sqlite3_analyzer.exe:	sqlite3_analyzer.c
	$(LTLINK) -DBUILD_sqlite -DTCLSH=2 -I$(TCLINCDIR) sqlite3_analyzer.c \
		/link $(LTLINKOPTS) $(LTLIBPATHS) $(LTLIBS) $(TLIBS)

clean:
	del /Q *.lo *.ilk *.lib *.obj *.pdb sqlite3.exe libsqlite3.lib

	del /Q sqlite3.h opcodes.c opcodes.h
	del /Q lemon.exe lempar.c parse.*
	del /Q mkkeywordhash.exe keywordhash.h


	-rmdir /Q/S tsrc
	del /Q .target_source
	del /Q tclsqlite3.exe
	del /Q testfixture.exe testfixture.exp test.db
	del /Q sqlite3.dll sqlite3.lib sqlite3.exp sqlite3.def
	del /Q sqlite3.c
	del /Q sqlite3_analyzer.exe sqlite3_analyzer.exp sqlite3_analyzer.c

sqlite3_analyzer.exe:	sqlite3_analyzer.c
	$(LTLINK) -DBUILD_sqlite -DTCLSH=2 -I$(TCLINCDIR) sqlite3_analyzer.c \
		/link $(LTLINKOPTS) $(LTLIBPATHS) $(LTLIBS) $(TLIBS)

clean:
	del /Q *.lo *.ilk *.lib *.obj *.pdb sqlite3.exe libsqlite3.lib
	del /Q *.da *.bb *.bbg gmon.out
	del /Q sqlite3.h opcodes.c opcodes.h
	del /Q lemon.exe lempar.c parse.*
	del /Q mkkeywordhash.exe keywordhash.h
	-rmdir /Q/S .deps
	-rmdir /Q/S .libs
	-rmdir /Q/S tsrc
	del /Q .target_source
	del /Q tclsqlite3.exe
	del /Q testfixture.exe testfixture.exp test.db
	del /Q sqlite3.dll sqlite3.lib sqlite3.exp sqlite3.def
	del /Q sqlite3.c
	del /Q sqlite3_analyzer.exe sqlite3_analyzer.exp sqlite3_analyzer.c

** index when a document is deleted or updated.  For deletions, we
** write an empty doclist (varint(docid) varint(POS_END)), for updates
** we simply write the new doclist.  Segment merges overwrite older
** data for a particular docid with newer data, so deletes or updates
** will eventually overtake the earlier data and knock it out.  The
** query logic likewise merges doclists so that newer data knocks out
** older data.
**
** TODO(shess) Provide a VACUUM type operation to clear out all
** deletions and duplications.  This would basically be a forced merge
** into a single segment.
*/

#include "fts3Int.h"
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

#if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)
# define SQLITE_CORE 1
................................................................................
  for(i=0; i<SizeofArray(p->aStmt); i++){
    sqlite3_finalize(p->aStmt[i]);
  }
  sqlite3_free(p->zSegmentsTbl);
  sqlite3_free(p->zReadExprlist);
  sqlite3_free(p->zWriteExprlist);
  sqlite3_free(p->zContentTbl);


  /* Invoke the tokenizer destructor to free the tokenizer. */
  p->pTokenizer->pModule->xDestroy(p->pTokenizer);

  sqlite3_free(p);
  return SQLITE_OK;
}
................................................................................
*/
static void fts3DeclareVtab(int *pRc, Fts3Table *p){
  if( *pRc==SQLITE_OK ){
    int i;                        /* Iterator variable */
    int rc;                       /* Return code */
    char *zSql;                   /* SQL statement passed to declare_vtab() */
    char *zCols;                  /* List of user defined columns */



    sqlite3_vtab_config(p->db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);

    /* Create a list of user columns for the virtual table */
    zCols = sqlite3_mprintf("%Q, ", p->azColumn[0]);
    for(i=1; zCols && i<p->nColumn; i++){
      zCols = sqlite3_mprintf("%z%Q, ", zCols, p->azColumn[i]);
    }

    /* Create the whole "CREATE TABLE" statement to pass to SQLite */
    zSql = sqlite3_mprintf(
        "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN)", zCols, p->zName

    );
    if( !zCols || !zSql ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_declare_vtab(p->db, zSql);
    }

................................................................................
*/
static int fts3CreateTables(Fts3Table *p){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Iterator variable */
  sqlite3 *db = p->db;            /* The database connection */

  if( p->zContentTbl==0 ){

    char *zContentCols;           /* Columns of %_content table */

    /* Create a list of user columns for the content table */
    zContentCols = sqlite3_mprintf("docid INTEGER PRIMARY KEY");
    for(i=0; zContentCols && i<p->nColumn; i++){
      char *z = p->azColumn[i];
      zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);
    }



    if( zContentCols==0 ) rc = SQLITE_NOMEM;
  
    /* Create the content table */
    fts3DbExec(&rc, db, 
       "CREATE TABLE %Q.'%q_content'(%s)",
       p->zDb, p->zName, zContentCols
    );
................................................................................
    }else{
      zFree = zFunction = fts3QuoteId(zFunc);
    }
    fts3Appendf(pRc, &zRet, "docid");
    for(i=0; i<p->nColumn; i++){
      fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);
    }



    sqlite3_free(zFree);
  }else{
    fts3Appendf(pRc, &zRet, "rowid");
    for(i=0; i<p->nColumn; i++){
      fts3Appendf(pRc, &zRet, ", x.'%q'", p->azColumn[i]);
    }


  }

  fts3Appendf(pRc, &zRet, "FROM '%q'.'%q%s' AS x", 
      p->zDb,
      (p->zContentTbl ? p->zContentTbl : p->zName),
      (p->zContentTbl ? "" : "_content")
  );
  return zRet;
}

................................................................................
  }else{
    zFree = zFunction = fts3QuoteId(zFunc);
  }
  fts3Appendf(pRc, &zRet, "?");
  for(i=0; i<p->nColumn; i++){
    fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);
  }



  sqlite3_free(zFree);
  return zRet;
}

/*
** This function interprets the string at (*pp) as a non-negative integer
** value. It reads the integer and sets *pnOut to the value read, then 
................................................................................
  /* The results of parsing supported FTS4 key=value options: */
  int bNoDocsize = 0;             /* True to omit %_docsize table */
  int bDescIdx = 0;               /* True to store descending indexes */
  char *zPrefix = 0;              /* Prefix parameter value (or NULL) */
  char *zCompress = 0;            /* compress=? parameter (or NULL) */
  char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */
  char *zContent = 0;             /* content=? parameter (or NULL) */


  assert( strlen(argv[0])==4 );
  assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
       || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)
  );

  nDb = (int)strlen(argv[1]) + 1;
................................................................................
        int nOpt;
      } aFts4Opt[] = {
        { "matchinfo",   9 },     /* 0 -> MATCHINFO */
        { "prefix",      6 },     /* 1 -> PREFIX */
        { "compress",    8 },     /* 2 -> COMPRESS */
        { "uncompress", 10 },     /* 3 -> UNCOMPRESS */
        { "order",       5 },     /* 4 -> ORDER */
        { "content",     7 }      /* 5 -> CONTENT */

      };

      int iOpt;
      if( !zVal ){
        rc = SQLITE_NOMEM;
      }else{
        for(iOpt=0; iOpt<SizeofArray(aFts4Opt); iOpt++){
................................................................................
              ){
                *pzErr = sqlite3_mprintf("unrecognized order: %s", zVal);
                rc = SQLITE_ERROR;
              }
              bDescIdx = (zVal[0]=='d' || zVal[0]=='D');
              break;

            default:              /* CONTENT */
              assert( iOpt==5 );
              sqlite3_free(zUncompress);
              zContent = zVal;
              zVal = 0;
              break;







          }
        }
        sqlite3_free(zVal);
      }
    }

    /* Otherwise, the argument is a column name. */
................................................................................
    sqlite3_free(zUncompress); 
    zCompress = 0;
    zUncompress = 0;
    if( nCol==0 ){
      sqlite3_free((void*)aCol); 
      aCol = 0;
      rc = fts3ContentColumns(db, argv[1], zContent, &aCol, &nCol, &nString);
    }
    assert( rc!=SQLITE_OK || nCol>0 );












  }
  if( rc!=SQLITE_OK ) goto fts3_init_out;

  if( nCol==0 ){
    assert( nString==0 );
    aCol[0] = "content";
    nString = 8;
................................................................................
  p->azColumn = (char **)&p[1];
  p->pTokenizer = pTokenizer;
  p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
  p->bHasDocsize = (isFts4 && bNoDocsize==0);
  p->bHasStat = isFts4;
  p->bDescIdx = bDescIdx;
  p->zContentTbl = zContent;

  zContent = 0;

  TESTONLY( p->inTransaction = -1 );
  TESTONLY( p->mxSavepoint = -1 );

  p->aIndex = (struct Fts3Index *)&p->azColumn[nCol];
  memcpy(p->aIndex, aIndex, sizeof(struct Fts3Index) * nIndex);
  p->nIndex = nIndex;
  for(i=0; i<nIndex; i++){
................................................................................

fts3_init_out:
  sqlite3_free(zPrefix);
  sqlite3_free(aIndex);
  sqlite3_free(zCompress);
  sqlite3_free(zUncompress);
  sqlite3_free(zContent);

  sqlite3_free((void *)aCol);
  if( rc!=SQLITE_OK ){
    if( p ){
      fts3DisconnectMethod((sqlite3_vtab *)p);
    }else if( pTokenizer ){
      pTokenizer->pModule->xDestroy(pTokenizer);
    }
................................................................................
**   2. Full-text search using a MATCH operator on a non-docid column.
**   3. Linear scan of %_content table.
*/
static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
  Fts3Table *p = (Fts3Table *)pVTab;
  int i;                          /* Iterator variable */
  int iCons = -1;                 /* Index of constraint to use */


  /* By default use a full table scan. This is an expensive option,
  ** so search through the constraints to see if a more efficient 
  ** strategy is possible.
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 500000;
  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
    if( pCons->usable==0 ) continue;

    /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */

    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
     && (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1 )
    ){
      pInfo->idxNum = FTS3_DOCID_SEARCH;
      pInfo->estimatedCost = 1.0;
      iCons = i;
    }

................................................................................
    */
    if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH 
     && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn
    ){
      pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
      pInfo->estimatedCost = 2.0;
      iCons = i;
      break;







    }
  }

  if( iCons>=0 ){
    pInfo->aConstraintUsage[iCons].argvIndex = 1;
    pInfo->aConstraintUsage[iCons].omit = 1;
  } 




  /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
  ** docid) order. Both ascending and descending are possible. 
  */
  if( pInfo->nOrderBy==1 ){
    struct sqlite3_index_orderby *pOrder = &pInfo->aOrderBy[0];
    if( pOrder->iColumn<0 || pOrder->iColumn==p->nColumn+1 ){
................................................................................
** 8th argument.
**
** This function returns SQLITE_OK if successful, or an SQLite error code
** otherwise.
*/
static int fts3SegReaderCursor(
  Fts3Table *p,                   /* FTS3 table handle */

  int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
  int iLevel,                     /* Level of segments to scan */
  const char *zTerm,              /* Term to query for */
  int nTerm,                      /* Size of zTerm in bytes */
  int isPrefix,                   /* True for a prefix search */
  int isScan,                     /* True to scan from zTerm to EOF */
  Fts3MultiSegReader *pCsr        /* Cursor object to populate */
................................................................................
    if( rc==SQLITE_OK && pSeg ){
      rc = fts3SegReaderCursorAppend(pCsr, pSeg);
    }
  }

  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts3AllSegdirs(p, iIndex, iLevel, &pStmt);
    }

    while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
      Fts3SegReader *pSeg = 0;

      /* Read the values returned by the SELECT into local variables. */
      sqlite3_int64 iStartBlock = sqlite3_column_int64(pStmt, 1);
................................................................................

/*
** Set up a cursor object for iterating through a full-text index or a 
** single level therein.
*/
int sqlite3Fts3SegReaderCursor(
  Fts3Table *p,                   /* FTS3 table handle */

  int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
  int iLevel,                     /* Level of segments to scan */
  const char *zTerm,              /* Term to query for */
  int nTerm,                      /* Size of zTerm in bytes */
  int isPrefix,                   /* True for a prefix search */
  int isScan,                     /* True to scan from zTerm to EOF */
  Fts3MultiSegReader *pCsr       /* Cursor object to populate */
................................................................................
  /* "isScan" is only set to true by the ft4aux module, an ordinary
  ** full-text tables. */
  assert( isScan==0 || p->aIndex==0 );

  memset(pCsr, 0, sizeof(Fts3MultiSegReader));

  return fts3SegReaderCursor(
      p, iIndex, iLevel, zTerm, nTerm, isPrefix, isScan, pCsr
  );
}

/*
** In addition to its current configuration, have the Fts3MultiSegReader
** passed as the 4th argument also scan the doclist for term zTerm/nTerm.
**
** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
*/
static int fts3SegReaderCursorAddZero(
  Fts3Table *p,                   /* FTS virtual table handle */

  const char *zTerm,              /* Term to scan doclist of */
  int nTerm,                      /* Number of bytes in zTerm */
  Fts3MultiSegReader *pCsr        /* Fts3MultiSegReader to modify */
){

  return fts3SegReaderCursor(p, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0,pCsr);

}

/*
** Open an Fts3MultiSegReader to scan the doclist for term zTerm/nTerm. Or,
** if isPrefix is true, to scan the doclist for all terms for which 
** zTerm/nTerm is a prefix. If successful, return SQLITE_OK and write
** a pointer to the new Fts3MultiSegReader to *ppSegcsr. Otherwise, return
................................................................................
    int bFound = 0;               /* True once an index has been found */
    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;

    if( isPrefix ){
      for(i=1; bFound==0 && i<p->nIndex; i++){
        if( p->aIndex[i].nPrefix==nTerm ){
          bFound = 1;
          rc = sqlite3Fts3SegReaderCursor(
              p, i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0, pSegcsr);

          pSegcsr->bLookup = 1;
        }
      }

      for(i=1; bFound==0 && i<p->nIndex; i++){
        if( p->aIndex[i].nPrefix==nTerm+1 ){
          bFound = 1;
          rc = sqlite3Fts3SegReaderCursor(
              p, i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 1, 0, pSegcsr
          );
          if( rc==SQLITE_OK ){
            rc = fts3SegReaderCursorAddZero(p, zTerm, nTerm, pSegcsr);


          }
        }
      }
    }

    if( bFound==0 ){
      rc = sqlite3Fts3SegReaderCursor(
          p, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr
      );
      pSegcsr->bLookup = !isPrefix;
    }
  }

  *ppSegcsr = pSegcsr;
  return rc;
................................................................................
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  UNUSED_PARAMETER(idxStr);
  UNUSED_PARAMETER(nVal);

  assert( idxNum>=0 && idxNum<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( nVal==0 || nVal==1 );
  assert( (nVal==0)==(idxNum==FTS3_FULLSCAN_SEARCH) );
  assert( p->pSegments==0 );

  /* In case the cursor has been used before, clear it now. */
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->aDoclist);
  sqlite3Fts3ExprFree(pCsr->pExpr);
................................................................................
    int iCol = idxNum-FTS3_FULLTEXT_SEARCH;
    const char *zQuery = (const char *)sqlite3_value_text(apVal[0]);

    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
      return SQLITE_NOMEM;
    }




    rc = sqlite3Fts3ExprParse(p->pTokenizer, p->azColumn, p->bHasStat, 
        p->nColumn, iCol, zQuery, -1, &pCsr->pExpr
    );
    if( rc!=SQLITE_OK ){
      if( rc==SQLITE_ERROR ){
        static const char *zErr = "malformed MATCH expression: [%s]";
        p->base.zErrMsg = sqlite3_mprintf(zErr, zQuery);
      }
      return rc;
................................................................................
  *pRowid = pCsr->iPrevId;
  return SQLITE_OK;
}

/* 
** This is the xColumn method, called by SQLite to request a value from
** the row that the supplied cursor currently points to.







*/
static int fts3ColumnMethod(
  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
  sqlite3_context *pContext,      /* Context for sqlite3_result_xxx() calls */
  int iCol                        /* Index of column to read value from */
){
  int rc = SQLITE_OK;             /* Return Code */
  Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;

  /* The column value supplied by SQLite must be in range. */
  assert( iCol>=0 && iCol<=p->nColumn+1 );

  if( iCol==p->nColumn+1 ){
    /* This call is a request for the "docid" column. Since "docid" is an 
    ** alias for "rowid", use the xRowid() method to obtain the value.
    */
    sqlite3_result_int64(pContext, pCsr->iPrevId);
  }else if( iCol==p->nColumn ){
    /* The extra column whose name is the same as the table.
    ** Return a blob which is a pointer to the cursor.
    */
    sqlite3_result_blob(pContext, &pCsr, sizeof(pCsr), SQLITE_TRANSIENT);


  }else{


    rc = fts3CursorSeek(0, pCsr);








    if( rc==SQLITE_OK && sqlite3_data_count(pCsr->pStmt)>(iCol+1) ){
      sqlite3_result_value(pContext, sqlite3_column_value(pCsr->pStmt, iCol+1));

    }
  }

  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  return rc;
}

** index when a document is deleted or updated.  For deletions, we
** write an empty doclist (varint(docid) varint(POS_END)), for updates
** we simply write the new doclist.  Segment merges overwrite older
** data for a particular docid with newer data, so deletes or updates
** will eventually overtake the earlier data and knock it out.  The
** query logic likewise merges doclists so that newer data knocks out
** older data.




*/

#include "fts3Int.h"
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

#if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)
# define SQLITE_CORE 1
................................................................................
  for(i=0; i<SizeofArray(p->aStmt); i++){
    sqlite3_finalize(p->aStmt[i]);
  }
  sqlite3_free(p->zSegmentsTbl);
  sqlite3_free(p->zReadExprlist);
  sqlite3_free(p->zWriteExprlist);
  sqlite3_free(p->zContentTbl);
  sqlite3_free(p->zLanguageid);

  /* Invoke the tokenizer destructor to free the tokenizer. */
  p->pTokenizer->pModule->xDestroy(p->pTokenizer);

  sqlite3_free(p);
  return SQLITE_OK;
}
................................................................................
*/
static void fts3DeclareVtab(int *pRc, Fts3Table *p){
  if( *pRc==SQLITE_OK ){
    int i;                        /* Iterator variable */
    int rc;                       /* Return code */
    char *zSql;                   /* SQL statement passed to declare_vtab() */
    char *zCols;                  /* List of user defined columns */
    const char *zLanguageid;

    zLanguageid = (p->zLanguageid ? p->zLanguageid : "__langid");
    sqlite3_vtab_config(p->db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);

    /* Create a list of user columns for the virtual table */
    zCols = sqlite3_mprintf("%Q, ", p->azColumn[0]);
    for(i=1; zCols && i<p->nColumn; i++){
      zCols = sqlite3_mprintf("%z%Q, ", zCols, p->azColumn[i]);
    }

    /* Create the whole "CREATE TABLE" statement to pass to SQLite */
    zSql = sqlite3_mprintf(
        "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN, %Q HIDDEN)", 
        zCols, p->zName, zLanguageid
    );
    if( !zCols || !zSql ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_declare_vtab(p->db, zSql);
    }

................................................................................
*/
static int fts3CreateTables(Fts3Table *p){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Iterator variable */
  sqlite3 *db = p->db;            /* The database connection */

  if( p->zContentTbl==0 ){
    const char *zLanguageid = p->zLanguageid;
    char *zContentCols;           /* Columns of %_content table */

    /* Create a list of user columns for the content table */
    zContentCols = sqlite3_mprintf("docid INTEGER PRIMARY KEY");
    for(i=0; zContentCols && i<p->nColumn; i++){
      char *z = p->azColumn[i];
      zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);
    }
    if( zLanguageid && zContentCols ){
      zContentCols = sqlite3_mprintf("%z, langid", zContentCols, zLanguageid);
    }
    if( zContentCols==0 ) rc = SQLITE_NOMEM;
  
    /* Create the content table */
    fts3DbExec(&rc, db, 
       "CREATE TABLE %Q.'%q_content'(%s)",
       p->zDb, p->zName, zContentCols
    );
................................................................................
    }else{
      zFree = zFunction = fts3QuoteId(zFunc);
    }
    fts3Appendf(pRc, &zRet, "docid");
    for(i=0; i<p->nColumn; i++){
      fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);
    }
    if( p->zLanguageid ){
      fts3Appendf(pRc, &zRet, ", x.%Q", "langid");
    }
    sqlite3_free(zFree);
  }else{
    fts3Appendf(pRc, &zRet, "rowid");
    for(i=0; i<p->nColumn; i++){
      fts3Appendf(pRc, &zRet, ", x.'%q'", p->azColumn[i]);
    }
    if( p->zLanguageid ){
      fts3Appendf(pRc, &zRet, ", x.%Q", p->zLanguageid);
    }
  }
  fts3Appendf(pRc, &zRet, " FROM '%q'.'%q%s' AS x", 
      p->zDb,
      (p->zContentTbl ? p->zContentTbl : p->zName),
      (p->zContentTbl ? "" : "_content")
  );
  return zRet;
}

................................................................................
  }else{
    zFree = zFunction = fts3QuoteId(zFunc);
  }
  fts3Appendf(pRc, &zRet, "?");
  for(i=0; i<p->nColumn; i++){
    fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);
  }
  if( p->zLanguageid ){
    fts3Appendf(pRc, &zRet, ", ?");
  }
  sqlite3_free(zFree);
  return zRet;
}

