SQLite

!ENDIF


# Additional compiler options for the shell.  These are only effective
# when the shell is not being dynamically linked.
#
!IF $(DYNAMIC_SHELL)==0 && $(FOR_WIN10)==0
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_SHELL_JSON1 -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_EXPLAIN_COMMENTS -DSQLITE_ENABLE_STMTVTAB
!ENDIF


# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	dll shell

/*
** 2017 July 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 contains the implementation of the "unionvtab" and "swarmvtab"
** virtual tables. These modules provide read-only access to multiple tables,
** possibly in multiple database files, via a single database object.
** The source tables must have the following characteristics:
**
**   * They must all be rowid tables (not VIRTUAL or WITHOUT ROWID
**     tables or views).
**
**   * Each table must have the same set of columns, declared in
**     the same order and with the same declared types.
**
**   * The tables must not feature a user-defined column named "_rowid_".
**
**   * Each table must contain a distinct range of rowid values.
**
** The difference between the two virtual table modules is that for 
** "unionvtab", all source tables must be located in the main database or
** in databases ATTACHed to the main database by the user. For "swarmvtab",
** the tables may be located in any database file on disk. The "swarmvtab"
** implementation takes care of opening and closing database files
** automatically.
**
** UNIONVTAB
**
**   A "unionvtab" virtual table is created as follows:
**
**     CREATE VIRTUAL TABLE <name> USING unionvtab(<sql-statement>);
**
**   The implementation evalutes <sql statement> whenever a unionvtab virtual
**   table is created or opened. It should return one row for each source
**   database table. The four columns required of each row are:
**
**     1. The name of the database containing the table ("main" or "temp" or
**        the name of an attached database). Or NULL to indicate that all
**        databases should be searched for the table in the usual fashion.
**
**     2. The name of the database table.
**
**     3. The smallest rowid in the range of rowids that may be stored in the
**        database table (an integer).
**
**     4. The largest rowid in the range of rowids that may be stored in the
**        database table (an integer).
**
** SWARMVTAB
**
**   A "swarmvtab" virtual table is created similarly to a unionvtab table:
**
**     CREATE VIRTUAL TABLE <name>
**      USING swarmvtab(<sql-statement>, <callback>);
**
**   The difference is that for a swarmvtab table, the first column returned
**   by the <sql statement> must return a path or URI that can be used to open
**   the database file containing the source table.  The <callback> option
**   is optional.  If included, it is the name of an application-defined
**   SQL function that is invoked with the URI of the file, if the file
**   does not already exist on disk.
*/

#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Largest and smallest possible 64-bit signed integers. These macros
** copied from sqliteInt.h.
*/
#ifndef LARGEST_INT64
# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
#endif
#ifndef SMALLEST_INT64
# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif

/*
** The following is also copied from sqliteInt.h. To facilitate coverage
** testing.
*/
#ifndef ALWAYS
# if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
#  define ALWAYS(X)      (1)
#  define NEVER(X)       (0)
# elif !defined(NDEBUG)
#  define ALWAYS(X)      ((X)?1:(assert(0),0))
#  define NEVER(X)       ((X)?(assert(0),1):0)
# else
#  define ALWAYS(X)      (X)
#  define NEVER(X)       (X)
# endif
#endif

/*
** The swarmvtab module attempts to keep the number of open database files
** at or below this limit. This may not be possible if there are too many
** simultaneous queries.
*/
#define SWARMVTAB_MAX_OPEN 9

typedef struct UnionCsr UnionCsr;
typedef struct UnionTab UnionTab;
typedef struct UnionSrc UnionSrc;

/*
** Each source table (row returned by the initialization query) is 
** represented by an instance of the following structure stored in the
** UnionTab.aSrc[] array.
*/
struct UnionSrc {
  char *zDb;                      /* Database containing source table */
  char *zTab;                     /* Source table name */
  sqlite3_int64 iMin;             /* Minimum rowid */
  sqlite3_int64 iMax;             /* Maximum rowid */

  /* Fields used by swarmvtab only */
  char *zFile;                    /* Database file containing table zTab */
  int nUser;                      /* Current number of users */
  sqlite3 *db;                    /* Database handle */
  UnionSrc *pNextClosable;        /* Next in list of closable sources */
};

/*
** Virtual table  type for union vtab.
*/
struct UnionTab {
  sqlite3_vtab base;              /* Base class - must be first */
  sqlite3 *db;                    /* Database handle */
  int bSwarm;                     /* 1 for "swarmvtab", 0 for "unionvtab" */
  int iPK;                        /* INTEGER PRIMARY KEY column, or -1 */
  int nSrc;                       /* Number of elements in the aSrc[] array */
  UnionSrc *aSrc;                 /* Array of source tables, sorted by rowid */

  /* Used by swarmvtab only */
  char *zSourceStr;               /* Expected unionSourceToStr() value */
  char *zNotFoundCallback;        /* UDF to invoke if file not found on open */
  UnionSrc *pClosable;            /* First in list of closable sources */
  int nOpen;                      /* Current number of open sources */
  int nMaxOpen;                   /* Maximum number of open sources */
};

/*
** Virtual table cursor type for union vtab.
*/
struct UnionCsr {
  sqlite3_vtab_cursor base;       /* Base class - must be first */
  sqlite3_stmt *pStmt;            /* SQL statement to run */

  /* Used by swarmvtab only */
  sqlite3_int64 iMaxRowid;        /* Last rowid to visit */
  int iTab;                       /* Index of table read by pStmt */
};

/*
** Given UnionTab table pTab and UnionSrc object pSrc, return the database
** handle that should be used to access the table identified by pSrc. This
** is the main db handle for "unionvtab" tables, or the source-specific 
** handle for "swarmvtab".
*/
#define unionGetDb(pTab, pSrc) ((pTab)->bSwarm ? (pSrc)->db : (pTab)->db)

/*
** If *pRc is other than SQLITE_OK when this function is called, it
** always returns NULL. Otherwise, it attempts to allocate and return
** a pointer to nByte bytes of zeroed memory. If the memory allocation
** is attempted but fails, NULL is returned and *pRc is set to 
** SQLITE_NOMEM.
*/

    char q = z[0];

    /* Set stack variable q to the close-quote character */
    if( q=='[' || q=='\'' || q=='"' || q=='`' ){
      int iIn = 1;
      int iOut = 0;
      if( q=='[' ) q = ']';  
      while( ALWAYS(z[iIn]) ){
        if( z[iIn]==q ){
          if( z[iIn+1]!=q ){
            /* Character iIn was the close quote. */
            iIn++;
            break;
          }else{
            /* Character iIn and iIn+1 form an escaped quote character. Skip

static sqlite3_stmt *unionPrepare(
  int *pRc,                       /* IN/OUT: Error code */
  sqlite3 *db,                    /* Database handle */
  const char *zSql,               /* SQL statement to prepare */
  char **pzErr                    /* OUT: Error message */
){
  sqlite3_stmt *pRet = 0;
  assert( pzErr );
  if( *pRc==SQLITE_OK ){
    int rc = sqlite3_prepare_v2(db, zSql, -1, &pRet, 0);
    if( rc!=SQLITE_OK ){
      *pzErr = sqlite3_mprintf("sql error: %s", sqlite3_errmsg(db));
      *pRc = rc;
    }
  }

/*
** Call sqlite3_reset() on SQL statement pStmt. If *pRc is set to 
** SQLITE_OK when this function is called, then it is set to the
** value returned by sqlite3_reset() before this function exits.
** In this case, *pzErr may be set to point to an error message
** buffer allocated by sqlite3_malloc().
*/
#if 0
static void unionReset(int *pRc, sqlite3_stmt *pStmt, char **pzErr){
  int rc = sqlite3_reset(pStmt);
  if( *pRc==SQLITE_OK ){
    *pRc = rc;
    if( rc ){
      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(sqlite3_db_handle(pStmt)));
    }
  }
}
#endif

/*
** Call sqlite3_finalize() on SQL statement pStmt. If *pRc is set to 
** SQLITE_OK when this function is called, then it is set to the
** value returned by sqlite3_finalize() before this function exits.
*/
static void unionFinalize(int *pRc, sqlite3_stmt *pStmt, char **pzErr){
  sqlite3 *db = sqlite3_db_handle(pStmt);
  int rc = sqlite3_finalize(pStmt);
  if( *pRc==SQLITE_OK ){
    *pRc = rc;
    if( rc ){
      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
    }
  }
}

/*
** This function is a no-op for unionvtab. For swarmvtab, it attempts to
** close open database files until at most nMax are open. An SQLite error
** code is returned if an error occurs, or SQLITE_OK otherwise.
*/
static void unionCloseSources(UnionTab *pTab, int nMax){
  while( pTab->pClosable && pTab->nOpen>nMax ){
    UnionSrc **pp;
    for(pp=&pTab->pClosable; (*pp)->pNextClosable; pp=&(*pp)->pNextClosable);
    assert( (*pp)->db );
    sqlite3_close((*pp)->db);
    (*pp)->db = 0;
    *pp = 0;
    pTab->nOpen--;
  }
}

/*
** xDisconnect method.
*/
static int unionDisconnect(sqlite3_vtab *pVtab){
  if( pVtab ){
    UnionTab *pTab = (UnionTab*)pVtab;
    int i;
    for(i=0; i<pTab->nSrc; i++){
      UnionSrc *pSrc = &pTab->aSrc[i];
      sqlite3_free(pSrc->zDb);
      sqlite3_free(pSrc->zTab);
      sqlite3_free(pSrc->zFile);
      sqlite3_close(pSrc->db);
    }
    sqlite3_free(pTab->zSourceStr);
    sqlite3_free(pTab->zNotFoundCallback);
    sqlite3_free(pTab->aSrc);
    sqlite3_free(pTab);
  }
  return SQLITE_OK;
}

/*
** Check that the table identified by pSrc is a rowid table. If not,
** return SQLITE_ERROR and set (*pzErr) to point to an English language
** error message. If the table is a rowid table and no error occurs,
** return SQLITE_OK and leave (*pzErr) unmodified.
*/
static int unionIsIntkeyTable(
  sqlite3 *db,                    /* Database handle */
  UnionSrc *pSrc,                 /* Source table to test */
  char **pzErr                    /* OUT: Error message */
){
  int bPk = 0;
  const char *zType = 0;
  int rc;

  sqlite3_table_column_metadata(
      db, pSrc->zDb, pSrc->zTab, "_rowid_", &zType, 0, 0, &bPk, 0
  );
  rc = sqlite3_errcode(db);
  if( rc==SQLITE_ERROR 
   || (rc==SQLITE_OK && (!bPk || sqlite3_stricmp("integer", zType)))
  ){
    rc = SQLITE_ERROR;
    *pzErr = sqlite3_mprintf("no such rowid table: %s%s%s",
        (pSrc->zDb ? pSrc->zDb : ""),
        (pSrc->zDb ? "." : ""),
        pSrc->zTab
    );
  }
  return rc;
}

/*
** This function is a no-op if *pRc is other than SQLITE_OK when it is
** called. In this case it returns NULL.
**
** Otherwise, this function checks that the source table passed as the
** second argument (a) exists, (b) is not a view and (c) has a column 
** named "_rowid_" of type "integer" that is the primary key.
** If this is not the case, *pRc is set to SQLITE_ERROR and NULL is
** returned.
**
** Finally, if the source table passes the checks above, a nul-terminated
** string describing the column names and types belonging to the source
** table is returned. Tables with the same set of column names and types 
** cause this function to return identical strings. Is is the responsibility
** of the caller to free the returned string using sqlite3_free() when
** it is no longer required.
*/
static char *unionSourceToStr(
  int *pRc,                       /* IN/OUT: Error code */
  UnionTab *pTab,                 /* Virtual table object */
  UnionSrc *pSrc,                 /* Source table to test */

  char **pzErr                    /* OUT: Error message */
){
  char *zRet = 0;
  if( *pRc==SQLITE_OK ){
    sqlite3 *db = unionGetDb(pTab, pSrc);

    int rc = unionIsIntkeyTable(db, pSrc, pzErr);
    sqlite3_stmt *pStmt = unionPrepare(&rc, db, 
        "SELECT group_concat(quote(name) || '.' || quote(type)) "
        "FROM pragma_table_info(?, ?)", pzErr

    );












    if( rc==SQLITE_OK ){
      sqlite3_bind_text(pStmt, 1, pSrc->zTab, -1, SQLITE_STATIC);
      sqlite3_bind_text(pStmt, 2, pSrc->zDb, -1, SQLITE_STATIC);
      if( SQLITE_ROW==sqlite3_step(pStmt) ){
        const char *z = (const char*)sqlite3_column_text(pStmt, 0);
        zRet = unionStrdup(&rc, z);
      }
      unionFinalize(&rc, pStmt, pzErr);
    }

    *pRc = rc;
  }

  return zRet;
}

/*
** Check that all configured source tables exist and have the same column
** names and datatypes. If this is not the case, or if some other error
** occurs, return an SQLite error code. In this case *pzErr may be set
** to point to an error message buffer allocated by sqlite3_mprintf().
** Or, if no problems regarding the source tables are detected and no
** other error occurs, SQLITE_OK is returned.
*/
static int unionSourceCheck(UnionTab *pTab, char **pzErr){
  int rc = SQLITE_OK;
  char *z0 = 0;
  int i;

  assert( *pzErr==0 );
  z0 = unionSourceToStr(&rc, pTab, &pTab->aSrc[0], pzErr);
  for(i=1; i<pTab->nSrc; i++){
    char *z = unionSourceToStr(&rc, pTab, &pTab->aSrc[i], pzErr);
    if( rc==SQLITE_OK && sqlite3_stricmp(z, z0) ){
      *pzErr = sqlite3_mprintf("source table schema mismatch");
      rc = SQLITE_ERROR;
    }
    sqlite3_free(z);
  }
  sqlite3_free(z0);

  return rc;
}


/*
** Try to open the swarmvtab database.  If initially unable, invoke the
** not-found callback UDF and then try again.
*/
static int unionOpenDatabaseInner(UnionTab *pTab, UnionSrc *pSrc, char **pzErr){
  int rc = SQLITE_OK;
  static const int openFlags = 
       SQLITE_OPEN_READONLY | SQLITE_OPEN_URI;
  rc = sqlite3_open_v2(pSrc->zFile, &pSrc->db, openFlags, 0);
  if( rc==SQLITE_OK ) return rc;
  if( pTab->zNotFoundCallback ){
    char *zSql = sqlite3_mprintf("SELECT \"%w\"(%Q);",
                    pTab->zNotFoundCallback, pSrc->zFile);
    sqlite3_close(pSrc->db);
    pSrc->db = 0;
    if( zSql==0 ){
      *pzErr = sqlite3_mprintf("out of memory");
      return SQLITE_NOMEM;
    }
    rc = sqlite3_exec(pTab->db, zSql, 0, 0, pzErr);
    sqlite3_free(zSql);
    if( rc ) return rc;
    rc = sqlite3_open_v2(pSrc->zFile, &pSrc->db, openFlags, 0);
  }
  if( rc!=SQLITE_OK ){
    *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(pSrc->db));
  }
  return rc;
}

/*
** This function may only be called for swarmvtab tables. The results of
** calling it on a unionvtab table are undefined.
**
** For a swarmvtab table, this function ensures that source database iSrc
** is open. If the database is opened successfully and the schema is as
** expected, or if it is already open when this function is called, SQLITE_OK
** is returned.
**
** Alternatively If an error occurs while opening the databases, or if the
** database schema is unsuitable, an SQLite error code is returned and (*pzErr)
** may be set to point to an English language error message. In this case it is
** the responsibility of the caller to eventually free the error message buffer
** using sqlite3_free(). 
*/
static int unionOpenDatabase(UnionTab *pTab, int iSrc, char **pzErr){
  int rc = SQLITE_OK;
  UnionSrc *pSrc = &pTab->aSrc[iSrc];

  assert( pTab->bSwarm && iSrc<pTab->nSrc );
  if( pSrc->db==0 ){
    unionCloseSources(pTab, pTab->nMaxOpen-1);
    rc = unionOpenDatabaseInner(pTab, pSrc, pzErr);
    if( rc==SQLITE_OK ){
      char *z = unionSourceToStr(&rc, pTab, pSrc, pzErr);
      if( rc==SQLITE_OK ){
        if( pTab->zSourceStr==0 ){
          pTab->zSourceStr = z;
        }else{
          if( sqlite3_stricmp(z, pTab->zSourceStr) ){
            *pzErr = sqlite3_mprintf("source table schema mismatch");
            rc = SQLITE_ERROR;

          }
          sqlite3_free(z);


        }
      }
    }

    if( rc==SQLITE_OK ){
      pSrc->pNextClosable = pTab->pClosable;
      pTab->pClosable = pSrc;
      pTab->nOpen++;
    }else{
      sqlite3_close(pSrc->db);
      pSrc->db = 0;
    }
  }

  return rc;
}


/*
** This function is a no-op for unionvtab tables. For swarmvtab, increment 
** the reference count for source table iTab. If the reference count was
** zero before it was incremented, also remove the source from the closable
** list.
*/
static void unionIncrRefcount(UnionTab *pTab, int iTab){
  if( pTab->bSwarm ){
    UnionSrc *pSrc = &pTab->aSrc[iTab];
    assert( pSrc->nUser>=0 && pSrc->db );
    if( pSrc->nUser==0 ){
      UnionSrc **pp;
      for(pp=&pTab->pClosable; *pp!=pSrc; pp=&(*pp)->pNextClosable);
      *pp = pSrc->pNextClosable;
      pSrc->pNextClosable = 0;
    }

    pSrc->nUser++;
  }
}

/*
** Finalize the SQL statement pCsr->pStmt and return the result.
**
** If this is a swarmvtab table (not unionvtab) and pCsr->pStmt was not
** NULL when this function was called, also decrement the reference
** count on the associated source table. If this means the source tables
** refcount is now zero, add it to the closable list.
*/
static int unionFinalizeCsrStmt(UnionCsr *pCsr){
  int rc = SQLITE_OK;
  if( pCsr->pStmt ){
    UnionTab *pTab = (UnionTab*)pCsr->base.pVtab;
    UnionSrc *pSrc = &pTab->aSrc[pCsr->iTab];
    rc = sqlite3_finalize(pCsr->pStmt);
    pCsr->pStmt = 0;
    if( pTab->bSwarm ){
      pSrc->nUser--;
      assert( pSrc->nUser>=0 );
      if( pSrc->nUser==0 ){
        pSrc->pNextClosable = pTab->pClosable;
        pTab->pClosable = pSrc;
      }
      unionCloseSources(pTab, pTab->nMaxOpen);
    }
  }
  return rc;
}

/* 
** xConnect/xCreate method.
**
** The argv[] array contains the following:
**
**   argv[0]   -> module name  ("unionvtab" or "swarmvtab")
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[3]   -> SQL statement
**   argv[4]   -> not-found callback UDF name
*/
static int unionConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  UnionTab *pTab = 0;
  int rc = SQLITE_OK;
  int bSwarm = (pAux==0 ? 0 : 1);
  const char *zVtab = (bSwarm ? "swarmvtab" : "unionvtab");


  if( sqlite3_stricmp("temp", argv[1]) ){
    /* unionvtab tables may only be created in the temp schema */
    *pzErr = sqlite3_mprintf("%s tables must be created in TEMP schema", zVtab);
    rc = SQLITE_ERROR;
  }else if( argc!=4 && argc!=5 ){
    *pzErr = sqlite3_mprintf("wrong number of arguments for %s", zVtab);
    rc = SQLITE_ERROR;
  }else{
    int nAlloc = 0;               /* Allocated size of pTab->aSrc[] */
    sqlite3_stmt *pStmt = 0;      /* Argument statement */
    char *zArg = unionStrdup(&rc, argv[3]);      /* Copy of argument to CVT */

    /* Prepare the SQL statement. Instead of executing it directly, sort

      /* Check for problems with the specified range of rowids */
      if( iMax<iMin || (pTab->nSrc>0 && iMin<=pTab->aSrc[pTab->nSrc-1].iMax) ){
        *pzErr = sqlite3_mprintf("rowid range mismatch error");
        rc = SQLITE_ERROR;
      }

      if( rc==SQLITE_OK ){
        pSrc = &pTab->aSrc[pTab->nSrc++];

        pSrc->zTab = unionStrdup(&rc, zTab);
        pSrc->iMin = iMin;
        pSrc->iMax = iMax;
        if( bSwarm ){
          pSrc->zFile = unionStrdup(&rc, zDb);
        }else{
          pSrc->zDb = unionStrdup(&rc, zDb);
        }
      }
    }
    unionFinalize(&rc, pStmt, pzErr);
    pStmt = 0;

