SQLite

/*
** 2003 April 6
**
** 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 to implement the ATTACH and DETACH commands.
**
** $Id: attach.c,v 1.55 2007/03/24 16:45:05 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
** identifiers are treated as strings, not possible column names or aliases.

    if( !aNew->pSchema ){
      rc = SQLITE_NOMEM;
    }else if( aNew->pSchema->file_format && aNew->pSchema->enc!=ENC(db) ){
      strcpy(zErr, 
        "attached databases must use the same text encoding as main database");
      goto attach_error;
    }
    sqlite3PagerLockingMode(sqlite3BtreePager(aNew->pBt), db->dfltLockMode);
  }
  aNew->zName = sqliteStrDup(zName);
  aNew->safety_level = 3;

#if SQLITE_HAS_CODEC
  {
    extern int sqlite3CodecAttach(sqlite3*, int, void*, int);

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** 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.
**
** @(#) $Id: pager.c,v 1.294 2007/03/24 16:45:05 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  void *pCodecArg;            /* First argument to xCodec() */
  int nHash;                  /* Size of the pager hash table */
  PgHdr **aHash;              /* Hash table to map page number to PgHdr */
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  Pager *pNext;               /* Linked list of pagers in this thread */
#endif
  char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */

  u32 iChangeCount;           /* Db change-counter for which cache is valid */
  u8 doNotSync;               /* Boolean. While true, do not spill the cache */
  u8 exclusiveMode;           /* Boolean. True if locking_mode==EXCLUSIVE */
  u8 changeCountDone;         /* Set after incrementing the change-counter */
};

/*
** If SQLITE_TEST is defined then increment the variable given in
** the argument
*/
#ifdef SQLITE_TEST

  return p;
}

/*
** Unlock the database file.
*/
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    if( !MEMDB ){
      sqlite3OsUnlock(pPager->fd, NO_LOCK);
      pPager->dbSize = -1;
      IOTRACE(("UNLOCK %p\n", pPager))
    }
    pPager->state = PAGER_UNLOCK;
    pPager->changeCountDone = 0;
  }
}

/*
** Execute a rollback if a transaction is active and unlock the 
** database file. This is a no-op if the pager has already entered
** the error-state.
*/
static void pagerUnlockAndRollback(Pager *pPager){
  if( pPager->errCode ) return;
  if( pPager->state>=PAGER_RESERVED ){
    sqlite3PagerRollback(pPager);
  }
  pager_unlock(pPager);

}


/*
** Unlock the database and clear the in-memory cache.  This routine
** sets the state of the pager back to what it was when it was first
** opened.  Any outstanding pages are invalidated and subsequent attempts

  pPager->nHash = 0;
  sqliteFree(pPager->aHash);
  pPager->nPage = 0;
  pPager->aHash = 0;
  pPager->nRef = 0;
}