/*
** This function interprets the string at (*pp) as a non-negative integer
** value. It reads the integer and sets *pnOut to the value read, then 
................................................................................
  /* The results of parsing supported FTS4 key=value options: */
  int bNoDocsize = 0;             /* True to omit %_docsize table */
  int bDescIdx = 0;               /* True to store descending indexes */
  char *zPrefix = 0;              /* Prefix parameter value (or NULL) */
  char *zCompress = 0;            /* compress=? parameter (or NULL) */
  char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */
  char *zContent = 0;             /* content=? parameter (or NULL) */
  char *zLanguageid = 0;          /* languageid=? parameter (or NULL) */

  assert( strlen(argv[0])==4 );
  assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
       || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)
  );

  nDb = (int)strlen(argv[1]) + 1;
................................................................................
        int nOpt;
      } aFts4Opt[] = {
        { "matchinfo",   9 },     /* 0 -> MATCHINFO */
        { "prefix",      6 },     /* 1 -> PREFIX */
        { "compress",    8 },     /* 2 -> COMPRESS */
        { "uncompress", 10 },     /* 3 -> UNCOMPRESS */
        { "order",       5 },     /* 4 -> ORDER */
        { "content",     7 },     /* 5 -> CONTENT */
        { "languageid", 10 }      /* 6 -> LANGUAGEID */
      };

      int iOpt;
      if( !zVal ){
        rc = SQLITE_NOMEM;
      }else{
        for(iOpt=0; iOpt<SizeofArray(aFts4Opt); iOpt++){
................................................................................
              ){
                *pzErr = sqlite3_mprintf("unrecognized order: %s", zVal);
                rc = SQLITE_ERROR;
              }
              bDescIdx = (zVal[0]=='d' || zVal[0]=='D');
              break;

            case 5:              /* CONTENT */

              sqlite3_free(zContent);
              zContent = zVal;
              zVal = 0;
              break;

            case 6:              /* LANGUAGEID */
              assert( iOpt==6 );
              sqlite3_free(zLanguageid);
              zLanguageid = zVal;
              zVal = 0;
              break;
          }
        }
        sqlite3_free(zVal);
      }
    }

    /* Otherwise, the argument is a column name. */
................................................................................
    sqlite3_free(zUncompress); 
    zCompress = 0;
    zUncompress = 0;
    if( nCol==0 ){
      sqlite3_free((void*)aCol); 
      aCol = 0;
      rc = fts3ContentColumns(db, argv[1], zContent, &aCol, &nCol, &nString);

      /* If a languageid= option was specified, remove the language id
      ** column from the aCol[] array. */ 
      if( rc==SQLITE_OK && zLanguageid ){
        int j;
        for(j=0; j<nCol; j++){
          if( sqlite3_stricmp(zLanguageid, aCol[j])==0 ){
            memmove(&aCol[j], &aCol[j+1], (nCol-j) * sizeof(aCol[0]));
            nCol--;
            break;
          }
        }
      }
    }
  }
  if( rc!=SQLITE_OK ) goto fts3_init_out;

  if( nCol==0 ){
    assert( nString==0 );
    aCol[0] = "content";
    nString = 8;
................................................................................
  p->azColumn = (char **)&p[1];
  p->pTokenizer = pTokenizer;
  p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
  p->bHasDocsize = (isFts4 && bNoDocsize==0);
  p->bHasStat = isFts4;
  p->bDescIdx = bDescIdx;
  p->zContentTbl = zContent;
  p->zLanguageid = zLanguageid;
  zContent = 0;
  zLanguageid = 0;
  TESTONLY( p->inTransaction = -1 );
  TESTONLY( p->mxSavepoint = -1 );

  p->aIndex = (struct Fts3Index *)&p->azColumn[nCol];
  memcpy(p->aIndex, aIndex, sizeof(struct Fts3Index) * nIndex);
  p->nIndex = nIndex;
  for(i=0; i<nIndex; i++){
................................................................................

fts3_init_out:
  sqlite3_free(zPrefix);
  sqlite3_free(aIndex);
  sqlite3_free(zCompress);
  sqlite3_free(zUncompress);
  sqlite3_free(zContent);
  sqlite3_free(zLanguageid);
  sqlite3_free((void *)aCol);
  if( rc!=SQLITE_OK ){
    if( p ){
      fts3DisconnectMethod((sqlite3_vtab *)p);
    }else if( pTokenizer ){
      pTokenizer->pModule->xDestroy(pTokenizer);
    }
................................................................................
**   2. Full-text search using a MATCH operator on a non-docid column.
**   3. Linear scan of %_content table.
*/
static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
  Fts3Table *p = (Fts3Table *)pVTab;
  int i;                          /* Iterator variable */
  int iCons = -1;                 /* Index of constraint to use */
  int iLangidCons = -1;           /* Index of langid=x constraint, if present */

  /* By default use a full table scan. This is an expensive option,
  ** so search through the constraints to see if a more efficient 
  ** strategy is possible.
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 500000;
  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
    if( pCons->usable==0 ) continue;

    /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */
    if( iCons<0 
     && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
     && (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1 )
    ){
      pInfo->idxNum = FTS3_DOCID_SEARCH;
      pInfo->estimatedCost = 1.0;
      iCons = i;
    }

................................................................................
    */
    if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH 
     && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn
    ){
      pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
      pInfo->estimatedCost = 2.0;
      iCons = i;

    }

    /* Equality constraint on the langid column */
    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
     && pCons->iColumn==p->nColumn + 2
    ){
      iLangidCons = i;
    }
  }

  if( iCons>=0 ){
    pInfo->aConstraintUsage[iCons].argvIndex = 1;
    pInfo->aConstraintUsage[iCons].omit = 1;
  } 
  if( iLangidCons>=0 ){
    pInfo->aConstraintUsage[iLangidCons].argvIndex = 2;
  } 

  /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
  ** docid) order. Both ascending and descending are possible. 
  */
  if( pInfo->nOrderBy==1 ){
    struct sqlite3_index_orderby *pOrder = &pInfo->aOrderBy[0];
    if( pOrder->iColumn<0 || pOrder->iColumn==p->nColumn+1 ){
................................................................................
** 8th argument.
**
** This function returns SQLITE_OK if successful, or an SQLite error code
** otherwise.
*/
static int fts3SegReaderCursor(
  Fts3Table *p,                   /* FTS3 table handle */
  int iLangid,                    /* Language id */
  int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
  int iLevel,                     /* Level of segments to scan */
  const char *zTerm,              /* Term to query for */
  int nTerm,                      /* Size of zTerm in bytes */
  int isPrefix,                   /* True for a prefix search */
  int isScan,                     /* True to scan from zTerm to EOF */
  Fts3MultiSegReader *pCsr        /* Cursor object to populate */
................................................................................
    if( rc==SQLITE_OK && pSeg ){
      rc = fts3SegReaderCursorAppend(pCsr, pSeg);
    }
  }

  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts3AllSegdirs(p, iLangid, iIndex, iLevel, &pStmt);
    }

    while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
      Fts3SegReader *pSeg = 0;

      /* Read the values returned by the SELECT into local variables. */
      sqlite3_int64 iStartBlock = sqlite3_column_int64(pStmt, 1);
................................................................................

/*
** Set up a cursor object for iterating through a full-text index or a 
** single level therein.
*/
int sqlite3Fts3SegReaderCursor(
  Fts3Table *p,                   /* FTS3 table handle */
  int iLangid,
  int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
  int iLevel,                     /* Level of segments to scan */
  const char *zTerm,              /* Term to query for */
  int nTerm,                      /* Size of zTerm in bytes */
  int isPrefix,                   /* True for a prefix search */
  int isScan,                     /* True to scan from zTerm to EOF */
  Fts3MultiSegReader *pCsr       /* Cursor object to populate */
................................................................................
  /* "isScan" is only set to true by the ft4aux module, an ordinary
  ** full-text tables. */
  assert( isScan==0 || p->aIndex==0 );

  memset(pCsr, 0, sizeof(Fts3MultiSegReader));

  return fts3SegReaderCursor(
      p, iLangid, iIndex, iLevel, zTerm, nTerm, isPrefix, isScan, pCsr
  );
}

/*
** In addition to its current configuration, have the Fts3MultiSegReader
** passed as the 4th argument also scan the doclist for term zTerm/nTerm.
**
** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
*/
static int fts3SegReaderCursorAddZero(
  Fts3Table *p,                   /* FTS virtual table handle */
  int iLangid,
  const char *zTerm,              /* Term to scan doclist of */
  int nTerm,                      /* Number of bytes in zTerm */
  Fts3MultiSegReader *pCsr        /* Fts3MultiSegReader to modify */
){
  return fts3SegReaderCursor(p, 
      iLangid, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0,pCsr
  );
}

/*
** Open an Fts3MultiSegReader to scan the doclist for term zTerm/nTerm. Or,
** if isPrefix is true, to scan the doclist for all terms for which 
** zTerm/nTerm is a prefix. If successful, return SQLITE_OK and write
** a pointer to the new Fts3MultiSegReader to *ppSegcsr. Otherwise, return
................................................................................
    int bFound = 0;               /* True once an index has been found */
    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;

    if( isPrefix ){
      for(i=1; bFound==0 && i<p->nIndex; i++){
        if( p->aIndex[i].nPrefix==nTerm ){
          bFound = 1;
          rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
              i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0, pSegcsr
          );
          pSegcsr->bLookup = 1;
        }
      }

      for(i=1; bFound==0 && i<p->nIndex; i++){
        if( p->aIndex[i].nPrefix==nTerm+1 ){
          bFound = 1;
          rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
              i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 1, 0, pSegcsr
          );
          if( rc==SQLITE_OK ){
            rc = fts3SegReaderCursorAddZero(
                p, pCsr->iLangid, zTerm, nTerm, pSegcsr
            );
          }
        }
      }
    }

    if( bFound==0 ){
      rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
          0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr
      );
      pSegcsr->bLookup = !isPrefix;
    }
  }

  *ppSegcsr = pSegcsr;
  return rc;
................................................................................
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  UNUSED_PARAMETER(idxStr);
  UNUSED_PARAMETER(nVal);

  assert( idxNum>=0 && idxNum<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( nVal==0 || nVal==1 || nVal==2 );
  assert( (nVal==0)==(idxNum==FTS3_FULLSCAN_SEARCH) );
  assert( p->pSegments==0 );

  /* In case the cursor has been used before, clear it now. */
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->aDoclist);
  sqlite3Fts3ExprFree(pCsr->pExpr);
................................................................................
    int iCol = idxNum-FTS3_FULLTEXT_SEARCH;
    const char *zQuery = (const char *)sqlite3_value_text(apVal[0]);

    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
      return SQLITE_NOMEM;
    }

    pCsr->iLangid = 0;
    if( nVal==2 ) pCsr->iLangid = sqlite3_value_int(apVal[1]);

    rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
        p->azColumn, p->bHasStat, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr
    );
    if( rc!=SQLITE_OK ){
      if( rc==SQLITE_ERROR ){
        static const char *zErr = "malformed MATCH expression: [%s]";
        p->base.zErrMsg = sqlite3_mprintf(zErr, zQuery);
      }
      return rc;
................................................................................
  *pRowid = pCsr->iPrevId;
  return SQLITE_OK;
}

/* 
** This is the xColumn method, called by SQLite to request a value from
** the row that the supplied cursor currently points to.
**
** If:
**
**   (iCol <  p->nColumn)   -> The value of the iCol'th user column.
**   (iCol == p->nColumn)   -> Magic column with the same name as the table.
**   (iCol == p->nColumn+1) -> Docid column
**   (iCol == p->nColumn+2) -> Langid column
*/
static int fts3ColumnMethod(
  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
  int iCol                        /* Index of column to read value from */
){
  int rc = SQLITE_OK;             /* Return Code */
  Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;

  /* The column value supplied by SQLite must be in range. */
  assert( iCol>=0 && iCol<=p->nColumn+2 );

  if( iCol==p->nColumn+1 ){
    /* This call is a request for the "docid" column. Since "docid" is an 
    ** alias for "rowid", use the xRowid() method to obtain the value.
    */
    sqlite3_result_int64(pCtx, pCsr->iPrevId);
  }else if( iCol==p->nColumn ){
    /* The extra column whose name is the same as the table.
    ** Return a blob which is a pointer to the cursor.  */

    sqlite3_result_blob(pCtx, &pCsr, sizeof(pCsr), SQLITE_TRANSIENT);
  }else if( iCol==p->nColumn+2 && pCsr->pExpr ){
    sqlite3_result_int64(pCtx, pCsr->iLangid);
  }else{
    /* The requested column is either a user column (one that contains 
    ** indexed data), or the language-id column.  */
    rc = fts3CursorSeek(0, pCsr);

    if( rc==SQLITE_OK ){
      if( iCol==p->nColumn+2 ){
        int iLangid = 0;
        if( p->zLanguageid ){
          iLangid = sqlite3_column_int(pCsr->pStmt, p->nColumn+1);
        }
        sqlite3_result_int(pCtx, iLangid);
      }else if( sqlite3_data_count(pCsr->pStmt)>(iCol+1) ){
        sqlite3_result_value(pCtx, sqlite3_column_value(pCsr->pStmt, iCol+1));
      }
    }
  }

  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  return rc;
}

  sqlite3 *db;                    /* The database connection */
  const char *zDb;                /* logical database name */
  const char *zName;              /* virtual table name */
  int nColumn;                    /* number of named columns in virtual table */
  char **azColumn;                /* column names.  malloced */
  sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
  char *zContentTbl;              /* content=xxx option, or NULL */


  /* Precompiled statements used by the implementation. Each of these 
  ** statements is run and reset within a single virtual table API call. 
  */
  sqlite3_stmt *aStmt[27];

  char *zReadExprlist;
  char *zWriteExprlist;

  int nNodeSize;                  /* Soft limit for node size */
  u8 bHasStat;                    /* True if %_stat table exists */
  u8 bHasDocsize;                 /* True if %_docsize table exists */
................................................................................
  u8 bDescIdx;                    /* True if doclists are in reverse order */
  int nPgsz;                      /* Page size for host database */
  char *zSegmentsTbl;             /* Name of %_segments table */
  sqlite3_blob *pSegments;        /* Blob handle open on %_segments table */

  /* TODO: Fix the first paragraph of this comment.
  **
  ** The following hash table is used to buffer pending index updates during
  ** transactions. Variable nPendingData estimates the memory size of the 
  ** pending data, including hash table overhead, but not malloc overhead. 
  ** When nPendingData exceeds nMaxPendingData, the buffer is flushed 
  ** automatically. Variable iPrevDocid is the docid of the most recently
  ** inserted record.
  **
  ** A single FTS4 table may have multiple full-text indexes. For each index
  ** there is an entry in the aIndex[] array. Index 0 is an index of all the
  ** terms that appear in the document set. Each subsequent index in aIndex[]
  ** is an index of prefixes of a specific length.
  */
  int nIndex;                     /* Size of aIndex[] */
................................................................................
  struct Fts3Index {
    int nPrefix;                  /* Prefix length (0 for main terms index) */
    Fts3Hash hPending;            /* Pending terms table for this index */
  } *aIndex;
  int nMaxPendingData;            /* Max pending data before flush to disk */
  int nPendingData;               /* Current bytes of pending data */
  sqlite_int64 iPrevDocid;        /* Docid of most recently inserted document */


#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
  /* State variables used for validating that the transaction control
  ** methods of the virtual table are called at appropriate times.  These
  ** values do not contribution to the FTS computation; they are used for
  ** verifying the SQLite core.
  */
  int inTransaction;     /* True after xBegin but before xCommit/xRollback */
  int mxSavepoint;       /* Largest valid xSavepoint integer */
#endif
};

/*
................................................................................
struct Fts3Cursor {
  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
  i16 eSearch;                    /* Search strategy (see below) */
  u8 isEof;                       /* True if at End Of Results */
  u8 isRequireSeek;               /* True if must seek pStmt to %_content row */
  sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */
  Fts3Expr *pExpr;                /* Parsed MATCH query string */

  int nPhrase;                    /* Number of matchable phrases in query */
  Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */
  sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
  char *pNextId;                  /* Pointer into the body of aDoclist */
  char *aDoclist;                 /* List of docids for full-text queries */
  int nDoclist;                   /* Size of buffer at aDoclist */
  u8 bDesc;                       /* True to sort in descending order */
................................................................................
void sqlite3Fts3PendingTermsClear(Fts3Table *);
int sqlite3Fts3Optimize(Fts3Table *);
int sqlite3Fts3SegReaderNew(int, int, sqlite3_int64,
  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
int sqlite3Fts3SegReaderPending(
  Fts3Table*,int,const char*,int,int,Fts3SegReader**);
void sqlite3Fts3SegReaderFree(Fts3SegReader *);
int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, sqlite3_stmt **);
int sqlite3Fts3ReadLock(Fts3Table *);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);

int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);

void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
................................................................................
#define FTS3_SEGCURSOR_PENDING        -1
#define FTS3_SEGCURSOR_ALL            -2

int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3MultiSegReader*, Fts3SegFilter*);
int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3MultiSegReader *);
void sqlite3Fts3SegReaderFinish(Fts3MultiSegReader *);

int sqlite3Fts3SegReaderCursor(
    Fts3Table *, int, int, const char *, int, int, int, Fts3MultiSegReader *);

/* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
#define FTS3_SEGMENT_REQUIRE_POS   0x00000001
#define FTS3_SEGMENT_IGNORE_EMPTY  0x00000002
#define FTS3_SEGMENT_COLUMN_FILTER 0x00000004
#define FTS3_SEGMENT_PREFIX        0x00000008
#define FTS3_SEGMENT_SCAN          0x00000010
................................................................................
void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
  const char *, const char *, int, int
);
void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, 
  char **, int, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
int sqlite3Fts3InitTerm(sqlite3 *db);
#endif





/* fts3_aux.c */
int sqlite3Fts3InitAux(sqlite3 *db);

void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *);

int sqlite3Fts3MsrIncrStart(

  sqlite3 *db;                    /* The database connection */
  const char *zDb;                /* logical database name */
  const char *zName;              /* virtual table name */
  int nColumn;                    /* number of named columns in virtual table */
  char **azColumn;                /* column names.  malloced */
  sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
  char *zContentTbl;              /* content=xxx option, or NULL */
  char *zLanguageid;              /* languageid=xxx option, or NULL */

  /* Precompiled statements used by the implementation. Each of these 
  ** statements is run and reset within a single virtual table API call. 
  */
  sqlite3_stmt *aStmt[28];

  char *zReadExprlist;
  char *zWriteExprlist;

  int nNodeSize;                  /* Soft limit for node size */
  u8 bHasStat;                    /* True if %_stat table exists */
  u8 bHasDocsize;                 /* True if %_docsize table exists */
................................................................................
  u8 bDescIdx;                    /* True if doclists are in reverse order */
  int nPgsz;                      /* Page size for host database */
  char *zSegmentsTbl;             /* Name of %_segments table */
  sqlite3_blob *pSegments;        /* Blob handle open on %_segments table */

  /* TODO: Fix the first paragraph of this comment.
  **
  ** The following array of hash tables is used to buffer pending index 
  ** updates during transactions. Variable nPendingData estimates the memory 
  ** size of the pending data, including hash table overhead, not including
  ** malloc overhead.  When nPendingData exceeds nMaxPendingData, the buffer 
  ** is flushed automatically. Variable iPrevDocid is the docid of the most 
  ** recently inserted record.
  **
  ** A single FTS4 table may have multiple full-text indexes. For each index
  ** there is an entry in the aIndex[] array. Index 0 is an index of all the
  ** terms that appear in the document set. Each subsequent index in aIndex[]
  ** is an index of prefixes of a specific length.
  */
  int nIndex;                     /* Size of aIndex[] */
................................................................................
  struct Fts3Index {
    int nPrefix;                  /* Prefix length (0 for main terms index) */
    Fts3Hash hPending;            /* Pending terms table for this index */
  } *aIndex;
  int nMaxPendingData;            /* Max pending data before flush to disk */
  int nPendingData;               /* Current bytes of pending data */
  sqlite_int64 iPrevDocid;        /* Docid of most recently inserted document */
  int iPrevLangid;                /* Langid of recently inserted document */

#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
  /* State variables used for validating that the transaction control
  ** methods of the virtual table are called at appropriate times.  These
  ** values do not contribute to FTS functionality; they are used for
  ** verifying the operation of the SQLite core.
  */
  int inTransaction;     /* True after xBegin but before xCommit/xRollback */
  int mxSavepoint;       /* Largest valid xSavepoint integer */
#endif
};

/*
................................................................................
struct Fts3Cursor {
  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
  i16 eSearch;                    /* Search strategy (see below) */
  u8 isEof;                       /* True if at End Of Results */
  u8 isRequireSeek;               /* True if must seek pStmt to %_content row */
  sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */
  Fts3Expr *pExpr;                /* Parsed MATCH query string */
  int iLangid;                    /* Language being queried for */
  int nPhrase;                    /* Number of matchable phrases in query */
  Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */
  sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
  char *pNextId;                  /* Pointer into the body of aDoclist */
  char *aDoclist;                 /* List of docids for full-text queries */
  int nDoclist;                   /* Size of buffer at aDoclist */
  u8 bDesc;                       /* True to sort in descending order */
................................................................................
void sqlite3Fts3PendingTermsClear(Fts3Table *);
int sqlite3Fts3Optimize(Fts3Table *);
int sqlite3Fts3SegReaderNew(int, int, sqlite3_int64,
  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
int sqlite3Fts3SegReaderPending(
  Fts3Table*,int,const char*,int,int,Fts3SegReader**);
void sqlite3Fts3SegReaderFree(Fts3SegReader *);
int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, int, sqlite3_stmt **);
int sqlite3Fts3ReadLock(Fts3Table *);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);

int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);

void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
................................................................................
#define FTS3_SEGCURSOR_PENDING        -1
#define FTS3_SEGCURSOR_ALL            -2

int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3MultiSegReader*, Fts3SegFilter*);
int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3MultiSegReader *);
void sqlite3Fts3SegReaderFinish(Fts3MultiSegReader *);

int sqlite3Fts3SegReaderCursor(Fts3Table *, 
    int, int, int, const char *, int, int, int, Fts3MultiSegReader *);

/* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
#define FTS3_SEGMENT_REQUIRE_POS   0x00000001
#define FTS3_SEGMENT_IGNORE_EMPTY  0x00000002
#define FTS3_SEGMENT_COLUMN_FILTER 0x00000004
#define FTS3_SEGMENT_PREFIX        0x00000008
#define FTS3_SEGMENT_SCAN          0x00000010
................................................................................
void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
  const char *, const char *, int, int
);
void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
  char **, int, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
int sqlite3Fts3InitTerm(sqlite3 *db);
#endif

int sqlite3Fts3OpenTokenizer(sqlite3_tokenizer *, int, const char *, int,
  sqlite3_tokenizer_cursor **
);

/* fts3_aux.c */
int sqlite3Fts3InitAux(sqlite3 *db);

void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *);

int sqlite3Fts3MsrIncrStart(

  if( idxNum&FTS4AUX_LE_CONSTRAINT ){
    int iIdx = (idxNum&FTS4AUX_GE_CONSTRAINT) ? 1 : 0;
    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iIdx]));
    pCsr->nStop = sqlite3_value_bytes(apVal[iIdx]);
    if( pCsr->zStop==0 ) return SQLITE_NOMEM;
  }

  rc = sqlite3Fts3SegReaderCursor(pFts3, 0, FTS3_SEGCURSOR_ALL,
      pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);
  }

  if( rc==SQLITE_OK ) rc = fts3auxNextMethod(pCursor);

  if( idxNum&FTS4AUX_LE_CONSTRAINT ){
    int iIdx = (idxNum&FTS4AUX_GE_CONSTRAINT) ? 1 : 0;
    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iIdx]));
    pCsr->nStop = sqlite3_value_bytes(apVal[iIdx]);
    if( pCsr->zStop==0 ) return SQLITE_NOMEM;
  }

  rc = sqlite3Fts3SegReaderCursor(pFts3, 0, 0, FTS3_SEGCURSOR_ALL,
      pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);
  }

  if( rc==SQLITE_OK ) rc = fts3auxNextMethod(pCursor);

**   FTSQUERY_PHRASE with a unary "-" attached to it. i.e. "mysql" in the
**   FTS3 query "sqlite -mysql". Otherwise, ParseContext.isNot is set to
**   zero.
*/
typedef struct ParseContext ParseContext;
struct ParseContext {
  sqlite3_tokenizer *pTokenizer;      /* Tokenizer module */

  const char **azCol;                 /* Array of column names for fts3 table */
  int bFts4;                          /* True to allow FTS4-only syntax */
  int nCol;                           /* Number of entries in azCol[] */
  int iDefaultCol;                    /* Default column to query */
  int isNot;                          /* True if getNextNode() sees a unary - */
  sqlite3_context *pCtx;              /* Write error message here */
  int nNest;                          /* Number of nested brackets */
................................................................................
*/
static void *fts3MallocZero(int nByte){
  void *pRet = sqlite3_malloc(nByte);
  if( pRet ) memset(pRet, 0, nByte);
  return pRet;
}





























/*
** Extract the next token from buffer z (length n) using the tokenizer
** and other information (column names etc.) in pParse. Create an Fts3Expr
** structure of type FTSQUERY_PHRASE containing a phrase consisting of this
** single token and set *ppExpr to point to it. If the end of the buffer is
** reached before a token is found, set *ppExpr to zero. It is the
................................................................................
  sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;
  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
  int rc;
  sqlite3_tokenizer_cursor *pCursor;
  Fts3Expr *pRet = 0;
  int nConsumed = 0;

  rc = pModule->xOpen(pTokenizer, z, n, &pCursor);
  if( rc==SQLITE_OK ){
    const char *zToken;
    int nToken, iStart, iEnd, iPosition;
    int nByte;                               /* total space to allocate */

    pCursor->pTokenizer = pTokenizer;
    rc = pModule->xNext(pCursor, &zToken, &nToken, &iStart, &iEnd, &iPosition);

    if( rc==SQLITE_OK ){
      nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase) + nToken;
      pRet = (Fts3Expr *)fts3MallocZero(nByte);
      if( !pRet ){
        rc = SQLITE_NOMEM;
      }else{
        pRet->eType = FTSQUERY_PHRASE;
................................................................................
  **
  **   Buffer zTemp: Contains copies of all tokens.
  **
  ** The second pass, in the block that begins "if( rc==SQLITE_DONE )" below,
  ** appends buffer zTemp to buffer p, and fills in the Fts3Expr and Fts3Phrase
  ** structures.
  */

  rc = pModule->xOpen(pTokenizer, zInput, nInput, &pCursor);
  if( rc==SQLITE_OK ){
    int ii;
    pCursor->pTokenizer = pTokenizer;
    for(ii=0; rc==SQLITE_OK; ii++){
      const char *zByte;
      int nByte, iBegin, iEnd, iPos;
      rc = pModule->xNext(pCursor, &zByte, &nByte, &iBegin, &iEnd, &iPos);
      if( rc==SQLITE_OK ){
        Fts3PhraseToken *pToken;

................................................................................
** that appears on the left-hand-side of the MATCH operator (the default
** column to match against for tokens for which a column name is not explicitly
** specified as part of the query string), or -1 if tokens may by default
** match any table column.
*/
int sqlite3Fts3ExprParse(
  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */

  char **azCol,                       /* Array of column names for fts3 table */
  int bFts4,                          /* True to allow FTS4-only syntax */
  int nCol,                           /* Number of entries in azCol[] */
  int iDefaultCol,                    /* Default column to query */
  const char *z, int n,               /* Text of MATCH query */
  Fts3Expr **ppExpr                   /* OUT: Parsed query structure */
){
  int nParsed;
  int rc;
  ParseContext sParse;


  sParse.pTokenizer = pTokenizer;

  sParse.azCol = (const char **)azCol;
  sParse.nCol = nCol;
  sParse.iDefaultCol = iDefaultCol;
  sParse.nNest = 0;
  sParse.bFts4 = bFts4;
  if( z==0 ){
    *ppExpr = 0;
    return SQLITE_OK;
  }
  if( n<0 ){
    n = (int)strlen(z);
................................................................................
    goto exprtest_out;
  }
  for(ii=0; ii<nCol; ii++){
    azCol[ii] = (char *)sqlite3_value_text(argv[ii+2]);
  }

  rc = sqlite3Fts3ExprParse(
      pTokenizer, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr
  );
  if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM ){
    sqlite3_result_error(context, "Error parsing expression", -1);
  }else if( rc==SQLITE_NOMEM || !(zBuf = exprToString(pExpr, 0)) ){
    sqlite3_result_error_nomem(context);
  }else{
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

**   FTSQUERY_PHRASE with a unary "-" attached to it. i.e. "mysql" in the
**   FTS3 query "sqlite -mysql". Otherwise, ParseContext.isNot is set to
**   zero.
*/
typedef struct ParseContext ParseContext;
struct ParseContext {
  sqlite3_tokenizer *pTokenizer;      /* Tokenizer module */
  int iLangid;                        /* Language id used with tokenizer */
  const char **azCol;                 /* Array of column names for fts3 table */
  int bFts4;                          /* True to allow FTS4-only syntax */
  int nCol;                           /* Number of entries in azCol[] */
  int iDefaultCol;                    /* Default column to query */
  int isNot;                          /* True if getNextNode() sees a unary - */
  sqlite3_context *pCtx;              /* Write error message here */
  int nNest;                          /* Number of nested brackets */
................................................................................
*/
static void *fts3MallocZero(int nByte){
  void *pRet = sqlite3_malloc(nByte);
  if( pRet ) memset(pRet, 0, nByte);
  return pRet;
}

int sqlite3Fts3OpenTokenizer(
  sqlite3_tokenizer *pTokenizer,
  int iLangid,
  const char *z,
  int n,
  sqlite3_tokenizer_cursor **ppCsr
){
  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
  sqlite3_tokenizer_cursor *pCsr = 0;
  int rc;

  rc = pModule->xOpen(pTokenizer, z, n, &pCsr);
  assert( rc==SQLITE_OK || pCsr==0 );
  if( rc==SQLITE_OK ){
    pCsr->pTokenizer = pTokenizer;
    if( pModule->iVersion>=1 ){
      rc = pModule->xLanguageid(pCsr, iLangid);
      if( rc!=SQLITE_OK ){
        pModule->xClose(pCsr);
        pCsr = 0;
      }
    }
  }
  *ppCsr = pCsr;
  return rc;
}


/*
** Extract the next token from buffer z (length n) using the tokenizer
** and other information (column names etc.) in pParse. Create an Fts3Expr
** structure of type FTSQUERY_PHRASE containing a phrase consisting of this
** single token and set *ppExpr to point to it. If the end of the buffer is
** reached before a token is found, set *ppExpr to zero. It is the
................................................................................
  sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;
  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
  int rc;
  sqlite3_tokenizer_cursor *pCursor;
  Fts3Expr *pRet = 0;
  int nConsumed = 0;

  rc = sqlite3Fts3OpenTokenizer(pTokenizer, pParse->iLangid, z, n, &pCursor);
  if( rc==SQLITE_OK ){
    const char *zToken;
    int nToken, iStart, iEnd, iPosition;
    int nByte;                               /* total space to allocate */


    rc = pModule->xNext(pCursor, &zToken, &nToken, &iStart, &iEnd, &iPosition);

    if( rc==SQLITE_OK ){
      nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase) + nToken;
      pRet = (Fts3Expr *)fts3MallocZero(nByte);
      if( !pRet ){
        rc = SQLITE_NOMEM;
      }else{
        pRet->eType = FTSQUERY_PHRASE;
................................................................................
  **
  **   Buffer zTemp: Contains copies of all tokens.
  **
  ** The second pass, in the block that begins "if( rc==SQLITE_DONE )" below,
  ** appends buffer zTemp to buffer p, and fills in the Fts3Expr and Fts3Phrase
  ** structures.
  */
  rc = sqlite3Fts3OpenTokenizer(
      pTokenizer, pParse->iLangid, zInput, nInput, &pCursor);
  if( rc==SQLITE_OK ){
    int ii;

    for(ii=0; rc==SQLITE_OK; ii++){
      const char *zByte;
      int nByte, iBegin, iEnd, iPos;
      rc = pModule->xNext(pCursor, &zByte, &nByte, &iBegin, &iEnd, &iPos);
      if( rc==SQLITE_OK ){
        Fts3PhraseToken *pToken;

................................................................................
** that appears on the left-hand-side of the MATCH operator (the default
** column to match against for tokens for which a column name is not explicitly
** specified as part of the query string), or -1 if tokens may by default
** match any table column.
*/
int sqlite3Fts3ExprParse(
  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
  int iLangid,                        /* Language id for tokenizer */
  char **azCol,                       /* Array of column names for fts3 table */
  int bFts4,                          /* True to allow FTS4-only syntax */
  int nCol,                           /* Number of entries in azCol[] */
  int iDefaultCol,                    /* Default column to query */
  const char *z, int n,               /* Text of MATCH query */
  Fts3Expr **ppExpr                   /* OUT: Parsed query structure */
){
  int nParsed;
  int rc;
  ParseContext sParse;

  memset(&sParse, 0, sizeof(ParseContext));
  sParse.pTokenizer = pTokenizer;
  sParse.iLangid = iLangid;
  sParse.azCol = (const char **)azCol;
  sParse.nCol = nCol;
  sParse.iDefaultCol = iDefaultCol;

  sParse.bFts4 = bFts4;
  if( z==0 ){
    *ppExpr = 0;
    return SQLITE_OK;
  }
  if( n<0 ){
    n = (int)strlen(z);
................................................................................
    goto exprtest_out;
  }
  for(ii=0; ii<nCol; ii++){
    azCol[ii] = (char *)sqlite3_value_text(argv[ii+2]);
  }

  rc = sqlite3Fts3ExprParse(
      pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr
  );
  if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM ){
    sqlite3_result_error(context, "Error parsing expression", -1);
  }else if( rc==SQLITE_NOMEM || !(zBuf = exprToString(pExpr, 0)) ){
    sqlite3_result_error_nomem(context);
  }else{
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

** This is done as part of extracting the snippet text, not when selecting
** the snippet. Snippet selection is done based on doclists only, so there
** is no way for fts3BestSnippet() to know whether or not the document 
** actually contains terms that follow the final highlighted term. 
*/
static int fts3SnippetShift(
  Fts3Table *pTab,                /* FTS3 table snippet comes from */

  int nSnippet,                   /* Number of tokens desired for snippet */
  const char *zDoc,               /* Document text to extract snippet from */
  int nDoc,                       /* Size of buffer zDoc in bytes */
  int *piPos,                     /* IN/OUT: First token of snippet */
  u64 *pHlmask                    /* IN/OUT: Mask of tokens to highlight */
){
  u64 hlmask = *pHlmask;          /* Local copy of initial highlight-mask */
................................................................................
      sqlite3_tokenizer_module *pMod;
      sqlite3_tokenizer_cursor *pC;
      pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;

      /* Open a cursor on zDoc/nDoc. Check if there are (nSnippet+nDesired)
      ** or more tokens in zDoc/nDoc.
      */
      rc = pMod->xOpen(pTab->pTokenizer, zDoc, nDoc, &pC);
      if( rc!=SQLITE_OK ){
        return rc;
      }
      pC->pTokenizer = pTab->pTokenizer;
      while( rc==SQLITE_OK && iCurrent<(nSnippet+nDesired) ){
        const char *ZDUMMY; int DUMMY1, DUMMY2, DUMMY3;
        rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &DUMMY2, &DUMMY3, &iCurrent);
      }
      pMod->xClose(pC);
      if( rc!=SQLITE_OK && rc!=SQLITE_DONE ){ return rc; }

................................................................................
    }
    return SQLITE_OK;
  }
  nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol);

  /* Open a token cursor on the document. */
  pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;
  rc = pMod->xOpen(pTab->pTokenizer, zDoc, nDoc, &pC);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pC->pTokenizer = pTab->pTokenizer;

  while( rc==SQLITE_OK ){
    int iBegin;                   /* Offset in zDoc of start of token */
    int iFin;                     /* Offset in zDoc of end of token */
    int isHighlight;              /* True for highlighted terms */

    rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &iBegin, &iFin, &iCurrent);
................................................................................
      }
      break;
    }
    if( iCurrent<iPos ){ continue; }

    if( !isShiftDone ){
      int n = nDoc - iBegin;

      rc = fts3SnippetShift(pTab, nSnippet, &zDoc[iBegin], n, &iPos, &hlmask);

      isShiftDone = 1;

      /* Now that the shift has been done, check if the initial "..." are
      ** required. They are required if (a) this is not the first fragment,
      ** or (b) this fragment does not begin at position 0 of its column. 
      */
      if( rc==SQLITE_OK && (iPos>0 || iFragment>0) ){
................................................................................
        continue;
      }
      rc = SQLITE_NOMEM;
      goto offsets_out;
    }

    /* Initialize a tokenizer iterator to iterate through column iCol. */

    rc = pMod->xOpen(pTab->pTokenizer, zDoc, nDoc, &pC);

    if( rc!=SQLITE_OK ) goto offsets_out;
    pC->pTokenizer = pTab->pTokenizer;

    rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);
    while( rc==SQLITE_OK ){
      int i;                      /* Used to loop through terms */
      int iMinPos = 0x7FFFFFFF;   /* Position of next token */
      TermOffset *pTerm = 0;      /* TermOffset associated with next token */

** This is done as part of extracting the snippet text, not when selecting
** the snippet. Snippet selection is done based on doclists only, so there
** is no way for fts3BestSnippet() to know whether or not the document 
** actually contains terms that follow the final highlighted term. 
*/
static int fts3SnippetShift(
  Fts3Table *pTab,                /* FTS3 table snippet comes from */
  int iLangid,                    /* Language id to use in tokenizing */
  int nSnippet,                   /* Number of tokens desired for snippet */
  const char *zDoc,               /* Document text to extract snippet from */
  int nDoc,                       /* Size of buffer zDoc in bytes */
  int *piPos,                     /* IN/OUT: First token of snippet */
  u64 *pHlmask                    /* IN/OUT: Mask of tokens to highlight */
){
  u64 hlmask = *pHlmask;          /* Local copy of initial highlight-mask */
................................................................................
      sqlite3_tokenizer_module *pMod;
      sqlite3_tokenizer_cursor *pC;
      pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;

      /* Open a cursor on zDoc/nDoc. Check if there are (nSnippet+nDesired)
      ** or more tokens in zDoc/nDoc.
      */
      rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, iLangid, zDoc, nDoc, &pC);
      if( rc!=SQLITE_OK ){
        return rc;
      }

      while( rc==SQLITE_OK && iCurrent<(nSnippet+nDesired) ){
        const char *ZDUMMY; int DUMMY1, DUMMY2, DUMMY3;
        rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &DUMMY2, &DUMMY3, &iCurrent);
      }
      pMod->xClose(pC);
      if( rc!=SQLITE_OK && rc!=SQLITE_DONE ){ return rc; }

................................................................................
    }
    return SQLITE_OK;
  }
  nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol);

  /* Open a token cursor on the document. */
  pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;
  rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid, zDoc,nDoc,&pC);
  if( rc!=SQLITE_OK ){
    return rc;
  }


  while( rc==SQLITE_OK ){
    int iBegin;                   /* Offset in zDoc of start of token */
    int iFin;                     /* Offset in zDoc of end of token */
    int isHighlight;              /* True for highlighted terms */

    rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &iBegin, &iFin, &iCurrent);
................................................................................
      }
      break;
    }
    if( iCurrent<iPos ){ continue; }

    if( !isShiftDone ){
      int n = nDoc - iBegin;
      rc = fts3SnippetShift(
          pTab, pCsr->iLangid, nSnippet, &zDoc[iBegin], n, &iPos, &hlmask
      );
      isShiftDone = 1;

      /* Now that the shift has been done, check if the initial "..." are
      ** required. They are required if (a) this is not the first fragment,
      ** or (b) this fragment does not begin at position 0 of its column. 
      */
      if( rc==SQLITE_OK && (iPos>0 || iFragment>0) ){
................................................................................
        continue;
      }
      rc = SQLITE_NOMEM;
      goto offsets_out;
    }

    /* Initialize a tokenizer iterator to iterate through column iCol. */
    rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid,
        zDoc, nDoc, &pC
    );
    if( rc!=SQLITE_OK ) goto offsets_out;


    rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);
    while( rc==SQLITE_OK ){
      int i;                      /* Used to loop through terms */
      int iMinPos = 0x7FFFFFFF;   /* Position of next token */
      TermOffset *pTerm = 0;      /* TermOffset associated with next token */

  testcase(pCsr->filter.zTerm);
  sqlite3Fts3SegReaderFinish(&pCsr->csr);
  memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr);

  pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
  pCsr->filter.flags |= FTS3_SEGMENT_SCAN;

  rc = sqlite3Fts3SegReaderCursor(pFts3, p->iIndex, FTS3_SEGCURSOR_ALL,
      pCsr->filter.zTerm, pCsr->filter.nTerm, 0, 1, &pCsr->csr
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);
  }
  if( rc==SQLITE_OK ){
    rc = fts3termNextMethod(pCursor);

  testcase(pCsr->filter.zTerm);
  sqlite3Fts3SegReaderFinish(&pCsr->csr);
  memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr);

  pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
  pCsr->filter.flags |= FTS3_SEGMENT_SCAN;

  rc = sqlite3Fts3SegReaderCursor(pFts3, 0, p->iIndex, FTS3_SEGCURSOR_ALL,
      pCsr->filter.zTerm, pCsr->filter.nTerm, 0, 1, &pCsr->csr
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);
  }
  if( rc==SQLITE_OK ){
    rc = fts3termNextMethod(pCursor);

**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file is not part of the production FTS code. It is only used for
** testing. It contains a Tcl command that can be used to test if a document
** matches an FTS NEAR expression.



*/

#include <tcl.h>
#include <string.h>
#include <assert.h>

#ifdef SQLITE_TEST
................................................................................

  Tcl_SetObjResult(interp, pRet);
  Tcl_DecrRefCount(pRet);
#endif
  return TCL_OK;
}






































































































































































































int Sqlitetestfts3_Init(Tcl_Interp *interp){
  Tcl_CreateObjCommand(interp, "fts3_near_match", fts3_near_match_cmd, 0, 0);
  Tcl_CreateObjCommand(interp, 
      "fts3_configure_incr_load", fts3_configure_incr_load_cmd, 0, 0
  );



  return TCL_OK;
}
#endif                  /* ifdef SQLITE_TEST */

**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file is not part of the production FTS code. It is only used for
** testing. It contains a Tcl command that can be used to test if a document
** matches an FTS NEAR expression.
**
** As of March 2012, it also contains a version 1 tokenizer used for testing
** that the sqlite3_tokenizer_module.xLanguage() method is invoked correctly.
*/

#include <tcl.h>
#include <string.h>
#include <assert.h>

#ifdef SQLITE_TEST
................................................................................