    /* Capture the not-found callback UDF name */
    if( rc==SQLITE_OK && argc>=5 ){
      pTab->zNotFoundCallback = unionStrdup(&rc, argv[4]);
      unionDequote(pTab->zNotFoundCallback);
    }

    /* It is an error if the SELECT statement returned zero rows. If only
    ** because there is no way to determine the schema of the virtual 
    ** table in this case.  */
    if( rc==SQLITE_OK && pTab->nSrc==0 ){
      *pzErr = sqlite3_mprintf("no source tables configured");
      rc = SQLITE_ERROR;
    }

    /* For unionvtab, verify that all source tables exist and have 
    ** compatible schemas. For swarmvtab, attach the first database and
    ** check that the first table is a rowid table only.  */
    if( rc==SQLITE_OK ){
      pTab->db = db;
      pTab->bSwarm = bSwarm;
      pTab->nMaxOpen = SWARMVTAB_MAX_OPEN;
      if( bSwarm ){
        rc = unionOpenDatabase(pTab, 0, pzErr);
      }else{
        rc = unionSourceCheck(pTab, pzErr);
      }
    }

    /* Compose a CREATE TABLE statement and pass it to declare_vtab() */
    if( rc==SQLITE_OK ){
      UnionSrc *pSrc = &pTab->aSrc[0];
      sqlite3 *tdb = unionGetDb(pTab, pSrc);
      pStmt = unionPreparePrintf(&rc, pzErr, tdb, "SELECT "
          "'CREATE TABLE xyz('"
          "    || group_concat(quote(name) || ' ' || type, ', ')"
          "    || ')',"
          "max((cid+1) * (type='INTEGER' COLLATE nocase AND pk=1))-1 "
          "FROM pragma_table_info(%Q, ?)", 
          pSrc->zTab, pSrc->zDb
      );
    }
    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zDecl = (const char*)sqlite3_column_text(pStmt, 0);
      rc = sqlite3_declare_vtab(db, zDecl);
      pTab->iPK = sqlite3_column_int(pStmt, 1);
    }

    unionFinalize(&rc, pStmt, pzErr);
  }

  if( rc!=SQLITE_OK ){
    unionDisconnect((sqlite3_vtab*)pTab);
    pTab = 0;
  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}


/*
** xOpen
*/
static int unionOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  UnionCsr *pCsr;
  int rc = SQLITE_OK;
  (void)p;  /* Suppress harmless warning */
  pCsr = (UnionCsr*)unionMalloc(&rc, sizeof(UnionCsr));
  *ppCursor = &pCsr->base;
  return rc;
}

/*
** xClose
*/
static int unionClose(sqlite3_vtab_cursor *cur){
  UnionCsr *pCsr = (UnionCsr*)cur;
  unionFinalizeCsrStmt(pCsr);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** This function does the work of the xNext() method. Except that, if it
** returns SQLITE_ROW, it should be called again within the same xNext()
** method call. See unionNext() for details.
*/
static int doUnionNext(UnionCsr *pCsr){
  int rc = SQLITE_OK;
  assert( pCsr->pStmt );
  if( sqlite3_step(pCsr->pStmt)!=SQLITE_ROW ){
    UnionTab *pTab = (UnionTab*)pCsr->base.pVtab;
    rc = unionFinalizeCsrStmt(pCsr);
    if( rc==SQLITE_OK && pTab->bSwarm ){
      pCsr->iTab++;
      if( pCsr->iTab<pTab->nSrc ){
        UnionSrc *pSrc = &pTab->aSrc[pCsr->iTab];
        if( pCsr->iMaxRowid>=pSrc->iMin ){
          /* It is necessary to scan the next table. */
          rc = unionOpenDatabase(pTab, pCsr->iTab, &pTab->base.zErrMsg);
          pCsr->pStmt = unionPreparePrintf(&rc, &pTab->base.zErrMsg, pSrc->db,
              "SELECT rowid, * FROM %Q %s %lld",
              pSrc->zTab,
              (pSrc->iMax>pCsr->iMaxRowid ? "WHERE _rowid_ <=" : "-- "),
              pCsr->iMaxRowid
          );
          if( rc==SQLITE_OK ){
            assert( pCsr->pStmt );
            unionIncrRefcount(pTab, pCsr->iTab);
            rc = SQLITE_ROW;
          }
        }
      }
    }
  }

  return rc;
}

/*
** xNext
*/
static int unionNext(sqlite3_vtab_cursor *cur){

  int rc;


  do {
    rc = doUnionNext((UnionCsr*)cur);


  }while( rc==SQLITE_ROW );

  return rc;
}

/*
** xColumn
*/
static int unionColumn(

        }else{
          iMin++;
        }
      }
    }
  }


  unionFinalizeCsrStmt(pCsr);
  if( bZero ){
    return SQLITE_OK;
  }

  for(i=0; i<pTab->nSrc; i++){
    UnionSrc *pSrc = &pTab->aSrc[i];
    if( iMin>pSrc->iMax || iMax<pSrc->iMin ){

        zSql = sqlite3_mprintf("%z WHERE rowid>=%lld", zSql, iMin);
        zWhere = "AND";
      }
      if( iMax!=LARGEST_INT64 && iMax<pSrc->iMax ){
        zSql = sqlite3_mprintf("%z %s rowid<=%lld", zSql, zWhere, iMax);
      }
    }

    if( pTab->bSwarm ){
      pCsr->iTab = i;
      pCsr->iMaxRowid = iMax;
      rc = unionOpenDatabase(pTab, i, &pTab->base.zErrMsg);
      break;
    }
  }

  if( zSql==0 ){
    return rc;
  }else{
    sqlite3 *db = unionGetDb(pTab, &pTab->aSrc[pCsr->iTab]);
    pCsr->pStmt = unionPrepare(&rc, db, zSql, &pTab->base.zErrMsg);
    if( pCsr->pStmt ){
      unionIncrRefcount(pTab, pCsr->iTab);
    }
    sqlite3_free(zSql);
  }
  if( rc!=SQLITE_OK ) return rc;
  return unionNext(pVtabCursor);
}

/*
** xBestIndex.
**

    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0                             /* xRollbackTo */
  };
  int rc;

  rc = sqlite3_create_module(db, "unionvtab", &unionModule, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "swarmvtab", &unionModule, (void*)db);
  }
  return rc;
}

#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef _WIN32
__declspec(dllexport)
#endif

  do_test 3.1 {
    list [catch {
      apply_rbu {
        CREATE TABLE data_xt(a, xt, rbu_rowid, rbu_control);
        INSERT INTO data_xt VALUES('a', 'b', 1, 0);
      }
    } msg] $msg
  } {1 {SQLITE_ERROR - SQL logic error}}
}

#--------------------------------------------------------------------
# Test that it is not possible to violate a NOT NULL constraint by
# applying an RBU update.
#
do_execsql_test 4.1 {

    2 ioerr-*  {
      {0 SQLITE_DONE} 
      {1 {SQLITE_IOERR - disk I/O error}}
      {1 SQLITE_IOERR}
      {1 SQLITE_IOERR_WRITE}
      {1 SQLITE_IOERR_READ}
      {1 SQLITE_IOERR_FSYNC}
      {1 {SQLITE_ERROR - SQL logic error}}
      {1 {SQLITE_ERROR - unable to open database: rbu.db}}
      {1 {SQLITE_IOERR - unable to open database: rbu.db}}
    }

    3 shmerr-*  {
      {0 SQLITE_DONE} 
      {1 {SQLITE_IOERR - disk I/O error}}

    {1 {SQLITE_IOERR - disk I/O error}}
    {1 SQLITE_IOERR} 
    {1 SQLITE_IOERR_WRITE} 
    {1 SQLITE_IOERR_FSYNC} 
    {1 SQLITE_IOERR_READ} 
    {1 {SQLITE_IOERR - unable to open database: test.db2}} 
    {1 {SQLITE_ERROR - unable to open database: test.db2}} 
    {1 {SQLITE_ERROR - SQL logic error}}
  }

  cantopen* {
    {1 {SQLITE_CANTOPEN - unable to open database: test.db2}}  
    {1 {SQLITE_CANTOPEN - unable to open database: test.db2}}  
    {1 {SQLITE_CANTOPEN - unable to open database file}}  
    {1 SQLITE_CANTOPEN} 

}

do_test 3.2 {
  list [catch { apply_rbu_update test.db {
    CREATE TABLE data_ft(x, rbu_rowid, rbu_control);
    INSERT INTO data_ft VALUES(NULL, 2, 1);
  } } msg] $msg]
} {1 {SQLITE_ERROR - SQL logic error]}}

do_test 3.3 {
  list [catch { apply_rbu_update test.db {
    CREATE TABLE data_ft(x, rbu_rowid, rbu_control);
    INSERT INTO data_ft VALUES('7 8 9', 1, 'x');
  } } msg] $msg]
} {1 {SQLITE_ERROR - SQL logic error]}}



finish_test

  */
  if( rc==SQLITE_OK && flags==SQLITE_ACCESS_EXISTS ){
    rbu_file *pDb = rbuFindMaindb(pRbuVfs, zPath);
    if( pDb && pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){
      if( *pResOut ){
        rc = SQLITE_CANTOPEN;
      }else{
        sqlite3_int64 sz = 0;
        rc = rbuVfsFileSize(&pDb->base, &sz);
        *pResOut = (sz>0);
      }
    }
  }

  return rc;
}

** "vfs=..." option may be passed as the zTarget option.
**
** IMPORTANT NOTE FOR ZIPVFS USERS: The RBU extension works with all of
** SQLite's built-in VFSs, including the multiplexor VFS. However it does
** not work out of the box with zipvfs. Refer to the comment describing
** the zipvfs_create_vfs() API below for details on using RBU with zipvfs.
*/
SQLITE_API sqlite3rbu *sqlite3rbu_open(
  const char *zTarget, 
  const char *zRbu,
  const char *zState
);

/*
** Open an RBU handle to perform an RBU vacuum on database file zTarget.

** new RBU vacuum operation.
**
** As with sqlite3rbu_open(), Zipvfs users should rever to the comment
** describing the sqlite3rbu_create_vfs() API function below for 
** a description of the complications associated with using RBU with 
** zipvfs databases.
*/
SQLITE_API sqlite3rbu *sqlite3rbu_vacuum(
  const char *zTarget, 
  const char *zState
);

/*
** Internally, each RBU connection uses a separate SQLite database 
** connection to access the target and rbu update databases. This

** If an error has occurred, either while opening or stepping the RBU object,
** this function may return NULL. The error code and message may be collected
** when sqlite3rbu_close() is called.
**
** Database handles returned by this function remain valid until the next
** call to any sqlite3rbu_xxx() function other than sqlite3rbu_db().
*/
SQLITE_API sqlite3 *sqlite3rbu_db(sqlite3rbu*, int bRbu);

/*
** Do some work towards applying the RBU update to the target db. 
**
** Return SQLITE_DONE if the update has been completely applied, or 
** SQLITE_OK if no error occurs but there remains work to do to apply
** the RBU update. If an error does occur, some other error code is 
** returned. 
**
** Once a call to sqlite3rbu_step() has returned a value other than
** SQLITE_OK, all subsequent calls on the same RBU handle are no-ops
** that immediately return the same value.
*/
SQLITE_API int sqlite3rbu_step(sqlite3rbu *pRbu);

/*
** Force RBU to save its state to disk.
**
** If a power failure or application crash occurs during an update, following
** system recovery RBU may resume the update from the point at which the state
** was last saved. In other words, from the most recent successful call to 
** sqlite3rbu_close() or this function.
**
** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
*/
SQLITE_API int sqlite3rbu_savestate(sqlite3rbu *pRbu);

/*
** Close an RBU handle. 
**
** If the RBU update has been completely applied, mark the RBU database
** as fully applied. Otherwise, assuming no error has occurred, save the
** current state of the RBU update appliation to the RBU database.
**
** If an error has already occurred as part of an sqlite3rbu_step()
** or sqlite3rbu_open() call, or if one occurs within this function, an
** SQLite error code is returned. Additionally, if pzErrmsg is not NULL,
** *pzErrmsg may be set to point to a buffer containing a utf-8 formatted
** English language error message. It is the responsibility of the caller to
** eventually free any such buffer using sqlite3_free().
**
** Otherwise, if no error occurs, this function returns SQLITE_OK if the
** update has been partially applied, or SQLITE_DONE if it has been 
** completely applied.
*/
SQLITE_API int sqlite3rbu_close(sqlite3rbu *pRbu, char **pzErrmsg);

/*
** Return the total number of key-value operations (inserts, deletes or 
** updates) that have been performed on the target database since the
** current RBU update was started.
*/
SQLITE_API sqlite3_int64 sqlite3rbu_progress(sqlite3rbu *pRbu);

/*
** Obtain permyriadage (permyriadage is to 10000 as percentage is to 100) 
** progress indications for the two stages of an RBU update. This API may
** be useful for driving GUI progress indicators and similar.
**
** An RBU update is divided into two stages:

** If the rbu_count table is present and populated correctly and this
** API is called during stage 1, the *pnOne output variable is set to the
** permyriadage progress of the same stage. If the rbu_count table does
** not exist, then (*pnOne) is set to -1 during stage 1. If the rbu_count
** table exists but is not correctly populated, the value of the *pnOne
** output variable during stage 1 is undefined.
*/
SQLITE_API void sqlite3rbu_bp_progress(sqlite3rbu *pRbu, int *pnOne, int*pnTwo);

/*
** Obtain an indication as to the current stage of an RBU update or vacuum.
** This function always returns one of the SQLITE_RBU_STATE_XXX constants
** defined in this file. Return values should be interpreted as follows:
**
** SQLITE_RBU_STATE_OAL:

*/
#define SQLITE_RBU_STATE_OAL        1
#define SQLITE_RBU_STATE_MOVE       2
#define SQLITE_RBU_STATE_CHECKPOINT 3
#define SQLITE_RBU_STATE_DONE       4
#define SQLITE_RBU_STATE_ERROR      5

SQLITE_API int sqlite3rbu_state(sqlite3rbu *pRbu);

/*
** Create an RBU VFS named zName that accesses the underlying file-system
** via existing VFS zParent. Or, if the zParent parameter is passed NULL, 
** then the new RBU VFS uses the default system VFS to access the file-system.
** The new object is registered as a non-default VFS with SQLite before 
** returning.

** that does not include the RBU layer results in an error.
**
** The overhead of adding the "rbu" VFS to the system is negligible for 
** non-RBU users. There is no harm in an application accessing the 
** file-system via "rbu" all the time, even if it only uses RBU functionality 
** occasionally.
*/
SQLITE_API int sqlite3rbu_create_vfs(const char *zName, const char *zParent);

/*
** Deregister and destroy an RBU vfs created by an earlier call to
** sqlite3rbu_create_vfs().
**
** VFS objects are not reference counted. If a VFS object is destroyed
** before all database handles that use it have been closed, the results
** are undefined.
*/
SQLITE_API void sqlite3rbu_destroy_vfs(const char *zName);

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

#endif /* _SQLITE3RBU_H */

  */
  if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){
    zErrDyn = sqlite3MPrintf(db, "too many attached databases - max %d", 
      db->aLimit[SQLITE_LIMIT_ATTACHED]
    );
    goto attach_error;
  }




  for(i=0; i<db->nDb; i++){
    char *z = db->aDb[i].zDbSName;
    assert( z && zName );
    if( sqlite3StrICmp(z, zName)==0 ){
      zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);
      goto attach_error;
    }

    sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName);
    goto detach_error;
  }
  if( i<2 ){
    sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName);
    goto detach_error;
  }





  if( sqlite3BtreeIsInReadTrans(pDb->pBt) || sqlite3BtreeIsInBackup(pDb->pBt) ){
    sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);
    goto detach_error;
  }

  sqlite3BtreeClose(pDb->pBt);
  pDb->pBt = 0;

    if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ){
      if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
        int rc = saveCursorPosition(p);
        if( SQLITE_OK!=rc ){
          return rc;
        }
      }else{
        testcase( p->iPage>=0 );
        btreeReleaseAllCursorPages(p);
      }
    }
    p = p->pNext;
  }while( p );
  return SQLITE_OK;
}

  BtCursor *p;
  int rc = SQLITE_OK;

  assert( (writeOnly==0 || writeOnly==1) && BTCF_WriteFlag==1 );
  if( pBtree ){
    sqlite3BtreeEnter(pBtree);
    for(p=pBtree->pBt->pCursor; p; p=p->pNext){

      if( writeOnly && (p->curFlags & BTCF_WriteFlag)==0 ){
        if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
          rc = saveCursorPosition(p);
          if( rc!=SQLITE_OK ){
            (void)sqlite3BtreeTripAllCursors(pBtree, rc, 0);
            break;
          }
        }
      }else{
        sqlite3BtreeClearCursor(p);
        p->eState = CURSOR_FAULT;
        p->skipNext = errCode;
      }

      btreeReleaseAllCursorPages(p);


    }
    sqlite3BtreeLeave(pBtree);
  }
  return rc;
}

/*

          pPrev->pNext = pCur->pNext;
          break;
        }
        pPrev = pPrev->pNext;
      }while( ALWAYS(pPrev) );
    }
    for(i=0; i<=pCur->iPage; i++){
      releasePageNotNull(pCur->apPage[i]);
    }
    unlockBtreeIfUnused(pBt);
    sqlite3_free(pCur->aOverflow);
    /* sqlite3_free(pCur); */
    sqlite3BtreeLeave(pBtree);
  }
  return SQLITE_OK;

  MemPage *pRoot;
  int rc = SQLITE_OK;

  assert( cursorOwnsBtShared(pCur) );
  assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
  assert( CURSOR_VALID   < CURSOR_REQUIRESEEK );
  assert( CURSOR_FAULT   > CURSOR_REQUIRESEEK );
  assert( pCur->eState < CURSOR_REQUIRESEEK || pCur->iPage<0 );







  if( pCur->iPage>=0 ){
    if( pCur->iPage ){
      do{
        assert( pCur->apPage[pCur->iPage]!=0 );
        releasePageNotNull(pCur->apPage[pCur->iPage--]);
      }while( pCur->iPage);
      goto skip_init;
    }
  }else if( pCur->pgnoRoot==0 ){
    pCur->eState = CURSOR_INVALID;
    return SQLITE_OK;
  }else{
    assert( pCur->iPage==(-1) );
    if( pCur->eState>=CURSOR_REQUIRESEEK ){
      if( pCur->eState==CURSOR_FAULT ){
        assert( pCur->skipNext!=SQLITE_OK );
        return pCur->skipNext;
      }
      sqlite3BtreeClearCursor(pCur);
    }
    rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->apPage[0],
                        0, pCur->curPagerFlags);
    if( rc!=SQLITE_OK ){
      pCur->eState = CURSOR_INVALID;
       return rc;
    }
    pCur->iPage = 0;

** overflow) into *pnSize.
*/
static int clearCell(
  MemPage *pPage,          /* The page that contains the Cell */
  unsigned char *pCell,    /* First byte of the Cell */
  CellInfo *pInfo          /* Size information about the cell */
){
  BtShared *pBt;
  Pgno ovflPgno;
  int rc;
  int nOvfl;
  u32 ovflPageSize;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pPage->xParseCell(pPage, pCell, pInfo);
  if( pInfo->nLocal==pInfo->nPayload ){
    return SQLITE_OK;  /* No overflow pages. Return without doing anything */
  }
  if( pCell+pInfo->nSize-1 > pPage->aData+pPage->maskPage ){
    /* Cell extends past end of page */
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  ovflPgno = get4byte(pCell + pInfo->nSize - 4);
  pBt = pPage->pBt;
  assert( pBt->usableSize > 4 );
  ovflPageSize = pBt->usableSize - 4;
  nOvfl = (pInfo->nPayload - pInfo->nLocal + ovflPageSize - 1)/ovflPageSize;
  assert( nOvfl>0 || 
    (CORRUPT_DB && (pInfo->nPayload + ovflPageSize)<ovflPageSize)
  );
  while( nOvfl-- ){