/*
** When this routine is called, the pager has the journal file open and
** a RESERVED or EXCLUSIVE lock on the database.  This routine releases
** the database lock and acquires a SHARED lock in its place.  The journal
** file is deleted and closed.
**
** TODO: Consider keeping the journal file open for temporary databases.
** This might give a performance improvement on windows where opening
** a file is an expensive operation.
*/
static int pager_unwritelock(Pager *pPager){
  PgHdr *pPg;
  int rc = SQLITE_OK;
  assert( !MEMDB );
  if( pPager->state<PAGER_RESERVED ){
    return SQLITE_OK;
  }
  sqlite3PagerStmtCommit(pPager);
  if( pPager->stmtOpen ){
    sqlite3OsClose(&pPager->stfd);
    pPager->stmtOpen = 0;
  }
  if( pPager->journalOpen ){
    if( pPager->exclusiveMode ){
      sqlite3OsTruncate(pPager->jfd, 0);
      sqlite3OsSeek(pPager->jfd, 0);
      pPager->journalOff = 0;
    }else{
      sqlite3OsClose(&pPager->jfd);
      pPager->journalOpen = 0;
      sqlite3OsDelete(pPager->zJournal);
    }
    sqliteFree( pPager->aInJournal );
    pPager->aInJournal = 0;
    for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
      pPg->inJournal = 0;
      pPg->dirty = 0;
      pPg->needSync = 0;
      pPg->alwaysRollback = 0;
#ifdef SQLITE_CHECK_PAGES
      pPg->pageHash = pager_pagehash(pPg);
#endif
    }
    pPager->pDirty = 0;
    pPager->dirtyCache = 0;
    pPager->nRec = 0;
  }else{
    assert( pPager->aInJournal==0 );
    assert( pPager->dirtyCache==0 || pPager->useJournal==0 );
  }
  if( !pPager->exclusiveMode ){
    rc = sqlite3OsUnlock(pPager->fd, SHARED_LOCK);
    pPager->state = PAGER_SHARED;
    pPager->origDbSize = 0;
  }else{
    sqlite3PagerPagecount(pPager);
    pPager->origDbSize = pPager->dbSize;
    pPager->aInJournal = sqliteMalloc( pPager->dbSize/8 + 1 );
    if( !pPager->aInJournal ){
      rc = SQLITE_NOMEM;
    }
  }
  pPager->setMaster = 0;
  pPager->needSync = 0;
  pPager->pFirstSynced = pPager->pFirst;
  pPager->dbSize = -1;
  return rc;
}

    if( pPager->xDestructor ){  /*** FIX ME:  Should this be xReinit? ***/
      pPager->xDestructor(pPg, pPager->pageSize);
    }
#ifdef SQLITE_CHECK_PAGES
    pPg->pageHash = pager_pagehash(pPg);
#endif
    CODEC1(pPager, pData, pPg->pgno, 3);

    /* If this was page 1, then restore the value of Pager.iChangeCount */
    if( pgno==1 ){
      pPager->iChangeCount = retrieve32bits(pPg, 24);
    }
  }
  return rc;
}

/*
** Parameter zMaster is the name of a master journal file. A single journal
** file that referred to the master journal file has just been rolled back.

  }  
  if( master_open ){
    sqlite3OsClose(&master);
  }
  return rc;
}

#if 0
/*
** Make every page in the cache agree with what is on disk.  In other words,
** reread the disk to reset the state of the cache.
**
** This routine is called after a rollback in which some of the dirty cache
** pages had never been written out to disk.  We need to roll back the
** cache content and the easiest way to do that is to reread the old content

#ifdef SQLITE_CHECK_PAGES
    pPg->pageHash = pager_pagehash(pPg);
#endif
  }
  pPager->pDirty = 0;
  return rc;
}
#endif

/*
** Truncate the main file of the given pager to the number of pages
** indicated.
*/
static int pager_truncate(Pager *pPager, int nPage){
  assert( pPager->state>=PAGER_EXCLUSIVE );

  ThreadData *pTsd = sqlite3ThreadData();
  assert( pPager );
  assert( pTsd && pTsd->nAlloc );
#endif

  disable_simulated_io_errors();
  pPager->errCode = 0;
  pPager->exclusiveMode = 0;
  pager_reset(pPager);
  pagerUnlockAndRollback(pPager);
  enable_simulated_io_errors();
  TRACE2("CLOSE %d\n", PAGERID(pPager));
  IOTRACE(("CLOSE %p\n", pPager))
  assert( pPager->errCode || (pPager->journalOpen==0 && pPager->stmtOpen==0) );
  if( pPager->journalOpen ){

          */
          u32 iChangeCount = retrieve32bits(pPage1, 24);
          pPager->nRef++;
          sqlite3PagerUnref(pPage1);
          pPager->nRef--;
          if( iChangeCount!=pPager->iChangeCount ){
            pager_reset(pPager);


          }
          pPager->iChangeCount = iChangeCount;
        }
      }
    }
    pPager->state = PAGER_SHARED;
  }