  Tcl_SetObjResult(interp, pRet);
  Tcl_DecrRefCount(pRet);
#endif
  return TCL_OK;
}

#ifdef SQLITE_ENABLE_FTS3
/**************************************************************************
** Beginning of test tokenizer code.
**
** For language 0, this tokenizer is similar to the default 'simple' 
** tokenizer. For other languages L, the following:
**
**   * Odd numbered languages are case-sensitive. Even numbered 
**     languages are not.
**
**   * Language ids 100 or greater are considered an error.
**
** The implementation assumes that the input contains only ASCII characters
** (i.e. those that may be encoded in UTF-8 using a single byte).
*/
typedef struct test_tokenizer {
  sqlite3_tokenizer base;
} test_tokenizer;

typedef struct test_tokenizer_cursor {
  sqlite3_tokenizer_cursor base;
  const char *aInput;          /* Input being tokenized */
  int nInput;                  /* Size of the input in bytes */
  int iInput;                  /* Current offset in aInput */
  int iToken;                  /* Index of next token to be returned */
  char *aBuffer;               /* Buffer containing current token */
  int nBuffer;                 /* Number of bytes allocated at pToken */
  int iLangid;                 /* Configured language id */
} test_tokenizer_cursor;

static int testTokenizerCreate(
  int argc, const char * const *argv,
  sqlite3_tokenizer **ppTokenizer
){
  test_tokenizer *pNew;

  pNew = sqlite3_malloc(sizeof(test_tokenizer));
  if( !pNew ) return SQLITE_NOMEM;
  memset(pNew, 0, sizeof(test_tokenizer));

  *ppTokenizer = (sqlite3_tokenizer *)pNew;
  return SQLITE_OK;
}

static int testTokenizerDestroy(sqlite3_tokenizer *pTokenizer){
  test_tokenizer *p = (test_tokenizer *)pTokenizer;
  sqlite3_free(p);
  return SQLITE_OK;
}

static int testTokenizerOpen(
  sqlite3_tokenizer *pTokenizer,         /* The tokenizer */
  const char *pInput, int nBytes,        /* String to be tokenized */
  sqlite3_tokenizer_cursor **ppCursor    /* OUT: Tokenization cursor */
){
  int rc = SQLITE_OK;                    /* Return code */
  test_tokenizer_cursor *pCsr;           /* New cursor object */

  UNUSED_PARAMETER(pTokenizer);

  pCsr = (test_tokenizer_cursor *)sqlite3_malloc(sizeof(test_tokenizer_cursor));
  if( pCsr==0 ){
    rc = SQLITE_NOMEM;
  }else{
    memset(pCsr, 0, sizeof(test_tokenizer_cursor));
    pCsr->aInput = pInput;
    if( nBytes<0 ){
      pCsr->nInput = strlen(pInput);
    }else{
      pCsr->nInput = nBytes;
    }
  }

  *ppCursor = (sqlite3_tokenizer_cursor *)pCsr;
  return rc;
}

static int testTokenizerClose(sqlite3_tokenizer_cursor *pCursor){
  test_tokenizer_cursor *pCsr = (test_tokenizer_cursor *)pCursor;
  sqlite3_free(pCsr->aBuffer);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

static int testIsTokenChar(char c){
  return (c>='a' && c<='z') || (c>='A' && c<='Z');
}
static int testTolower(char c){
  char ret = c;
  if( ret>='A' && ret<='Z') ret = ret - ('A'-'a');
  return ret;
}

static int testTokenizerNext(
  sqlite3_tokenizer_cursor *pCursor,  /* Cursor returned by testTokenizerOpen */
  const char **ppToken,               /* OUT: *ppToken is the token text */
  int *pnBytes,                       /* OUT: Number of bytes in token */
  int *piStartOffset,                 /* OUT: Starting offset of token */
  int *piEndOffset,                   /* OUT: Ending offset of token */
  int *piPosition                     /* OUT: Position integer of token */
){
  test_tokenizer_cursor *pCsr = (test_tokenizer_cursor *)pCursor;
  int rc = SQLITE_OK;
  const char *p;
  const char *pEnd;

  p = &pCsr->aInput[pCsr->iInput];
  pEnd = &pCsr->aInput[pCsr->nInput];

  /* Skip past any white-space */
  assert( p<=pEnd );
  while( p<pEnd && testIsTokenChar(*p)==0 ) p++;

  if( p==pEnd ){
    rc = SQLITE_DONE;
  }else{
    /* Advance to the end of the token */
    const char *pToken = p;
    int nToken;
    while( p<pEnd && testIsTokenChar(*p) ) p++;
    nToken = p-pToken;

    /* Copy the token into the buffer */
    if( nToken>pCsr->nBuffer ){
      sqlite3_free(pCsr->aBuffer);
      pCsr->aBuffer = sqlite3_malloc(nToken);
    }
    if( pCsr->aBuffer==0 ){
      rc = SQLITE_NOMEM;
    }else{
      int i;

      if( pCsr->iLangid & 0x00000001 ){
        for(i=0; i<nToken; i++) pCsr->aBuffer[i] = pToken[i];
      }else{
        for(i=0; i<nToken; i++) pCsr->aBuffer[i] = testTolower(pToken[i]);
      }
      pCsr->iToken++;
      pCsr->iInput = p - pCsr->aInput;

      *ppToken = pCsr->aBuffer;
      *pnBytes = nToken;
      *piStartOffset = pToken - pCsr->aInput;
      *piEndOffset = p - pCsr->aInput;
      *piPosition = pCsr->iToken;
    }
  }

  return rc;
}

static int testTokenizerLanguage(
  sqlite3_tokenizer_cursor *pCursor,
  int iLangid
){
  int rc = SQLITE_OK;
  test_tokenizer_cursor *pCsr = (test_tokenizer_cursor *)pCursor;
  pCsr->iLangid = iLangid;
  if( pCsr->iLangid>=100 ){
    rc = SQLITE_ERROR;
  }
  return rc;
}
#endif

static int fts3_test_tokenizer_cmd(
  ClientData clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
#ifdef SQLITE_ENABLE_FTS3
  static const sqlite3_tokenizer_module testTokenizerModule = {
    1,
    testTokenizerCreate,
    testTokenizerDestroy,
    testTokenizerOpen,
    testTokenizerClose,
    testTokenizerNext,
    testTokenizerLanguage
  };
  const sqlite3_tokenizer_module *pPtr = &testTokenizerModule;
  if( objc!=1 ){
    Tcl_WrongNumArgs(interp, 1, objv, "");
    return TCL_ERROR;
  }
  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(
    (const unsigned char *)&pPtr, sizeof(sqlite3_tokenizer_module *)
  ));
#endif
  return TCL_OK;
}

/* 
** End of tokenizer code.
**************************************************************************/ 

int Sqlitetestfts3_Init(Tcl_Interp *interp){
  Tcl_CreateObjCommand(interp, "fts3_near_match", fts3_near_match_cmd, 0, 0);
  Tcl_CreateObjCommand(interp, 
      "fts3_configure_incr_load", fts3_configure_incr_load_cmd, 0, 0
  );
  Tcl_CreateObjCommand(
      interp, "fts3_test_tokenizer", fts3_test_tokenizer_cmd, 0, 0
  );
  return TCL_OK;
}
#endif                  /* ifdef SQLITE_TEST */

  Tcl_IncrRefCount(pRet);

  if( SQLITE_OK!=p->xCreate(zArg ? 1 : 0, &zArg, &pTokenizer) ){
    zErr = "error in xCreate()";
    goto finish;
  }
  pTokenizer->pModule = p;
  if( SQLITE_OK!=p->xOpen(pTokenizer, zInput, nInput, &pCsr) ){
    zErr = "error in xOpen()";
    goto finish;
  }
  pCsr->pTokenizer = pTokenizer;

  while( SQLITE_OK==p->xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos) ){
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(iPos));
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));
    zToken = &zInput[iStart];
    nToken = iEnd-iStart;
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));

  Tcl_IncrRefCount(pRet);

  if( SQLITE_OK!=p->xCreate(zArg ? 1 : 0, &zArg, &pTokenizer) ){
    zErr = "error in xCreate()";
    goto finish;
  }
  pTokenizer->pModule = p;
  if( sqlite3Fts3OpenTokenizer(pTokenizer, 0, zInput, nInput, &pCsr) ){
    zErr = "error in xOpen()";
    goto finish;
  }


  while( SQLITE_OK==p->xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos) ){
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(iPos));
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));
    zToken = &zInput[iStart];
    nToken = iEnd-iStart;
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));

typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
typedef struct sqlite3_tokenizer sqlite3_tokenizer;
typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;

struct sqlite3_tokenizer_module {

  /*
  ** Structure version. Should always be set to 0.
  */
  int iVersion;

  /*
  ** Create a new tokenizer. The values in the argv[] array are the
  ** arguments passed to the "tokenizer" clause of the CREATE VIRTUAL
  ** TABLE statement that created the fts3 table. For example, if
................................................................................
  int (*xNext)(
    sqlite3_tokenizer_cursor *pCursor,   /* Tokenizer cursor */
    const char **ppToken, int *pnBytes,  /* OUT: Normalized text for token */
    int *piStartOffset,  /* OUT: Byte offset of token in input buffer */
    int *piEndOffset,    /* OUT: Byte offset of end of token in input buffer */
    int *piPosition      /* OUT: Number of tokens returned before this one */
  );









};

struct sqlite3_tokenizer {
  const sqlite3_tokenizer_module *pModule;  /* The module for this tokenizer */
  /* Tokenizer implementations will typically add additional fields */
};

typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
typedef struct sqlite3_tokenizer sqlite3_tokenizer;
typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;

struct sqlite3_tokenizer_module {

  /*
  ** Structure version. Should always be set to 0 or 1.
  */
  int iVersion;

  /*
  ** Create a new tokenizer. The values in the argv[] array are the
  ** arguments passed to the "tokenizer" clause of the CREATE VIRTUAL
  ** TABLE statement that created the fts3 table. For example, if
................................................................................
  int (*xNext)(
    sqlite3_tokenizer_cursor *pCursor,   /* Tokenizer cursor */
    const char **ppToken, int *pnBytes,  /* OUT: Normalized text for token */
    int *piStartOffset,  /* OUT: Byte offset of token in input buffer */
    int *piEndOffset,    /* OUT: Byte offset of end of token in input buffer */
    int *piPosition      /* OUT: Number of tokens returned before this one */
  );

  /***********************************************************************
  ** Methods below this point are only available if iVersion>=1.
  */

  /* 
  ** Configure the language id of a tokenizer cursor.
  */
  int (*xLanguageid)(sqlite3_tokenizer_cursor *pCsr, int iLangid);
};

struct sqlite3_tokenizer {
  const sqlite3_tokenizer_module *pModule;  /* The module for this tokenizer */
  /* Tokenizer implementations will typically add additional fields */
};

#define SQL_REPLACE_DOCTOTAL          23

#define SQL_SELECT_ALL_PREFIX_LEVEL   24
#define SQL_DELETE_ALL_TERMS_SEGDIR   25

#define SQL_DELETE_SEGDIR_RANGE       26



/*
** This function is used to obtain an SQLite prepared statement handle
** for the statement identified by the second argument. If successful,
** *pp is set to the requested statement handle and SQLITE_OK returned.
** Otherwise, an SQLite error code is returned and *pp is set to 0.
**
** If argument apVal is not NULL, then it must point to an array with
................................................................................
/* 21 */  "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
/* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=0",
/* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(0,?)",
/* 24 */  "",
/* 25 */  "",

/* 26 */ "DELETE FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?",


  };
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt;

  assert( SizeofArray(azSql)==SizeofArray(p->aStmt) );
  assert( eStmt<SizeofArray(azSql) && eStmt>=0 );
................................................................................
    }
  }else{
    rc = SQLITE_OK;
  }

  return rc;
}














/*
** Set *ppStmt to a statement handle that may be used to iterate through
** all rows in the %_segdir table, from oldest to newest. If successful,
** return SQLITE_OK. If an error occurs while preparing the statement, 
** return an SQLite error code.
**
................................................................................
**   1: start_block
**   2: leaves_end_block
**   3: end_block
**   4: root
*/
int sqlite3Fts3AllSegdirs(
  Fts3Table *p,                   /* FTS3 table */

  int iIndex,                     /* Index for p->aIndex[] */
  int iLevel,                     /* Level to select */
  sqlite3_stmt **ppStmt           /* OUT: Compiled statement */
){
  int rc;
  sqlite3_stmt *pStmt = 0;

................................................................................
  assert( iLevel<FTS3_SEGDIR_MAXLEVEL );
  assert( iIndex>=0 && iIndex<p->nIndex );

  if( iLevel<0 ){
    /* "SELECT * FROM %_segdir WHERE level BETWEEN ? AND ? ORDER BY ..." */
    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE, &pStmt, 0);
    if( rc==SQLITE_OK ){ 

      sqlite3_bind_int(pStmt, 1, iIndex*FTS3_SEGDIR_MAXLEVEL);
      sqlite3_bind_int(pStmt, 2, (iIndex+1)*FTS3_SEGDIR_MAXLEVEL-1);

    }
  }else{
    /* "SELECT * FROM %_segdir WHERE level = ? ORDER BY ..." */
    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
    if( rc==SQLITE_OK ){ 
      sqlite3_bind_int(pStmt, 1, iLevel+iIndex*FTS3_SEGDIR_MAXLEVEL);
    }
  }
  *ppStmt = pStmt;
  return rc;
}


................................................................................
** pending-terms hash-table. The docid used is that currently stored in
** p->iPrevDocid, and the column is specified by argument iCol.
**
** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.
*/
static int fts3PendingTermsAdd(
  Fts3Table *p,                   /* Table into which text will be inserted */

  const char *zText,              /* Text of document to be inserted */
  int iCol,                       /* Column into which text is being inserted */
  u32 *pnWord                     /* OUT: Number of tokens inserted */
){
  int rc;
  int iStart;
  int iEnd;
................................................................................
  ** zText==0. In this case, add zero token entries to the hash table and 
  ** return early. */
  if( zText==0 ){
    *pnWord = 0;
    return SQLITE_OK;
  }

  rc = pModule->xOpen(pTokenizer, zText, -1, &pCsr);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pCsr->pTokenizer = pTokenizer;

  xNext = pModule->xNext;
  while( SQLITE_OK==rc
      && SQLITE_OK==(rc = xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos))
  ){
    int i;
    if( iPos>=nWord ) nWord = iPos+1;
................................................................................
}

/* 
** Calling this function indicates that subsequent calls to 
** fts3PendingTermsAdd() are to add term/position-list pairs for the
** contents of the document with docid iDocid.
*/
static int fts3PendingTermsDocid(Fts3Table *p, sqlite_int64 iDocid){






  /* TODO(shess) Explore whether partially flushing the buffer on
  ** forced-flush would provide better performance.  I suspect that if
  ** we ordered the doclists by size and flushed the largest until the
  ** buffer was half empty, that would let the less frequent terms
  ** generate longer doclists.
  */


  if( iDocid<=p->iPrevDocid || p->nPendingData>p->nMaxPendingData ){

    int rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;
  }
  p->iPrevDocid = iDocid;

  return SQLITE_OK;
}

/*
** Discard the contents of the pending-terms hash tables. 
*/
void sqlite3Fts3PendingTermsClear(Fts3Table *p){
................................................................................
** This function is called by the xUpdate() method as part of an INSERT
** operation. It adds entries for each term in the new record to the
** pendingTerms hash table.
**
** Argument apVal is the same as the similarly named argument passed to
** fts3InsertData(). Parameter iDocid is the docid of the new row.
*/
static int fts3InsertTerms(Fts3Table *p, sqlite3_value **apVal, u32 *aSz){





  int i;                          /* Iterator variable */
  for(i=2; i<p->nColumn+2; i++){
    const char *zText = (const char *)sqlite3_value_text(apVal[i]);
    int rc = fts3PendingTermsAdd(p, zText, i-2, &aSz[i-2]);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
  }
  return SQLITE_OK;
}
................................................................................
**   apVal[0]                Not used for INSERT.
**   apVal[1]                rowid
**   apVal[2]                Left-most user-defined column
**   ...
**   apVal[p->nColumn+1]     Right-most user-defined column
**   apVal[p->nColumn+2]     Hidden column with same name as table
**   apVal[p->nColumn+3]     Hidden "docid" column (alias for rowid)

*/
static int fts3InsertData(
  Fts3Table *p,                   /* Full-text table */
  sqlite3_value **apVal,          /* Array of values to insert */
  sqlite3_int64 *piDocid          /* OUT: Docid for row just inserted */
){
  int rc;                         /* Return code */
................................................................................
  **
  **   INSERT INTO %_content VALUES(?, ?, ?, ...)
  **
  ** The statement features N '?' variables, where N is the number of user
  ** defined columns in the FTS3 table, plus one for the docid field.
  */
  rc = fts3SqlStmt(p, SQL_CONTENT_INSERT, &pContentInsert, &apVal[1]);
  if( rc!=SQLITE_OK ){
    return rc;



  }


  /* There is a quirk here. The users INSERT statement may have specified
  ** a value for the "rowid" field, for the "docid" field, or for both.
  ** Which is a problem, since "rowid" and "docid" are aliases for the
  ** same value. For example:
  **
  **   INSERT INTO fts3tbl(rowid, docid) VALUES(1, 2);
................................................................................
    fts3SqlExec(&rc, p, SQL_DELETE_ALL_DOCSIZE, 0);
  }
  if( p->bHasStat ){
    fts3SqlExec(&rc, p, SQL_DELETE_ALL_STAT, 0);
  }
  return rc;
}










/*
** The first element in the apVal[] array is assumed to contain the docid
** (an integer) of a row about to be deleted. Remove all terms from the
** full-text index.
*/
static void fts3DeleteTerms( 
................................................................................
  sqlite3_stmt *pSelect;

  if( *pRC ) return;
  rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid);
  if( rc==SQLITE_OK ){
    if( SQLITE_ROW==sqlite3_step(pSelect) ){
      int i;


      for(i=1; i<=p->nColumn; i++){
        const char *zText = (const char *)sqlite3_column_text(pSelect, i);
        rc = fts3PendingTermsAdd(p, zText, -1, &aSz[i-1]);


        if( rc!=SQLITE_OK ){
          sqlite3_reset(pSelect);
          *pRC = rc;
          return;
        }
        aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
      }
    }
    rc = sqlite3_reset(pSelect);
  }else{
    sqlite3_reset(pSelect);
  }
  *pRC = rc;
}

/*
** Forward declaration to account for the circular dependency between
** functions fts3SegmentMerge() and fts3AllocateSegdirIdx().
*/
static int fts3SegmentMerge(Fts3Table *, int, int);

/* 
** This function allocates a new level iLevel index in the segdir table.
** Usually, indexes are allocated within a level sequentially starting
** with 0, so the allocated index is one greater than the value returned
** by:
**
................................................................................
** allocated index is 0.
**
** If successful, *piIdx is set to the allocated index slot and SQLITE_OK
** returned. Otherwise, an SQLite error code is returned.
*/
static int fts3AllocateSegdirIdx(
  Fts3Table *p, 

  int iIndex,                     /* Index for p->aIndex */
  int iLevel, 
  int *piIdx
){
  int rc;                         /* Return Code */
  sqlite3_stmt *pNextIdx;         /* Query for next idx at level iLevel */
  int iNext = 0;                  /* Result of query pNextIdx */




  /* Set variable iNext to the next available segdir index at level iLevel. */
  rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pNextIdx, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int(pNextIdx, 1, iIndex*FTS3_SEGDIR_MAXLEVEL + iLevel);


    if( SQLITE_ROW==sqlite3_step(pNextIdx) ){
      iNext = sqlite3_column_int(pNextIdx, 0);
    }
    rc = sqlite3_reset(pNextIdx);
  }

  if( rc==SQLITE_OK ){
    /* If iNext is FTS3_MERGE_COUNT, indicating that level iLevel is already
    ** full, merge all segments in level iLevel into a single iLevel+1
    ** segment and allocate (newly freed) index 0 at level iLevel. Otherwise,
    ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext.
    */
    if( iNext>=FTS3_MERGE_COUNT ){
      rc = fts3SegmentMerge(p, iIndex, iLevel);
      *piIdx = 0;
    }else{
      *piIdx = iNext;
    }
  }

  return rc;
................................................................................
** Set *pnMax to the largest segment level in the database for the index
** iIndex.
**
** Segment levels are stored in the 'level' column of the %_segdir table.
**
** Return SQLITE_OK if successful, or an SQLite error code if not.
*/
static int fts3SegmentMaxLevel(Fts3Table *p, int iIndex, int *pnMax){





  sqlite3_stmt *pStmt;
  int rc;
  assert( iIndex>=0 && iIndex<p->nIndex );

  /* Set pStmt to the compiled version of:
  **
  **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?
  **
  ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).
  */
  rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_bind_int(pStmt, 1, iIndex*FTS3_SEGDIR_MAXLEVEL);
  sqlite3_bind_int(pStmt, 2, (iIndex+1)*FTS3_SEGDIR_MAXLEVEL - 1);


  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    *pnMax = sqlite3_column_int(pStmt, 0);
  }
  return sqlite3_reset(pStmt);
}

/*
................................................................................
**   2) deletes all %_segdir entries with level iLevel, or all %_segdir
**      entries regardless of level if (iLevel<0).
**
** SQLITE_OK is returned if successful, otherwise an SQLite error code.
*/
static int fts3DeleteSegdir(
  Fts3Table *p,                   /* Virtual table handle */

  int iIndex,                     /* Index for p->aIndex */
  int iLevel,                     /* Level of %_segdir entries to delete */
  Fts3SegReader **apSegment,      /* Array of SegReader objects */
  int nReader                     /* Size of array apSegment */
){
  int rc;                         /* Return Code */
  int i;                          /* Iterator variable */
................................................................................
    return rc;
  }

  assert( iLevel>=0 || iLevel==FTS3_SEGCURSOR_ALL );
  if( iLevel==FTS3_SEGCURSOR_ALL ){
    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_RANGE, &pDelete, 0);
    if( rc==SQLITE_OK ){
      sqlite3_bind_int(pDelete, 1, iIndex*FTS3_SEGDIR_MAXLEVEL);
      sqlite3_bind_int(pDelete, 2, (iIndex+1) * FTS3_SEGDIR_MAXLEVEL - 1);