    /* Must make sure nOverflow is reset to zero even if the balance()
    ** fails. Internal data structure corruption will result otherwise. 
    ** Also, set the cursor state to invalid. This stops saveCursorPosition()
    ** from trying to save the current position of the cursor.  */
    pCur->apPage[pCur->iPage]->nOverflow = 0;
    pCur->eState = CURSOR_INVALID;
    if( (flags & BTREE_SAVEPOSITION) && rc==SQLITE_OK ){
      btreeReleaseAllCursorPages(pCur);
      if( pCur->pKeyInfo ){
        assert( pCur->pKey==0 );
        pCur->pKey = sqlite3Malloc( pX->nKey );
        if( pCur->pKey==0 ){
          rc = SQLITE_NOMEM;
        }else{
          memcpy(pCur->pKey, pX->pKey, pX->nKey);
        }
      }
      pCur->eState = CURSOR_REQUIRESEEK;
      pCur->nKey = pX->nKey;
    }
  }
  assert( pCur->iPage<0 || pCur->apPage[pCur->iPage]->nOverflow==0 );

end_insert:
  return rc;
}

/*
** Delete the entry that the cursor is pointing to. 

        pCur->ix = pPage->nCell-1;
      }else{
        pCur->skipNext = 1;
      }
    }else{
      rc = moveToRoot(pCur);
      if( bPreserve ){
        btreeReleaseAllCursorPages(pCur);
        pCur->eState = CURSOR_REQUIRESEEK;
      }
    }
  }
  return rc;
}

**     (3)  Bypass the creation of the sqlite_master table entry
**          for the PRIMARY KEY as the primary key index is now
**          identified by the sqlite_master table entry of the table itself.
**     (4)  Set the Index.tnum of the PRIMARY KEY Index object in the
**          schema to the rootpage from the main table.
**     (5)  Add all table columns to the PRIMARY KEY Index object
**          so that the PRIMARY KEY is a covering index.  The surplus
**          columns are part of KeyInfo.nAllField and are not used for
**          sorting or lookup or uniqueness checks.
**     (6)  Replace the rowid tail on all automatically generated UNIQUE
**          indices with the PRIMARY KEY columns.
**
** For virtual tables, only (1) is performed.
*/
static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){

                       SQLITE_IDXTYPE_PRIMARYKEY);
    if( db->mallocFailed ) return;
    pPk = sqlite3PrimaryKeyIndex(pTab);
    pTab->iPKey = -1;
  }else{
    pPk = sqlite3PrimaryKeyIndex(pTab);










    /*
    ** Remove all redundant columns from the PRIMARY KEY.  For example, change
    ** "PRIMARY KEY(a,b,a,b,c,b,c,d)" into just "PRIMARY KEY(a,b,c,d)".  Later
    ** code assumes the PRIMARY KEY contains no repeated columns.
    */
    for(i=j=1; i<pPk->nKeyCol; i++){
      if( hasColumn(pPk->aiColumn, j, pPk->aiColumn[i]) ){
        pPk->nColumn--;
      }else{
        pPk->aiColumn[j++] = pPk->aiColumn[i];
      }
    }
    pPk->nKeyCol = j;
  }
  assert( pPk!=0 );
  pPk->isCovering = 1;
  if( !db->init.imposterTable ) pPk->uniqNotNull = 1;
  nPk = pPk->nKeyCol;

  /* Bypass the creation of the PRIMARY KEY btree and the sqlite_master
  ** table entry. This is only required if currently generating VDBE
  ** code for a CREATE TABLE (not when parsing one as part of reading
  ** a database schema).  */
  if( v && pPk->tnum>0 ){
    assert( db->init.busy==0 );
    sqlite3VdbeChangeOpcode(v, pPk->tnum, OP_Goto);
  }

  /* The root page of the PRIMARY KEY is the table root page */
  pPk->tnum = pTab->tnum;

  /* Update the in-memory representation of all UNIQUE indices by converting
  ** the final rowid column into one or more columns of the PRIMARY KEY.
  */

    sqlite3VdbeAddOp4Int(v, OP_SorterCompare, iSorter, j2, regRecord,
                         pIndex->nKeyCol); VdbeCoverage(v);
    sqlite3UniqueConstraint(pParse, OE_Abort, pIndex);
  }else{
    addr2 = sqlite3VdbeCurrentAddr(v);
  }
  sqlite3VdbeAddOp3(v, OP_SorterData, iSorter, regRecord, iIdx);
  sqlite3VdbeAddOp1(v, OP_SeekEnd, iIdx);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, regRecord);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2); VdbeCoverage(v);
  sqlite3VdbeJumpHere(v, addr1);

  sqlite3VdbeAddOp1(v, OP_Close, iTab);

  "ENABLE_8_3_NAMES=" CTIMEOPT_VAL(SQLITE_ENABLE_8_3_NAMES),
#endif
#if SQLITE_ENABLE_API_ARMOR
  "ENABLE_API_ARMOR",
#endif
#if SQLITE_ENABLE_ATOMIC_WRITE
  "ENABLE_ATOMIC_WRITE",
#endif
#if SQLITE_ENABLE_BATCH_ATOMIC_WRITE
  "ENABLE_BATCH_ATOMIC_WRITE",
#endif
#if SQLITE_ENABLE_CEROD
  "ENABLE_CEROD",
#endif
#if SQLITE_ENABLE_COLUMN_METADATA
  "ENABLE_COLUMN_METADATA",
#endif

      addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
    }else{
      addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
      assert( (pDest->tabFlags & TF_Autoincrement)==0 );
    }
    sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
    if( db->mDbFlags & DBFLAG_Vacuum ){
      sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
      insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|
                           OPFLAG_APPEND|OPFLAG_USESEEKRESULT;
    }else{
      insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND;
    }
    sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,
                      (char*)pDest, P4_TABLE);

    sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
    if( db->mDbFlags & DBFLAG_Vacuum ){
      /* This INSERT command is part of a VACUUM operation, which guarantees
      ** that the destination table is empty. If all indexed columns use
      ** collation sequence BINARY, then it can also be assumed that the
      ** index will be populated by inserting keys in strictly sorted 
      ** order. In this case, instead of seeking within the b-tree as part
      ** of every OP_IdxInsert opcode, an OP_SeekEnd is added before the
      ** OP_IdxInsert to seek to the point within the b-tree where each key 
      ** should be inserted. This is faster.
      **
      ** If any of the indexed columns use a collation sequence other than
      ** BINARY, this optimization is disabled. This is because the user 
      ** might change the definition of a collation sequence and then run
      ** a VACUUM command. In that case keys may not be written in strictly
      ** sorted order.  */
      for(i=0; i<pSrcIdx->nColumn; i++){
        const char *zColl = pSrcIdx->azColl[i];
        if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
      }
      if( i==pSrcIdx->nColumn ){
        idxInsFlags = OPFLAG_USESEEKRESULT;
        sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
      }
    }
    if( !HasRowid(pSrc) && pDestIdx->idxType==2 ){
      idxInsFlags |= OPFLAG_NCHANGE;
    }
    sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);
    sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);

){
  MemJournal *p = (MemJournal *)pJfd;
  u8 *zOut = zBuf;
  int nRead = iAmt;
  int iChunkOffset;
  FileChunk *pChunk;

#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
  if( (iAmt+iOfst)>p->endpoint.iOffset ){
    return SQLITE_IOERR_SHORT_READ;
  }
#endif

  assert( (iAmt+iOfst)<=p->endpoint.iOffset );
  assert( p->readpoint.iOffset==0 || p->readpoint.pChunk!=0 );

  else{
    /* An in-memory journal file should only ever be appended to. Random
    ** access writes are not required. The only exception to this is when
    ** the in-memory journal is being used by a connection using the
    ** atomic-write optimization. In this case the first 28 bytes of the
    ** journal file may be written as part of committing the transaction. */ 
    assert( iOfst==p->endpoint.iOffset || iOfst==0 );
#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
    if( iOfst==0 && p->pFirst ){
      assert( p->nChunkSize>iAmt );
      memcpy((u8*)p->pFirst->zChunk, zBuf, iAmt);
    }else
#else
    assert( iOfst>0 || p->pFirst==0 );
#endif

/*
** Open an in-memory journal file.
*/
void sqlite3MemJournalOpen(sqlite3_file *pJfd){
  sqlite3JournalOpen(0, 0, pJfd, 0, -1);
}

#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
/*
** If the argument p points to a MemJournal structure that is not an 
** in-memory-only journal file (i.e. is one that was opened with a +ve
** nSpill parameter or as SQLITE_OPEN_MAIN_JOURNAL), and the underlying 
** file has not yet been created, create it now.
*/
int sqlite3JournalCreate(sqlite3_file *pJfd){
  int rc = SQLITE_OK;
  MemJournal *p = (MemJournal*)pJfd;
  if( p->pMethod==&MemJournalMethods && (
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
     p->nSpill>0
#else
     /* While this appears to not be possible without ATOMIC_WRITE, the
     ** paths are complex, so it seems prudent to leave the test in as
     ** a NEVER(), in case our analysis is subtly flawed. */
     NEVER(p->nSpill>0)
#endif
#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
     || (p->flags & SQLITE_OPEN_MAIN_JOURNAL)
#endif
  )){
    rc = memjrnlCreateFile(p);
  }
  return rc;
}
#endif

/*
** The file-handle passed as the only argument is open on a journal file.

/*
** standard include files.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <errno.h>
#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
# include <sys/mman.h>
#endif

#if SQLITE_MAX_MMAP_SIZE>0
  int nFetchOut;                      /* Number of outstanding xFetch refs */
  sqlite3_int64 mmapSize;             /* Usable size of mapping at pMapRegion */
  sqlite3_int64 mmapSizeActual;       /* Actual size of mapping at pMapRegion */
  sqlite3_int64 mmapSizeMax;          /* Configured FCNTL_MMAP_SIZE value */
  void *pMapRegion;                   /* Memory mapped region */
#endif

  int sectorSize;                     /* Device sector size */
  int deviceCharacteristics;          /* Precomputed device characteristics */

#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)
  unsigned fsFlags;                   /* cached details from statfs() */
#endif
#if OS_VXWORKS

/*
** Explicitly call the 64-bit version of lseek() on Android. Otherwise, lseek()
** is the 32-bit version, even if _FILE_OFFSET_BITS=64 is defined.
*/
#ifdef __ANDROID__
# define lseek lseek64
#endif

#ifdef __linux__
/*
** Linux-specific IOCTL magic numbers used for controlling F2FS
*/
#define F2FS_IOCTL_MAGIC        0xf5
#define F2FS_IOC_START_ATOMIC_WRITE     _IO(F2FS_IOCTL_MAGIC, 1)
#define F2FS_IOC_COMMIT_ATOMIC_WRITE    _IO(F2FS_IOCTL_MAGIC, 2)
#define F2FS_IOC_START_VOLATILE_WRITE   _IO(F2FS_IOCTL_MAGIC, 3)
#define F2FS_IOC_ABORT_VOLATILE_WRITE   _IO(F2FS_IOCTL_MAGIC, 5)
#define F2FS_IOC_GET_FEATURES           _IOR(F2FS_IOCTL_MAGIC, 12, u32)
#define F2FS_FEATURE_ATOMIC_WRITE 0x0004
#endif /* __linux__ */


/*
** Different Unix systems declare open() in different ways.  Same use
** open(const char*,int,mode_t).  Others use open(const char*,int,...).
** The difference is important when using a pointer to the function.
**
** The safest way to deal with the problem is to always use this wrapper

#if defined(HAVE_LSTAT)
  { "lstat",         (sqlite3_syscall_ptr)lstat,          0 },
#else
  { "lstat",         (sqlite3_syscall_ptr)0,              0 },
#endif
#define osLstat      ((int(*)(const char*,struct stat*))aSyscall[27].pCurrent)

  { "ioctl",         (sqlite3_syscall_ptr)ioctl,          0 },
#define osIoctl ((int(*)(int,int,...))aSyscall[28].pCurrent)

}; /* End of the overrideable system calls */


/*
** On some systems, calls to fchown() will trigger a message in a security
** log if they come from non-root processes.  So avoid calling fchown() if

    }
    case SQLITE_FCNTL_FILEID: {
      i64 *aId = (i64*)pArg;
      aId[0] = (i64)(pFile->pInode->fileId.dev);
      aId[1] = (i64)(pFile->pInode->fileId.ino);
      return SQLITE_OK;
    }
#if defined(__linux__) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
    case SQLITE_FCNTL_BEGIN_ATOMIC_WRITE: {
      int rc = osIoctl(pFile->h, F2FS_IOC_START_ATOMIC_WRITE);
      return rc ? SQLITE_IOERR_BEGIN_ATOMIC : SQLITE_OK;
    }
    case SQLITE_FCNTL_COMMIT_ATOMIC_WRITE: {
      int rc = osIoctl(pFile->h, F2FS_IOC_COMMIT_ATOMIC_WRITE);
      return rc ? SQLITE_IOERR_COMMIT_ATOMIC : SQLITE_OK;
    }
    case SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE: {
      int rc = osIoctl(pFile->h, F2FS_IOC_ABORT_VOLATILE_WRITE);
      return rc ? SQLITE_IOERR_ROLLBACK_ATOMIC : SQLITE_OK;
    }
#endif /* __linux__ && SQLITE_ENABLE_BATCH_ATOMIC_WRITE */

    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = pFile->eFileLock;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_LAST_ERRNO: {
      *(int*)pArg = pFile->lastErrno;
      return SQLITE_OK;

    }
#endif /* SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__) */
  }
  return SQLITE_NOTFOUND;
}

/*
** If pFd->sectorSize is non-zero when this function is called, it is a
** no-op. Otherwise, the values of pFd->sectorSize and 
** pFd->deviceCharacteristics are set according to the file-system 
** characteristics. 
**
** There are two versions of this function. One for QNX and one for all


** other systems.
*/
#ifndef __QNXNTO__
static void setDeviceCharacteristics(unixFile *pFd){
  assert( pFd->deviceCharacteristics==0 || pFd->sectorSize!=0 );
  if( pFd->sectorSize==0 ){
#if defined(__linux__) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
    int res;
    u32 f = 0;

    /* Check for support for F2FS atomic batch writes. */
    res = osIoctl(pFd->h, F2FS_IOC_GET_FEATURES, &f);
    if( res==0 && (f & F2FS_FEATURE_ATOMIC_WRITE) ){
      pFd->deviceCharacteristics = SQLITE_IOCAP_BATCH_ATOMIC;
    }
#endif /* __linux__ && SQLITE_ENABLE_BATCH_ATOMIC_WRITE */

    /* Set the POWERSAFE_OVERWRITE flag if requested. */
    if( pFd->ctrlFlags & UNIXFILE_PSOW ){
      pFd->deviceCharacteristics |= SQLITE_IOCAP_POWERSAFE_OVERWRITE;
    }

    pFd->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;


  }
}
#else
#include <sys/dcmd_blk.h>
#include <sys/statvfs.h>

static void setDeviceCharacteristics(unixFile *pFile){
  if( pFile->sectorSize == 0 ){
    struct statvfs fsInfo;
       
    /* Set defaults for non-supported filesystems */
    pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;
    pFile->deviceCharacteristics = 0;
    if( fstatvfs(pFile->h, &fsInfo) == -1 ) {

  }
  /* Last chance verification.  If the sector size isn't a multiple of 512
  ** then it isn't valid.*/
  if( pFile->sectorSize % 512 != 0 ){
    pFile->deviceCharacteristics = 0;
    pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;
  }

}
#endif

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and its journal file) that the sector size will be the
** same for both.
*/
static int unixSectorSize(sqlite3_file *id){
  unixFile *pFd = (unixFile*)id;
  setDeviceCharacteristics(pFd);
  return pFd->sectorSize;
}

/*
** Return the device characteristics for the file.
**
** This VFS is set up to return SQLITE_IOCAP_POWERSAFE_OVERWRITE by default.
** However, that choice is controversial since technically the underlying
** file system does not always provide powersafe overwrites.  (In other
** words, after a power-loss event, parts of the file that were never
** written might end up being altered.)  However, non-PSOW behavior is very,
** very rare.  And asserting PSOW makes a large reduction in the amount
** of required I/O for journaling, since a lot of padding is eliminated.
**  Hence, while POWERSAFE_OVERWRITE is on by default, there is a file-control
** available to turn it off and URI query parameter available to turn it off.
*/
static int unixDeviceCharacteristics(sqlite3_file *id){
  unixFile *pFd = (unixFile*)id;



  setDeviceCharacteristics(pFd);




  return pFd->deviceCharacteristics;
}

#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0

/*
** Return the system page size.
**

    UNIXVFS("unix-proxy",    proxyIoFinder ),
#endif
  };
  unsigned int i;          /* Loop counter */

  /* Double-check that the aSyscall[] array has been constructed
  ** correctly.  See ticket [bb3a86e890c8e96ab] */
  assert( ArraySize(aSyscall)==29 );

  /* Register all VFSes defined in the aVfs[] array */
  for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
    sqlite3_vfs_register(&aVfs[i], i==0);
  }
  return SQLITE_OK; 
}

      assert( p->eLock==EXCLUSIVE_LOCK );
      assert( pPager->errCode==SQLITE_OK );
      assert( !pagerUseWal(pPager) );
      assert( p->eLock>=EXCLUSIVE_LOCK );
      assert( isOpen(p->jfd) 
           || p->journalMode==PAGER_JOURNALMODE_OFF 
           || p->journalMode==PAGER_JOURNALMODE_WAL 
           || (sqlite3OsDeviceCharacteristics(p->fd)&SQLITE_IOCAP_BATCH_ATOMIC)
      );
      assert( pPager->dbOrigSize<=pPager->dbHintSize );
      break;

    case PAGER_WRITER_FINISHED:
      assert( p->eLock==EXCLUSIVE_LOCK );
      assert( pPager->errCode==SQLITE_OK );
      assert( !pagerUseWal(pPager) );
      assert( isOpen(p->jfd) 
           || p->journalMode==PAGER_JOURNALMODE_OFF 
           || p->journalMode==PAGER_JOURNALMODE_WAL 
           || (sqlite3OsDeviceCharacteristics(p->fd)&SQLITE_IOCAP_BATCH_ATOMIC)
      );
      break;

    case PAGER_ERROR:
      /* There must be at least one outstanding reference to the pager if
      ** in ERROR state. Otherwise the pager should have already dropped
      ** back to OPEN state.

      IOTRACE(("LOCK %p %d\n", pPager, eLock))
    }
  }
  return rc;
}

/*
** This function determines whether or not the atomic-write or
** atomic-batch-write optimizations can be used with this pager. The
** atomic-write optimization can be used if:
**
**  (a) the value returned by OsDeviceCharacteristics() indicates that
**      a database page may be written atomically, and
**  (b) the value returned by OsSectorSize() is less than or equal
**      to the page size.
**
** If it can be used, then the value returned is the size of the journal 
** file when it contains rollback data for exactly one page.
**
** The atomic-batch-write optimization can be used if OsDeviceCharacteristics()
** returns a value with the SQLITE_IOCAP_BATCH_ATOMIC bit set. -1 is
** returned in this case.
**
** If neither optimization can be used, 0 is returned.


