test walslow-1.seed=$seed.$iTest.2 {
      execsql "PRAGMA wal_checkpoint;"
      execsql { PRAGMA integrity_check }
    } {ok}

    do_test walslow-1.seed=$seed.$iTest.3 {
      file delete -force testX.db testX.db-wal
      file copy test.db testX.db
      file copy test.db-wal testX.db-wal
  
      sqlite3 db2 testX.db
      execsql { PRAGMA journal_mode = WAL } db2
      execsql { PRAGMA integrity_check } db2
    } {ok}
  
    do_test walslow-1.seed=$seed.$iTest.4 {
      execsql { SELECT count(*) FROM t1 WHERE a!=b } db2
    } [execsql { SELECT count(*) FROM t1 WHERE a!=b }]
    db2 close
  }
}


finish_test

Added test/walthread.test.

































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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# 2010 April 13
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode with multiple threads.
#

set testdir [file dirname $argv0]

source $testdir/tester.tcl
source $testdir/lock_common.tcl
if {[run_thread_tests]==0} { finish_test ; return }
ifcapable !wal             { finish_test ; return }

set sqlite_walsummary_mmap_incr 64

# How long, in seconds, to run each test for. If a test is set to run for
# 0 seconds, it is omitted entirely.
#
set seconds(walthread-1) 20
set seconds(walthread-2) 20
set seconds(walthread-3) 20
set seconds(walthread-4) 20
set seconds(walthread-5) 1

# The parameter is the name of a variable in the callers context. The
# variable may or may not exist when this command is invoked.
#
# If the variable does exist, its value is returned. Otherwise, this
# command uses [vwait] to wait until it is set, then returns the value.
# In other words, this is a version of the [set VARNAME] command that
# blocks until a variable exists.
#
proc wait_for_var {varname} {
  if {0==[uplevel [list info exists $varname]]} {
    uplevel [list vwait $varname]
  }
  uplevel [list set $varname]
}

# The argument is the name of a list variable in the callers context. The 
# first element of the list is removed and returned. For example:
#
#   set L {a b c}
#   set x [lshift L]
#   assert { $x == "a" && $L == "b c" }
#
proc lshift {lvar} {
  upvar $lvar L
  set ret [lindex $L 0]
  set L [lrange $L 1 end]
  return $ret
}


#-------------------------------------------------------------------------
#   do_thread_test TESTNAME OPTIONS...
# 
# where OPTIONS are: 
#
#   -seconds   SECONDS                How many seconds to run the test for
#   -init      SCRIPT                 Script to run before test.
#   -thread    NAME COUNT SCRIPT      Scripts to run in threads (or processes).
#   -processes BOOLEAN                True to use processes instead of threads.
#   -check     SCRIPT                 Script to run after test.
#
proc do_thread_test {args} {

  set A $args

  set P(testname) [lshift A]
  set P(seconds) 5
  set P(init) ""
  set P(threads) [list]
  set P(processes) 0
  set P(check) {
    set ic [db eval "PRAGMA integrity_check"]
    if {$ic != "ok"} { error $ic }
  }

  unset -nocomplain ::done

  while {[llength $A]>0} {
    set a [lshift A]
    switch -glob -- $a {
      -seconds {
        set P(seconds) [lshift A]
      }

      -init {
        set P(init) [lshift A]
      }

      -processes {
        set P(processes) [lshift A]
      }

      -check {
        set P(check) [lshift A]
      }

      -thread {
        set name  [lshift A]
        set count [lshift A]
        set prg   [lshift A]
        lappend P(threads) [list $name $count $prg]
      }

      default {
        error "Unknown option: $a"
      }
    }
  }

  if {$P(seconds) == 0} {
    puts "Skipping $P(testname)"
    return
  }

  puts "Running $P(testname) for $P(seconds) seconds..."