    }
  }else{
    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pDelete, 0);
    if( rc==SQLITE_OK ){
      sqlite3_bind_int(pDelete, 1, iIndex*FTS3_SEGDIR_MAXLEVEL + iLevel);
    }
  }

  if( rc==SQLITE_OK ){
    sqlite3_step(pDelete);
    rc = sqlite3_reset(pDelete);
  }
................................................................................
** currently present in the database.
**
** If this function is called with iLevel<0, but there is only one
** segment in the database, SQLITE_DONE is returned immediately. 
** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, 
** an SQLite error code is returned.
*/
static int fts3SegmentMerge(Fts3Table *p, int iIndex, int iLevel){





  int rc;                         /* Return code */
  int iIdx = 0;                   /* Index of new segment */
  int iNewLevel = 0;              /* Level/index to create new segment at */
  SegmentWriter *pWriter = 0;     /* Used to write the new, merged, segment */
  Fts3SegFilter filter;           /* Segment term filter condition */
  Fts3MultiSegReader csr;        /* Cursor to iterate through level(s) */
  int bIgnoreEmpty = 0;           /* True to ignore empty segments */

  assert( iLevel==FTS3_SEGCURSOR_ALL
       || iLevel==FTS3_SEGCURSOR_PENDING
       || iLevel>=0
  );
  assert( iLevel<FTS3_SEGDIR_MAXLEVEL );
  assert( iIndex>=0 && iIndex<p->nIndex );

  rc = sqlite3Fts3SegReaderCursor(p, iIndex, iLevel, 0, 0, 1, 0, &csr);
  if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished;

  if( iLevel==FTS3_SEGCURSOR_ALL ){
    /* This call is to merge all segments in the database to a single
    ** segment. The level of the new segment is equal to the the numerically 
    ** greatest segment level currently present in the database for this
    ** index. The idx of the new segment is always 0.  */
    if( csr.nSegment==1 ){
      rc = SQLITE_DONE;
      goto finished;
    }
    rc = fts3SegmentMaxLevel(p, iIndex, &iNewLevel);
    bIgnoreEmpty = 1;

  }else if( iLevel==FTS3_SEGCURSOR_PENDING ){
    iNewLevel = iIndex * FTS3_SEGDIR_MAXLEVEL; 
    rc = fts3AllocateSegdirIdx(p, iIndex, 0, &iIdx);
  }else{
    /* This call is to merge all segments at level iLevel. find the next
    ** available segment index at level iLevel+1. The call to
    ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
    ** a single iLevel+2 segment if necessary.  */
    rc = fts3AllocateSegdirIdx(p, iIndex, iLevel+1, &iIdx);
    iNewLevel = iIndex * FTS3_SEGDIR_MAXLEVEL + iLevel+1;
  }
  if( rc!=SQLITE_OK ) goto finished;
  assert( csr.nSegment>0 );
  assert( iNewLevel>=(iIndex*FTS3_SEGDIR_MAXLEVEL) );
  assert( iNewLevel<((iIndex+1)*FTS3_SEGDIR_MAXLEVEL) );

  memset(&filter, 0, sizeof(Fts3SegFilter));
  filter.flags = FTS3_SEGMENT_REQUIRE_POS;
  filter.flags |= (bIgnoreEmpty ? FTS3_SEGMENT_IGNORE_EMPTY : 0);

  rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);
  while( SQLITE_OK==rc ){
................................................................................
    rc = fts3SegWriterAdd(p, &pWriter, 1, 
        csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);
  }
  if( rc!=SQLITE_OK ) goto finished;
  assert( pWriter );

  if( iLevel!=FTS3_SEGCURSOR_PENDING ){

    rc = fts3DeleteSegdir(p, iIndex, iLevel, csr.apSegment, csr.nSegment);

    if( rc!=SQLITE_OK ) goto finished;
  }
  rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);

 finished:
  fts3SegWriterFree(pWriter);
  sqlite3Fts3SegReaderFinish(&csr);
................................................................................
/* 
** Flush the contents of pendingTerms to level 0 segments.
*/
int sqlite3Fts3PendingTermsFlush(Fts3Table *p){
  int rc = SQLITE_OK;
  int i;
  for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
    rc = fts3SegmentMerge(p, i, FTS3_SEGCURSOR_PENDING);
    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
  }
  sqlite3Fts3PendingTermsClear(p);
  return rc;
}

/*
................................................................................
  }
  sqlite3_bind_blob(pStmt, 1, pBlob, nBlob, SQLITE_STATIC);
  sqlite3_step(pStmt);
  *pRC = sqlite3_reset(pStmt);
  sqlite3_free(a);
}





static int fts3DoOptimize(Fts3Table *p, int bReturnDone){
  int i;
  int bSeenDone = 0;




  int rc = SQLITE_OK;





  for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
    rc = fts3SegmentMerge(p, i, FTS3_SEGCURSOR_ALL);
    if( rc==SQLITE_DONE ){
      bSeenDone = 1;
      rc = SQLITE_OK;
    }
  }





  sqlite3Fts3SegmentsClose(p);
  sqlite3Fts3PendingTermsClear(p);

  return (rc==SQLITE_OK && bReturnDone && bSeenDone) ? SQLITE_DONE : rc;
}

/*
................................................................................
        aSzIns = &aSz[p->nColumn+1];
        aSzDel = &aSzIns[p->nColumn+1];
      }
    }

    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      int iCol;

      rc = fts3PendingTermsDocid(p, sqlite3_column_int64(pStmt, 0));
      aSz[p->nColumn] = 0;
      for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
        const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
        rc = fts3PendingTermsAdd(p, z, iCol, &aSz[iCol]);
        aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
      }
      if( p->bHasDocsize ){
        fts3InsertDocsize(&rc, p, aSz);
      }
      if( rc!=SQLITE_OK ){
        sqlite3_finalize(pStmt);
................................................................................
    assert( pCsr->isRequireSeek==0 );
    iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
  
    for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
      const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
      sqlite3_tokenizer_cursor *pTC = 0;
  
      rc = pModule->xOpen(pT, zText, -1, &pTC);
      while( rc==SQLITE_OK ){
        char const *zToken;       /* Buffer containing token */
        int nToken;               /* Number of bytes in token */
        int iDum1, iDum2;         /* Dummy variables */
        int iPos;                 /* Position of token in zText */
  
        pTC->pTokenizer = pT;
        rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
        for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
          Fts3PhraseToken *pPT = pDef->pToken;
          if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
           && (pPT->bFirst==0 || iPos==0)
           && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
           && (0==memcmp(zToken, pPT->z, pPT->n))
................................................................................
    if( isEmpty ){
      /* Deleting this row means the whole table is empty. In this case
      ** delete the contents of all three tables and throw away any
      ** data in the pendingTerms hash table.  */
      rc = fts3DeleteAll(p, 1);
      *pnDoc = *pnDoc - 1;
    }else{
      sqlite3_int64 iRemove = sqlite3_value_int64(pRowid);
      rc = fts3PendingTermsDocid(p, iRemove);
      fts3DeleteTerms(&rc, p, pRowid, aSzDel);
      if( p->zContentTbl==0 ){
        fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);
        if( sqlite3_changes(p->db) ) *pnDoc = *pnDoc - 1;
      }else{
        *pnDoc = *pnDoc - 1;
      }
................................................................................
  }

  return rc;
}

/*
** This function does the work for the xUpdate method of FTS3 virtual
** tables.









*/
int sqlite3Fts3UpdateMethod(
  sqlite3_vtab *pVtab,            /* FTS3 vtab object */
  int nArg,                       /* Size of argument array */
  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
................................................................................
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  u32 *aSzIns = 0;                /* Sizes of inserted documents */
  u32 *aSzDel;                    /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;

  assert( p->pSegments==0 );





  /* Check for a "special" INSERT operation. One of the form:
  **
  **   INSERT INTO xyz(xyz) VALUES('command');
  */
  if( nArg>1 
   && sqlite3_value_type(apVal[0])==SQLITE_NULL 
   && sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL 
  ){
    rc = fts3SpecialInsert(p, apVal[p->nColumn+2]);
    goto update_out;
  }






  /* Allocate space to hold the change in document sizes */
  aSzIns = sqlite3_malloc( sizeof(aSzIns[0])*(p->nColumn+1)*2 );
  if( aSzIns==0 ){
    rc = SQLITE_NOMEM;
    goto update_out;
  }
................................................................................
    assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER );
    rc = fts3DeleteByRowid(p, apVal[0], &nChng, aSzDel);
    isRemove = 1;
  }
  
  /* If this is an INSERT or UPDATE operation, insert the new record. */
  if( nArg>1 && rc==SQLITE_OK ){

    if( bInsertDone==0 ){
      rc = fts3InsertData(p, apVal, pRowid);
      if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
        rc = FTS_CORRUPT_VTAB;
      }
    }
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){
      rc = fts3PendingTermsDocid(p, *pRowid);
    }
    if( rc==SQLITE_OK ){
      assert( p->iPrevDocid==*pRowid );
      rc = fts3InsertTerms(p, apVal, aSzIns);
    }
    if( p->bHasDocsize ){
      fts3InsertDocsize(&rc, p, aSzIns);
    }
    nChng++;
  }

#define SQL_REPLACE_DOCTOTAL          23

#define SQL_SELECT_ALL_PREFIX_LEVEL   24
#define SQL_DELETE_ALL_TERMS_SEGDIR   25

#define SQL_DELETE_SEGDIR_RANGE       26

#define SQL_SELECT_ALL_LANGID         27

/*
** This function is used to obtain an SQLite prepared statement handle
** for the statement identified by the second argument. If successful,
** *pp is set to the requested statement handle and SQLITE_OK returned.
** Otherwise, an SQLite error code is returned and *pp is set to 0.
**
** If argument apVal is not NULL, then it must point to an array with
................................................................................
/* 21 */  "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
/* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=0",
/* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(0,?)",
/* 24 */  "",
/* 25 */  "",

/* 26 */ "DELETE FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?",
/* 27 */ "SELECT DISTINCT level / (1024 * ?) FROM %Q.'%q_segdir'",

  };
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt;

  assert( SizeofArray(azSql)==SizeofArray(p->aStmt) );
  assert( eStmt<SizeofArray(azSql) && eStmt>=0 );
................................................................................
    }
  }else{
    rc = SQLITE_OK;
  }

  return rc;
}

static sqlite3_int64 getAbsoluteLevel(
  Fts3Table *p, 
  int iLangid, 
  int iIndex, 
  int iLevel
){
  assert( iLangid>=0 );
  assert( p->nIndex>0 );
  assert( iIndex>=0 && iIndex<p->nIndex );
  return (iLangid * p->nIndex + iIndex) * FTS3_SEGDIR_MAXLEVEL + iLevel;
}


/*
** Set *ppStmt to a statement handle that may be used to iterate through
** all rows in the %_segdir table, from oldest to newest. If successful,
** return SQLITE_OK. If an error occurs while preparing the statement, 
** return an SQLite error code.
**
................................................................................
**   1: start_block
**   2: leaves_end_block
**   3: end_block
**   4: root
*/
int sqlite3Fts3AllSegdirs(
  Fts3Table *p,                   /* FTS3 table */
  int iLangid,                    /* Language being queried */
  int iIndex,                     /* Index for p->aIndex[] */
  int iLevel,                     /* Level to select */
  sqlite3_stmt **ppStmt           /* OUT: Compiled statement */
){
  int rc;
  sqlite3_stmt *pStmt = 0;

................................................................................
  assert( iLevel<FTS3_SEGDIR_MAXLEVEL );
  assert( iIndex>=0 && iIndex<p->nIndex );

  if( iLevel<0 ){
    /* "SELECT * FROM %_segdir WHERE level BETWEEN ? AND ? ORDER BY ..." */
    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE, &pStmt, 0);
    if( rc==SQLITE_OK ){ 
      sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
      sqlite3_bind_int(pStmt, 2, 
          getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
      );
    }
  }else{
    /* "SELECT * FROM %_segdir WHERE level = ? ORDER BY ..." */
    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
    if( rc==SQLITE_OK ){ 
      sqlite3_bind_int(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel));
    }
  }
  *ppStmt = pStmt;
  return rc;
}


................................................................................
** pending-terms hash-table. The docid used is that currently stored in
** p->iPrevDocid, and the column is specified by argument iCol.
**
** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.
*/
static int fts3PendingTermsAdd(
  Fts3Table *p,                   /* Table into which text will be inserted */
  int iLangid,                    /* Language id to use */
  const char *zText,              /* Text of document to be inserted */
  int iCol,                       /* Column into which text is being inserted */
  u32 *pnWord                     /* OUT: Number of tokens inserted */
){
  int rc;
  int iStart;
  int iEnd;
................................................................................
  ** zText==0. In this case, add zero token entries to the hash table and 
  ** return early. */
  if( zText==0 ){
    *pnWord = 0;
    return SQLITE_OK;
  }

  rc = sqlite3Fts3OpenTokenizer(pTokenizer, iLangid, zText, -1, &pCsr);
  if( rc!=SQLITE_OK ){
    return rc;
  }


  xNext = pModule->xNext;
  while( SQLITE_OK==rc
      && SQLITE_OK==(rc = xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos))
  ){
    int i;
    if( iPos>=nWord ) nWord = iPos+1;
................................................................................
}

/* 
** Calling this function indicates that subsequent calls to 
** fts3PendingTermsAdd() are to add term/position-list pairs for the
** contents of the document with docid iDocid.
*/
static int fts3PendingTermsDocid(
  Fts3Table *p,                   /* Full-text table handle */
  int iLangid,                    /* Language id of row being written */
  sqlite_int64 iDocid             /* Docid of row being written */
){
  assert( iLangid>=0 );

  /* TODO(shess) Explore whether partially flushing the buffer on
  ** forced-flush would provide better performance.  I suspect that if
  ** we ordered the doclists by size and flushed the largest until the
  ** buffer was half empty, that would let the less frequent terms
  ** generate longer doclists.
  */
  if( iDocid<=p->iPrevDocid 
   || p->iPrevLangid!=iLangid
   || p->nPendingData>p->nMaxPendingData 
  ){
    int rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;
  }
  p->iPrevDocid = iDocid;
  p->iPrevLangid = iLangid;
  return SQLITE_OK;
}

/*
** Discard the contents of the pending-terms hash tables. 
*/
void sqlite3Fts3PendingTermsClear(Fts3Table *p){
................................................................................
** This function is called by the xUpdate() method as part of an INSERT
** operation. It adds entries for each term in the new record to the
** pendingTerms hash table.
**
** Argument apVal is the same as the similarly named argument passed to
** fts3InsertData(). Parameter iDocid is the docid of the new row.
*/
static int fts3InsertTerms(
  Fts3Table *p, 
  int iLangid, 
  sqlite3_value **apVal, 
  u32 *aSz
){
  int i;                          /* Iterator variable */
  for(i=2; i<p->nColumn+2; i++){
    const char *zText = (const char *)sqlite3_value_text(apVal[i]);
    int rc = fts3PendingTermsAdd(p, iLangid, zText, i-2, &aSz[i-2]);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
  }
  return SQLITE_OK;
}
................................................................................
**   apVal[0]                Not used for INSERT.
**   apVal[1]                rowid
**   apVal[2]                Left-most user-defined column
**   ...
**   apVal[p->nColumn+1]     Right-most user-defined column
**   apVal[p->nColumn+2]     Hidden column with same name as table
**   apVal[p->nColumn+3]     Hidden "docid" column (alias for rowid)
**   apVal[p->nColumn+4]     Hidden languageid column
*/
static int fts3InsertData(
  Fts3Table *p,                   /* Full-text table */
  sqlite3_value **apVal,          /* Array of values to insert */
  sqlite3_int64 *piDocid          /* OUT: Docid for row just inserted */
){
  int rc;                         /* Return code */
................................................................................
  **
  **   INSERT INTO %_content VALUES(?, ?, ?, ...)
  **
  ** The statement features N '?' variables, where N is the number of user
  ** defined columns in the FTS3 table, plus one for the docid field.
  */
  rc = fts3SqlStmt(p, SQL_CONTENT_INSERT, &pContentInsert, &apVal[1]);
  if( rc==SQLITE_OK && p->zLanguageid ){
    rc = sqlite3_bind_int(
        pContentInsert, p->nColumn+2, 
        sqlite3_value_int(apVal[p->nColumn+4])
    );
  }
  if( rc!=SQLITE_OK ) return rc;

  /* There is a quirk here. The users INSERT statement may have specified
  ** a value for the "rowid" field, for the "docid" field, or for both.
  ** Which is a problem, since "rowid" and "docid" are aliases for the
  ** same value. For example:
  **
  **   INSERT INTO fts3tbl(rowid, docid) VALUES(1, 2);
................................................................................
    fts3SqlExec(&rc, p, SQL_DELETE_ALL_DOCSIZE, 0);
  }
  if( p->bHasStat ){
    fts3SqlExec(&rc, p, SQL_DELETE_ALL_STAT, 0);
  }
  return rc;
}

/*
**
*/
static int langidFromSelect(Fts3Table *p, sqlite3_stmt *pSelect){
  int iLangid = 0;
  if( p->zLanguageid ) iLangid = sqlite3_column_int(pSelect, p->nColumn+1);
  return iLangid;
}

/*
** The first element in the apVal[] array is assumed to contain the docid
** (an integer) of a row about to be deleted. Remove all terms from the
** full-text index.
*/
static void fts3DeleteTerms( 
................................................................................
  sqlite3_stmt *pSelect;

  if( *pRC ) return;
  rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid);
  if( rc==SQLITE_OK ){
    if( SQLITE_ROW==sqlite3_step(pSelect) ){
      int i;
      int iLangid = langidFromSelect(p, pSelect);
      rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pSelect, 0));
      for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){
        const char *zText = (const char *)sqlite3_column_text(pSelect, i);
        rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[i-1]);
        aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
      }
      if( rc!=SQLITE_OK ){
        sqlite3_reset(pSelect);
        *pRC = rc;
        return;


      }
    }
    rc = sqlite3_reset(pSelect);
  }else{
    sqlite3_reset(pSelect);
  }
  *pRC = rc;
}

/*
** Forward declaration to account for the circular dependency between
** functions fts3SegmentMerge() and fts3AllocateSegdirIdx().
*/
static int fts3SegmentMerge(Fts3Table *, int, int, int);

/* 
** This function allocates a new level iLevel index in the segdir table.
** Usually, indexes are allocated within a level sequentially starting
** with 0, so the allocated index is one greater than the value returned
** by:
**
................................................................................
** allocated index is 0.
**
** If successful, *piIdx is set to the allocated index slot and SQLITE_OK
** returned. Otherwise, an SQLite error code is returned.
*/
static int fts3AllocateSegdirIdx(
  Fts3Table *p, 
  int iLangid,                    /* Language id */
  int iIndex,                     /* Index for p->aIndex */
  int iLevel, 
  int *piIdx
){
  int rc;                         /* Return Code */
  sqlite3_stmt *pNextIdx;         /* Query for next idx at level iLevel */
  int iNext = 0;                  /* Result of query pNextIdx */

  assert( iLangid>=0 );
  assert( p->nIndex>=1 );

  /* Set variable iNext to the next available segdir index at level iLevel. */
  rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pNextIdx, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int64(
        pNextIdx, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel)
    );
    if( SQLITE_ROW==sqlite3_step(pNextIdx) ){
      iNext = sqlite3_column_int(pNextIdx, 0);
    }
    rc = sqlite3_reset(pNextIdx);
  }

  if( rc==SQLITE_OK ){
    /* If iNext is FTS3_MERGE_COUNT, indicating that level iLevel is already
    ** full, merge all segments in level iLevel into a single iLevel+1
    ** segment and allocate (newly freed) index 0 at level iLevel. Otherwise,
    ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext.
    */
    if( iNext>=FTS3_MERGE_COUNT ){
      rc = fts3SegmentMerge(p, iLangid, iIndex, iLevel);
      *piIdx = 0;
    }else{
      *piIdx = iNext;
    }
  }

  return rc;
................................................................................
** Set *pnMax to the largest segment level in the database for the index
** iIndex.
**
** Segment levels are stored in the 'level' column of the %_segdir table.
**
** Return SQLITE_OK if successful, or an SQLite error code if not.
*/
static int fts3SegmentMaxLevel(
  Fts3Table *p, 
  int iLangid,
  int iIndex, 
  int *pnMax
){
  sqlite3_stmt *pStmt;
  int rc;
  assert( iIndex>=0 && iIndex<p->nIndex );

  /* Set pStmt to the compiled version of:
  **
  **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?
  **
  ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).
  */
  rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_bind_int(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
  sqlite3_bind_int(pStmt, 2, 
      getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
  );
  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    *pnMax = sqlite3_column_int(pStmt, 0);
  }
  return sqlite3_reset(pStmt);
}