  TRACE2("ROLLBACK %d\n", PAGERID(pPager));
  if( MEMDB ){
    PgHdr *p;
    for(p=pPager->pAll; p; p=p->pNextAll){
      PgHistory *pHist;
      assert( !p->alwaysRollback );
      if( !p->dirty ){
        assert( p->inJournal==0 );
        assert( p->inStmt==0 );
        assert( !((PgHistory *)PGHDR_TO_HIST(p, pPager))->pOrig );
        assert( !((PgHistory *)PGHDR_TO_HIST(p, pPager))->pStmt );
        continue;
      }

      pHist = PGHDR_TO_HIST(p, pPager);
      if( pHist->pOrig ){

  /* Increment the value just read and write it back to byte 24. */
  change_counter++;
  put32bits(((char*)PGHDR_TO_DATA(pPgHdr))+24, change_counter);
  pPager->iChangeCount = change_counter;

  /* Release the page reference. */
  sqlite3PagerUnref(pPgHdr);
  pPager->changeCountDone = 1;
  return SQLITE_OK;
}

/*
** Sync the database file for the pager pPager. zMaster points to the name
** of a master journal file that should be written into the individual
** journal file. zMaster may be NULL, which is interpreted as no master

** Return a pointer to the Pager.nExtra bytes of "extra" space 
** allocated along with the specified page.
*/
void *sqlite3PagerGetExtra(DbPage *pPg){
  Pager *pPager = pPg->pPager;
  return (pPager?PGHDR_TO_EXTRA(pPg, pPager):0);
}

/*
** Get/set the locking-mode for this pager. Parameter eMode must be one
** of PAGER_LOCKINGMODE_QUERY, PAGER_LOCKINGMODE_NORMAL or 
** PAGER_LOCKINGMODE_EXCLUSIVE. If the parameter is not _QUERY, then
** the locking-mode is set to the value specified.
**
** The returned value is either PAGER_LOCKINGMODE_NORMAL or
** PAGER_LOCKINGMODE_EXCLUSIVE, indicating the current (possibly updated)
** locking-mode.
*/
int sqlite3PagerLockingMode(Pager *pPager, int eMode){
  if( eMode>=0 ){
    pPager->exclusiveMode = eMode;
  }
  return (int)pPager->exclusiveMode;
}

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
/*
** Return the current state of the file lock for the given pager.
** The return value is one of NO_LOCK, SHARED_LOCK, RESERVED_LOCK,
** PENDING_LOCK, or EXCLUSIVE_LOCK.
*/

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.55 2007/03/24 16:45:05 danielk1977 Exp $
*/

#ifndef _PAGER_H_
#define _PAGER_H_

/*
** The default size of a database page.

** Allowed values for the flags parameter to sqlite3PagerOpen().
**
** NOTE: This values must match the corresponding BTREE_ values in btree.h.
*/
#define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
#define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */

/*
** Valid values for the second argument to sqlite3PagerLockingMode().
*/
#define PAGER_LOCKINGMODE_QUERY      -1
#define PAGER_LOCKINGMODE_NORMAL      0
#define PAGER_LOCKINGMODE_EXCLUSIVE   1

/*
** See source code comments for a detailed description of the following
** routines:
*/
int sqlite3PagerOpen(Pager **ppPager, const char *zFilename,
                     int nExtra, int flags);

void sqlite3PagerSetCodec(Pager*,void*(*)(void*,void*,Pgno,int),void*);
int sqlite3PagerMovepage(Pager*,DbPage*,Pgno);
int sqlite3PagerReset(Pager*);
int sqlite3PagerReleaseMemory(int);

void *sqlite3PagerGetData(DbPage *); 
void *sqlite3PagerGetExtra(DbPage *); 
int sqlite3PagerLockingMode(Pager *, int);

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
int sqlite3PagerLockstate(Pager*);
#endif