*/

static int jrnlBufferSize(Pager *pPager){
  assert( !MEMDB );

#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
  int dc;                           /* Device characteristics */



  assert( isOpen(pPager->fd) );
  dc = sqlite3OsDeviceCharacteristics(pPager->fd);
#endif

#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
  if( dc&SQLITE_IOCAP_BATCH_ATOMIC ){
    return -1;
  }
#endif

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
  {
    int nSector = pPager->sectorSize;
    int szPage = pPager->pageSize;

    assert(SQLITE_IOCAP_ATOMIC512==(512>>8));
    assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));
    if( 0==(dc&(SQLITE_IOCAP_ATOMIC|(szPage>>8)) || nSector>szPage) ){
      return 0;
    }
  }

  return JOURNAL_HDR_SZ(pPager) + JOURNAL_PG_SZ(pPager);
#endif

  return 0;


}

/*
** If SQLITE_CHECK_PAGES is defined then we do some sanity checking
** on the cache using a hash function.  This is used for testing
** and debugging only.
*/
#ifdef SQLITE_CHECK_PAGES

  assert( assert_pager_state(pPager) );
  assert( pPager->eState!=PAGER_ERROR );
  if( pPager->eState<PAGER_WRITER_LOCKED && pPager->eLock<RESERVED_LOCK ){
    return SQLITE_OK;
  }

  releaseAllSavepoints(pPager);
  assert( isOpen(pPager->jfd) || pPager->pInJournal==0 
      || (sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_BATCH_ATOMIC)
  );
  if( isOpen(pPager->jfd) ){
    assert( !pagerUseWal(pPager) );

    /* Finalize the journal file. */
    if( sqlite3JournalIsInMemory(pPager->jfd) ){
      /* assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ); */
      sqlite3OsClose(pPager->jfd);

  if( pagerUseWal(pPager) ){
    /* Write a single frame for this page to the log. */
    rc = subjournalPageIfRequired(pPg); 
    if( rc==SQLITE_OK ){
      rc = pagerWalFrames(pPager, pPg, 0, 0);
    }
  }else{
    
#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
    if( pPager->tempFile==0 ){
      rc = sqlite3JournalCreate(pPager->jfd);
      if( rc!=SQLITE_OK ) return pager_error(pPager, rc);
    }
#endif
  
    /* Sync the journal file if required. */
    if( pPg->flags&PGHDR_NEED_SYNC 
     || pPager->eState==PAGER_WRITER_CACHEMOD
    ){
      rc = syncJournal(pPager, 1);
    }

        rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1);
      }
      sqlite3PagerUnref(pPageOne);
      if( rc==SQLITE_OK ){
        sqlite3PcacheCleanAll(pPager->pPCache);
      }
    }else{
      /* The bBatch boolean is true if the batch-atomic-write commit method
      ** should be used.  No rollback journal is created if batch-atomic-write
      ** is enabled.
      */
      sqlite3_file *fd = pPager->fd;
#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
      const int bBatch = zMaster==0    /* An SQLITE_IOCAP_BATCH_ATOMIC commit */
        && (sqlite3OsDeviceCharacteristics(fd) & SQLITE_IOCAP_BATCH_ATOMIC)
        && !pPager->noSync
        && sqlite3JournalIsInMemory(pPager->jfd);
#else
# define bBatch 0
#endif

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
      /* 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 

      ** 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.
      */
      if( bBatch==0 ){
        PgHdr *pPg;
        assert( isOpen(pPager->jfd) 
            || pPager->journalMode==PAGER_JOURNALMODE_OFF 
            || pPager->journalMode==PAGER_JOURNALMODE_WAL 
            );
        if( !zMaster && isOpen(pPager->jfd) 
         && pPager->journalOff==jrnlBufferSize(pPager) 
         && pPager->dbSize>=pPager->dbOrigSize
         && (!(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 
#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
      if( zMaster ){
        rc = sqlite3JournalCreate(pPager->jfd);
        if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
      }
#endif
      rc = pager_incr_changecounter(pPager, 0);
#endif
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
  
      /* 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);

      ** journal requires a sync here. However, in locking_mode=exclusive
      ** on a system under memory pressure it is just possible that this is 
      ** not the case. In this case it is likely enough that the redundant
      ** xSync() call will be changed to a no-op by the OS anyhow. 
      */
      rc = syncJournal(pPager, 0);
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

      if( bBatch ){
        /* The pager is now in DBMOD state. But regardless of what happens
        ** next, attempting to play the journal back into the database would
        ** be unsafe. Close it now to make sure that does not happen.  */
        sqlite3OsClose(pPager->jfd);
        rc = sqlite3OsFileControl(fd, SQLITE_FCNTL_BEGIN_ATOMIC_WRITE, 0);
        if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
      }
      rc = pager_write_pagelist(pPager,sqlite3PcacheDirtyList(pPager->pPCache));
      if( bBatch ){
        if( rc==SQLITE_OK ){
          rc = sqlite3OsFileControl(fd, SQLITE_FCNTL_COMMIT_ATOMIC_WRITE, 0);
        }else{
          sqlite3OsFileControl(fd, SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE, 0);
        }
      }

      if( rc!=SQLITE_OK ){
        assert( rc!=SQLITE_IOERR_BLOCKED );
        goto commit_phase_one_exit;
      }
      sqlite3PcacheCleanAll(pPager->pPCache);

      /* If the file on disk is smaller than the database image, use 

    A = 0;
    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", X.n, X.z);
  }
}
columnlist ::= columnlist COMMA columnname carglist.
columnlist ::= columnname carglist.
columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}

// Declare some tokens early in order to influence their values, to 
// improve performance and reduce the executable size.  The goal here is
// to get the "jump" operations in ISNULL through ESCAPE to have numeric
// values that are early enough so that all jump operations are clustered
// at the beginning, but also so that the comparison tokens NE through GE
// are as large as possible so that they are near to FUNCTION, which is a
// token synthesized by addopcodes.tcl.
//
%token ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST.
%token CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL.
%token OR AND NOT IS MATCH LIKE_KW BETWEEN IN ISNULL NOTNULL NE EQ.
%token GT LE LT GE ESCAPE.

// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
  ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW

** structure. Unless SQLITE_PCACHE_SEPARATE_HEADER is defined, a buffer of
** PgHdr1.pCache->szPage bytes is allocated directly before this structure 
** in memory.
*/
struct PgHdr1 {
  sqlite3_pcache_page page;      /* Base class. Must be first. pBuf & pExtra */
  unsigned int iKey;             /* Key value (page number) */

  u8 isBulkLocal;                /* This page from bulk local storage */
  u8 isAnchor;                   /* This is the PGroup.lru element */
  PgHdr1 *pNext;                 /* Next in hash table chain */
  PCache1 *pCache;               /* Cache that currently owns this page */
  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
};

/*
** A page is pinned if it is no on the LRU list
*/
#define PAGE_IS_PINNED(p)    ((p)->pLruNext==0)
#define PAGE_IS_UNPINNED(p)  ((p)->pLruNext!=0)

/* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 
** of one or more PCaches that are able to recycle each other's unpinned
** pages when they are under memory pressure.  A PGroup is an instance of
** the following object.
**
** This page cache implementation works in one of two modes:
**

** This function is used internally to remove the page pPage from the 
** PGroup LRU list, if is part of it. If pPage is not part of the PGroup
** LRU list, then this function is a no-op.
**
** The PGroup mutex must be held when this function is called.
*/
static PgHdr1 *pcache1PinPage(PgHdr1 *pPage){


  assert( pPage!=0 );
  assert( PAGE_IS_UNPINNED(pPage) );

  assert( pPage->pLruNext );
  assert( pPage->pLruPrev );
  assert( sqlite3_mutex_held(pPage->pCache->pGroup->mutex) );
  pPage->pLruPrev->pLruNext = pPage->pLruNext;
  pPage->pLruNext->pLruPrev = pPage->pLruPrev;
  pPage->pLruNext = 0;
  pPage->pLruPrev = 0;

  assert( pPage->isAnchor==0 );
  assert( pPage->pCache->pGroup->lru.isAnchor==1 );
  pPage->pCache->nRecyclable--;
  return pPage;
}


/*
** Remove the page supplied as an argument from the hash table 
** (PCache1.apHash structure) that it is currently stored in.

  PGroup *pGroup = pCache->pGroup;
  PgHdr1 *p;
  assert( sqlite3_mutex_held(pGroup->mutex) );
  while( pGroup->nCurrentPage>pGroup->nMaxPage
      && (p=pGroup->lru.pLruPrev)->isAnchor==0
  ){
    assert( p->pCache->pGroup==pGroup );
    assert( PAGE_IS_UNPINNED(p) );
    pcache1PinPage(p);
    pcache1RemoveFromHash(p, 1);
  }
  if( pCache->nPage==0 && pCache->pBulk ){
    sqlite3_free(pCache->pBulk);
    pCache->pBulk = pCache->pFree = 0;
  }

    PgHdr1 *pPage;
    assert( h<pCache->nHash );
    pp = &pCache->apHash[h]; 
    while( (pPage = *pp)!=0 ){
      if( pPage->iKey>=iLimit ){
        pCache->nPage--;
        *pp = pPage->pNext;
        if( PAGE_IS_UNPINNED(pPage) ) pcache1PinPage(pPage);
        pcache1FreePage(pPage);
      }else{
        pp = &pPage->pNext;
        TESTONLY( if( nPage>=0 ) nPage++; )
      }
    }
    if( h==iStop ) break;

  /* Step 4. Try to recycle a page. */
  if( pCache->bPurgeable
   && !pGroup->lru.pLruPrev->isAnchor
   && ((pCache->nPage+1>=pCache->nMax) || pcache1UnderMemoryPressure(pCache))
  ){
    PCache1 *pOther;
    pPage = pGroup->lru.pLruPrev;
    assert( PAGE_IS_UNPINNED(pPage) );
    pcache1RemoveFromHash(pPage, 0);
    pcache1PinPage(pPage);
    pOther = pPage->pCache;
    if( pOther->szAlloc != pCache->szAlloc ){
      pcache1FreePage(pPage);
      pPage = 0;
    }else{

    unsigned int h = iKey % pCache->nHash;
    pCache->nPage++;
    pPage->iKey = iKey;
    pPage->pNext = pCache->apHash[h];
    pPage->pCache = pCache;
    pPage->pLruPrev = 0;
    pPage->pLruNext = 0;

    *(void **)pPage->page.pExtra = 0;
    pCache->apHash[h] = pPage;
    if( iKey>pCache->iMaxKey ){
      pCache->iMaxKey = iKey;
    }
  }
  return pPage;

  while( pPage && pPage->iKey!=iKey ){ pPage = pPage->pNext; }

  /* Step 2: If the page was found in the hash table, then return it.
  ** If the page was not in the hash table and createFlag is 0, abort.
  ** Otherwise (page not in hash and createFlag!=0) continue with
  ** subsequent steps to try to create the page. */
  if( pPage ){
    if( PAGE_IS_UNPINNED(pPage) ){
      return pcache1PinPage(pPage);
    }else{
      return pPage;
    }
  }else if( createFlag ){
    /* Steps 3, 4, and 5 implemented by this subroutine */
    return pcache1FetchStage2(pCache, iKey, createFlag);

  assert( pPage->pCache==pCache );
  pcache1EnterMutex(pGroup);

  /* It is an error to call this function if the page is already 
  ** part of the PGroup LRU list.
  */
  assert( pPage->pLruPrev==0 && pPage->pLruNext==0 );
  assert( PAGE_IS_PINNED(pPage) );

  if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){
    pcache1RemoveFromHash(pPage, 1);
  }else{
    /* Add the page to the PGroup LRU list. */
    PgHdr1 **ppFirst = &pGroup->lru.pLruNext;
    pPage->pLruPrev = &pGroup->lru;
    (pPage->pLruNext = *ppFirst)->pLruPrev = pPage;
    *ppFirst = pPage;
    pCache->nRecyclable++;

  }

  pcache1LeaveMutex(pCache->pGroup);
}

/*
** Implementation of the sqlite3_pcache.xRekey method. 

       &&  (p=pcache1.grp.lru.pLruPrev)!=0
       &&  p->isAnchor==0
    ){
      nFree += pcache1MemSize(p->page.pBuf);
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
      nFree += sqlite3MemSize(p);
#endif
      assert( PAGE_IS_UNPINNED(p) );
      pcache1PinPage(p);
      pcache1RemoveFromHash(p, 1);
    }
    pcache1LeaveMutex(&pcache1.grp);
  }
  return nFree;
}

  int *pnMax,          /* OUT: Global maximum cache size */
  int *pnMin,          /* OUT: Sum of PCache1.nMin for purgeable caches */
  int *pnRecyclable    /* OUT: Total number of pages available for recycling */
){
  PgHdr1 *p;
  int nRecyclable = 0;
  for(p=pcache1.grp.lru.pLruNext; p && !p->isAnchor; p=p->pLruNext){
    assert( PAGE_IS_UNPINNED(p) );
    nRecyclable++;
  }
  *pnCurrent = pcache1.grp.nCurrentPage;
  *pnMax = (int)pcache1.grp.nMaxPage;
  *pnMin = (int)pcache1.grp.nMinPage;
  *pnRecyclable = nRecyclable;
}
#endif

  return i;
}

/*
** Free all memory allocations in the pParse object
*/
void sqlite3ParserReset(Parse *pParse){

  sqlite3 *db = pParse->db;
  sqlite3DbFree(db, pParse->aLabel);
  sqlite3ExprListDelete(db, pParse->pConstExpr);
  if( db ){
    assert( db->lookaside.bDisable >= pParse->disableLookaside );
    db->lookaside.bDisable -= pParse->disableLookaside;
  }
  pParse->disableLookaside = 0;

}

/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare(
  sqlite3 *db,              /* Database handle. */

    }
    VdbeCoverage(v);
    sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat);
    pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
    if( pParse->db->mallocFailed ) return;
    pOp->p2 = nKey + nData;
    pKI = pOp->p4.pKeyInfo;
    memset(pKI->aSortOrder, 0, pKI->nKeyField); /* Makes OP_Jump testable */
    sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO);
    testcase( pKI->nAllField > pKI->nKeyField+2 );
    pOp->p4.pKeyInfo = keyInfoFromExprList(pParse, pSort->pOrderBy, nOBSat,
                                           pKI->nAllField-pKI->nKeyField-1);
    addrJmp = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);
    pSort->labelBkOut = sqlite3VdbeMakeLabel(v);
    pSort->regReturn = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
    sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
    if( iLimit ){

** X extra columns.
*/
KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
  int nExtra = (N+X)*(sizeof(CollSeq*)+1) - sizeof(CollSeq*);
  KeyInfo *p = sqlite3DbMallocRawNN(db, sizeof(KeyInfo) + nExtra);
  if( p ){
    p->aSortOrder = (u8*)&p->aColl[N+X];
    p->nKeyField = (u16)N;
    p->nAllField = (u16)(N+X);
    p->enc = ENC(db);
    p->db = db;
    p->nRef = 1;
    memset(&p[1], 0, nExtra);
  }else{
    sqlite3OomFault(db);
  }

      assert( pTab && pExpr->pTab==pTab );
      if( pS ){
        /* The "table" is actually a sub-select or a view in the FROM clause
        ** of the SELECT statement. Return the declaration type and origin
        ** data for the result-set column of the sub-select.
        */
        if( iCol>=0 && iCol<pS->pEList->nExpr ){
          /* If iCol is less than zero, then the expression requests the
          ** rowid of the sub-select or view. This expression is legal (see 
          ** test case misc2.2.2) - it always evaluates to NULL.



          */
          NameContext sNC;
          Expr *p = pS->pEList->a[iCol].pExpr;
          sNC.pSrcList = pS->pSrc;
          sNC.pNext = pNC;
          sNC.pParse = pNC->pParse;
          zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol, &estWidth); 

    zType = columnType(&sNC, p, 0, 0, 0, 0);
#endif
    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
  }
#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
}














/*
** Compute the column names for a SELECT statement.
**
** The only guarantee that SQLite makes about column names is that if the
** column has an AS clause assigning it a name, that will be the name used.
** That is the only documented guarantee.  However, countless applications

**
**    full=ON, short=ANY:       If the result refers directly to a table column,
**                              then the result column name with the table name
**                              prefix, ex: TABLE.COLUMN.  Otherwise use zSpan.
*/
static void generateColumnNames(
  Parse *pParse,      /* Parser context */
  Select *pSelect     /* Generate column names for this SELECT statement */

){
  Vdbe *v = pParse->pVdbe;
  int i;
  Table *pTab;
  SrcList *pTabList;
  ExprList *pEList;
  sqlite3 *db = pParse->db;
  int fullName;    /* TABLE.COLUMN if no AS clause and is a direct table ref */
  int srcName;     /* COLUMN or TABLE.COLUMN if no AS clause and is direct */

#ifndef SQLITE_OMIT_EXPLAIN
  /* If this is an EXPLAIN, skip this step */
  if( pParse->explain ){
    return;
  }
#endif

  if( pParse->colNamesSet || db->mallocFailed ) return;
  /* Column names are determined by the left-most term of a compound select */
  while( pSelect->pPrior ) pSelect = pSelect->pPrior;
  pTabList = pSelect->pSrc;
  pEList = pSelect->pEList;
  assert( v!=0 );
  assert( pTabList!=0 );
  pParse->colNamesSet = 1;
  fullName = (db->flags & SQLITE_FullColNames)!=0;
  srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;
  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
    Expr *p = pEList->a[i].pExpr;

    assert( p!=0 );
    if( pEList->a[i].zName ){
      /* An AS clause always takes first priority */
      char *zName = pEList->a[i].zName;
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
    }else if( srcName && p->op==TK_COLUMN ){



      char *zCol;
      int iCol = p->iColumn;
      pTab = p->pTab;
      assert( pTab!=0 );
      if( iCol<0 ) iCol = pTab->iPKey;
      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
      if( iCol<0 ){
        zCol = "rowid";
      }else{
        zCol = pTab->aCol[iCol].zName;
      }

      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */
      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
      if( dest.eDest!=priorOp ){
        int iCont, iBreak, iStart;
        assert( p->pEList );





        iBreak = sqlite3VdbeMakeLabel(v);
        iCont = sqlite3VdbeMakeLabel(v);
        computeLimitRegisters(pParse, p, iBreak);
        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
        iStart = sqlite3VdbeCurrentAddr(v);
        selectInnerLoop(pParse, p, p->pEList, unionTab,
                        0, 0, &dest, iCont, iBreak);

      p->pLimit = pLimit;
      p->pOffset = pOffset;

      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );





      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
      computeLimitRegisters(pParse, p, iBreak);
      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
      r1 = sqlite3GetTempReg(pParse);
      iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);
      sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); VdbeCoverage(v);

  sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);

  /* Jump to the this point in order to terminate the query.
  */
  sqlite3VdbeResolveLabel(v, labelEnd);









  /* Reassembly the compound query so that it will be freed correctly
  ** by the calling function */
  if( p->pPrior ){
    sqlite3SelectDelete(db, p->pPrior);
  }
  p->pPrior = pPrior;
  pPrior->pNext = p;

){
  const char *zSavedAuthContext = pParse->zAuthContext;
  Select *pParent;    /* Current UNION ALL term of the other query */
  Select *pSub;       /* The inner query or "subquery" */
  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
  SrcList *pSrc;      /* The FROM clause of the outer query */
  SrcList *pSubSrc;   /* The FROM clause of the subquery */

  int iParent;        /* VDBE cursor number of the pSub result set temp table */
  int iNewParent = -1;/* Replacement table for iParent */
  int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */    
  int i;              /* Loop counter */
  Expr *pWhere;                    /* The WHERE clause */
  struct SrcList_item *pSubitem;   /* The subquery */
  sqlite3 *db = pParse->db;

    **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
    **   \                     \_____________ subquery __________/          /
    **    \_____________________ outer query ______________________________/
    **
    ** We look at every expression in the outer query and every place we see
    ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
    */








    if( pSub->pOrderBy ){
      /* At this point, any non-zero iOrderByCol values indicate that the
      ** ORDER BY column expression is identical to the iOrderByCol'th
      ** expression returned by SELECT statement pSub. Since these values
      ** do not necessarily correspond to columns in SELECT statement pParent,
      ** zero them before transfering the ORDER BY clause.
      **

  isAgg = (p->selFlags & SF_Aggregate)!=0;
#if SELECTTRACE_ENABLED
  if( sqlite3SelectTrace & 0x100 ){
    SELECTTRACE(0x100,pParse,p, ("after name resolution:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif

  /* Get a pointer the VDBE under construction, allocating a new VDBE if one
  ** does not already exist */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto select_end;
  if( pDest->eDest==SRT_Output ){
    generateColumnNames(pParse, p);
  }

  /* Try to flatten subqueries in the FROM clause up into the main query
  */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
    struct SrcList_item *pItem = &pTabList->a[i];
    Select *pSub = pItem->pSelect;

    if( db->mallocFailed ) goto select_end;
    if( !IgnorableOrderby(pDest) ){
      sSort.pOrderBy = p->pOrderBy;
    }
  }
#endif






#ifndef SQLITE_OMIT_COMPOUND_SELECT
  /* Handle compound SELECT statements using the separate multiSelect()
  ** procedure.
  */
  if( p->pPrior ){
    rc = multiSelect(pParse, p, pDest);
    explainSetInteger(pParse->iSelectId, iRestoreSelectId);

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  explainSetInteger(pParse->iSelectId, iRestoreSelectId);







  sqlite3DbFree(db, sAggInfo.aCol);
  sqlite3DbFree(db, sAggInfo.aFunc);
#if SELECTTRACE_ENABLED
  SELECTTRACE(1,pParse,p,("end processing\n"));
  pParse->nSelectIndent--;
#endif
  return rc;
}

#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
#define SQLITE_IOERR_BEGIN_ATOMIC      (SQLITE_IOERR | (29<<8))
#define SQLITE_IOERR_COMMIT_ATOMIC     (SQLITE_IOERR | (30<<8))
#define SQLITE_IOERR_ROLLBACK_ATOMIC   (SQLITE_IOERR | (31<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_BUSY_DEADLOCK           (SQLITE_BUSY   |  (3<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))

** file that were written at the application level might have changed
** and that adjacent bytes, even bytes within the same sector are
** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
** flag indicates that a file cannot be deleted when open.  The
** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
** read-only media and cannot be changed even by processes with
** elevated privileges.
**
** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
** filesystem supports doing multiple write operations atomically when those
** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
*/
#define SQLITE_IOCAP_ATOMIC                 0x00000001
#define SQLITE_IOCAP_ATOMIC512              0x00000002
#define SQLITE_IOCAP_ATOMIC1K               0x00000004
#define SQLITE_IOCAP_ATOMIC2K               0x00000008
#define SQLITE_IOCAP_ATOMIC4K               0x00000010
#define SQLITE_IOCAP_ATOMIC8K               0x00000020
#define SQLITE_IOCAP_ATOMIC16K              0x00000040
#define SQLITE_IOCAP_ATOMIC32K              0x00000080
#define SQLITE_IOCAP_ATOMIC64K              0x00000100
#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
#define SQLITE_IOCAP_IMMUTABLE              0x00002000
#define SQLITE_IOCAP_BATCH_ATOMIC           0x00004000

/*
** CAPI3REF: File Locking Levels
**
** SQLite uses one of these integer values as the second
** argument to calls it makes to the xLock() and xUnlock() methods
** of an [sqlite3_io_methods] object.