  catch { db close }
  file delete -force test.db test.db-journal test.db-wal

  sqlite3 db test.db
  eval $P(init)
  catch { db close }

  foreach T $P(threads) {
    set name  [lindex $T 0]
    set count [lindex $T 1]
    set prg   [lindex $T 2]

    for {set i 1} {$i <= $count} {incr i} {
      set vars "
        set E(pid) $i
        set E(nthread) $count
        set E(seconds) $P(seconds)
      "
      set program [string map [list %TEST% $prg %VARS% $vars] {

        %VARS%

        proc usleep {ms} {
          set ::usleep 0
          after $ms {set ::usleep 1}
          vwait ::usleep
        }

        proc integrity_check {{db db}} {
          set ic [$db eval {PRAGMA integrity_check}]
          if {$ic != "ok"} {error $ic}
        }

        proc busyhandler {n} { usleep 10 ; return 0 }

        sqlite3 db test.db
        db busy busyhandler
        db eval { SELECT randomblob($E(pid)*5) }

        set ::finished 0
        after [expr $E(seconds) * 1000] {set ::finished 1}
        proc tt_continue {} { update ; expr ($::finished==0) }

        set rc [catch { %TEST% } msg]

        catch { db close }
        list $rc $msg
      }]

      if {$P(processes)==0} {
        sqlthread spawn ::done($name,$i) $program
      } else {
        testfixture_nb ::done($name,$i) $program
      }
    }
  }

  set report "  Results:"
  foreach T $P(threads) {
    set name  [lindex $T 0]
    set count [lindex $T 1]
    set prg   [lindex $T 2]

    set reslist [list]
    for {set i 1} {$i <= $count} {incr i} {
      set res [wait_for_var ::done($name,$i)]
      lappend reslist [lindex $res 1]
      do_test $P(testname).$name.$i [list lindex $res 0] 0
    }

    append report "   $name $reslist"
  }
  puts $report

  sqlite3 db test.db
  set res ""
  if {[catch $P(check) msg]} { set res $msg }
  do_test $P(testname).check [list set {} $res] ""
}

# A wrapper around [do_thread_test] which runs the specified test twice.
# Once using processes, once using threads. This command takes the same
# arguments as [do_thread_test], except specifying the -processes switch
# is illegal.
#
proc do_thread_test2 {args} {
  set name [lindex $args 0]
  if {[lsearch $args -processes]>=0} { error "bad option: -processes"}
  uplevel [lreplace $args 0 0 do_thread_test "$name-threads" -processes 0]
  uplevel [lreplace $args 0 0 do_thread_test "$name-processes" -processes 1]
}


#--------------------------------------------------------------------------
# Start 10 threads. Each thread performs both read and write 
# transactions. Each read transaction consists of:
#
#   1) Reading the md5sum of all but the last table row,
#   2) Running integrity check.
#   3) Reading the value stored in the last table row,
#   4) Check that the values read in steps 1 and 3 are the same, and that
#      the md5sum of all but the last table row has not changed.
#
# Each write transaction consists of:
#
#   1) Modifying the contents of t1 (inserting, updating, deleting rows).
#   2) Appending a new row to the table containing the md5sum() of all
#      rows in the table.
#
# Each of the N threads runs N read transactions followed by a single write
# transaction in a loop as fast as possible.
#
# There is also a single checkpointer thread. It runs the following loop:
#
#   1) Execute "PRAGMA wal_checkpoint"
#   2) Sleep for 500 ms.
#
do_thread_test2 walthread-1 -seconds $seconds(walthread-1) -init {
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(x PRIMARY KEY);
    PRAGMA lock_status;
    INSERT INTO t1 VALUES(randomblob(100));
    INSERT INTO t1 VALUES(randomblob(100));
    INSERT INTO t1 SELECT md5sum(x) FROM t1;
  }
} -thread main 10 {

  proc read_transaction {} {
    set results [db eval {
      BEGIN;
        PRAGMA integrity_check;
        SELECT md5sum(x) FROM t1 WHERE rowid != (SELECT max(rowid) FROM t1);
        SELECT x FROM t1 WHERE rowid = (SELECT max(rowid) FROM t1);
        SELECT md5sum(x) FROM t1 WHERE rowid != (SELECT max(rowid) FROM t1);
      COMMIT;
    }]