/*
................................................................................
**   2) deletes all %_segdir entries with level iLevel, or all %_segdir
**      entries regardless of level if (iLevel<0).
**
** SQLITE_OK is returned if successful, otherwise an SQLite error code.
*/
static int fts3DeleteSegdir(
  Fts3Table *p,                   /* Virtual table handle */
  int iLangid,                    /* Language id */
  int iIndex,                     /* Index for p->aIndex */
  int iLevel,                     /* Level of %_segdir entries to delete */
  Fts3SegReader **apSegment,      /* Array of SegReader objects */
  int nReader                     /* Size of array apSegment */
){
  int rc;                         /* Return Code */
  int i;                          /* Iterator variable */
................................................................................
    return rc;
  }

  assert( iLevel>=0 || iLevel==FTS3_SEGCURSOR_ALL );
  if( iLevel==FTS3_SEGCURSOR_ALL ){
    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_RANGE, &pDelete, 0);
    if( rc==SQLITE_OK ){
      sqlite3_bind_int(pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
      sqlite3_bind_int(pDelete, 2, 
          getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
      );
    }
  }else{
    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pDelete, 0);
    if( rc==SQLITE_OK ){
      sqlite3_bind_int(pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex,iLevel));
    }
  }

  if( rc==SQLITE_OK ){
    sqlite3_step(pDelete);
    rc = sqlite3_reset(pDelete);
  }
................................................................................
** currently present in the database.
**
** If this function is called with iLevel<0, but there is only one
** segment in the database, SQLITE_DONE is returned immediately. 
** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, 
** an SQLite error code is returned.
*/
static int fts3SegmentMerge(
  Fts3Table *p, 
  int iLangid,                    /* Language id to merge */
  int iIndex,                     /* Index in p->aIndex[] to merge */
  int iLevel                      /* Level to merge */
){
  int rc;                         /* Return code */
  int iIdx = 0;                   /* Index of new segment */
  int iNewLevel = 0;              /* Level/index to create new segment at */
  SegmentWriter *pWriter = 0;     /* Used to write the new, merged, segment */
  Fts3SegFilter filter;           /* Segment term filter condition */
  Fts3MultiSegReader csr;         /* Cursor to iterate through level(s) */
  int bIgnoreEmpty = 0;           /* True to ignore empty segments */

  assert( iLevel==FTS3_SEGCURSOR_ALL
       || iLevel==FTS3_SEGCURSOR_PENDING
       || iLevel>=0
  );
  assert( iLevel<FTS3_SEGDIR_MAXLEVEL );
  assert( iIndex>=0 && iIndex<p->nIndex );

  rc = sqlite3Fts3SegReaderCursor(p, iLangid, iIndex, iLevel, 0, 0, 1, 0, &csr);
  if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished;

  if( iLevel==FTS3_SEGCURSOR_ALL ){
    /* This call is to merge all segments in the database to a single
    ** segment. The level of the new segment is equal to the the numerically 
    ** greatest segment level currently present in the database for this
    ** index. The idx of the new segment is always 0.  */
    if( csr.nSegment==1 ){
      rc = SQLITE_DONE;
      goto finished;
    }
    rc = fts3SegmentMaxLevel(p, iLangid, iIndex, &iNewLevel);
    bIgnoreEmpty = 1;

  }else if( iLevel==FTS3_SEGCURSOR_PENDING ){
    iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, 0);
    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, 0, &iIdx);
  }else{
    /* This call is to merge all segments at level iLevel. find the next
    ** available segment index at level iLevel+1. The call to
    ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
    ** a single iLevel+2 segment if necessary.  */
    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, iLevel+1, &iIdx);
    iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, iLevel+1);
  }
  if( rc!=SQLITE_OK ) goto finished;
  assert( csr.nSegment>0 );
  assert( iNewLevel>=getAbsoluteLevel(p, iLangid, iIndex, 0) );
  assert( iNewLevel<getAbsoluteLevel(p, iLangid, iIndex,FTS3_SEGDIR_MAXLEVEL) );

  memset(&filter, 0, sizeof(Fts3SegFilter));
  filter.flags = FTS3_SEGMENT_REQUIRE_POS;
  filter.flags |= (bIgnoreEmpty ? FTS3_SEGMENT_IGNORE_EMPTY : 0);

  rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);
  while( SQLITE_OK==rc ){
................................................................................
    rc = fts3SegWriterAdd(p, &pWriter, 1, 
        csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);
  }
  if( rc!=SQLITE_OK ) goto finished;
  assert( pWriter );

  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
    rc = fts3DeleteSegdir(
        p, iLangid, iIndex, iLevel, csr.apSegment, csr.nSegment
    );
    if( rc!=SQLITE_OK ) goto finished;
  }
  rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);

 finished:
  fts3SegWriterFree(pWriter);
  sqlite3Fts3SegReaderFinish(&csr);
................................................................................
/* 
** Flush the contents of pendingTerms to level 0 segments.
*/
int sqlite3Fts3PendingTermsFlush(Fts3Table *p){
  int rc = SQLITE_OK;
  int i;
  for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
    rc = fts3SegmentMerge(p, p->iPrevLangid, i, FTS3_SEGCURSOR_PENDING);
    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
  }
  sqlite3Fts3PendingTermsClear(p);
  return rc;
}

/*
................................................................................
  }
  sqlite3_bind_blob(pStmt, 1, pBlob, nBlob, SQLITE_STATIC);
  sqlite3_step(pStmt);
  *pRC = sqlite3_reset(pStmt);
  sqlite3_free(a);
}

/*
** Merge the entire database so that there is one segment for each 
** iIndex/iLangid combination.
*/
static int fts3DoOptimize(Fts3Table *p, int bReturnDone){

  int bSeenDone = 0;
  int rc;
  sqlite3_stmt *pAllLangid = 0;

  rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);
  if( rc==SQLITE_OK ){
    int rc2;
    sqlite3_bind_int(pAllLangid, 1, p->nIndex);
    while( sqlite3_step(pAllLangid)==SQLITE_ROW ){
      int i;
      int iLangid = sqlite3_column_int(pAllLangid, 0);
      for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
        rc = fts3SegmentMerge(p, iLangid, i, FTS3_SEGCURSOR_ALL);
        if( rc==SQLITE_DONE ){
          bSeenDone = 1;
          rc = SQLITE_OK;
        }
      }
    }
    rc2 = sqlite3_reset(pAllLangid);
    if( rc==SQLITE_OK ) rc = rc2;
  }

  sqlite3Fts3SegmentsClose(p);
  sqlite3Fts3PendingTermsClear(p);

  return (rc==SQLITE_OK && bReturnDone && bSeenDone) ? SQLITE_DONE : rc;
}

/*
................................................................................
        aSzIns = &aSz[p->nColumn+1];
        aSzDel = &aSzIns[p->nColumn+1];
      }
    }

    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      int iCol;
      int iLangid = langidFromSelect(p, pStmt);
      rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pStmt, 0));
      aSz[p->nColumn] = 0;
      for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
        const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
        rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
        aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
      }
      if( p->bHasDocsize ){
        fts3InsertDocsize(&rc, p, aSz);
      }
      if( rc!=SQLITE_OK ){
        sqlite3_finalize(pStmt);
................................................................................
    assert( pCsr->isRequireSeek==0 );
    iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
  
    for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
      const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
      sqlite3_tokenizer_cursor *pTC = 0;
  
      rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
      while( rc==SQLITE_OK ){
        char const *zToken;       /* Buffer containing token */
        int nToken;               /* Number of bytes in token */
        int iDum1, iDum2;         /* Dummy variables */
        int iPos;                 /* Position of token in zText */
  

        rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
        for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
          Fts3PhraseToken *pPT = pDef->pToken;
          if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
           && (pPT->bFirst==0 || iPos==0)
           && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
           && (0==memcmp(zToken, pPT->z, pPT->n))
................................................................................
    if( isEmpty ){
      /* Deleting this row means the whole table is empty. In this case
      ** delete the contents of all three tables and throw away any
      ** data in the pendingTerms hash table.  */
      rc = fts3DeleteAll(p, 1);
      *pnDoc = *pnDoc - 1;
    }else{


      fts3DeleteTerms(&rc, p, pRowid, aSzDel);
      if( p->zContentTbl==0 ){
        fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);
        if( sqlite3_changes(p->db) ) *pnDoc = *pnDoc - 1;
      }else{
        *pnDoc = *pnDoc - 1;
      }
................................................................................
  }

  return rc;
}

/*
** This function does the work for the xUpdate method of FTS3 virtual
** tables. The schema of the virtual table being:
**
**     CREATE TABLE <table name>( 
**       <user COLUMns>,
**       <table name> HIDDEN, 
**       docid HIDDEN, 
**       <langid> HIDDEN
**     );
**
** 
*/
int sqlite3Fts3UpdateMethod(
  sqlite3_vtab *pVtab,            /* FTS3 vtab object */
  int nArg,                       /* Size of argument array */
  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
................................................................................
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  u32 *aSzIns = 0;                /* Sizes of inserted documents */
  u32 *aSzDel;                    /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;

  assert( p->pSegments==0 );
  assert( 
      nArg==1                     /* DELETE operations */
   || nArg==(2 + p->nColumn + 3)  /* INSERT or UPDATE operations */
  );

  /* Check for a "special" INSERT operation. One of the form:
  **
  **   INSERT INTO xyz(xyz) VALUES('command');
  */
  if( nArg>1 
   && sqlite3_value_type(apVal[0])==SQLITE_NULL 
   && sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL 
  ){
    rc = fts3SpecialInsert(p, apVal[p->nColumn+2]);
    goto update_out;
  }

  if( nArg>1 && sqlite3_value_int(apVal[2 + p->nColumn + 2])<0 ){
    rc = SQLITE_CONSTRAINT;
    goto update_out;
  }

  /* Allocate space to hold the change in document sizes */
  aSzIns = sqlite3_malloc( sizeof(aSzIns[0])*(p->nColumn+1)*2 );
  if( aSzIns==0 ){
    rc = SQLITE_NOMEM;
    goto update_out;
  }
................................................................................
    assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER );
    rc = fts3DeleteByRowid(p, apVal[0], &nChng, aSzDel);
    isRemove = 1;
  }
  
  /* If this is an INSERT or UPDATE operation, insert the new record. */
  if( nArg>1 && rc==SQLITE_OK ){
    int iLangid = sqlite3_value_int(apVal[2 + p->nColumn + 2]);
    if( bInsertDone==0 ){
      rc = fts3InsertData(p, apVal, pRowid);
      if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
        rc = FTS_CORRUPT_VTAB;
      }
    }
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){
      rc = fts3PendingTermsDocid(p, iLangid, *pRowid);
    }
    if( rc==SQLITE_OK ){
      assert( p->iPrevDocid==*pRowid );
      rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);
    }
    if( p->bHasDocsize ){
      fts3InsertDocsize(&rc, p, aSzIns);
    }
    nChng++;
  }

    while( *pp!=p ){
      pp = &(*pp)->pNext;
    }
    *pp = p->pNext;
  }

  /* If a transaction is still open on the Btree, roll it back. */
  sqlite3BtreeRollback(p->pDest);

  /* Set the error code of the destination database handle. */
  rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
  sqlite3Error(p->pDestDb, rc, 0);

  /* Exit the mutexes and free the backup context structure. */
  if( p->pDestDb ){

    while( *pp!=p ){
      pp = &(*pp)->pNext;
    }
    *pp = p->pNext;
  }

  /* If a transaction is still open on the Btree, roll it back. */
  sqlite3BtreeRollback(p->pDest, SQLITE_OK);

  /* Set the error code of the destination database handle. */
  rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
  sqlite3Error(p->pDestDb, rc, 0);

  /* Exit the mutexes and free the backup context structure. */
  if( p->pDestDb ){

    }
  }

  /* Rollback any active transaction and free the handle structure.
  ** The call to sqlite3BtreeRollback() drops any table-locks held by
  ** this handle.
  */
  sqlite3BtreeRollback(p);
  sqlite3BtreeLeave(p);

  /* If there are still other outstanding references to the shared-btree
  ** structure, return now. The remainder of this procedure cleans 
  ** up the shared-btree.
  */
  assert( p->wantToLock==0 && p->locked==0 );
................................................................................
** the rollback.  The rollback may have deleted tables
** or moved root pages, so it is not sufficient to
** save the state of the cursor.  The cursor must be
** invalidated.
*/
void sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode){
  BtCursor *p;

  sqlite3BtreeEnter(pBtree);
  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
    int i;
    sqlite3BtreeClearCursor(p);
    p->eState = CURSOR_FAULT;
    p->skipNext = errCode;
    for(i=0; i<=p->iPage; i++){
................................................................................
** invalided by this operation.  Any attempt to use a cursor
** that was open at the beginning of this operation will result
** in an error.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.
*/
int sqlite3BtreeRollback(Btree *p){
  int rc;
  BtShared *pBt = p->pBt;
  MemPage *pPage1;

  sqlite3BtreeEnter(p);

  rc = saveAllCursors(pBt, 0, 0);
#ifndef SQLITE_OMIT_SHARED_CACHE

  if( rc!=SQLITE_OK ){
    /* This is a horrible situation. An IO or malloc() error occurred whilst
    ** trying to save cursor positions. If this is an automatic rollback (as

    ** the result of a constraint, malloc() failure or IO error) then 
    ** the cache may be internally inconsistent (not contain valid trees) so
    ** we cannot simply return the error to the caller. Instead, abort 
    ** all queries that may be using any of the cursors that failed to save.
    */
    sqlite3BtreeTripAllCursors(p, rc);
  }
#endif
  btreeIntegrity(p);

  if( p->inTrans==TRANS_WRITE ){
    int rc2;

    assert( TRANS_WRITE==pBt->inTransaction );
    rc2 = sqlite3PagerRollback(pBt->pPager);

    }
  }

  /* Rollback any active transaction and free the handle structure.
  ** The call to sqlite3BtreeRollback() drops any table-locks held by
  ** this handle.
  */
  sqlite3BtreeRollback(p, SQLITE_OK);
  sqlite3BtreeLeave(p);

  /* If there are still other outstanding references to the shared-btree
  ** structure, return now. The remainder of this procedure cleans 
  ** up the shared-btree.
  */
  assert( p->wantToLock==0 && p->locked==0 );
................................................................................
** the rollback.  The rollback may have deleted tables
** or moved root pages, so it is not sufficient to
** save the state of the cursor.  The cursor must be
** invalidated.
*/
void sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode){
  BtCursor *p;
  if( pBtree==0 ) return;
  sqlite3BtreeEnter(pBtree);
  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
    int i;
    sqlite3BtreeClearCursor(p);
    p->eState = CURSOR_FAULT;
    p->skipNext = errCode;
    for(i=0; i<=p->iPage; i++){
................................................................................
** invalided by this operation.  Any attempt to use a cursor
** that was open at the beginning of this operation will result
** in an error.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.
*/
int sqlite3BtreeRollback(Btree *p, int tripCode){
  int rc;
  BtShared *pBt = p->pBt;
  MemPage *pPage1;

  sqlite3BtreeEnter(p);
  if( tripCode==SQLITE_OK ){
    rc = tripCode = saveAllCursors(pBt, 0, 0);

  }else{
    rc = SQLITE_OK;


  }
  if( tripCode ){




    sqlite3BtreeTripAllCursors(p, tripCode);
  }

  btreeIntegrity(p);

  if( p->inTrans==TRANS_WRITE ){
    int rc2;

    assert( TRANS_WRITE==pBt->inTransaction );
    rc2 = sqlite3PagerRollback(pBt->pPager);

int sqlite3BtreeGetReserve(Btree*);
int sqlite3BtreeSetAutoVacuum(Btree *, int);
int sqlite3BtreeGetAutoVacuum(Btree *);
int sqlite3BtreeBeginTrans(Btree*,int);
int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
int sqlite3BtreeCommitPhaseTwo(Btree*, int);
int sqlite3BtreeCommit(Btree*);
int sqlite3BtreeRollback(Btree*);
int sqlite3BtreeBeginStmt(Btree*,int);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
int sqlite3BtreeIsInBackup(Btree*);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *pBtree);

int sqlite3BtreeGetReserve(Btree*);
int sqlite3BtreeSetAutoVacuum(Btree *, int);
int sqlite3BtreeGetAutoVacuum(Btree *);
int sqlite3BtreeBeginTrans(Btree*,int);
int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
int sqlite3BtreeCommitPhaseTwo(Btree*, int);
int sqlite3BtreeCommit(Btree*);
int sqlite3BtreeRollback(Btree*,int);
int sqlite3BtreeBeginStmt(Btree*,int);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
int sqlite3BtreeIsInBackup(Btree*);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *pBtree);

    ** (or -9223372036854775808) since when you do abs() of that
    ** number of you get the same value back again.  To do this
    ** in a way that is testable, mask the sign bit off of negative
    ** values, resulting in a positive value.  Then take the 
    ** 2s complement of that positive value.  The end result can
    ** therefore be no less than -9223372036854775807.
    */
    r = -(r ^ (((sqlite3_int64)1)<<63));
  }
  sqlite3_result_int64(context, r);
}

/*
** Implementation of randomblob(N).  Return a random blob
** that is N bytes long.

    ** (or -9223372036854775808) since when you do abs() of that
    ** number of you get the same value back again.  To do this
    ** in a way that is testable, mask the sign bit off of negative
    ** values, resulting in a positive value.  Then take the 
    ** 2s complement of that positive value.  The end result can
    ** therefore be no less than -9223372036854775807.
    */
    r = -(r & LARGEST_INT64);
  }
  sqlite3_result_int64(context, r);
}

/*
** Implementation of randomblob(N).  Return a random blob
** that is N bytes long.

#endif
  
  sqlite3_free(db);
  return SQLITE_OK;
}

/*
** Rollback all database files.



*/
void sqlite3RollbackAll(sqlite3 *db){
  int i;
  int inTrans = 0;
  assert( sqlite3_mutex_held(db->mutex) );
  sqlite3BeginBenignMalloc();
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].pBt ){

      if( sqlite3BtreeIsInTrans(db->aDb[i].pBt) ){
        inTrans = 1;
      }
      sqlite3BtreeRollback(db->aDb[i].pBt);
      db->aDb[i].inTrans = 0;
    }
  }
  sqlite3VtabRollback(db);
  sqlite3EndBenignMalloc();

  if( db->flags&SQLITE_InternChanges ){
................................................................................
    /* SQLITE_MISUSE      */ "library routine called out of sequence",
    /* SQLITE_NOLFS       */ "large file support is disabled",
    /* SQLITE_AUTH        */ "authorization denied",
    /* SQLITE_FORMAT      */ "auxiliary database format error",
    /* SQLITE_RANGE       */ "bind or column index out of range",
    /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
  };







  rc &= 0xff;
  if( ALWAYS(rc>=0) && rc<(int)(sizeof(aMsg)/sizeof(aMsg[0])) && aMsg[rc]!=0 ){

    return aMsg[rc];
  }else{
    return "unknown error";
  }




}

/*
** This routine implements a busy callback that sleeps and tries
** again until a timeout value is reached.  The timeout value is
** an integer number of milliseconds passed in as the first
** argument.
................................................................................
  db->xProfile = xProfile;
  db->pProfileArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
#endif /* SQLITE_OMIT_TRACE */

/*** EXPERIMENTAL ***
**
** Register a function to be invoked when a transaction comments.
** If the invoked function returns non-zero, then the commit becomes a
** rollback.
*/
void *sqlite3_commit_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  int (*xCallback)(void*),  /* Function to invoke on each commit */
  void *pArg                /* Argument to the function */

#endif
  
  sqlite3_free(db);
  return SQLITE_OK;
}

/*
** Rollback all database files.  If tripCode is not SQLITE_OK, then
** any open cursors are invalidated ("tripped" - as in "tripping a circuit
** breaker") and made to return tripCode if there are any further
** attempts to use that cursor.
*/
void sqlite3RollbackAll(sqlite3 *db, int tripCode){
  int i;
  int inTrans = 0;
  assert( sqlite3_mutex_held(db->mutex) );
  sqlite3BeginBenignMalloc();
  for(i=0; i<db->nDb; i++){
    Btree *p = db->aDb[i].pBt;
    if( p ){
      if( sqlite3BtreeIsInTrans(p) ){
        inTrans = 1;
      }
      sqlite3BtreeRollback(p, tripCode);
      db->aDb[i].inTrans = 0;
    }
  }
  sqlite3VtabRollback(db);
  sqlite3EndBenignMalloc();

  if( db->flags&SQLITE_InternChanges ){
................................................................................
    /* SQLITE_MISUSE      */ "library routine called out of sequence",
    /* SQLITE_NOLFS       */ "large file support is disabled",
    /* SQLITE_AUTH        */ "authorization denied",
    /* SQLITE_FORMAT      */ "auxiliary database format error",
    /* SQLITE_RANGE       */ "bind or column index out of range",
    /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
  };
  const char *zErr = "unknown error";
  switch( rc ){
    case SQLITE_ABORT_ROLLBACK: {
      zErr = "abort due to ROLLBACK";
      break;
    }
    default: {
      rc &= 0xff;

      if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
        zErr = aMsg[rc];


      }
      break;
    }
  }
  return zErr;
}

/*
** This routine implements a busy callback that sleeps and tries
** again until a timeout value is reached.  The timeout value is
** an integer number of milliseconds passed in as the first
** argument.
................................................................................
  db->xProfile = xProfile;
  db->pProfileArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
#endif /* SQLITE_OMIT_TRACE */

/*

** Register a function to be invoked when a transaction commits.
** If the invoked function returns non-zero, then the commit becomes a
** rollback.
*/
void *sqlite3_commit_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  int (*xCallback)(void*),  /* Function to invoke on each commit */
  void *pArg                /* Argument to the function */

**
**    HAVE_MALLOC_USABLE_SIZE     The configure script sets this symbol if
**                                the malloc_usable_size() interface exists
**                                on the target platform.  Or, this symbol
**                                can be set manually, if desired.
**                                If an equivalent interface exists by
**                                a different name, using a separate -D
**                                option to rename it.  This symbol will
**                                be enabled automatically on windows
**                                systems, and malloc_usable_size() will
**                                be redefined to _msize(), unless the
**                                SQLITE_WITHOUT_MSIZE macro is defined.
**    
**    SQLITE_WITHOUT_ZONEMALLOC   Some older macs lack support for the zone
**                                memory allocator.  Set this symbol to enable
**                                building on older macs.
**
**    SQLITE_WITHOUT_MSIZE        Set this symbol to disable the use of
**                                _msize() on windows systems.  This might
**                                be necessary when compiling for Delphi,
................................................................................
** This version of the memory allocator is the default.  It is
** used when no other memory allocator is specified using compile-time
** macros.
*/
#ifdef SQLITE_SYSTEM_MALLOC

/*
** Windows systems have malloc_usable_size() but it is called _msize().
** The use of _msize() is automatic, but can be disabled by compiling
** with -DSQLITE_WITHOUT_MSIZE
*/
#if !defined(HAVE_MALLOC_USABLE_SIZE) && SQLITE_OS_WIN \
      && !defined(SQLITE_WITHOUT_MSIZE)
# define HAVE_MALLOC_USABLE_SIZE 1
# define SQLITE_MALLOCSIZE _msize
#endif

#if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC)

/*
** Use the zone allocator available on apple products unless the
................................................................................
** Use standard C library malloc and free on non-Apple systems.  
** Also used by Apple systems if SQLITE_WITHOUT_ZONEMALLOC is defined.
*/
#define SQLITE_MALLOC(x)    malloc(x)
#define SQLITE_FREE(x)      free(x)
#define SQLITE_REALLOC(x,y) realloc((x),(y))


#if defined(HAVE_MALLOC_H) && defined(HAVE_MALLOC_USABLE_SIZE)
# include <malloc.h>    /* Needed for malloc_usable_size on linux */
#endif
#ifdef HAVE_MALLOC_USABLE_SIZE
# ifndef SQLITE_MALLOCSIZE
#  define SQLITE_MALLOCSIZE(x) malloc_usable_size(x)
# endif
#else

**
**    HAVE_MALLOC_USABLE_SIZE     The configure script sets this symbol if
**                                the malloc_usable_size() interface exists
**                                on the target platform.  Or, this symbol
**                                can be set manually, if desired.
**                                If an equivalent interface exists by
**                                a different name, using a separate -D
**                                option to rename it.