** <li> [SQLITE_IOCAP_ATOMIC32K]
** <li> [SQLITE_IOCAP_ATOMIC64K]
** <li> [SQLITE_IOCAP_SAFE_APPEND]
** <li> [SQLITE_IOCAP_SEQUENTIAL]
** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
** <li> [SQLITE_IOCAP_IMMUTABLE]
** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
** </ul>
**
** The SQLITE_IOCAP_ATOMIC property means that all writes of
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
** mean that writes of blocks that are nnn bytes in size and
** are aligned to an address which is an integer multiple of
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means

** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
** VFS should return SQLITE_NOTFOUND for this opcode.
**
** <li>[[SQLITE_FCNTL_RBU]]
** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
** this opcode.  
**
** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
** the file descriptor is placed in "batch write mode", which
** means all subsequent write operations will be deferred and done
** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].  Systems
** that do not support batch atomic writes will return SQLITE_NOTFOUND.
** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
** no VFS interface calls on the same [sqlite3_file] file descriptor
** except for calls to the xWrite method and the xFileControl method
** with [SQLITE_FCNTL_SIZE_HINT].
**
** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
** operations since the previous successful call to 
** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
** This file control returns [SQLITE_OK] if and only if the writes were
** all performed successfully and have been committed to persistent storage.
** ^Regardless of whether or not it is successful, this file control takes
** the file descriptor out of batch write mode so that all subsequent
** write operations are independent.
** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
**
** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
** operations since the previous successful call to 
** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
** ^This file control takes the file descriptor out of batch write mode
** so that all subsequent write operations are independent.
** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
#define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
#define SQLITE_FCNTL_LAST_ERRNO              4
#define SQLITE_FCNTL_SIZE_HINT               5

#define SQLITE_FCNTL_WAL_BLOCK              24
#define SQLITE_FCNTL_ZIPVFS                 25
#define SQLITE_FCNTL_RBU                    26
#define SQLITE_FCNTL_VFS_POINTER            27
#define SQLITE_FCNTL_JOURNAL_POINTER        28
#define SQLITE_FCNTL_WIN32_GET_HANDLE       29
#define SQLITE_FCNTL_PDB                    30
#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE     31
#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
#define SQLITE_FCNTL_FILEID                 34
#define SQLITE_FCNTL_SERVER_MODE            35

/* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO

** The default value of "20" was choosen to minimize the run-time of the
** speedtest1 test program with options: --shrink-memory --reprepare
*/
#ifndef SQLITE_DEFAULT_PCACHE_INITSZ
# define SQLITE_DEFAULT_PCACHE_INITSZ 20
#endif

/*
** The compile-time options SQLITE_MMAP_READWRITE and 
** SQLITE_ENABLE_BATCH_ATOMIC_WRITE are not compatible with one another.
** You must choose one or the other (or neither) but not both.
*/
#if defined(SQLITE_MMAP_READWRITE) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
#error Cannot use both SQLITE_MMAP_READWRITE and SQLITE_ENABLE_BATCH_ATOMIC_WRITE
#endif

/*
** GCC does not define the offsetof() macro so we'll have to do it
** ourselves.
*/
#ifndef offsetof
#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
#endif

** Note that aSortOrder[] and aColl[] have nField+1 slots.  There
** are nField slots for the columns of an index then one extra slot
** for the rowid at the end.
*/
struct KeyInfo {
  u32 nRef;           /* Number of references to this KeyInfo object */
  u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
  u16 nKeyField;      /* Number of key columns in the index */
  u16 nAllField;      /* Total columns, including key plus others */
  sqlite3 *db;        /* The database connection */
  u8 *aSortOrder;     /* Sort order for each column. */
  CollSeq *aColl[1];  /* Collating sequence for each term of the key */
};

/*
** This object holds a record which has been parsed out into individual

#define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */
#define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */
#define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */
int sqlite3FindInIndex(Parse *, Expr *, u32, int*, int*);

int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
int sqlite3JournalSize(sqlite3_vfs *);
#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
  int sqlite3JournalCreate(sqlite3_file *);
#endif

int sqlite3JournalIsInMemory(sqlite3_file *p);
void sqlite3MemJournalOpen(sqlite3_file *);

void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p);

static int SQLITE_TCLAPI md5file_cmd(
  void*cd,
  Tcl_Interp *interp,
  int argc,
  const char **argv
){
  FILE *in;
  int ofst;
  int amt;
  MD5Context ctx;
  void (*converter)(unsigned char*, char*);
  unsigned char digest[16];
  char zBuf[10240];

  if( argc!=2 && argc!=4 ){
    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
        " FILENAME [OFFSET AMT]\"", (char*)0);
    return TCL_ERROR;
  }
  if( argc==4 ){
    ofst = atoi(argv[2]);
    amt = atoi(argv[3]);
  }else{
    ofst = 0;
    amt = 2147483647;
  }
  in = fopen(argv[1],"rb");
  if( in==0 ){
    Tcl_AppendResult(interp,"unable to open file \"", argv[1],
         "\" for reading", (char*)0);
    return TCL_ERROR;
  }
  fseek(in, ofst, SEEK_SET);
  MD5Init(&ctx);

  while( amt>0 ){
    int n;
    n = (int)fread(zBuf, 1, sizeof(zBuf)<=amt ? sizeof(zBuf) : amt, in);
    if( n<=0 ) break;
    MD5Update(&ctx, (unsigned char*)zBuf, (unsigned)n);
    amt -= n;
  }
  fclose(in);
  MD5Final(digest, &ctx);
  converter = (void(*)(unsigned char*,char*))cd;
  converter(digest, zBuf);
  Tcl_AppendResult(interp, zBuf, (char*)0);
  return TCL_OK;

  }
  zFile = (const char*)Tcl_GetString(objv[1]);
  rc = sqlite3_delete_database(zFile);

  Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
  return TCL_OK;
}

/*
** Usage: atomic_batch_write PATH
*/
static int SQLITE_TCLAPI test_atomic_batch_write(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  char *zFile = 0;                /* Path to file to test */
  sqlite3 *db = 0;                /* Database handle */
  sqlite3_file *pFd = 0;          /* SQLite fd open on zFile */
  int bRes = 0;                   /* Integer result of this command */
  int dc = 0;                     /* Device-characteristics mask */
  int rc;                         /* sqlite3_open() return code */

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "PATH");
    return TCL_ERROR;
  }
  zFile = Tcl_GetString(objv[1]);

  rc = sqlite3_open(zFile, &db);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, sqlite3_errmsg(db), 0);
    sqlite3_close(db);
    return TCL_ERROR;
  }

  rc = sqlite3_file_control(db, "main", SQLITE_FCNTL_FILE_POINTER, (void*)&pFd);
  dc = pFd->pMethods->xDeviceCharacteristics(pFd);
  if( dc & SQLITE_IOCAP_BATCH_ATOMIC ){
    bRes = 1;
  }

  Tcl_SetObjResult(interp, Tcl_NewIntObj(bRes));
  sqlite3_close(db);
  return TCL_OK;
}

/*
** Usage:  sqlite3_next_stmt  DB  STMT
**
** Return the next statment in sequence after STMT.
*/
static int SQLITE_TCLAPI test_next_stmt(

     { "sqlite3_snapshot_cmp", test_snapshot_cmp, 0 },
     { "sqlite3_snapshot_recover", test_snapshot_recover, 0 },
     { "sqlite3_snapshot_get_blob", test_snapshot_get_blob, 0 },
     { "sqlite3_snapshot_open_blob", test_snapshot_open_blob, 0 },
     { "sqlite3_snapshot_cmp_blob", test_snapshot_cmp_blob, 0 },
#endif
     { "sqlite3_delete_database", test_delete_database, 0 },
     { "atomic_batch_write",      test_atomic_batch_write,     0   },
  };
  static int bitmask_size = sizeof(Bitmask)*8;
  static int longdouble_size = sizeof(LONGDOUBLE_TYPE);
  int i;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;
  extern int sqlite3_like_count;

    { "atomic8k",            SQLITE_IOCAP_ATOMIC8K              },
    { "atomic16k",           SQLITE_IOCAP_ATOMIC16K             },
    { "atomic32k",           SQLITE_IOCAP_ATOMIC32K             },
    { "atomic64k",           SQLITE_IOCAP_ATOMIC64K             },
    { "sequential",          SQLITE_IOCAP_SEQUENTIAL            },
    { "safe_append",         SQLITE_IOCAP_SAFE_APPEND           },
    { "powersafe_overwrite", SQLITE_IOCAP_POWERSAFE_OVERWRITE   },
    { "batch-atomic",        SQLITE_IOCAP_BATCH_ATOMIC          },
    { 0, 0 }
  };

  int i;
  int iDc = 0;
  int iSectorSize = 0;
  int setSectorsize = 0;

  if( processDevSymArgs(interp, objc-1, &objv[1], &iDc, &iSectorSize) ){
    return TCL_ERROR;
  }
  devsym_register(iDc, iSectorSize);

  return TCL_OK;
}

/*
** tclcmd: sqlite3_crash_on_write N
*/
static int SQLITE_TCLAPI writeCrashObjCmd(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  void devsym_crash_on_write(int);
  int nWrite = 0;

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "NWRITE");
    return TCL_ERROR;
  }
  if( Tcl_GetIntFromObj(interp, objv[1], &nWrite) ){
    return TCL_ERROR;
  }

  devsym_crash_on_write(nWrite);
  return TCL_OK;
}

/*
** tclcmd: unregister_devsim
*/
static int SQLITE_TCLAPI dsUnregisterObjCmd(
  void * clientData,

*/
int Sqlitetest6_Init(Tcl_Interp *interp){
#ifndef SQLITE_OMIT_DISKIO
  Tcl_CreateObjCommand(interp, "sqlite3_crash_enable", crashEnableCmd, 0, 0);
  Tcl_CreateObjCommand(interp, "sqlite3_crashparams", crashParamsObjCmd, 0, 0);
  Tcl_CreateObjCommand(interp, "sqlite3_crash_now", crashNowCmd, 0, 0);
  Tcl_CreateObjCommand(interp, "sqlite3_simulate_device", devSymObjCmd, 0, 0);
  Tcl_CreateObjCommand(interp, "sqlite3_crash_on_write", writeCrashObjCmd,0,0);
  Tcl_CreateObjCommand(interp, "unregister_devsim", dsUnregisterObjCmd, 0, 0);
  Tcl_CreateObjCommand(interp, "register_jt_vfs", jtObjCmd, 0, 0);
  Tcl_CreateObjCommand(interp, "unregister_jt_vfs", jtUnregisterObjCmd, 0, 0);
#endif
  return TCL_OK;
}

#endif /* SQLITE_TEST */

*/
#define DEVSYM_MAX_PATHNAME 512

/*
** Name used to identify this VFS.
*/
#define DEVSYM_VFS_NAME "devsym"
#define WRITECRASH_NAME "writecrash"

typedef struct devsym_file devsym_file;
struct devsym_file {
  sqlite3_file base;
  sqlite3_file *pReal;
};

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*);


















































struct DevsymGlobal {
  sqlite3_vfs *pVfs;
  int iDeviceChar;
  int iSectorSize;
  int nWriteCrash;
};
struct DevsymGlobal g = {0, 0, 512, 0};

/*
** Close an devsym-file.
*/
static int devsymClose(sqlite3_file *pFile){
  devsym_file *p = (devsym_file *)pFile;
  sqlite3OsClose(p->pReal);

static int devsymOpen(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
static sqlite3_io_methods devsym_io_methods = {
  2,                                /* iVersion */
  devsymClose,                      /* xClose */
  devsymRead,                       /* xRead */
  devsymWrite,                      /* xWrite */
  devsymTruncate,                   /* xTruncate */
  devsymSync,                       /* xSync */
  devsymFileSize,                   /* xFileSize */
  devsymLock,                       /* xLock */
  devsymUnlock,                     /* xUnlock */
  devsymCheckReservedLock,          /* xCheckReservedLock */
  devsymFileControl,                /* xFileControl */
  devsymSectorSize,                 /* xSectorSize */
  devsymDeviceCharacteristics,      /* xDeviceCharacteristics */
  devsymShmMap,                     /* xShmMap */
  devsymShmLock,                    /* xShmLock */
  devsymShmBarrier,                 /* xShmBarrier */
  devsymShmUnmap                    /* xShmUnmap */
};

  int rc;
  devsym_file *p = (devsym_file *)pFile;
  p->pReal = (sqlite3_file *)&p[1];
  rc = sqlite3OsOpen(g.pVfs, zName, p->pReal, flags, pOutFlags);
  if( p->pReal->pMethods ){
    pFile->pMethods = &devsym_io_methods;
  }

/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int devsymCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return g.pVfs->xCurrentTime(g.pVfs, pTimeOut);
}

/*
** Return the sector-size in bytes for an writecrash-file.
*/
static int writecrashSectorSize(sqlite3_file *pFile){
  devsym_file *p = (devsym_file *)pFile;
  return sqlite3OsSectorSize(p->pReal);
}

/*
** Return the device characteristic flags supported by an writecrash-file.
*/
static int writecrashDeviceCharacteristics(sqlite3_file *pFile){
  devsym_file *p = (devsym_file *)pFile;
  return sqlite3OsDeviceCharacteristics(p->pReal);
}

/*
** Write data to an writecrash-file.
*/
static int writecrashWrite(
  sqlite3_file *pFile, 
  const void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  devsym_file *p = (devsym_file *)pFile;
  if( g.nWriteCrash>0 ){
    g.nWriteCrash--;
    if( g.nWriteCrash==0 ) abort();
  }
  return sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
}

/*
** Open an writecrash file handle.
*/
static int writecrashOpen(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
static sqlite3_io_methods writecrash_io_methods = {
  2,                                /* iVersion */
  devsymClose,                      /* xClose */
  devsymRead,                       /* xRead */
  writecrashWrite,                  /* xWrite */
  devsymTruncate,                   /* xTruncate */
  devsymSync,                       /* xSync */
  devsymFileSize,                   /* xFileSize */
  devsymLock,                       /* xLock */
  devsymUnlock,                     /* xUnlock */
  devsymCheckReservedLock,          /* xCheckReservedLock */
  devsymFileControl,                /* xFileControl */
  writecrashSectorSize,             /* xSectorSize */
  writecrashDeviceCharacteristics,  /* xDeviceCharacteristics */
  devsymShmMap,                     /* xShmMap */
  devsymShmLock,                    /* xShmLock */
  devsymShmBarrier,                 /* xShmBarrier */
  devsymShmUnmap                    /* xShmUnmap */
};

  int rc;
  devsym_file *p = (devsym_file *)pFile;
  p->pReal = (sqlite3_file *)&p[1];
  rc = sqlite3OsOpen(g.pVfs, zName, p->pReal, flags, pOutFlags);
  if( p->pReal->pMethods ){
    pFile->pMethods = &writecrash_io_methods;
  }
  return rc;
}

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 */
  devsymAccess,             /* xAccess */
  devsymFullPathname,       /* xFullPathname */
#ifndef SQLITE_OMIT_LOAD_EXTENSION
  devsymDlOpen,             /* xDlOpen */
  devsymDlError,            /* xDlError */
  devsymDlSym,              /* xDlSym */
  devsymDlClose,            /* xDlClose */
#else
  0,                        /* xDlOpen */
  0,                        /* xDlError */
  0,                        /* xDlSym */
  0,                        /* xDlClose */
#endif /* SQLITE_OMIT_LOAD_EXTENSION */
  devsymRandomness,         /* xRandomness */
  devsymSleep,              /* xSleep */
  devsymCurrentTime,        /* xCurrentTime */
  0,                        /* xGetLastError */
  0                         /* xCurrentTimeInt64 */
};

static sqlite3_vfs writecrash_vfs = {
  2,                     /* iVersion */
  sizeof(devsym_file),      /* szOsFile */
  DEVSYM_MAX_PATHNAME,      /* mxPathname */
  0,                     /* pNext */
  WRITECRASH_NAME,          /* zName */
  0,                     /* pAppData */
  writecrashOpen,           /* xOpen */
  devsymDelete,             /* xDelete */
  devsymAccess,             /* xAccess */
  devsymFullPathname,       /* xFullPathname */
#ifndef SQLITE_OMIT_LOAD_EXTENSION
  devsymDlOpen,             /* xDlOpen */
  devsymDlError,            /* xDlError */
  devsymDlSym,              /* xDlSym */
  devsymDlClose,            /* xDlClose */
#else
  0,                        /* xDlOpen */
  0,                        /* xDlError */
  0,                        /* xDlSym */
  0,                        /* xDlClose */
#endif /* SQLITE_OMIT_LOAD_EXTENSION */
  devsymRandomness,         /* xRandomness */
  devsymSleep,              /* xSleep */
  devsymCurrentTime,        /* xCurrentTime */
  0,                        /* xGetLastError */
  0                         /* xCurrentTimeInt64 */
};


/*
** 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;
    writecrash_vfs.szOsFile += g.pVfs->szOsFile;
    sqlite3_vfs_register(&devsym_vfs, 0);
    sqlite3_vfs_register(&writecrash_vfs, 0);
  }
  if( iDeviceChar>=0 ){
    g.iDeviceChar = iDeviceChar;
  }else{
    g.iDeviceChar = 0;
  }
  if( iSectorSize>=0 ){
    g.iSectorSize = iSectorSize;
  }else{
    g.iSectorSize = 512;
  }
}

void devsym_unregister(){
  sqlite3_vfs_unregister(&devsym_vfs);
  g.pVfs = 0;
  g.iDeviceChar = 0;
  g.iSectorSize = 0;
}

void devsym_crash_on_write(int nWrite){
  if( g.pVfs==0 ){
    g.pVfs = sqlite3_vfs_find(0);
    devsym_vfs.szOsFile += g.pVfs->szOsFile;
    writecrash_vfs.szOsFile += g.pVfs->szOsFile;
    sqlite3_vfs_register(&devsym_vfs, 0);
    sqlite3_vfs_register(&writecrash_vfs, 0);
  }
  g.nWriteCrash = nWrite;
}

#endif

        flags3 = (pIn3->flags & ~MEM_TypeMask) | (flags3 & MEM_TypeMask);
      }
    }
    assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 );
    res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);
  }
compare_op:
  /* At this point, res is negative, zero, or positive if reg[P1] is
  ** less than, equal to, or greater than reg[P3], respectively.  Compute
  ** the answer to this operator in res2, depending on what the comparison
  ** operator actually is.  The next block of code depends on the fact
  ** that the 6 comparison operators are consecutive integers in this
  ** order:  NE, EQ, GT, LE, LT, GE */
  assert( OP_Eq==OP_Ne+1 ); assert( OP_Gt==OP_Ne+2 ); assert( OP_Le==OP_Ne+3 );
  assert( OP_Lt==OP_Ne+4 ); assert( OP_Ge==OP_Ne+5 );
  if( res<0 ){                        /* ne, eq, gt, le, lt, ge */
    static const unsigned char aLTb[] = { 1,  0,  0,  1,  1,  0 };
    res2 = aLTb[pOp->opcode - OP_Ne];
  }else if( res==0 ){
    static const unsigned char aEQb[] = { 0,  1,  0,  1,  0,  1 };
    res2 = aEQb[pOp->opcode - OP_Ne];
  }else{
    static const unsigned char aGTb[] = { 1,  0,  1,  0,  0,  1 };
    res2 = aGTb[pOp->opcode - OP_Ne];



  }

  /* Undo any changes made by applyAffinity() to the input registers. */
  assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) );
  pIn1->flags = flags1;
  assert( (pIn3->flags & MEM_Dyn) == (flags3 & MEM_Dyn) );
  pIn3->flags = flags3;

  if( pOp->p5 & SQLITE_STOREP2 ){
    pOut = &aMem[pOp->p2];
    iCompare = res;

    if( (pOp->p5 & SQLITE_KEEPNULL)!=0 ){
      /* The KEEPNULL flag prevents OP_Eq from overwriting a NULL with 1
      ** and prevents OP_Ne from overwriting NULL with 0.  This flag
      ** is only used in contexts where either:
      **   (1) op==OP_Eq && (r[P2]==NULL || r[P2]==0)
      **   (2) op==OP_Ne && (r[P2]==NULL || r[P2]==1)
      ** Therefore it is not necessary to check the content of r[P2] for

#endif /* SQLITE_DEBUG */
  for(i=0; i<n; i++){
    idx = aPermute ? aPermute[i] : i;
    assert( memIsValid(&aMem[p1+idx]) );
    assert( memIsValid(&aMem[p2+idx]) );
    REGISTER_TRACE(p1+idx, &aMem[p1+idx]);
    REGISTER_TRACE(p2+idx, &aMem[p2+idx]);
    assert( i<pKeyInfo->nKeyField );
    pColl = pKeyInfo->aColl[i];
    bRev = pKeyInfo->aSortOrder[i];
    iCompare = sqlite3MemCompare(&aMem[p1+idx], &aMem[p2+idx], pColl);
    if( iCompare ){
      if( bRev ) iCompare = -iCompare;
      break;
    }

    ** before reaching this instruction. */
    assert( p2>=2 );
  }
  if( pOp->p4type==P4_KEYINFO ){
    pKeyInfo = pOp->p4.pKeyInfo;
    assert( pKeyInfo->enc==ENC(db) );
    assert( pKeyInfo->db==db );
    nField = pKeyInfo->nAllField;
  }else if( pOp->p4type==P4_INT32 ){
    nField = pOp->p4.i;
  }
  assert( pOp->p1>=0 );
  assert( nField>=0 );
  testcase( nField==0 );  /* Table with INTEGER PRIMARY KEY and nothing else */
  pCur = allocateCursor(p, pOp->p1, nField, iDb, CURTYPE_BTREE);

  if( pC->eCurType==CURTYPE_BTREE ){
    assert( pC->uc.pCursor!=0 );
    sqlite3BtreeClearCursor(pC->uc.pCursor);
  }
  break;
}

/* Opcode: SeekEnd P1 * * * *
**
** Position cursor P1 at the end of the btree for the purpose of
** appending a new entry onto the btree.
**
** It is assumed that the cursor is used only for appending and so
** if the cursor is valid, then the cursor must already be pointing
** at the end of the btree and so no changes are made to
** the cursor.
*/
/* Opcode: Last P1 P2 * * *
**
** The next use of the Rowid or Column or Prev instruction for P1 
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
**
** This opcode leaves the cursor configured to move in reverse order,
** from the end toward the beginning.  In other words, the cursor is
** configured to use Prev, not Next.