    if {[llength $results]!=4
     || [lindex $results 0] != "ok"
     || [lindex $results 1] != [lindex $results 2]
     || [lindex $results 2] != [lindex $results 3]
    } {
      error "Failed read transaction: $results"
    }
  }

  proc write_transaction {} {
    db eval {
      BEGIN;
        INSERT INTO t1 VALUES(randomblob(100));
        INSERT INTO t1 VALUES(randomblob(100));
        INSERT INTO t1 SELECT md5sum(x) FROM t1;
      COMMIT;
    }
  }

  set nRun 0
  while {[tt_continue]} {
    read_transaction
    write_transaction 
    incr nRun
  }
  set nRun

} -thread ckpt 1 {
  set nRun 0
  while {[tt_continue]} {
    db eval "PRAGMA wal_checkpoint"
    usleep 500
    incr nRun
  }
  set nRun
}

#--------------------------------------------------------------------------
# This test has clients run the following procedure as fast as possible
# in a loop:
#
#   1. Open a database handle.
#   2. Execute a read-only transaction on the db.
#   3. Do "PRAGMA journal_mode = XXX", where XXX is one of WAL or DELETE.
#      Ignore any SQLITE_BUSY error.
#   4. Execute a write transaction to insert a row into the db.
#   5. Run "PRAGMA integrity_check"
#
# At present, there are 4 clients in total. 2 do "journal_mode = WAL", and
# two do "journal_mode = DELETE".
#
# Each client returns a string of the form "W w, R r", where W is the 
# number of write-transactions performed using a WAL journal, and D is
# the number of write-transactions performed using a rollback journal.
# For example, "192 w, 185 r".
#
do_thread_test2 walthread-2 -seconds $seconds(walthread-2) -init {
  execsql { CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE) }
} -thread RB 2 {

  db close
  set nRun 0
  set nDel 0
  while {[tt_continue]} {
    sqlite3 db test.db
    db busy busyhandler
    db eval { SELECT * FROM sqlite_master }
    catch { db eval { PRAGMA journal_mode = DELETE } }
    db eval {
      BEGIN;
      INSERT INTO t1 VALUES(NULL, randomblob(100+$E(pid)));
    }
    incr nRun 1
    incr nDel [file exists test.db-journal]
    if {[file exists test.db-journal] + [file exists test.db-wal] != 1} {
      error "File-system looks bad..."
    }
    db eval COMMIT

    integrity_check
    db close
  }
  list $nRun $nDel
  set {} "[expr $nRun-$nDel] w, $nDel r"

} -thread WAL 2 {
  db close
  set nRun 0
  set nDel 0
  while {[tt_continue]} {
    sqlite3 db test.db
    db busy busyhandler
    db eval { SELECT * FROM sqlite_master }
    catch { db eval { PRAGMA journal_mode = WAL } }
    db eval {
      BEGIN;
      INSERT INTO t1 VALUES(NULL, randomblob(110+$E(pid)));
    }
    incr nRun 1
    incr nDel [file exists test.db-journal]
    if {[file exists test.db-journal] + [file exists test.db-wal] != 1} {
      error "File-system looks bad..."
    }
    db eval COMMIT

    integrity_check
    db close
  }
  set {} "[expr $nRun-$nDel] w, $nDel r"
}

do_thread_test walthread-3 -seconds $seconds(walthread-3) -init {
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(cnt PRIMARY KEY, sum1, sum2);
    CREATE INDEX i1 ON t1(sum1);
    CREATE INDEX i2 ON t1(sum2);
    INSERT INTO t1 VALUES(0, 0, 0);
  }
} -thread t 10 {

  set nextwrite $E(pid)

  proc wal_hook {zDb nEntry} {
    if {$nEntry>10} { return 1 }
    return 0
  }
  db wal_hook wal_hook

  while {[tt_continue]} {
    set max 0
    while { $max != ($nextwrite-1) && [tt_continue] } {
      set max [db eval { SELECT max(cnt) FROM t1 }]
    }

    if {[tt_continue]} {
      set sum1 [db eval { SELECT sum(cnt) FROM t1 }]
      set sum2 [db eval { SELECT sum(sum1) FROM t1 }]
      db eval { INSERT INTO t1 VALUES($nextwrite, $sum1, $sum2) }
      incr nextwrite $E(nthread)
      integrity_check
    }
  }

  set {} ok
} -check {
  puts "  Final db contains [db eval {SELECT count(*) FROM t1}] rows"
  puts "  Final integrity-check says: [db eval {PRAGMA integrity_check}]"