#ifdef SQLITE_TEST
void sqlite3PagerRefdump(Pager*);
int pager3_refinfo_enable;
#endif

#endif /* _PAGER_H_ */

/*
** 2003 April 6
**
** 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 to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.130 2007/03/24 16:45:05 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/

/*
** Interpret the given string as a boolean value.
*/
static int getBoolean(const char *z){
  return getSafetyLevel(z)&1;
}

/*
** Interpret the given string as a locking mode value.
*/
static int getLockingMode(const char *z){
  if( z ){
    if( 0==sqlite3StrICmp(z, "exclusive") ) return PAGER_LOCKINGMODE_EXCLUSIVE;
    if( 0==sqlite3StrICmp(z, "normal") ) return PAGER_LOCKINGMODE_NORMAL;
  }
  return PAGER_LOCKINGMODE_QUERY;
}

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** Interpret the given string as a temp db location. Return 1 for file
** backed temporary databases, 2 for the Red-Black tree in memory database
** and 0 to use the compile-time default.
*/

    if( !zRight ){
      int size = pBt ? sqlite3BtreeGetPageSize(pBt) : 0;
      returnSingleInt(pParse, "page_size", size);
    }else{
      sqlite3BtreeSetPageSize(pBt, atoi(zRight), -1);
    }
  }else

  /*
  **  PRAGMA [database.]locking_mode
  **  PRAGMA [database.]locking_mode = (normal|exclusive)
  */
  if( sqlite3StrICmp(zLeft,"locking_mode")==0 ){
    const char *zRet = "normal";
    int eMode = getLockingMode(zRight);

    if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){
      /* Simple "PRAGMA locking_mode;" statement. This is a query for
      ** the current default locking mode (which may be different to
      ** the locking-mode of the main database).
      */
      eMode = db->dfltLockMode;
    }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 locking-mode must be
        ** set on all attached databases, as well as the main db file.
        **
        ** Also, the sqlite3.dfltLockMode variable is set so that
        ** any subsequently attached databases also use the specified
        ** locking mode.
        */
        int ii;
        assert(pDb==&db->aDb[0]);
        for(ii=2; ii<db->nDb; ii++){
          pPager = sqlite3BtreePager(db->aDb[ii].pBt);
          sqlite3PagerLockingMode(pPager, eMode);
        }
        db->dfltLockMode = eMode;
      }
      pPager = sqlite3BtreePager(pDb->pBt);
      eMode = sqlite3PagerLockingMode(pPager, eMode);
    }

    assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
    if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
      zRet = "exclusive";
    }
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", P3_STATIC);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, zRet, 0);
    sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
  }else
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  /*
  **  PRAGMA [database.]auto_vacuum
  **  PRAGMA [database.]auto_vacuum=N
  **
  ** Get or set the (boolean) value of the database 'auto-vacuum' parameter.

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.543 2007/03/24 16:45:05 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Extra interface definitions for those who need them
*/

  Hash aCollSeq;                /* All collating sequences */
  BusyHandler busyHandler;      /* Busy callback */
  int busyTimeout;              /* Busy handler timeout, in msec */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
#ifdef SQLITE_SSE
  sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
#endif
  u8 dfltLockMode;              /* Default locking-mode for attached dbs */
};

/*
** A macro to discover the encoding of a database.
*/
#define ENC(db) ((db)->aDb[0].pSchema->enc)

# 2007 March 24
#
# 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.
#
# $Id: exclusive.test,v 1.1 2007/03/24 16:45:05 danielk1977 Exp $

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

ifcapable {!pager_pragmas} {
  finish_test
  return
}

file delete -force test2.db-journal
file delete -force test2.db
file delete -force test3.db-journal
file delete -force test3.db
file delete -force test4.db-journal
file delete -force test4.db