*/
case OP_SeekEnd:
case OP_Last: {        /* jump */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  res = 0;
  assert( pCrsr!=0 );

#ifdef SQLITE_DEBUG
  pC->seekOp = pOp->opcode;
#endif
  if( pOp->opcode==OP_SeekEnd ){
    assert( pOp->p2==0 );
    pC->seekResult = -1;
    if( sqlite3BtreeCursorIsValidNN(pCrsr) ){
      break;
    }
  }
  rc = sqlite3BtreeLast(pCrsr, &res);
  pC->nullRow = (u8)res;
  pC->deferredMoveto = 0;
  pC->cacheStatus = CACHE_STALE;
  if( rc ) goto abort_due_to_error;
  if( pOp->p2>0 ){
    VdbeBranchTaken(res!=0,2);
    if( res ) goto jump_to_p2;



  }
  break;
}

/* Opcode: IfSmaller P1 P2 P3 * *
**
** Estimate the number of rows in the table P1.  Jump to P2 if that

  for(i=0; i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      int nEntry;
      sqlite3BtreeEnter(pBt);
      nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
      sqlite3BtreeLeave(pBt);
      if( nEntry>0 && db->xWalCallback && rc==SQLITE_OK ){
        rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
      }
    }
  }
#endif
  return rc;
}

  }

#ifndef SQLITE_OMIT_TRACE
  /* If the statement completed successfully, invoke the profile callback */
  if( rc!=SQLITE_ROW ) checkProfileCallback(db, p);
#endif

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

/*
** This is the top-level implementation of sqlite3_step().  Call
** sqlite3Step() to do most of the work.  If a schema error occurs,
** call sqlite3Reprepare() and try again.
*/
int sqlite3_step(sqlite3_stmt *pStmt){
  int rc = SQLITE_OK;      /* Result from sqlite3Step() */

  Vdbe *v = (Vdbe*)pStmt;  /* the prepared statement */
  int cnt = 0;             /* Counter to prevent infinite loop of reprepares */
  sqlite3 *db;             /* The database connection */

  if( vdbeSafetyNotNull(v) ){
    return SQLITE_MISUSE_BKPT;
  }
  db = v->db;
  sqlite3_mutex_enter(db->mutex);
  v->doingRerun = 0;
  while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
         && cnt++ < SQLITE_MAX_SCHEMA_RETRY ){
    int savedPc = v->pc;
    rc = sqlite3Reprepare(v);
    if( rc!=SQLITE_OK ){





      /* This case occurs after failing to recompile an sql statement. 
      ** The error message from the SQL compiler has already been loaded 
      ** into the database handle. This block copies the error message 
      ** from the database handle into the statement and sets the statement
      ** program counter to 0 to ensure that when the statement is 
      ** finalized or reset the parser error message is available via
      ** sqlite3_errmsg() and sqlite3_errcode().
      */
      const char *zErr = (const char *)sqlite3_value_text(db->pErr); 
      sqlite3DbFree(db, v->zErrMsg);
      if( !db->mallocFailed ){
        v->zErrMsg = sqlite3DbStrDup(db, zErr);
        v->rc = rc = sqlite3ApiExit(db, rc);
      } else {
        v->zErrMsg = 0;
        v->rc = rc = SQLITE_NOMEM_BKPT;
      }
      break;
    }
    sqlite3_reset(pStmt);
    if( savedPc>=0 ) v->doingRerun = 1;
    assert( v->expired==0 );
  }
  sqlite3_mutex_leave(db->mutex);
  return rc;
}


/*
** Extract the user data from a sqlite3_context structure and return a

  int nKey, 
  const void *pKey
){
  UnpackedRecord *pRet;           /* Return value */

  pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
  if( pRet ){
    memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nKeyField+1));
    sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
  }
  return pRet;
}

/*
** This function is called from within a pre-update callback to retrieve

#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
/*
** This function is called from within a pre-update callback to retrieve
** the number of columns in the row being updated, deleted or inserted.
*/
int sqlite3_preupdate_count(sqlite3 *db){
  PreUpdate *p = db->pPreUpdate;
  return (p ? p->keyinfo.nKeyField : 0);
}
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
/*
** This function is designed to be called from within a pre-update callback
** only. It returns zero if the change that caused the callback was made

        case OP_Checkpoint:
#endif
        case OP_Vacuum:
        case OP_JournalMode: {
          p->readOnly = 0;
          p->bIsReader = 1;
          break;
        }
        case OP_Next:
        case OP_NextIfOpen:
        case OP_SorterNext: {
          pOp->p4.xAdvance = sqlite3BtreeNext;
          pOp->p4type = P4_ADVANCE;
          /* The code generator never codes any of these opcodes as a jump
          ** to a label.  They are always coded as a jump backwards to a 
          ** known address */
          assert( pOp->p2>=0 );
          break;
        }
        case OP_Prev:
        case OP_PrevIfOpen: {
          pOp->p4.xAdvance = sqlite3BtreePrevious;
          pOp->p4type = P4_ADVANCE;
          /* The code generator never codes any of these opcodes as a jump
          ** to a label.  They are always coded as a jump backwards to a 
          ** known address */
          assert( pOp->p2>=0 );
          break;
        }
#ifndef SQLITE_OMIT_VIRTUALTABLE
        case OP_VUpdate: {
          if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
          break;
        }
        case OP_VFilter: {
          int n;
          assert( (pOp - p->aOp) >= 3 );
          assert( pOp[-1].opcode==OP_Integer );
          n = pOp[-1].p1;
          if( n>nMaxArgs ) nMaxArgs = n;
          /* Fall through into the default case */
        }
#endif
        default: {
          if( pOp->p2<0 ){
            /* The mkopcodeh.tcl script has so arranged things that the only
            ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to
            ** have non-negative values for P2. */
            assert( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 );
            assert( ADDR(pOp->p2)<pParse->nLabel );
            pOp->p2 = aLabel[ADDR(pOp->p2)];

          }




          break;
        }
      }
      /* The mkopcodeh.tcl script has so arranged things that the only
      ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to
      ** have non-negative values for P2. */
      assert( (sqlite3OpcodeProperty[pOp->opcode]&OPFLG_JUMP)==0 || pOp->p2>=0);



    }
    if( pOp==p->aOp ) break;
    pOp--;
  }
  sqlite3DbFree(p->db, pParse->aLabel);
  pParse->aLabel = 0;
  pParse->nLabel = 0;

  assert( nTemp>=20 );
  sqlite3StrAccumInit(&x, 0, zTemp, nTemp, 0);
  switch( pOp->p4type ){
    case P4_KEYINFO: {
      int j;
      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
      assert( pKeyInfo->aSortOrder!=0 );
      sqlite3XPrintf(&x, "k(%d", pKeyInfo->nKeyField);
      for(j=0; j<pKeyInfo->nKeyField; j++){
        CollSeq *pColl = pKeyInfo->aColl[j];
        const char *zColl = pColl ? pColl->zName : "";
        if( strcmp(zColl, "BINARY")==0 ) zColl = "B";
        sqlite3XPrintf(&x, ",%s%s", pKeyInfo->aSortOrder[j] ? "-" : "", zColl);
      }
      sqlite3StrAccumAppend(&x, ")", 1);
      break;

** If an OOM error occurs, NULL is returned.
*/
UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(
  KeyInfo *pKeyInfo               /* Description of the record */
){
  UnpackedRecord *p;              /* Unpacked record to return */
  int nByte;                      /* Number of bytes required for *p */
  nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nKeyField+1);
  p = (UnpackedRecord *)sqlite3DbMallocRaw(pKeyInfo->db, nByte);
  if( !p ) return 0;
  p->aMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];
  assert( pKeyInfo->aSortOrder!=0 );
  p->pKeyInfo = pKeyInfo;
  p->nField = pKeyInfo->nKeyField + 1;
  return p;
}

/*
** Given the nKey-byte encoding of a record in pKey[], populate the 
** UnpackedRecord structure indicated by the fourth argument with the
** contents of the decoded record.

    /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
    pMem->szMalloc = 0;
    pMem->z = 0;
    d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
    pMem++;
    if( (++u)>=p->nField ) break;
  }
  assert( u<=pKeyInfo->nKeyField + 1 );
  p->nField = u;
}

#ifdef SQLITE_DEBUG
/*
** This function compares two index or table record keys in the same way
** as the sqlite3VdbeRecordCompare() routine. Unlike VdbeRecordCompare(),

  ** to ignore the compiler warnings and leave this variable uninitialized.
  */
  /*  mem1.u.i = 0;  // not needed, here to silence compiler warning */
  
  idx1 = getVarint32(aKey1, szHdr1);
  if( szHdr1>98307 ) return SQLITE_CORRUPT;
  d1 = szHdr1;
  assert( pKeyInfo->nAllField>=pPKey2->nField || CORRUPT_DB );
  assert( pKeyInfo->aSortOrder!=0 );
  assert( pKeyInfo->nKeyField>0 );
  assert( idx1<=szHdr1 || CORRUPT_DB );
  do{
    u32 serial_type1;

    /* Read the serial types for the next element in each key. */
    idx1 += getVarint32( aKey1+idx1, serial_type1 );

}
#endif

#ifdef SQLITE_DEBUG
/*
** Count the number of fields (a.k.a. columns) in the record given by
** pKey,nKey.  The verify that this count is less than or equal to the
** limit given by pKeyInfo->nAllField.
**
** If this constraint is not satisfied, it means that the high-speed
** vdbeRecordCompareInt() and vdbeRecordCompareString() routines will
** not work correctly.  If this assert() ever fires, it probably means
** that the KeyInfo.nKeyField or KeyInfo.nAllField values were computed
** incorrectly.
*/
static void vdbeAssertFieldCountWithinLimits(
  int nKey, const void *pKey,   /* The record to verify */ 
  const KeyInfo *pKeyInfo       /* Compare size with this KeyInfo */
){
  int nField = 0;
  u32 szHdr;
  u32 idx;
  u32 notUsed;
  const unsigned char *aKey = (const unsigned char*)pKey;

  if( CORRUPT_DB ) return;
  idx = getVarint32(aKey, szHdr);
  assert( nKey>=0 );
  assert( szHdr<=(u32)nKey );
  while( idx<szHdr ){
    idx += getVarint32(aKey+idx, notUsed);
    nField++;
  }
  assert( nField <= pKeyInfo->nAllField );
}
#else
# define vdbeAssertFieldCountWithinLimits(A,B,C)
#endif

/*
** Both *pMem1 and *pMem2 contain string values. Compare the two values

      pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
      return 0;  /* Corruption */
    }
    i = 0;
  }

  VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
  assert( pPKey2->pKeyInfo->nAllField>=pPKey2->nField 
       || CORRUPT_DB );
  assert( pPKey2->pKeyInfo->aSortOrder!=0 );
  assert( pPKey2->pKeyInfo->nKeyField>0 );
  assert( idx1<=szHdr1 || CORRUPT_DB );
  do{
    u32 serial_type;

    /* RHS is an integer */
    if( pRhs->flags & MEM_Int ){
      serial_type = aKey1[idx1];

  ** buffer passed to varintRecordCompareInt() this makes it convenient to
  ** limit the size of the header to 64 bytes in cases where the first field
  ** is an integer.
  **
  ** The easiest way to enforce this limit is to consider only records with
  ** 13 fields or less. If the first field is an integer, the maximum legal
  ** header size is (12*5 + 1 + 1) bytes.  */
  if( p->pKeyInfo->nAllField<=13 ){
    int flags = p->aMem[0].flags;
    if( p->pKeyInfo->aSortOrder[0] ){
      p->r1 = 1;
      p->r2 = -1;
    }else{
      p->r1 = -1;
      p->r2 = 1;

  preupdate.v = v;
  preupdate.pCsr = pCsr;
  preupdate.op = op;
  preupdate.iNewReg = iReg;
  preupdate.keyinfo.db = db;
  preupdate.keyinfo.enc = ENC(db);
  preupdate.keyinfo.nKeyField = pTab->nCol;
  preupdate.keyinfo.aSortOrder = (u8*)&fakeSortOrder;
  preupdate.iKey1 = iKey1;
  preupdate.iKey2 = iKey2;
  preupdate.pTab = pTab;

  db->pPreUpdate = &preupdate;
  db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);
  db->pPreUpdate = 0;
  sqlite3DbFree(db, preupdate.aRecord);
  vdbeFreeUnpacked(db, preupdate.keyinfo.nKeyField+1, preupdate.pUnpacked);
  vdbeFreeUnpacked(db, preupdate.keyinfo.nKeyField+1, preupdate.pNewUnpacked);
  if( preupdate.aNew ){
    int i;
    for(i=0; i<pCsr->nField; i++){
      sqlite3VdbeMemRelease(&preupdate.aNew[i]);
    }
    sqlite3DbFreeNN(db, preupdate.aNew);
  }
}
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  sqlite3_blob **ppBlob   /* Handle for accessing the blob returned here */
){
  int nAttempt = 0;
  int iCol;               /* Index of zColumn in row-record */
  int rc = SQLITE_OK;
  char *zErr = 0;
  Table *pTab;

  Incrblob *pBlob = 0;
  Parse sParse;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppBlob==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  *ppBlob = 0;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zTable==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  wrFlag = !!wrFlag;                /* wrFlag = (wrFlag ? 1 : 0); */

  sqlite3_mutex_enter(db->mutex);

  pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));




  do {
    memset(&sParse, 0, sizeof(Parse));
    if( !pBlob ) goto blob_open_out;
    sParse.db = db;
    sqlite3DbFree(db, zErr);
    zErr = 0;

    sqlite3BtreeEnterAll(db);
    pTab = sqlite3LocateTable(&sParse, 0, zTable, zDb);
    if( pTab && IsVirtual(pTab) ){
      pTab = 0;
      sqlite3ErrorMsg(&sParse, "cannot open virtual table: %s", zTable);
    }
    if( pTab && !HasRowid(pTab) ){
      pTab = 0;
      sqlite3ErrorMsg(&sParse, "cannot open table without rowid: %s", zTable);
    }
#ifndef SQLITE_OMIT_VIEW
    if( pTab && pTab->pSelect ){
      pTab = 0;
      sqlite3ErrorMsg(&sParse, "cannot open view: %s", zTable);
    }
#endif
    if( !pTab ){
      if( sParse.zErrMsg ){
        sqlite3DbFree(db, zErr);
        zErr = sParse.zErrMsg;
        sParse.zErrMsg = 0;
      }
      rc = SQLITE_ERROR;
      sqlite3BtreeLeaveAll(db);
      goto blob_open_out;
    }
    pBlob->pTab = pTab;
    pBlob->zDb = db->aDb[sqlite3SchemaToIndex(db, pTab->pSchema)].zDbSName;

        zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);
        rc = SQLITE_ERROR;
        sqlite3BtreeLeaveAll(db);
        goto blob_open_out;
      }
    }

    pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(&sParse);
    assert( pBlob->pStmt || db->mallocFailed );
    if( pBlob->pStmt ){
      
      /* This VDBE program seeks a btree cursor to the identified 
      ** db/table/row entry. The reason for using a vdbe program instead
      ** of writing code to use the b-tree layer directly is that the
      ** vdbe program will take advantage of the various transaction,

        ** we can invoke OP_Column to fill in the vdbe cursors type 
        ** and offset cache without causing any IO.
        */
        aOp[1].p4type = P4_INT32;
        aOp[1].p4.i = pTab->nCol+1;
        aOp[3].p2 = pTab->nCol;

        sParse.nVar = 0;
        sParse.nMem = 1;
        sParse.nTab = 1;
        sqlite3VdbeMakeReady(v, &sParse);
      }
    }
   
    pBlob->iCol = iCol;
    pBlob->db = db;
    sqlite3BtreeLeaveAll(db);
    if( db->mallocFailed ){

    *ppBlob = (sqlite3_blob *)pBlob;
  }else{
    if( pBlob && pBlob->pStmt ) sqlite3VdbeFinalize((Vdbe *)pBlob->pStmt);
    sqlite3DbFree(db, pBlob);
  }
  sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : 0), zErr);
  sqlite3DbFree(db, zErr);
  sqlite3ParserReset(&sParse);

  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Close a blob handle that was previously created using

      int nCol = pIdx->nColumn;   /* Number of index columns including rowid */
  
      nByte = sizeof(Mem) * nCol + ROUND8(sizeof(UnpackedRecord));
      pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte);
      if( pRec ){
        pRec->pKeyInfo = sqlite3KeyInfoOfIndex(p->pParse, pIdx);
        if( pRec->pKeyInfo ){
          assert( pRec->pKeyInfo->nAllField==nCol );
          assert( pRec->pKeyInfo->enc==ENC(db) );
          pRec->aMem = (Mem *)((u8*)pRec + ROUND8(sizeof(UnpackedRecord)));
          for(i=0; i<nCol; i++){
            pRec->aMem[i].flags = MEM_Null;
            pRec->aMem[i].db = db;
          }
        }else{