  # Check that the contents of the database are Ok.
  set c 0
  set s1 0
  set s2 0
  db eval { SELECT cnt, sum1, sum2 FROM t1 ORDER BY cnt } {
    if {$c != $cnt || $s1 != $sum1 || $s2 != $sum2} {
      error "database content is invalid"
    }
    incr s2 $s1
    incr s1 $c
    incr c 1
  }
}

do_thread_test2 walthread-4 -seconds $seconds(walthread-4) -init {
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE);
  }
} -thread r 1 {
  # This connection only ever reads the database. Therefore the 
  # busy-handler is not required. Disable it to check that this is true.
  db busy {}
  while {[tt_continue]} integrity_check
  set {} ok
} -thread w 1 {

  proc wal_hook {zDb nEntry} {
    if {$nEntry>15} { return 1 }
    return 0
  }
  db wal_hook wal_hook
  set row 1
  while {[tt_continue]} {
    db eval { REPLACE INTO t1 VALUES($row, randomblob(300)) }
    incr row
    if {$row == 10} { set row 1 }
  }

  set {} ok
}


# This test case attempts to provoke a deadlock condition that existed in
# the unix VFS at one point. The problem occurred only while recovering a 
# very large wal file (one that requires a wal-index larger than the 
# initial default allocation of 64KB).
#
do_thread_test walthread-5 -seconds $seconds(walthread-5) -init {

  proc log_file_size {nFrame pgsz} {
    expr {12 + ($pgsz+16)*$nFrame}
  }

  execsql {
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(x);
    BEGIN;
      INSERT INTO t1 VALUES(randomblob(900));
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*     2 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*     4 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*     8 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*    16 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*    32 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*    64 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*   128 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*   256 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*   512 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  1024 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  2048 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  4096 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  8192 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /* 16384 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /* 32768 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;      /* 65536 */
    COMMIT;
  }

  file copy -force test.db-wal bak.db-wal
  file copy -force test.db bak.db
  db close

  file copy -force bak.db-wal test.db-wal
  file copy -force bak.db test.db

  if {[file size test.db-wal] < [log_file_size [expr 64*1024] 1024]} {
    error "Somehow failed to create a large log file"
  }
  puts "Database with large log file recovered. Now running clients..."
} -thread T 5 {
  db eval { SELECT count(*) FROM t1 }
}

finish_test

Changes to tool/mksqlite3c.tcl.

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...
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   sqlite3ext.h
   sqlite3.h
   sqliteicu.h
   sqliteInt.h
   sqliteLimit.h
   vdbe.h
   vdbeInt.h

} {
  set available_hdr($hdr) 1
}
set available_hdr(sqliteInt.h) 0

# 78 stars used for comment formatting.
set s78 \
................................................................................
   os_unix.c
   os_win.c

   bitvec.c
   pcache.c
   pcache1.c
   rowset.c

   pager.c

   btmutex.c
   btree.c
   backup.c

   vdbemem.c







>







 







>







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   sqlite3ext.h
   sqlite3.h
   sqliteicu.h
   sqliteInt.h
   sqliteLimit.h
   vdbe.h
   vdbeInt.h
   wal.h
} {
  set available_hdr($hdr) 1
}
set available_hdr(sqliteInt.h) 0

# 78 stars used for comment formatting.
set s78 \
................................................................................
   os_unix.c
   os_win.c

   bitvec.c
   pcache.c
   pcache1.c
   rowset.c
   wal.c
   pager.c

   btmutex.c
   btree.c
   backup.c

   vdbemem.c