#----------------------------------------------------------------------
# Test cases exclusive-1.X test the PRAGMA logic.
#
do_test exclusive-1.0 {
  execsql {
    pragma locking_mode;
    pragma main.locking_mode;
  } 
} {normal normal}
do_test exclusive-1.1 {
  execsql {
    pragma locking_mode = exclusive;
  } 
} {exclusive}
do_test exclusive-1.2 {
  execsql {
    pragma locking_mode;
    pragma main.locking_mode;
  } 
} {exclusive exclusive}
do_test exclusive-1.3 {
  execsql {
    pragma locking_mode = normal;
  } 
} {normal}
do_test exclusive-1.4 {
  execsql {
    pragma locking_mode;
    pragma main.locking_mode;
  } 
} {normal normal}
do_test exclusive-1.5 {
  execsql {
    pragma locking_mode = invalid;
  } 
} {normal}
do_test exclusive-1.6 {
  execsql {
    pragma locking_mode;
    pragma main.locking_mode;
  } 
} {normal normal}
do_test exclusive-1.7 {
  execsql {
    pragma locking_mode = exclusive;
    ATTACH 'test2.db' as aux;
  }
  execsql {
    pragma main.locking_mode;
    pragma aux.locking_mode;
  }
} {exclusive exclusive}
do_test exclusive-1.8 {
  execsql {
    pragma main.locking_mode = normal;
  }
  execsql {
    pragma main.locking_mode;
    pragma aux.locking_mode;
  }
} {normal exclusive}
do_test exclusive-1.9 {
  execsql {
    pragma locking_mode;
  }
} {exclusive}
do_test exclusive-1.10 {
  execsql {
    ATTACH 'test3.db' as aux2;
  }
  execsql {
    pragma main.locking_mode;
    pragma aux.locking_mode;
    pragma aux2.locking_mode;
  }
} {normal exclusive exclusive}
do_test exclusive-1.11 {
  execsql {
    pragma aux.locking_mode = normal;
  }
  execsql {
    pragma main.locking_mode;
    pragma aux.locking_mode;
    pragma aux2.locking_mode;
  }
} {normal normal exclusive}
do_test exclusive-1.12 {
  execsql {
    pragma locking_mode = normal;
  }
  execsql {
    pragma main.locking_mode;
    pragma aux.locking_mode;
    pragma aux2.locking_mode;
  }
} {normal normal normal}
do_test exclusive-1.13 {
  execsql {
    ATTACH 'test4.db' as aux3;
  }
  execsql {
    pragma main.locking_mode;
    pragma aux.locking_mode;
    pragma aux2.locking_mode;
    pragma aux3.locking_mode;
  }
} {normal normal normal normal}

do_test exclusive-1.99 {
  execsql {
    DETACH aux;
    DETACH aux2;
    DETACH aux3;
  }
} {}

#----------------------------------------------------------------------
# Test cases exclusive-2.X verify that connections in exclusive 
# locking_mode do not relinquish locks.
#
do_test exclusive-2.0 {
  execsql {
    CREATE TABLE abc(a, b, c);
    INSERT INTO abc VALUES(1, 2, 3);
    PRAGMA locking_mode = exclusive;
  }
} {exclusive}
do_test exclusive-2.1 {
  sqlite3 db2 test.db
  execsql {
    INSERT INTO abc VALUES(4, 5, 6);
    SELECT * FROM abc;
  } db2
} {1 2 3 4 5 6}
do_test exclusive-2.2 {
  # This causes connection 'db' (in exclusive mode) to establish 
  # a shared-lock on the db. The other connection should now be
  # locked out as a writer.
  execsql {
    SELECT * FROM abc;
  } db
} {1 2 3 4 5 6}
do_test exclusive-2.4 {
  execsql {
    SELECT * FROM abc;
  } db2
} {1 2 3 4 5 6}
do_test exclusive-2.5 {
  catchsql {
    INSERT INTO abc VALUES(7, 8, 9);
  } db2
} {1 {database is locked}}
do_test exclusive-2.6 {
  # Because connection 'db' only has a shared-lock, the other connection
  # will be able to get a RESERVED, but will fail to upgrade to EXCLUSIVE.
  execsql {
    BEGIN;
    INSERT INTO abc VALUES(7, 8, 9);
  } db2
  catchsql {
    COMMIT
  } db2
} {1 {database is locked}}
do_test exclusive-2.7 {
  catchsql {
    COMMIT
  } db2
} {1 {database is locked}}
do_test exclusive-2.8 {
  execsql {
    ROLLBACK;
  } db2
} {}