** Unless it is NULL, the argument must be an UnpackedRecord object returned
** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes
** the object.
*/
void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){
  if( pRec ){
    int i;
    int nCol = pRec->pKeyInfo->nAllField;
    Mem *aMem = pRec->aMem;
    sqlite3 *db = aMem[0].db;
    for(i=0; i<nCol; i++){
      sqlite3VdbeMemRelease(&aMem[i]);
    }
    sqlite3KeyInfoUnref(pRec->pKeyInfo);
    sqlite3DbFreeNN(db, pRec);

  getVarint32(&p2[1], n2);
  res = memcmp(v1, v2, (MIN(n1, n2) - 13)/2);
  if( res==0 ){
    res = n1 - n2;
  }

  if( res==0 ){
    if( pTask->pSorter->pKeyInfo->nKeyField>1 ){
      res = vdbeSorterCompareTail(
          pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2
      );
    }
  }else{
    if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){
      res = res * -1;

      if( *v1 & 0x80 ) res = -1;
    }else{
      if( *v2 & 0x80 ) res = +1;
    }
  }

  if( res==0 ){
    if( pTask->pSorter->pKeyInfo->nKeyField>1 ){
      res = vdbeSorterCompareTail(
          pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2
      );
    }
  }else if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){
    res = res * -1;
  }

  return res;
}

/*
** Initialize the temporary index cursor just opened as a sorter cursor.
**
** Usually, the sorter module uses the value of (pCsr->pKeyInfo->nKeyField)
** to determine the number of fields that should be compared from the
** records being sorted. However, if the value passed as argument nField
** is non-zero and the sorter is able to guarantee a stable sort, nField
** is used instead. This is used when sorting records for a CREATE INDEX
** statement. In this case, keys are always delivered to the sorter in
** order of the primary key, which happens to be make up the final part 
** of the records being sorted. So if the sort is stable, there is never

  if( nWorker>=SORTER_MAX_MERGE_COUNT ){
    nWorker = SORTER_MAX_MERGE_COUNT-1;
  }
#endif

  assert( pCsr->pKeyInfo && pCsr->pBtx==0 );
  assert( pCsr->eCurType==CURTYPE_SORTER );
  szKeyInfo = sizeof(KeyInfo) + (pCsr->pKeyInfo->nKeyField-1)*sizeof(CollSeq*);
  sz = sizeof(VdbeSorter) + nWorker * sizeof(SortSubtask);

  pSorter = (VdbeSorter*)sqlite3DbMallocZero(db, sz + szKeyInfo);
  pCsr->uc.pSorter = pSorter;
  if( pSorter==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }else{
    pSorter->pKeyInfo = pKeyInfo = (KeyInfo*)((u8*)pSorter + sz);
    memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo);
    pKeyInfo->db = 0;
    if( nField && nWorker==0 ){

      pKeyInfo->nKeyField = nField;
    }
    pSorter->pgsz = pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
    pSorter->nTask = nWorker + 1;
    pSorter->iPrev = (u8)(nWorker - 1);
    pSorter->bUseThreads = (pSorter->nTask>1);
    pSorter->db = db;
    for(i=0; i<pSorter->nTask; i++){

        assert( pSorter->iMemory==0 );
        pSorter->nMemory = pgsz;
        pSorter->list.aMemory = (u8*)sqlite3Malloc(pgsz);
        if( !pSorter->list.aMemory ) rc = SQLITE_NOMEM_BKPT;
      }
    }

    if( pKeyInfo->nAllField<13 
     && (pKeyInfo->aColl[0]==0 || pKeyInfo->aColl[0]==db->pDfltColl)
    ){
      pSorter->typeMask = SORTER_TYPE_INTEGER | SORTER_TYPE_TEXT;
    }
  }

  return rc;

** structure at pTask->pUnpacked. Return SQLITE_OK if successful (or 
** if no allocation was required), or SQLITE_NOMEM otherwise.
*/
static int vdbeSortAllocUnpacked(SortSubtask *pTask){
  if( pTask->pUnpacked==0 ){
    pTask->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pTask->pSorter->pKeyInfo);
    if( pTask->pUnpacked==0 ) return SQLITE_NOMEM_BKPT;
    pTask->pUnpacked->nField = pTask->pSorter->pKeyInfo->nKeyField;
    pTask->pUnpacked->errCode = 0;
  }
  return SQLITE_OK;
}


/*

/*
** This function is used to set the schema of a virtual table.  It is only
** valid to call this function from within the xCreate() or xConnect() of a
** virtual table module.
*/
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
  VtabCtx *pCtx;

  int rc = SQLITE_OK;
  Table *pTab;
  char *zErr = 0;
  Parse sParse;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pCtx = db->pVtabCtx;
  if( !pCtx || pCtx->bDeclared ){
    sqlite3Error(db, SQLITE_MISUSE);
    sqlite3_mutex_leave(db->mutex);
    return SQLITE_MISUSE_BKPT;
  }
  pTab = pCtx->pTab;
  assert( IsVirtual(pTab) );


  memset(&sParse, 0, sizeof(sParse));


  sParse.declareVtab = 1;
  sParse.db = db;
  sParse.nQueryLoop = 1;

  if( SQLITE_OK==sqlite3RunParser(&sParse, zCreateTable, &zErr) 
   && sParse.pNewTable
   && !db->mallocFailed
   && !sParse.pNewTable->pSelect
   && !IsVirtual(sParse.pNewTable)
  ){
    if( !pTab->aCol ){
      Table *pNew = sParse.pNewTable;
      Index *pIdx;
      pTab->aCol = pNew->aCol;
      pTab->nCol = pNew->nCol;
      pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);
      pNew->nCol = 0;
      pNew->aCol = 0;
      assert( pTab->pIndex==0 );
      if( !HasRowid(pNew) && pCtx->pVTable->pMod->pModule->xUpdate!=0 ){
        rc = SQLITE_ERROR;
      }
      pIdx = pNew->pIndex;
      if( pIdx ){
        assert( pIdx->pNext==0 );
        pTab->pIndex = pIdx;
        pNew->pIndex = 0;
        pIdx->pTable = pTab;
      }
    }
    pCtx->bDeclared = 1;
  }else{
    sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
    sqlite3DbFree(db, zErr);
    rc = SQLITE_ERROR;
  }
  sParse.declareVtab = 0;

  if( sParse.pVdbe ){
    sqlite3VdbeFinalize(sParse.pVdbe);
  }
  sqlite3DeleteTable(db, sParse.pNewTable);
  sqlite3ParserReset(&sParse);



  assert( (rc&0xff)==rc );
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

# 2015-11-07
#
# 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 WITH clause.
#

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

db close
if {[atomic_batch_write test.db]==0} {
  puts "No f2fs atomic-batch-write support. Skipping tests..."
  finish_test
  return
}

reset_db

do_execsql_test 1.0 {
  CREATE TABLE t1(x, y);
  BEGIN;
    INSERT INTO t1 VALUES(1, 2);
}

do_test 1.1 { file exists test.db-journal } {0}

do_execsql_test 1.2 {
  COMMIT;
}


finish_test

  execsql {
    BEGIN;
  }
} {}
do_test attach2-6.2 {
  catchsql {
    ATTACH 'test3.db' as aux2;
    DETACH aux2;
  }
} {0 {}}

# EVIDENCE-OF: R-59740-55581 This statement will fail if SQLite is in
# the middle of a transaction.
#
do_test attach2-6.3 {
  catchsql {
    DETACH aux;
  }






} {0 {}}

db close

finish_test

#
#***********************************************************************
# This file implements regression tests for SQLite library. 
#
# The focus of this file is testing how SQLite generates the names
# of columns in a result set.
#


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

# Rules (applied in order):
#
# (1) If there is an AS clause, use it.

do_test colname-8.1 {
  db eval {
    CREATE TABLE "t3893"("x");
    INSERT INTO t3893 VALUES(123);
    SELECT "y"."x" FROM (SELECT "x" FROM "t3893") AS "y";
  }
} {123}

# 2017-07-29: Interaction between column naming and query flattening.
# For years now, the query flattener has inserted AS clauses on the
# outer query that were the original SQL text of the column.  This caused
# column-name shifts when the query flattener was enhanced, breaking
# legacy applications.  See https://sqlite.org/src/info/41c27bc0ff1d3135
# for details.
#
# To fix this, the column naming logic was moved ahead of the query
# flattener so that column names are assigned before the query flattener
# runs.
#
db close
sqlite3 db :memory:
do_test colname-9.100 {
  db eval {
    CREATE TABLE t1(a,b);
    INSERT INTO t1 VALUES(1,2);
    CREATE VIEW v1(x,y) AS SELECT a,b FROM t1;
  }
  execsql2 {SELECT v1.x, (Y) FROM v1}
  # Prior to the fix, this would return:  "v1.x 1 (Y) 2"
} {x 1 y 2}
do_test colname-9.110 {
  execsql2 {SELECT * FROM v1}
} {x 1 y 2}
do_test colname-9.120 {
  db eval {
    CREATE VIEW v2(x,y) AS SELECT a,b FROM t1 LIMIT 10;
  }
  execsql2 {SELECT * FROM v2 WHERE 1}
} {x 1 y 2}
do_test colname-9.130 {
  execsql2 {SELECT v2.x, [v2].[y] FROM v2 WHERE 1}
} {x 1 y 2}
do_test colname-9.140 {
  execsql2 {SELECT +x, +y FROM v2 WHERE 1}
} {+x 1 +y 2}

do_test colname-9.200 {
  db eval {
    CREATE TABLE t2(c,d);
    INSERT INTO t2 VALUES(3,4);
    CREATE VIEW v3 AS SELECT c AS a, d AS b FROM t2;
  }
  execsql2 {SELECT t1.a, v3.a AS n FROM t1 LEFT JOIN v3}
} {a 1 n 3}
do_test colname-9.211 {
  execsql2 {SELECT t1.a AS n, v3.a FROM t1 JOIN v3}
} {n 1 a 3}
do_test colname-9.210 {
  execsql2 {SELECT t1.a, v3.a AS n FROM t1 JOIN v3}
} {a 1 n 3}


finish_test

#
# We need to check this to verify that if in the unlikely event a rollback
# causes a database file to grow, the database grows to its previous size
# on disk, not to the minimum size required to hold the database image.
#
do_test fallocate-1.7 {
  execsql { BEGIN; INSERT INTO t1 VALUES(1, 2); }
  if {[permutation] != "inmemory_journal"
   && [permutation] != "atomic-batch-write"
  } {
    hexio_get_int [hexio_read test.db-journal 16 4]
  } else {
    set {} 1024
  }
} {1024}
do_test fallocate-1.8 { execsql { COMMIT } } {}

# The following tests can only work if the current SQLite VFS has the concept
# of a current directory.
#
ifcapable curdir {
# Make sure a database connection still works after changing the
# working directory.
#
if {[atomic_batch_write test.db]==0} {
  do_test misc1-14.1 {
    file mkdir tempdir
    cd tempdir
    execsql {BEGIN}
    file exists ./test.db-journal
  } {0}
  do_test misc1-14.2a {
    execsql {UPDATE t1 SET a=a||'x' WHERE 0}
    file exists ../test.db-journal
  } {0}
  do_test misc1-14.2b {
    execsql {UPDATE t1 SET a=a||'y' WHERE 1}
    file exists ../test.db-journal
  } {1}
  do_test misc1-14.3 {
    cd ..
    forcedelete tempdir
    execsql {COMMIT}
    file exists ./test.db-journal
  } {0}
}
}

# A failed create table should not leave the table in the internal
# data structures.  Ticket #238.
#
do_test misc1-15.1.1 {
  catchsql {

  int rc = iNow>=p->iCutoffTime;
  sqlite3_int64 iDiff = iNow - p->iLastCb;
  if( iDiff > p->mxInterval ) p->mxInterval = iDiff;
  p->nCb++;
  return rc;
}
#endif

/*
** Disallow debugging pragmas such as "PRAGMA vdbe_debug" and
** "PRAGMA parser_trace" since they can dramatically increase the
** amount of output without actually testing anything useful.
*/
static int block_debug_pragmas(
  void *Notused,
  int eCode,
  const char *zArg1,
  const char *zArg2,
  const char *zArg3,
  const char *zArg4
){
  if( eCode==SQLITE_PRAGMA
   && (sqlite3_strnicmp("vdbe_", zArg1, 5)==0
        || sqlite3_stricmp("parser_trace", zArg1)==0)
  ){
    return SQLITE_DENY;
  }
  return SQLITE_OK;
}

/*
** Callback for sqlite3_exec().
*/
static int exec_handler(void *pCnt, int argc, char **argv, char **namev){
  int i;
  if( argv ){

  /* Set a limit on the maximum size of a prepared statement */
  sqlite3_limit(cx.db, SQLITE_LIMIT_VDBE_OP, 25000);

  /* Bit 1 of the selector enables foreign key constraints */
  sqlite3_db_config(cx.db, SQLITE_DBCONFIG_ENABLE_FKEY, uSelector&1, &rc);
  uSelector >>= 1;

  /* Do not allow debugging pragma statements that might cause excess output */
  sqlite3_set_authorizer(cx.db, block_debug_pragmas, 0);

  /* Remaining bits of the selector determine a limit on the number of
  ** output rows */
  execCnt = uSelector + 1;

  /* Run the SQL.  The sqlite_exec() interface expects a zero-terminated
  ** string, so make a copy. */

  which do not work with a VFS that uses the pVfs argument passed to
  sqlite3_vfs methods.
} -files [
  test_set $allquicktests -exclude *malloc* *ioerr* *fault* oserror.test \
  pager1.test syscall.test sysfault.test tkt3457.test quota* superlock* \
  wal* mmap*
]

test_suite "atomic-batch-write" -prefix "" -description {
  Like veryquick.test, but must be run on a file-system that supports
  atomic-batch-writes. Tests that depend on the journal file being present
  are omitted.
} -files [
  test_set $allquicktests -exclude *malloc* *ioerr* *fault* *bigfile* *_err* \
      *fts5corrupt* *fts5big* *fts5aj*  \
      crash8.test delete_db.test        \
      exclusive.test journal3.test      \
      journal1.test                     \
      jrnlmode.test jrnlmode2.test      \
      lock4.test pager1.test            \
      pager3.test sharedA.test          \
      symlink.test stmt.test            \
      sync.test sync2.test              \
      tempdb.test tkt3457.test          \
      vacuum5.test wal2.test            \
      walmode.test zerodamage.test
] -initialize {
  if {[atomic_batch_write test.db]==0} {
    error "File system does NOT support atomic-batch-write"
  }
}

lappend ::testsuitelist xxx
#-------------------------------------------------------------------------
# Define the coverage related test suites:
#
#   coverage-wal
#

do_test rollback-1.9 {
  sqlite3_finalize $STMT
} {SQLITE_OK}

if {$tcl_platform(platform) == "unix" 
 && [permutation] ne "onefile"
 && [permutation] ne "inmemory_journal"
 && [permutation] ne "atomic-batch-write"
} {
  do_test rollback-2.1 {
    execsql {
      BEGIN;
      INSERT INTO t3 VALUES('hello world');
    }
    forcecopy test.db testA.db

#-------------------------------------------------------------------------
# The following tests - savepoint-10.* - test the interaction of 
# savepoints and ATTACH statements.
# 

# First make sure it is not possible to attach or detach a database while
# a savepoint is open (it is not possible if any transaction is open).
#
# UPDATE 2017-07-26:  It is not possible to ATTACH and DETACH within a
# a transaction.
#
do_test savepoint-10.1.1 {
  catchsql {
    SAVEPOINT one;
    ATTACH 'test2.db' AS aux;
    DETACH aux;
  }
} {0 {}}
do_test savepoint-10.1.2 {
  execsql {
    RELEASE one;
    ATTACH 'test2.db' AS aux;
  }
  catchsql {
    SAVEPOINT one;
    DETACH aux;
    ATTACH 'test2.db' AS aux;
  }
} {0 {}}
do_test savepoint-10.1.3 {
  execsql {
    RELEASE one;
    DETACH aux;
  }
} {}

# 2017-07-30
#
# 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 tests to show that certain CREATE TABLE statements
# generate identical database files.  For example, changes in identifier
# names, white-space, and formatting of the CREATE TABLE statement should
# produce identical table content.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix schema6

# Command:   check_same_database_content TESTNAME SQL1 SQL2 SQL3 ...
#
# This command creates fresh databases using SQL1 and subsequent arguments
# and checks to make sure the content of all database files is byte-for-byte
# identical.  Page 1 of the database files is allowed to be different, since
# page 1 contains the sqlite_master table which is expected to vary.
#
proc check_same_database_content {basename args} {
  set i 0
  set hash {}
  foreach sql $args {
    catch {db close}
    forcedelete test.db
    sqlite3 db test.db
    db eval $sql
    set pgsz [db one {PRAGMA page_size}]
    db close
    set sz [file size test.db]
    set thishash [md5file test.db $pgsz [expr {$sz-$pgsz}]]
    if {$i==0} {
      set hash $thishash
    } else {
      do_test $basename-$i "set x $thishash" $hash
    }
    incr i
  }
}

# Command:   check_different_database_content TESTNAME SQL1 SQL2 SQL3 ...
#
# This command creates fresh databases using SQL1 and subsequent arguments
# and checks to make sure the content of all database files is different
# in ways other than on page 1.
#
proc check_different_database_content {basename args} {
  set i 0
  set hashes {}
  foreach sql $args {
    forcedelete test.db
    sqlite3 db test.db
    db eval $sql
    set pgsz [db one {PRAGMA page_size}]
    db close
    set sz [file size test.db]
    set thishash [md5file test.db $pgsz [expr {$sz-$pgsz}]]
    set j [lsearch $hashes $thishash]
    if {$j>=0} {
      do_test $basename-$i "set x {$i is the same as $j}" "All are different"
    } else {
      do_test $basename-$i "set x {All are different}" "All are different"
    }
    lappend hashes $thishash
    incr i
  }
}

check_same_database_content 100 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(xyz INTEGER, abc, PRIMARY KEY(xyz), UNIQUE(abc));
  INSERT INTO t1(xyz,abc) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(xyz INTEGER, abc, UNIQUE(abc), PRIMARY KEY(xyz));
  INSERT INTO t1(xyz,abc) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY ASC, b UNIQUE);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
  CREATE UNIQUE INDEX t1b ON t1(b);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
  CREATE UNIQUE INDEX t1b ON t1(b);
}

check_same_database_content 110 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY UNIQUE, b UNIQUE);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER UNIQUE PRIMARY KEY, b UNIQUE);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER UNIQUE PRIMARY KEY, b UNIQUE, UNIQUE(a));
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER UNIQUE PRIMARY KEY, b);
  CREATE UNIQUE INDEX t1b ON t1(b);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER UNIQUE PRIMARY KEY, b);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
  CREATE UNIQUE INDEX t1b ON t1(b);
}

check_same_database_content 120 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE) WITHOUT ROWID;
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(xyz INTEGER, abc, PRIMARY KEY(xyz), UNIQUE(abc))WITHOUT ROWID;
  INSERT INTO t1(xyz,abc) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(xyz INTEGER, abc, UNIQUE(abc), PRIMARY KEY(xyz))WITHOUT ROWID;
  INSERT INTO t1(xyz,abc) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY ASC, b UNIQUE) WITHOUT ROWID;
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY UNIQUE, b UNIQUE) WITHOUT ROWID;
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER UNIQUE PRIMARY KEY, b UNIQUE) WITHOUT ROWID;
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER UNIQUE PRIMARY KEY, b UNIQUE, UNIQUE(a))
       WITHOUT ROWID;
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b) WITHOUT ROWID;
  CREATE UNIQUE INDEX t1b ON t1(b);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b) WITHOUT ROWID;
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
  CREATE UNIQUE INDEX t1b ON t1(b);
}

check_different_database_content 130 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY UNIQUE, b UNIQUE);
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
} {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE) WITHOUT ROWID;
  INSERT INTO t1(a,b) VALUES(123,'Four score and seven years ago...');
}


finish_test

# 2017-07-15
#
# 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 file is the "swarmvtab" extension
#

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

ifcapable !vtab {
  finish_test
  return
}

load_static_extension db unionvtab

set nFile $sqlite_open_file_count

do_execsql_test 1.0 {
  CREATE TABLE t0(a INTEGER PRIMARY KEY, b TEXT);
  WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<400) 
  INSERT INTO t0 SELECT i, hex(randomblob(50)) FROM s;