**
**    SQLITE_WITHOUT_ZONEMALLOC   Some older macs lack support for the zone
**                                memory allocator.  Set this symbol to enable
**                                building on older macs.
**
**    SQLITE_WITHOUT_MSIZE        Set this symbol to disable the use of
**                                _msize() on windows systems.  This might
**                                be necessary when compiling for Delphi,
................................................................................
** This version of the memory allocator is the default.  It is
** used when no other memory allocator is specified using compile-time
** macros.
*/
#ifdef SQLITE_SYSTEM_MALLOC

/*
** The MSVCRT has malloc_usable_size() but it is called _msize().
** The use of _msize() is automatic, but can be disabled by compiling
** with -DSQLITE_WITHOUT_MSIZE
*/

#if defined(_MSC_VER) && !defined(SQLITE_WITHOUT_MSIZE)

# define SQLITE_MALLOCSIZE _msize
#endif

#if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC)

/*
** Use the zone allocator available on apple products unless the
................................................................................
** Use standard C library malloc and free on non-Apple systems.  
** Also used by Apple systems if SQLITE_WITHOUT_ZONEMALLOC is defined.
*/
#define SQLITE_MALLOC(x)    malloc(x)
#define SQLITE_FREE(x)      free(x)
#define SQLITE_REALLOC(x,y) realloc((x),(y))

#if (defined(_MSC_VER) && !defined(SQLITE_WITHOUT_MSIZE)) \
      || (defined(HAVE_MALLOC_H) && defined(HAVE_MALLOC_USABLE_SIZE))
# include <malloc.h>    /* Needed for malloc_usable_size on linux */
#endif
#ifdef HAVE_MALLOC_USABLE_SIZE
# ifndef SQLITE_MALLOCSIZE
#  define SQLITE_MALLOCSIZE(x) malloc_usable_size(x)
# endif
#else

typedef struct unixFile unixFile;
struct unixFile {
  sqlite3_io_methods const *pMethod;  /* Always the first entry */
  sqlite3_vfs *pVfs;                  /* The VFS that created this unixFile */
  unixInodeInfo *pInode;              /* Info about locks on this inode */
  int h;                              /* The file descriptor */
  unsigned char eFileLock;            /* The type of lock held on this fd */
  unsigned char ctrlFlags;            /* Behavioral bits.  UNIXFILE_* flags */
  int lastErrno;                      /* The unix errno from last I/O error */
  void *lockingContext;               /* Locking style specific state */
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
#if SQLITE_ENABLE_LOCKING_STYLE
................................................................................
#else
# define UNIXFILE_DIRSYNC    0x00
#endif
#define UNIXFILE_PSOW        0x10     /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
#define UNIXFILE_DELETE      0x20     /* Delete on close */
#define UNIXFILE_URI         0x40     /* Filename might have query parameters */
#define UNIXFILE_NOLOCK      0x80     /* Do no file locking */


/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*
................................................................................

  { "mkdir",        (sqlite3_syscall_ptr)mkdir,           0 },
#define osMkdir     ((int(*)(const char*,mode_t))aSyscall[18].pCurrent)

  { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
#define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)







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

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable
** system call named zName.
................................................................................
  for(i++; i<ArraySize(aSyscall); i++){
    if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
  }
  return 0;
}

/*
** Retry open() calls that fail due to EINTR














*/
static int robust_open(const char *z, int f, int m){
  int rc;








  do{ rc = osOpen(z,f,m); }while( rc<0 && errno==EINTR );



  return rc;
}

/*
** Helper functions to obtain and relinquish the global mutex. The
** global mutex is used to protect the unixInodeInfo and
** vxworksFileId objects used by this file, all of which may be 
................................................................................
  pInode = pDbFd->pInode;
  pShmNode = pInode->pShmNode;
  if( pShmNode==0 ){
    struct stat sStat;                 /* fstat() info for database file */

    /* Call fstat() to figure out the permissions on the database file. If
    ** a new *-shm file is created, an attempt will be made to create it
    ** with the same permissions. The actual permissions the file is created
    ** with are subject to the current umask setting.
    */
    if( osFstat(pDbFd->h, &sStat) && pInode->bProcessLock==0 ){
      rc = SQLITE_IOERR_FSTAT;
      goto shm_open_err;
    }

    const char *zBasePath = pDbFd->zPath;
................................................................................
        pShmNode->isReadonly = 1;
      }
      pShmNode->h = robust_open(zShmFilename, openFlags, (sStat.st_mode&0777));
      if( pShmNode->h<0 ){
        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
        goto shm_open_err;
      }











  
      /* Check to see if another process is holding the dead-man switch.
      ** If not, truncate the file to zero length. 
      */
      rc = SQLITE_OK;
      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
        if( robust_ftruncate(pShmNode->h, 0) ){
................................................................................
/*
** This function is called by unixOpen() to determine the unix permissions
** to create new files with. If no error occurs, then SQLITE_OK is returned
** and a value suitable for passing as the third argument to open(2) is
** written to *pMode. If an IO error occurs, an SQLite error code is 
** returned and the value of *pMode is not modified.
**
** If the file being opened is a temporary file, it is always created with
** the octal permissions 0600 (read/writable by owner only). If the file
** is a database or master journal file, it is created with the permissions 
** mask SQLITE_DEFAULT_FILE_PERMISSIONS.
**
** Finally, if the file being opened is a WAL or regular journal file, then 
** this function queries the file-system for the permissions on the 
** corresponding database file and sets *pMode to this value. Whenever 
** possible, WAL and journal files are created using the same permissions 
** as the associated database file.
**
** If the SQLITE_ENABLE_8_3_NAMES option is enabled, then the
** original filename is unavailable.  But 8_3_NAMES is only used for
................................................................................
  const char *zPath,              /* Path of file (possibly) being created */
  int flags,                      /* Flags passed as 4th argument to xOpen() */
  mode_t *pMode,                  /* OUT: Permissions to open file with */
  uid_t *pUid,                    /* OUT: uid to set on the file */
  gid_t *pGid                     /* OUT: gid to set on the file */
){
  int rc = SQLITE_OK;             /* Return Code */
  *pMode = SQLITE_DEFAULT_FILE_PERMISSIONS;


  if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
    char zDb[MAX_PATHNAME+1];     /* Database file path */
    int nDb;                      /* Number of valid bytes in zDb */
    struct stat sStat;            /* Output of stat() on database file */

    /* zPath is a path to a WAL or journal file. The following block derives
    ** the path to the associated database file from zPath. This block handles
................................................................................

#if SQLITE_ENABLE_DATA_PROTECTION
  p->protFlags = (flags & SQLITE_OPEN_FILEPROTECTION_MASK);
#endif
    
  if( fd<0 ){
    mode_t openMode;              /* Permissions to create file with */
    uid_t uid;
    gid_t gid;
    rc = findCreateFileMode(zName, flags, &openMode, &uid, &gid);
    if( rc!=SQLITE_OK ){
      assert( !p->pUnused );
      assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );
      return rc;
    }
    fd = robust_open(zName, openFlags, openMode);
................................................................................
      if( euid==0 && (euid!=uid || getegid()!=gid) ){
        if( fchown(fd, uid, gid) ){
          rc = SQLITE_CANTOPEN_BKPT;
          goto open_finished;
        }
      }
    }











  }
  assert( fd>=0 );
  if( pOutFlags ){
    *pOutFlags = flags;
  }

  if( p->pUnused ){
................................................................................
  }else{
    pUnused = sqlite3_malloc(sizeof(*pUnused));
    if( !pUnused ){
      return SQLITE_NOMEM;
    }
  }
  if( fd<0 ){
    fd = robust_open(path, openFlags, SQLITE_DEFAULT_FILE_PERMISSIONS);
    terrno = errno;
    if( fd<0 && errno==ENOENT && islockfile ){
      if( proxyCreateLockPath(path) == SQLITE_OK ){
        fd = robust_open(path, openFlags, SQLITE_DEFAULT_FILE_PERMISSIONS);
      }
    }
  }
  if( fd<0 ){
    openFlags = O_RDONLY;
    fd = robust_open(path, openFlags, SQLITE_DEFAULT_FILE_PERMISSIONS);
    terrno = errno;
  }
  if( fd<0 ){
    sqlite3_free(pUnused);
    if( islockfile ){
      return SQLITE_BUSY;
    }
................................................................................
  /* read the conch content */
  readLen = osPread(conchFile->h, buf, PROXY_MAXCONCHLEN, 0);
  if( readLen<PROXY_PATHINDEX ){
    sqlite3_snprintf(sizeof(errmsg),errmsg,"read error (len %d)",(int)readLen);
    goto end_breaklock;
  }
  /* write it out to the temporary break file */
  fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL),
                   SQLITE_DEFAULT_FILE_PERMISSIONS);
  if( fd<0 ){
    sqlite3_snprintf(sizeof(errmsg), errmsg, "create failed (%d)", errno);
    goto end_breaklock;
  }
  if( osPwrite(fd, buf, readLen, 0) != (ssize_t)readLen ){
    sqlite3_snprintf(sizeof(errmsg), errmsg, "write failed (%d)", errno);
    goto end_breaklock;
................................................................................
            return SQLITE_IOERR_CLOSE;
          }
#else
          robust_close(pFile, pFile->h, __LINE__);
#endif
        }
        pFile->h = -1;
        fd = robust_open(pCtx->dbPath, pFile->openFlags,
                      SQLITE_DEFAULT_FILE_PERMISSIONS);
        OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));
        if( fd>=0 ){
          pFile->h = fd;
        }else{
          rc=SQLITE_CANTOPEN_BKPT; /* SQLITE_BUSY? proxyTakeConch called
           during locking */
        }
................................................................................
    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)==20 );

  /* 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; 
}

typedef struct unixFile unixFile;
struct unixFile {
  sqlite3_io_methods const *pMethod;  /* Always the first entry */
  sqlite3_vfs *pVfs;                  /* The VFS that created this unixFile */
  unixInodeInfo *pInode;              /* Info about locks on this inode */
  int h;                              /* The file descriptor */
  unsigned char eFileLock;            /* The type of lock held on this fd */
  unsigned short int ctrlFlags;       /* Behavioral bits.  UNIXFILE_* flags */
  int lastErrno;                      /* The unix errno from last I/O error */
  void *lockingContext;               /* Locking style specific state */
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
#if SQLITE_ENABLE_LOCKING_STYLE
................................................................................
#else
# define UNIXFILE_DIRSYNC    0x00
#endif
#define UNIXFILE_PSOW        0x10     /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
#define UNIXFILE_DELETE      0x20     /* Delete on close */
#define UNIXFILE_URI         0x40     /* Filename might have query parameters */
#define UNIXFILE_NOLOCK      0x80     /* Do no file locking */
#define UNIXFILE_CHOWN      0x100     /* File ownership was changed */

/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*
................................................................................

  { "mkdir",        (sqlite3_syscall_ptr)mkdir,           0 },
#define osMkdir     ((int(*)(const char*,mode_t))aSyscall[18].pCurrent)

  { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
#define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)

  { "fchown",       (sqlite3_syscall_ptr)fchown,          0 },
#define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)

  { "umask",        (sqlite3_syscall_ptr)umask,           0 },
#define osUmask     ((mode_t(*)(mode_t))aSyscall[21].pCurrent)

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

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable
** system call named zName.
................................................................................
  for(i++; i<ArraySize(aSyscall); i++){
    if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
  }
  return 0;
}

/*
** Invoke open().  Do so multiple times, until it either succeeds or
** files for some reason other than EINTR.
**
** If the file creation mode "m" is 0 then set it to the default for
** SQLite.  The default is SQLITE_DEFAULT_FILE_PERMISSIONS (normally
** 0644) as modified by the system umask.  If m is not 0, then
** make the file creation mode be exactly m ignoring the umask.
**
** The m parameter will be non-zero only when creating -wal, -journal,
** and -shm files.  We want those files to have *exactly* the same
** permissions as their original database, unadulterated by the umask.
** In that way, if a database file is -rw-rw-rw or -rw-rw-r-, and a
** transaction crashes and leaves behind hot journals, then any
** process that is able to write to the database will also be able to
** recover the hot journals.
*/
static int robust_open(const char *z, int f, mode_t m){
  int rc;
  mode_t m2;
  mode_t origM = 0;
  if( m==0 ){
    m2 = SQLITE_DEFAULT_FILE_PERMISSIONS;
  }else{
    m2 = m;
    origM = osUmask(0);
  }
  do{ rc = osOpen(z,f,m2); }while( rc<0 && errno==EINTR );
  if( m ){
    osUmask(origM);
  }
  return rc;
}

/*
** Helper functions to obtain and relinquish the global mutex. The
** global mutex is used to protect the unixInodeInfo and
** vxworksFileId objects used by this file, all of which may be 
................................................................................
  pInode = pDbFd->pInode;
  pShmNode = pInode->pShmNode;
  if( pShmNode==0 ){
    struct stat sStat;                 /* fstat() info for database file */

    /* Call fstat() to figure out the permissions on the database file. If
    ** a new *-shm file is created, an attempt will be made to create it
    ** with the same permissions.

    */
    if( osFstat(pDbFd->h, &sStat) && pInode->bProcessLock==0 ){
      rc = SQLITE_IOERR_FSTAT;
      goto shm_open_err;
    }

    const char *zBasePath = pDbFd->zPath;
................................................................................
        pShmNode->isReadonly = 1;
      }
      pShmNode->h = robust_open(zShmFilename, openFlags, (sStat.st_mode&0777));
      if( pShmNode->h<0 ){
        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
        goto shm_open_err;
      }

      /* If this process is running as root, make sure that the SHM file
      ** is owned by the same user that owns the original database.  Otherwise,
      ** the original owner will not be able to connect. If this process is
      ** not root, the following fchown() will fail, but we don't care.  The
      ** if(){..} and the UNIXFILE_CHOWN flag are purely to silence compiler
      ** warnings.
      */
      if( osFchown(pShmNode->h, sStat.st_uid, sStat.st_gid)==0 ){
        pDbFd->ctrlFlags |= UNIXFILE_CHOWN;
      }
  
      /* Check to see if another process is holding the dead-man switch.
      ** If not, truncate the file to zero length. 
      */
      rc = SQLITE_OK;
      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
        if( robust_ftruncate(pShmNode->h, 0) ){
................................................................................
/*
** This function is called by unixOpen() to determine the unix permissions
** to create new files with. If no error occurs, then SQLITE_OK is returned
** and a value suitable for passing as the third argument to open(2) is
** written to *pMode. If an IO error occurs, an SQLite error code is 
** returned and the value of *pMode is not modified.
**
** In most cases cases, this routine sets *pMode to 0, which will become
** an indication to robust_open() to create the file using

** SQLITE_DEFAULT_FILE_PERMISSIONS adjusted by the umask.

** But if the file being opened is a WAL or regular journal file, then 
** this function queries the file-system for the permissions on the 
** corresponding database file and sets *pMode to this value. Whenever 
** possible, WAL and journal files are created using the same permissions 
** as the associated database file.
**
** If the SQLITE_ENABLE_8_3_NAMES option is enabled, then the
** original filename is unavailable.  But 8_3_NAMES is only used for
................................................................................
  const char *zPath,              /* Path of file (possibly) being created */
  int flags,                      /* Flags passed as 4th argument to xOpen() */
  mode_t *pMode,                  /* OUT: Permissions to open file with */
  uid_t *pUid,                    /* OUT: uid to set on the file */
  gid_t *pGid                     /* OUT: gid to set on the file */
){
  int rc = SQLITE_OK;             /* Return Code */
  *pMode = 0;
  *pUid = 0;
  *pGid = 0;
  if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
    char zDb[MAX_PATHNAME+1];     /* Database file path */
    int nDb;                      /* Number of valid bytes in zDb */
    struct stat sStat;            /* Output of stat() on database file */

    /* zPath is a path to a WAL or journal file. The following block derives
    ** the path to the associated database file from zPath. This block handles
................................................................................

#if SQLITE_ENABLE_DATA_PROTECTION
  p->protFlags = (flags & SQLITE_OPEN_FILEPROTECTION_MASK);
#endif
    
  if( fd<0 ){
    mode_t openMode;              /* Permissions to create file with */
    uid_t uid;                    /* Userid for the file */
    gid_t gid;                    /* Groupid for the file */
    rc = findCreateFileMode(zName, flags, &openMode, &uid, &gid);
    if( rc!=SQLITE_OK ){
      assert( !p->pUnused );
      assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );
      return rc;
    }
    fd = robust_open(zName, openFlags, openMode);
................................................................................
      if( euid==0 && (euid!=uid || getegid()!=gid) ){
        if( fchown(fd, uid, gid) ){
          rc = SQLITE_CANTOPEN_BKPT;
          goto open_finished;
        }
      }
    }

    /* If this process is running as root and if creating a new rollback
    ** journal or WAL file, set the ownership of the journal or WAL to be
    ** the same as the original database.  If we are not running as root,
    ** then the fchown() call will fail, but that's ok.  The "if(){}" and
    ** the setting of the UNIXFILE_CHOWN flag are purely to silence compiler
    ** warnings from gcc.
    */
    if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
      if( osFchown(fd, uid, gid)==0 ){ p->ctrlFlags |= UNIXFILE_CHOWN; }
    }
  }
  assert( fd>=0 );
  if( pOutFlags ){
    *pOutFlags = flags;
  }

  if( p->pUnused ){
................................................................................
  }else{
    pUnused = sqlite3_malloc(sizeof(*pUnused));
    if( !pUnused ){
      return SQLITE_NOMEM;
    }
  }
  if( fd<0 ){
    fd = robust_open(path, openFlags, 0);
    terrno = errno;
    if( fd<0 && errno==ENOENT && islockfile ){
      if( proxyCreateLockPath(path) == SQLITE_OK ){
        fd = robust_open(path, openFlags, 0);
      }
    }
  }
  if( fd<0 ){
    openFlags = O_RDONLY;
    fd = robust_open(path, openFlags, 0);
    terrno = errno;
  }
  if( fd<0 ){
    sqlite3_free(pUnused);
    if( islockfile ){
      return SQLITE_BUSY;
    }
................................................................................
  /* read the conch content */
  readLen = osPread(conchFile->h, buf, PROXY_MAXCONCHLEN, 0);
  if( readLen<PROXY_PATHINDEX ){
    sqlite3_snprintf(sizeof(errmsg),errmsg,"read error (len %d)",(int)readLen);
    goto end_breaklock;
  }
  /* write it out to the temporary break file */
  fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL), 0);

  if( fd<0 ){
    sqlite3_snprintf(sizeof(errmsg), errmsg, "create failed (%d)", errno);
    goto end_breaklock;
  }
  if( osPwrite(fd, buf, readLen, 0) != (ssize_t)readLen ){
    sqlite3_snprintf(sizeof(errmsg), errmsg, "write failed (%d)", errno);
    goto end_breaklock;
................................................................................
            return SQLITE_IOERR_CLOSE;
          }
#else
          robust_close(pFile, pFile->h, __LINE__);
#endif
        }
        pFile->h = -1;
        fd = robust_open(pCtx->dbPath, pFile->openFlags, 0);

        OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));
        if( fd>=0 ){
          pFile->h = fd;
        }else{
          rc=SQLITE_CANTOPEN_BKPT; /* SQLITE_BUSY? proxyTakeConch called
           during locking */
        }
................................................................................
    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)==22 );

  /* 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; 
}

      rc = sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags,
                           pPager->pageSize, (u8*)pPager->pTmpSpace);
      pPager->pWal = 0;
    }
  }
  return rc;
}















#ifdef SQLITE_HAS_CODEC
/*
** This function is called by the wal module when writing page content
** into the log file.
**
** This function returns a pointer to a buffer containing the encrypted

      rc = sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags,
                           pPager->pageSize, (u8*)pPager->pTmpSpace);
      pPager->pWal = 0;
    }
  }
  return rc;
}

#ifdef SQLITE_ENABLE_ZIPVFS
/*
** A read-lock must be held on the pager when this function is called. If
** the pager is in WAL mode and the WAL file currently contains one or more
** frames, return the size in bytes of the page images stored within the
** WAL frames. Otherwise, if this is not a WAL database or the WAL file
** is empty, return 0.
*/
int sqlite3PagerWalFramesize(Pager *pPager){
  assert( pPager->eState==PAGER_READER );
  return sqlite3WalFramesize(pPager->pWal);
}
#endif

#ifdef SQLITE_HAS_CODEC
/*
** This function is called by the wal module when writing page content
** into the log file.
**
** This function returns a pointer to a buffer containing the encrypted

int sqlite3PagerSharedLock(Pager *pPager);

int sqlite3PagerCheckpoint(Pager *pPager, int, int*, int*);
int sqlite3PagerWalSupported(Pager *pPager);
int sqlite3PagerWalCallback(Pager *pPager);
int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
int sqlite3PagerCloseWal(Pager *pPager);