do_test exclusive-2.9 {
  # Write the database to establish the exclusive lock with connection 'db.
  execsql {
    INSERT INTO abc VALUES(7, 8, 9);
  } db
  catchsql {
    SELECT * FROM abc;
  } db2
} {1 {database is locked}}
do_test exclusive-2.10 {
  # Changing the locking-mode does not release any locks.
  execsql {
    PRAGMA locking_mode = normal;
  } db
  catchsql {
    SELECT * FROM abc;
  } db2
} {1 {database is locked}}
do_test exclusive-2.11 {
  # After changing the locking mode, accessing the db releases locks.
  execsql {
    SELECT * FROM abc;
  } db
  execsql {
    SELECT * FROM abc;
  } db2
} {1 2 3 4 5 6 7 8 9}
db2 close

#----------------------------------------------------------------------
# Tests exclusive-3.X - test that a connection in exclusive mode 
# truncates instead of deletes the journal file when committing 
# a transaction.
#
proc filestate {fname} {
  set exists 0
  set content 0
  if {[file exists $fname]} {
    set exists 1
    set content [expr {[file size $fname] > 0}]
  }
  list $exists $content
}
do_test exclusive-3.0 {
  filestate test.db-journal
} {0 0}
do_test exclusive-3.1 {
  execsql {
    PRAGMA locking_mode = exclusive;
    BEGIN;
    DELETE FROM abc;
  }
  filestate test.db-journal
} {1 1}
do_test exclusive-3.2 {
  execsql {
    COMMIT;
  }
  filestate test.db-journal
} {1 0}
do_test exclusive-3.3 {
  execsql {
    INSERT INTO abc VALUES('A', 'B', 'C');
    SELECT * FROM abc;
  }
} {A B C}
do_test exclusive-3.4 {
  execsql {
    BEGIN;
    UPDATE abc SET a = 1, b = 2, c = 3;
    ROLLBACK;
    SELECT * FROM abc;
  }
} {1 2 3}
do_test exclusive-3.5 {
  filestate test.db-journal
} {1 0}
do_test exclusive-3.6 {
  execsql {
    PRAGMA locking_mode = normal;
    SELECT * FROM abc;
  }
  filestate test.db-journal
} {0 0}

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

if 0 {

do_test exclusive-4.0 {
  execsql { PRAGMA default_cache_size=10; }
  db close
  sqlite3 db test.db
  execsql { PRAGMA locking_mode = exclusive; }
  execsql {
    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;
    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;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    COMMIT;
    SELECT count(*) FROM t3;
  }
} {1024}
set sig [signature]
do_test exclusive-4.1 {
  execsql {
    BEGIN;
    DELETE FROM t3 WHERE random()%10!=0;
    INSERT INTO t3 SELECT randstr(10,10)||x FROM t3;
    INSERT INTO t3 SELECT randstr(10,10)||x FROM t3;
    ROLLBACK;
  }
  signature
} $sig

}

finish_test

# 2001 September 15
#
# 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 script is database locks.
#
# $Id: trans.test,v 1.33 2007/03/24 16:45:05 danielk1977 Exp $


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


# Create several tables to work with.

#
do_test trans-9.1 {
  execsql {
    PRAGMA default_cache_size=10;
  }
  db close
  sqlite3 db test.db
  # execsql { PRAGMA locking_mode = exclusive; }
  execsql {
    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;