  CREATE TABLE dir(f, t, imin, imax);
}

do_test 1.1 {
  for {set i 0} {$i < 40} {incr i} {
    set iMin [expr $i*10 + 1]
    set iMax [expr $iMin+9]

    forcedelete "test.db$i"
    execsql [subst {
      ATTACH 'test.db$i' AS aux;
      CREATE TABLE aux.t$i (a INTEGER PRIMARY KEY, b TEXT);
      INSERT INTO aux.t$i SELECT * FROM t0 WHERE a BETWEEN $iMin AND $iMax;
      DETACH aux;
      INSERT INTO dir VALUES('test.db$i', 't$i', $iMin, $iMax);
    }]
  }

  execsql {
    CREATE VIRTUAL TABLE temp.s1 USING swarmvtab('SELECT * FROM dir');
  }
} {}

do_execsql_test 1.2 { 
  DROP TABLE s1; 
} {}

do_execsql_test 1.3 {
  CREATE VIRTUAL TABLE temp.s1 USING swarmvtab('SELECT * FROM dir');
  SELECT count(*) FROM s1 WHERE rowid<50;
} {49}

proc do_compare_test {tn where} {
  set sql [subst {
    SELECT (SELECT group_concat(a || ',' || b, ',') FROM t0 WHERE $where) 
           IS 
           (SELECT group_concat(a || ',' || b, ',') FROM s1 WHERE $where)
  }]

  uplevel [list do_execsql_test $tn $sql 1]
}

do_compare_test 1.4.1 "rowid = 700"
do_compare_test 1.4.2 "rowid = -1"
do_compare_test 1.4.3 "rowid = 0"
do_compare_test 1.4.4 "rowid = 55"
do_compare_test 1.4.5 "rowid BETWEEN 20 AND 100"
do_compare_test 1.4.6 "rowid > 350"
do_compare_test 1.4.7 "rowid >= 350"
do_compare_test 1.4.8 "rowid >= 200"
do_compare_test 1.4.9 "1"

# Multiple simultaneous cursors.
#
do_execsql_test 1.5.1.(5-seconds-or-so) {
  SELECT count(*) FROM s1 a, s1 b WHERE b.rowid<=200;
} {80000}
do_execsql_test 1.5.2 {
  SELECT count(*) FROM s1 a, s1 b, s1 c 
  WHERE a.rowid=b.rowid AND b.rowid=c.rowid;
} {400}

# Empty source tables.
#
do_test 1.6.0 {
  for {set i 0} {$i < 20} {incr i} {
    sqlite3 db2 test.db$i
    db2 eval " DELETE FROM t$i "
    db2 close
  }
  db eval { DELETE FROM t0 WHERE rowid<=200 }
} {}

do_compare_test 1.6.1 "rowid = 700"
do_compare_test 1.6.2 "rowid = -1"
do_compare_test 1.6.3 "rowid = 0"
do_compare_test 1.6.4 "rowid = 55"
do_compare_test 1.6.5 "rowid BETWEEN 20 AND 100"
do_compare_test 1.6.6 "rowid > 350"
do_compare_test 1.6.7 "rowid >= 350"
do_compare_test 1.6.8 "rowid >= 200"
do_compare_test 1.6.9 "1"
do_compare_test 1.6.10 "rowid >= 5"

do_test 1.x {
  set sqlite_open_file_count
} [expr $nFile+9]

do_test 1.y { db close } {}

# Delete all the database files created above.
#
for {set i 0} {$i < 40} {incr i} { forcedelete "test.db$i" }

#-------------------------------------------------------------------------
# Test some error conditions:
#
#   2.1: Database file does not exist.
#   2.2: Table does not exist.
#   2.3: Table schema does not match.
#   2.4: Syntax error in SELECT statement.
#
reset_db
load_static_extension db unionvtab
do_test 2.0.1 {
  db eval {
    CREATE TABLE t0(a INTEGER PRIMARY KEY, b TEXT);
    WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<400) 
      INSERT INTO t0 SELECT i, hex(randomblob(50)) FROM s;
    CREATE TABLE dir(f, t, imin, imax);
  }

  for {set i 0} {$i < 40} {incr i} {
    set iMin [expr $i*10 + 1]
    set iMax [expr $iMin+9]

    forcedelete "test.db$i"
    db eval [subst {
      ATTACH 'test.db$i' AS aux;
      CREATE TABLE aux.t$i (a INTEGER PRIMARY KEY, b TEXT);
      INSERT INTO aux.t$i SELECT * FROM t0 WHERE a BETWEEN $iMin AND $iMax;
      DETACH aux;
      INSERT INTO dir VALUES('test.db$i', 't$i', $iMin, $iMax);
    }]
  }
  execsql {
    CREATE VIRTUAL TABLE temp.s1 USING swarmvtab('SELECT * FROM dir');
  }
} {}

do_test 2.0.2 {
  forcedelete test.db5

  sqlite3 db2 test.db15
  db2 eval { DROP TABLE t15 }
  db2 close

  sqlite3 db2 test.db25
  db2 eval { 
    DROP TABLE t25;
    CREATE TABLE t25(x, y, z PRIMARY KEY);
  }
  db2 close
} {}

do_catchsql_test 2.1 {
  SELECT * FROM s1 WHERE rowid BETWEEN 1 AND 100;
} {1 {unable to open database file}}
do_catchsql_test 2.2 {
  SELECT * FROM s1 WHERE rowid BETWEEN 101 AND 200;
} {1 {no such rowid table: t15}}
do_catchsql_test 2.3 {
  SELECT * FROM s1 WHERE rowid BETWEEN 201 AND 300;
} {1 {source table schema mismatch}}

do_catchsql_test 2.4 {
  CREATE VIRTUAL TABLE temp.x1 USING swarmvtab('SELECT * FROMdir');
} {1 {sql error: near "FROMdir": syntax error}}
do_catchsql_test 2.5 {
  CREATE VIRTUAL TABLE temp.x1 USING swarmvtab('SELECT * FROMdir', 'fetchdb');
} {1 {sql error: near "FROMdir": syntax error}}

for {set i 0} {$i < 40} {incr i} {
  forcedelete "test.db$i"
}

#-------------------------------------------------------------------------
# Test the outcome of the fetch function throwing an exception.
#
proc fetch_db {file} {
  error "fetch_db error!"
}

db func fetch_db fetch_db

do_catchsql_test 3.1 {
  CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
    'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
    ', 'fetch_db_no_such_function'
  );
} {1 {no such function: fetch_db_no_such_function}}

do_catchsql_test 3.2 {
  CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
    'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
    ', 'fetch_db'
  );
} {1 {fetch_db error!}}

do_execsql_test 3.3.1 {
  ATTACH 'test.db1' AS aux;
  CREATE TABLE aux.t1(a INTEGER PRIMARY KEY, b);
  INSERT INTO aux.t1 VALUES(1, NULL);
  INSERT INTO aux.t1 VALUES(2, NULL);
  INSERT INTO aux.t1 VALUES(9, NULL);
  DETACH aux;
  CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
    'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
    ', 'fetch_db'
  );
} {}

do_catchsql_test 3.3 { SELECT * FROM xyz } {1 {fetch_db error!}}



finish_test

# 2017-07-15
#
# 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 file is the "swarmvtab" extension
#

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

ifcapable !vtab {
  finish_test
  return
}


db close
foreach name [glob -nocomplain test*.db] {
  forcedelete $name
}
sqlite3 db test.db
load_static_extension db unionvtab
proc create_database {filename} {
  sqlite3 dbx $filename
  set num [regsub -all {[^0-9]+} $filename {}]
  set num [string trimleft $num 0]
  set start [expr {$num*1000}]
  set end [expr {$start+999}]
  dbx eval {
    CREATE TABLE t2(a INTEGER PRIMARY KEY,b);
    WITH RECURSIVE c(x) AS (
      VALUES($start) UNION ALL SELECT x+1 FROM c WHERE x<$end
    )
    INSERT INTO t2(a,b) SELECT x, printf('**%05d**',x) FROM c;
  }
  dbx close
}
db func create_database create_database
do_execsql_test 100 {
  CREATE TABLE t1(filename, tablename, istart, iend);
  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<99)
  INSERT INTO t1 SELECT printf('test%03d.db',x),'t2',x*1000,x*1000+999 FROM c;
  CREATE VIRTUAL TABLE temp.v1 USING swarmvtab(
    'SELECT * FROM t1', 'create_database'
  );
} {}
do_execsql_test 110 {
  SELECT b FROM v1 WHERE a=3875;
} {**03875**}
do_test 120 {
  lsort [glob -nocomplain test?*.db]
} {test001.db test003.db}
do_execsql_test 130 {
  SELECT b FROM v1 WHERE a BETWEEN 3999 AND 4000 ORDER BY a;
} {**03999** **04000**}
do_test 140 {
  lsort [glob -nocomplain test?*.db]
} {test001.db test003.db test004.db}
do_execsql_test 150 {
  SELECT b FROM v1 WHERE a>=99998;
} {**99998** **99999**}
do_test 160 {
  lsort -dictionary [glob -nocomplain test?*.db]
} {test001.db test003.db test004.db test099.db}

finish_test

# 2017-07-15
#
# 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 file is error handling in the swarmvtab extension.
#

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

ifcapable !vtab {
  finish_test
  return
}

proc fetch_db {file} {
  forcedelete $file
  sqlite3 dbX $file
  dbX eval { CREATE TABLE t1(a INTEGER PRIMARY KEY, b) }
  dbX close
}

forcedelete test.db1
do_execsql_test 1.0 {
  ATTACH 'test.db1' AS aux;
  CREATE TABLE aux.t1(a INTEGER PRIMARY KEY, b);
  INSERT INTO aux.t1 VALUES(1, NULL);
  INSERT INTO aux.t1 VALUES(2, NULL);
  INSERT INTO aux.t1 VALUES(9, NULL);
  DETACH aux;
} {}

faultsim_save_and_close
do_faultsim_test 1.1 -faults oom* -prep {
  faultsim_restore_and_reopen
  db func fetch_db fetch_db
  load_static_extension db unionvtab
  db eval {
    CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
        'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
        ', 'fetch_db'
    );
  }
} -body {
  execsql { SELECT a FROM xyz }
} -test {
  faultsim_test_result {0 {1 2 9}} {1 {sql error: out of memory}}
}

finish_test

# Tests for the xNextSystemCall method.
#
foreach s {
    open close access getcwd stat fstat ftruncate
    fcntl read pread write pwrite fchmod fallocate
    pread64 pwrite64 unlink openDirectory mkdir rmdir 
    statvfs fchown geteuid umask mmap munmap mremap
    getpagesize readlink lstat ioctl
} {
  if {[test_syscall exists $s]} {lappend syscall_list $s}
}
do_test 3.1 { lsort [test_syscall list] } [lsort $syscall_list]

#-------------------------------------------------------------------------
# This test verifies that if a call to open() fails and errno is set to

    puts $f $tclbody
  }
  if {[string length $sql]>0} {
    puts $f "db eval {"
    puts $f   "$sql"
    puts $f "}"
  }
  close $f
  set r [catch {
    exec [info nameofexec] crash.tcl >@stdout
  } msg]

  # Windows/ActiveState TCL returns a slightly different
  # error message.  We map that to the expected message
  # so that we don't have to change all of the test
  # cases.
  if {$::tcl_platform(platform)=="windows"} {
    if {$msg=="child killed: unknown signal"} {
      set msg "child process exited abnormally"
    }
  }

  lappend r $msg
}

#   crash_on_write ?-devchar DEVCHAR? CRASHDELAY SQL
#
proc crash_on_write {args} {

  set nArg [llength $args]
  if {$nArg<2 || $nArg%2} {
    error "bad args: $args"
  }
  set zSql [lindex $args end]
  set nDelay [lindex $args end-1]

  set devchar {}
  for {set ii 0} {$ii < $nArg-2} {incr ii 2} {
    set opt [lindex $args $ii]
    switch -- [lindex $args $ii] {
      -devchar {
        set devchar [lindex $args [expr $ii+1]]
      }

      default { error "unrecognized option: $opt" }
    }
  }

  set f [open crash.tcl w]
  puts $f "sqlite3_crash_on_write $nDelay"
  puts $f "sqlite3_test_control_pending_byte $::sqlite_pending_byte"
  puts $f "sqlite3 db test.db -vfs writecrash"
  puts $f "db eval {$zSql}"
  puts $f "set {} {}"

  close $f
  set r [catch {
    exec [info nameofexec] crash.tcl >@stdout
  } msg]

  # Windows/ActiveState TCL returns a slightly different
  # error message.  We map that to the expected message

}
do_faultsim_test 1.2 -faults oom* -prep {
} -body {
  execsql { SELECT * FROM uuu }
} -test {
  faultsim_test_result {0 {1 one 2 two 3 three 10 ten 11 eleven 12 twelve 20 twenty 21 twenty-one 22 twenty-two}} 
}

#-------------------------------------------------------------------------
# Error while registering the two vtab modules.
do_faultsim_test 2.0 -faults * -prep {
  catch { db close }
  sqlite3 db :memory:
} -body {
  load_static_extension db unionvtab
} -test {
  faultsim_test_result {0 {}} {1 {initialization of unionvtab failed: }}
}



finish_test

  }
} {1 2 1}
do_test whereA-4.6 {
  count {
    SELECT x FROM t2 ORDER BY x DESC;
  }
} {2 1 1}

# Ticket https://sqlite.org/src/tktview/cb91bf4290c211  2017-08-01
# Assertion fault following PRAGMA reverse_unordered_selects=ON.
# 
do_execsql_test whereA-5.1 {
  PRAGMA reverse_unordered_selects=on;
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(a,b);
  INSERT INTO t1 VALUES(1,2);
  CREATE INDEX t1b ON t1(b);
  SELECT a FROM t1 WHERE b=-99 OR b>1;
} {1}


finish_test

} {1 {CHECK constraint failed: t70a}}
do_catchsql_test 7.3 {
  CREATE TABLE t70b(
     a INT CHECK( rowid!=33 ),
     b TEXT PRIMARY KEY
  ) WITHOUT ROWID;
} {1 {no such column: rowid}}

# 2017-07-30: OSSFuzz discovered that an extra entry was being
# added in the sqlite_master table for an "INTEGER PRIMARY KEY UNIQUE"
# WITHOUT ROWID table.  Make sure this has now been fixed.
#
db close
sqlite3 db :memory:
do_execsql_test 8.1 {
  CREATE TABLE t1(x INTEGER PRIMARY KEY UNIQUE, b) WITHOUT ROWID;
  CREATE INDEX t1x ON t1(x);
  INSERT INTO t1(x,b) VALUES('funny','buffalo');
  SELECT type, name, '|' FROM sqlite_master;
} {table t1 | index t1x |}


  
finish_test

# 2009 January 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.
#
#***********************************************************************
#
# Test the outcome of a writer crashing within a call to the VFS
# xWrite function.
#


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

do_not_use_codec


if {$tcl_platform(platform)=="windows"} {
  finish_test
  return
}

do_execsql_test 1.0 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b BLOB UNIQUE);
  WITH s(i) AS (
    VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100
  )
  INSERT INTO t1 SELECT NULL, randomblob(900) FROM s;
} {}

set bGo 1
for {set tn 1} {$bGo} {incr tn} {

db close
sqlite3 db test.db

  do_test 1.$tn.1 {
    set res [crash_on_write $tn {
      UPDATE t1 SET b = randomblob(899) WHERE (a%3)==0
    }]
    set bGo 0
    if {[string match {1 {child killed:*}} $res]} {
      set res {0 {}}
      set bGo 1
    }
    set res
  } {0 {}}

#db close
#sqlite3 db test.db

  do_execsql_test 1.$tn.2 { PRAGMA integrity_check } {ok}

db close
sqlite3 db test.db

  do_execsql_test 1.$tn.3 { PRAGMA integrity_check } {ok}
}



finish_test

SET PROCESSOR=%1

IF DEFINED PROCESSOR (
  CALL :fn_UnquoteVariable PROCESSOR
) ELSE (
  GOTO usage
)

SET PROCESSOR=%PROCESSOR:AMD64=x64%

%_VECHO% Processor = '%PROCESSOR%'

SET DUMMY2=%2

IF DEFINED DUMMY2 (
  GOTO usage

}
close $in

# The following are the extra token codes to be added.  SPACE and 
# ILLEGAL *must* be the last two token codes and they must be in that order.
#
set extras {





  ISNOT


  FUNCTION
  COLUMN
  AGG_FUNCTION
  AGG_COLUMN
  UMINUS
  UPLUS
  REGISTER
  VECTOR
  SELECT_COLUMN
  IF_NULL_ROW
  ASTERISK
  SPAN
  END_OF_FILE
  UNCLOSED_STRING
  SPACE
  ILLEGAL
}
if {[lrange $extras end-1 end]!="SPACE ILLEGAL"} {
  error "SPACE and ILLEGAL must be the last two token codes and they\
         must be in that order"
}

  RESYNC_AFTER_RULE_ERROR,
  RESYNC_AFTER_DECL_ERROR,
  WAITING_FOR_DESTRUCTOR_SYMBOL,
  WAITING_FOR_DATATYPE_SYMBOL,
  WAITING_FOR_FALLBACK_ID,
  WAITING_FOR_WILDCARD_ID,
  WAITING_FOR_CLASS_ID,
  WAITING_FOR_CLASS_TOKEN,
  WAITING_FOR_TOKEN_NAME
};
struct pstate {
  char *filename;       /* Name of the input file */
  int tokenlineno;      /* Linenumber at which current token starts */
  int errorcnt;         /* Number of errors so far */
  char *tokenstart;     /* Text of current token */
  struct lemon *gp;     /* Global state vector */

        }else if( strcmp(x,"destructor")==0 ){
          psp->state = WAITING_FOR_DESTRUCTOR_SYMBOL;
        }else if( strcmp(x,"type")==0 ){
          psp->state = WAITING_FOR_DATATYPE_SYMBOL;
        }else if( strcmp(x,"fallback")==0 ){
          psp->fallback = 0;
          psp->state = WAITING_FOR_FALLBACK_ID;
        }else if( strcmp(x,"token")==0 ){
          psp->state = WAITING_FOR_TOKEN_NAME;
        }else if( strcmp(x,"wildcard")==0 ){
          psp->state = WAITING_FOR_WILDCARD_ID;
        }else if( strcmp(x,"token_class")==0 ){
          psp->state = WAITING_FOR_CLASS_ID;
        }else{
          ErrorMsg(psp->filename,psp->tokenlineno,
            "Unknown declaration keyword: \"%%%s\".",x);

            "More than one fallback assigned to token %s", x);
          psp->errorcnt++;
        }else{
          sp->fallback = psp->fallback;
          psp->gp->has_fallback = 1;
        }
      }
      break;
    case WAITING_FOR_TOKEN_NAME:
      /* Tokens do not have to be declared before use.  But they can be
      ** in order to control their assigned integer number.  The number for
      ** each token is assigned when it is first seen.  So by including
      **
      **     %token ONE TWO THREE
      **
      ** early in the grammar file, that assigns small consecutive values
      ** to each of the tokens ONE TWO and THREE.
      */
      if( x[0]=='.' ){
        psp->state = WAITING_FOR_DECL_OR_RULE;
      }else if( !ISUPPER(x[0]) ){
        ErrorMsg(psp->filename, psp->tokenlineno,
          "%%token argument \"%s\" should be a token", x);
        psp->errorcnt++;
      }else{
        (void)Symbol_new(x);
      }
      break;
    case WAITING_FOR_WILDCARD_ID:
      if( x[0]=='.' ){
        psp->state = WAITING_FOR_DECL_OR_RULE;
      }else if( !ISUPPER(x[0]) ){
        ErrorMsg(psp->filename, psp->tokenlineno,
          "%%wildcard argument \"%s\" should be a token", x);

  if {![info exists used($i)]} {
    set def($i) "OP_NotUsed_$i"
  }
  if {$i>$max} {set max $i}
  set name $def($i)
  puts -nonewline [format {#define %-16s %3d} $name $i]
  set com {}
  if {$jump($name)} {
    lappend com "jump"
  }
  if {[info exists sameas($i)]} {
    lappend com "same as $sameas($i)"
  }
  if {[info exists synopsis($name)]} {
    lappend com "synopsis: $synopsis($name)"




  }

  if {[llength $com]} {
    puts -nonewline [format " /* %-42s */" [join $com {, }]]
  }
  puts ""
}

if {$max>255} {
  error "More than 255 opcodes - VdbeOp.opcode is of type u8!"
}

    } elseif {$addstatic
               && ![regexp {^(static|typedef|SQLITE_PRIVATE)} $line]} {
      # Skip adding the SQLITE_PRIVATE or SQLITE_API keyword before
      # functions if this header file does not need it.
      if {![info exists varonly_hdr($tail)]
       && [regexp $declpattern $line all rettype funcname rest]} {
        regsub {^SQLITE_API } $line {} line
        regsub {^SQLITE_API } $rettype {} rettype

        # Add the SQLITE_PRIVATE or SQLITE_API keyword before functions.
        # so that linkage can be modified at compile-time.
        if {[regexp {^sqlite3[a-z]*_} $funcname]} {
          set line SQLITE_API
          append line " " [string trim $rettype]
          if {[string index $rettype end] ne "*"} {
            append line " "