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

int sqlite3PagerSharedLock(Pager *pPager);

int sqlite3PagerCheckpoint(Pager *pPager, int, int*, int*);
int sqlite3PagerWalSupported(Pager *pPager);
int sqlite3PagerWalCallback(Pager *pPager);
int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
int sqlite3PagerCloseWal(Pager *pPager);
#ifdef SQLITE_ENABLE_ZIPVFS
  int sqlite3PagerWalFramesize(Pager *pPager);
#endif

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

  int minusFlag       /* True if a '-' sign preceded <value> */
){
  char *zLeft = 0;       /* Nul-terminated UTF-8 string <id> */
  char *zRight = 0;      /* Nul-terminated UTF-8 string <value>, or NULL */
  const char *zDb = 0;   /* The database name */
  Token *pId;            /* Pointer to <id> token */
  int iDb;               /* Database index for <database> */


  sqlite3 *db = pParse->db;
  Db *pDb;

  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db);

  if( v==0 ) return;
  sqlite3VdbeRunOnlyOnce(v);
  pParse->nMem = 2;

  /* Interpret the [database.] part of the pragma statement. iDb is the
  ** index of the database this pragma is being applied to in db.aDb[]. */
  iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
................................................................................
  }

  assert( pId2 );
  zDb = pId2->n>0 ? pDb->zName : 0;
  if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
    goto pragma_out;
  }




























 
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
  /*
  **  PRAGMA [database.]default_cache_size
  **  PRAGMA [database.]default_cache_size=N
  **
  ** The first form reports the current persistent setting for the
................................................................................
      db->nextAutovac = (u8)eAuto;
      if( ALWAYS(eAuto>=0) ){
        /* Call SetAutoVacuum() to set initialize the internal auto and
        ** incr-vacuum flags. This is required in case this connection
        ** creates the database file. It is important that it is created
        ** as an auto-vacuum capable db.
        */
        int rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
        if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
          /* When setting the auto_vacuum mode to either "full" or 
          ** "incremental", write the value of meta[6] in the database
          ** file. Before writing to meta[6], check that meta[3] indicates
          ** that this really is an auto-vacuum capable database.
          */
          static const VdbeOpList setMeta6[] = {
................................................................................
            "temp_store_directory", SQLITE_STATIC);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
      }
    }else{
#ifndef SQLITE_OMIT_WSD
      if( zRight[0] ){
        int rc;
        int res;
        rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
        if( rc!=SQLITE_OK || res==0 ){
          sqlite3ErrorMsg(pParse, "not a writable directory");
          goto pragma_out;
        }
      }

  int minusFlag       /* True if a '-' sign preceded <value> */
){
  char *zLeft = 0;       /* Nul-terminated UTF-8 string <id> */
  char *zRight = 0;      /* Nul-terminated UTF-8 string <value>, or NULL */
  const char *zDb = 0;   /* The database name */
  Token *pId;            /* Pointer to <id> token */
  int iDb;               /* Database index for <database> */
  char *aFcntl[4];       /* Argument to SQLITE_FCNTL_PRAGMA */
  int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */
  sqlite3 *db = pParse->db;    /* The database connection */

  Db *pDb;                     /* The specific database being pragmaed */
  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db);  /* Prepared statement */

  if( v==0 ) return;
  sqlite3VdbeRunOnlyOnce(v);
  pParse->nMem = 2;

  /* Interpret the [database.] part of the pragma statement. iDb is the
  ** index of the database this pragma is being applied to in db.aDb[]. */
  iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
................................................................................
  }

  assert( pId2 );
  zDb = pId2->n>0 ? pDb->zName : 0;
  if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
    goto pragma_out;
  }

  /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
  ** connection.  If it returns SQLITE_OK, then assume that the VFS
  ** handled the pragma and generate a no-op prepared statement.
  */
  aFcntl[0] = 0;
  aFcntl[1] = zLeft;
  aFcntl[2] = zRight;
  aFcntl[3] = 0;
  rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_PRAGMA, (void*)aFcntl);
  if( rc==SQLITE_OK ){
    if( aFcntl[0] ){
      int mem = ++pParse->nMem;
      sqlite3VdbeAddOp4(v, OP_String8, 0, mem, 0, aFcntl[0], 0);
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "result", SQLITE_STATIC);
      sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
      sqlite3_free(aFcntl[0]);
    }
  }else if( rc!=SQLITE_NOTFOUND ){
    if( aFcntl[0] ){
      sqlite3ErrorMsg(pParse, "%s", aFcntl[0]);
      sqlite3_free(aFcntl[0]);
    }
    pParse->nErr++;
    pParse->rc = rc;
  }else
                            
 
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
  /*
  **  PRAGMA [database.]default_cache_size
  **  PRAGMA [database.]default_cache_size=N
  **
  ** The first form reports the current persistent setting for the
................................................................................
      db->nextAutovac = (u8)eAuto;
      if( ALWAYS(eAuto>=0) ){
        /* Call SetAutoVacuum() to set initialize the internal auto and
        ** incr-vacuum flags. This is required in case this connection
        ** creates the database file. It is important that it is created
        ** as an auto-vacuum capable db.
        */
        rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
        if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
          /* When setting the auto_vacuum mode to either "full" or 
          ** "incremental", write the value of meta[6] in the database
          ** file. Before writing to meta[6], check that meta[3] indicates
          ** that this really is an auto-vacuum capable database.
          */
          static const VdbeOpList setMeta6[] = {
................................................................................
            "temp_store_directory", SQLITE_STATIC);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
      }
    }else{
#ifndef SQLITE_OMIT_WSD
      if( zRight[0] ){

        int res;
        rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
        if( rc!=SQLITE_OK || res==0 ){
          sqlite3ErrorMsg(pParse, "not a writable directory");
          goto pragma_out;
        }
      }

  int cnt;                    /* Index added to make the name unique */
  Column *aCol, *pCol;        /* For looping over result columns */
  int nCol;                   /* Number of columns in the result set */
  Expr *p;                    /* Expression for a single result column */
  char *zName;                /* Column name */
  int nName;                  /* Size of name in zName[] */

  *pnCol = nCol = pEList->nExpr;
  aCol = *paCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
  if( aCol==0 ) return SQLITE_NOMEM;
  for(i=0, pCol=aCol; i<nCol; i++, pCol++){
    /* Get an appropriate name for the column
    */
    p = pEList->a[i].pExpr;
    assert( p->pRight==0 || ExprHasProperty(p->pRight, EP_IntValue)

  int cnt;                    /* Index added to make the name unique */
  Column *aCol, *pCol;        /* For looping over result columns */
  int nCol;                   /* Number of columns in the result set */
  Expr *p;                    /* Expression for a single result column */
  char *zName;                /* Column name */
  int nName;                  /* Size of name in zName[] */

  *pnCol = nCol = pEList ? pEList->nExpr : 0;
  aCol = *paCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
  if( aCol==0 ) return SQLITE_NOMEM;
  for(i=0, pCol=aCol; i<nCol; i++, pCol++){
    /* Get an appropriate name for the column
    */
    p = pEList->a[i].pExpr;
    assert( p->pRight==0 || ExprHasProperty(p->pRight, EP_IntValue)

#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))


/*
** CAPI3REF: Flags For File Open Operations
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
................................................................................
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
** opcode causes the xFileControl method to write the current state of
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
** into an integer that the pArg argument points to. This capability
** is used during testing and only needs to be supported when SQLITE_TEST
** is defined.
**

** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
** layer a hint of how large the database file will grow to be during the
** current transaction.  This hint is not guaranteed to be accurate but it
** is often close.  The underlying VFS might choose to preallocate database
** file space based on this hint in order to help writes to the database
** file run faster.
**

** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
** extends and truncates the database file in chunks of a size specified
** by the user. The fourth argument to [sqlite3_file_control()] should 
** point to an integer (type int) containing the new chunk-size to use
** for the nominated database. Allocating database file space in large
** chunks (say 1MB at a time), may reduce file-system fragmentation and
** improve performance on some systems.
**

** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
** to the [sqlite3_file] object associated with a particular database
** connection.  See the [sqlite3_file_control()] documentation for
** additional information.
**

** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
** SQLite and sent to all VFSes in place of a call to the xSync method
** when the database connection has [PRAGMA synchronous] set to OFF.)^
** Some specialized VFSes need this signal in order to operate correctly
** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
** VFSes do not need this signal and should silently ignore this opcode.
** Applications should not call [sqlite3_file_control()] with this
** opcode as doing so may disrupt the operation of the specialized VFSes
** that do require it.  
**

** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
** retry counts and intervals for certain disk I/O operations for the
** windows [VFS] in order to provide robustness in the presence of
** anti-virus programs.  By default, the windows VFS will retry file read,
** file write, and file delete operations up to 10 times, with a delay
** of 25 milliseconds before the first retry and with the delay increasing
** by an additional 25 milliseconds with each subsequent retry.  This
................................................................................
** within the same process.  The argument is a pointer to an array of two
** integers where the first integer i the new retry count and the second
** integer is the delay.  If either integer is negative, then the setting
** is not changed but instead the prior value of that setting is written
** into the array entry, allowing the current retry settings to be
** interrogated.  The zDbName parameter is ignored.
**

** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
** persistent [WAL | Write AHead Log] setting.  By default, the auxiliary
** write ahead log and shared memory files used for transaction control
** are automatically deleted when the latest connection to the database
** closes.  Setting persistent WAL mode causes those files to persist after
** close.  Persisting the files is useful when other processes that do not
** have write permission on the directory containing the database file want
................................................................................
** to read the database file, as the WAL and shared memory files must exist
** in order for the database to be readable.  The fourth parameter to
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
** WAL mode.  If the integer is -1, then it is overwritten with the current
** WAL persistence setting.
**

** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
** xDeviceCharacteristics methods. The fourth parameter to
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
** mode.  If the integer is -1, then it is overwritten with the current
** zero-damage mode setting.
**

** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
** a write transaction to indicate that, unless it is rolled back for some
** reason, the entire database file will be overwritten by the current 
** transaction. This is used by VACUUM operations.
**

** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
** final bottom-level VFS are written into memory obtained from 
** [sqlite3_malloc()] and the result is stored in the char* variable
** that the fourth parameter of [sqlite3_file_control()] points to.
** The caller is responsible for freeing the memory when done.  As with
** all file-control actions, there is no guarantee that this will actually
** do anything.  Callers should initialize the char* variable to a NULL
** pointer in case this file-control is not implemented.  This file-control
** is intended for diagnostic use only.
























*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
................................................................................
#define SQLITE_FCNTL_FILE_POINTER            7
#define SQLITE_FCNTL_SYNC_OMITTED            8
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13


/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only
................................................................................
  void *pNotifyArg                            /* Argument to pass to xNotify */
);


/*
** CAPI3REF: String Comparison
**
** ^The [sqlite3_strnicmp()] API allows applications and extensions to
** compare the contents of two buffers containing UTF-8 strings in a
** case-independent fashion, using the same definition of case independence 
** that SQLite uses internally when comparing identifiers.
*/

int sqlite3_strnicmp(const char *, const char *, int);

/*
** CAPI3REF: Error Logging Interface
**
** ^The [sqlite3_log()] interface writes a message into the error log
** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].

#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))

/*
** CAPI3REF: Flags For File Open Operations
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
................................................................................
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
** opcode causes the xFileControl method to write the current state of
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
** into an integer that the pArg argument points to. This capability
** is used during testing and only needs to be supported when SQLITE_TEST
** is defined.
** <ul>
** <li>[[SQLITE_FCNTL_SIZE_HINT]]
** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
** layer a hint of how large the database file will grow to be during the
** current transaction.  This hint is not guaranteed to be accurate but it
** is often close.  The underlying VFS might choose to preallocate database
** file space based on this hint in order to help writes to the database
** file run faster.
**
** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
** extends and truncates the database file in chunks of a size specified
** by the user. The fourth argument to [sqlite3_file_control()] should 
** point to an integer (type int) containing the new chunk-size to use
** for the nominated database. Allocating database file space in large
** chunks (say 1MB at a time), may reduce file-system fragmentation and
** improve performance on some systems.
**
** <li>[[SQLITE_FCNTL_FILE_POINTER]]
** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
** to the [sqlite3_file] object associated with a particular database
** connection.  See the [sqlite3_file_control()] documentation for
** additional information.
**
** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
** SQLite and sent to all VFSes in place of a call to the xSync method
** when the database connection has [PRAGMA synchronous] set to OFF.)^
** Some specialized VFSes need this signal in order to operate correctly
** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
** VFSes do not need this signal and should silently ignore this opcode.
** Applications should not call [sqlite3_file_control()] with this
** opcode as doing so may disrupt the operation of the specialized VFSes
** that do require it.  
**
** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
** retry counts and intervals for certain disk I/O operations for the
** windows [VFS] in order to provide robustness in the presence of
** anti-virus programs.  By default, the windows VFS will retry file read,
** file write, and file delete operations up to 10 times, with a delay
** of 25 milliseconds before the first retry and with the delay increasing
** by an additional 25 milliseconds with each subsequent retry.  This
................................................................................
** within the same process.  The argument is a pointer to an array of two
** integers where the first integer i the new retry count and the second
** integer is the delay.  If either integer is negative, then the setting
** is not changed but instead the prior value of that setting is written
** into the array entry, allowing the current retry settings to be
** interrogated.  The zDbName parameter is ignored.
**
** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
** persistent [WAL | Write AHead Log] setting.  By default, the auxiliary
** write ahead log and shared memory files used for transaction control
** are automatically deleted when the latest connection to the database
** closes.  Setting persistent WAL mode causes those files to persist after
** close.  Persisting the files is useful when other processes that do not
** have write permission on the directory containing the database file want
................................................................................
** to read the database file, as the WAL and shared memory files must exist
** in order for the database to be readable.  The fourth parameter to
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
** WAL mode.  If the integer is -1, then it is overwritten with the current
** WAL persistence setting.
**
** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
** xDeviceCharacteristics methods. The fourth parameter to
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
** mode.  If the integer is -1, then it is overwritten with the current
** zero-damage mode setting.
**
** <li>[[SQLITE_FCNTL_OVERWRITE]]
** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
** a write transaction to indicate that, unless it is rolled back for some
** reason, the entire database file will be overwritten by the current 
** transaction. This is used by VACUUM operations.
**
** <li>[[SQLITE_FCNTL_VFSNAME]]
** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
** final bottom-level VFS are written into memory obtained from 
** [sqlite3_malloc()] and the result is stored in the char* variable
** that the fourth parameter of [sqlite3_file_control()] points to.
** The caller is responsible for freeing the memory when done.  As with
** all file-control actions, there is no guarantee that this will actually
** do anything.  Callers should initialize the char* variable to a NULL
** pointer in case this file-control is not implemented.  This file-control
** is intended for diagnostic use only.
**
** <li>[[SQLITE_FCNTL_PRAGMA]]
** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 
** file control is sent to the open [sqlite3_file] object corresponding
** to the database file to which the pragma statement refers. ^The argument
** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
** pointers to strings (char**) in which the second element of the array
** is the name of the pragma and the third element is the argument to the
** pragma or NULL if the pragma has no argument.  ^The handler for an
** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
** of the char** argument point to a string obtained from [sqlite3_mprintf()]
** or the equivalent and that string will become the result of the pragma or
** the error message if the pragma fails. ^If the
** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 
** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
** file control returns [SQLITE_OK], then the parser assumes that the
** VFS has handled the PRAGMA itself and the parser generates a no-op
** prepared statement.  ^If the [SQLITE_FCNTL_PRAGMA] file control returns
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
** that the VFS encountered an error while handling the [PRAGMA] and the
** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
** file control occurs at the beginning of pragma statement analysis and so
** it is able to override built-in [PRAGMA] statements.
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
................................................................................
#define SQLITE_FCNTL_FILE_POINTER            7
#define SQLITE_FCNTL_SYNC_OMITTED            8
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
#define SQLITE_FCNTL_PRAGMA                 14

/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only
................................................................................
  void *pNotifyArg                            /* Argument to pass to xNotify */
);


/*
** CAPI3REF: String Comparison
**
** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
** and extensions to compare the contents of two buffers containing UTF-8
** strings in a case-independent fashion, using the same definition of "case
** independence" that SQLite uses internally when comparing identifiers.
*/
int sqlite3_stricmp(const char *, const char *);
int sqlite3_strnicmp(const char *, const char *, int);

/*
** CAPI3REF: Error Logging Interface
**
** ^The [sqlite3_log()] interface writes a message into the error log
** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].

# define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
# define sqlite3Tolower(x)   tolower((unsigned char)(x))
#endif

/*
** Internal function prototypes
*/
int sqlite3StrICmp(const char *, const char *);
int sqlite3Strlen30(const char*);
#define sqlite3StrNICmp sqlite3_strnicmp

int sqlite3MallocInit(void);
void sqlite3MallocEnd(void);
void *sqlite3Malloc(int);
void *sqlite3MallocZero(int);
................................................................................
int sqlite3ExprListCompare(ExprList*, ExprList*);
void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3PrngSaveState(void);
void sqlite3PrngRestoreState(void);
void sqlite3PrngResetState(void);
void sqlite3RollbackAll(sqlite3*);
void sqlite3CodeVerifySchema(Parse*, int);
void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
void sqlite3BeginTransaction(Parse*, int);
void sqlite3CommitTransaction(Parse*);
void sqlite3RollbackTransaction(Parse*);
void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);

# define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
# define sqlite3Tolower(x)   tolower((unsigned char)(x))
#endif

/*
** Internal function prototypes
*/
#define sqlite3StrICmp sqlite3_stricmp
int sqlite3Strlen30(const char*);
#define sqlite3StrNICmp sqlite3_strnicmp

int sqlite3MallocInit(void);
void sqlite3MallocEnd(void);
void *sqlite3Malloc(int);
void *sqlite3MallocZero(int);
................................................................................
int sqlite3ExprListCompare(ExprList*, ExprList*);
void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3PrngSaveState(void);
void sqlite3PrngRestoreState(void);
void sqlite3PrngResetState(void);
void sqlite3RollbackAll(sqlite3*,int);
void sqlite3CodeVerifySchema(Parse*, int);
void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
void sqlite3BeginTransaction(Parse*, int);
void sqlite3CommitTransaction(Parse*);
void sqlite3RollbackTransaction(Parse*);
void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);

**
**    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.
**
*************************************************************************
**
** Code for demonstartion virtual table that generates variations
** on an input word at increasing edit distances from the original.
**
** A fuzzer virtual table is created like this:
**
**     CREATE VIRTUAL TABLE temp.f USING fuzzer;
**
** The name of the new virtual table in the example above is "f".
** Note that all fuzzer virtual tables must be TEMP tables.  The
** "temp." prefix in front of the table name is required when the
** table is being created.  The "temp." prefix can be omitted when
** using the table as long as the name is unambiguous.
**
** Before being used, the fuzzer needs to be programmed by giving it
** character transformations and a cost associated with each transformation.
** Examples:

**
**    INSERT INTO f(cFrom,cTo,Cost) VALUES('','a',100);







**







** The above statement says that the cost of inserting a letter 'a' is
** 100.  (All costs are integers.  We recommend that costs be scaled so
** that the average cost is around 100.)
**
**    INSERT INTO f(cFrom,cTo,Cost) VALUES('b','',87);
**
** The above statement says that the cost of deleting a single letter
** 'b' is 87.
**
**    INSERT INTO f(cFrom,cTo,Cost) VALUES('o','oe',38);
**    INSERT INTO f(cFrom,cTo,Cost) VALUES('oe','o',40);
**
** This third example says that the cost of transforming the single

** letter "o" into the two-letter sequence "oe" is 38 and that the
** cost of transforming "oe" back into "o" is 40.
**
** After all the transformation costs have been set, the fuzzer table










** can be queried as follows:
**
**    SELECT word, distance FROM f
**     WHERE word MATCH 'abcdefg'
**       AND distance<200;
**
** This first query outputs the string "abcdefg" and all strings that
** can be derived from that string by appling the specified transformations.
** The strings are output together with their total transformation cost
** (called "distance") and appear in order of increasing cost.  No string
** is output more than once.  If there are multiple ways to transform the
** target string into the output string then the lowest cost transform is
** the one that is returned.  In the example, the search is limited to 
** strings with a total distance of less than 200.



**
** It is important to put some kind of a limit on the fuzzer output.  This
** can be either in the form of a LIMIT clause at the end of the query,
** or better, a "distance<NNN" constraint where NNN is some number.  The
** running time and memory requirement is exponential in the value of NNN 
** so you want to make sure that NNN is not too big.  A value of NNN that
** is about twice the average transformation cost seems to give good results.
................................................................................
**    WHERE f.word MATCH $prefix
**      AND f.distance<=200
**      AND vocabulary.w BETWEEN f.word AND (f.word || x'F7BFBFBF')
**    LIMIT 50
**
** This last query will show up to 50 words out of the vocabulary that
** match or nearly match the $prefix.





























*/






#include "sqlite3.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
typedef struct fuzzer_vtab fuzzer_vtab;
typedef struct fuzzer_cursor fuzzer_cursor;
typedef struct fuzzer_rule fuzzer_rule;
typedef struct fuzzer_seen fuzzer_seen;
typedef struct fuzzer_stem fuzzer_stem;

/*


** Type of the "cost" of an edit operation.  Might be changed to
** "float" or "double" or "sqlite3_int64" in the future.




*/
typedef int fuzzer_cost;












/*
** Each transformation rule is stored as an instance of this object.
** All rules are kept on a linked list sorted by rCost.
*/
struct fuzzer_rule {
  fuzzer_rule *pNext;        /* Next rule in order of increasing rCost */

  fuzzer_cost rCost;         /* Cost of this transformation */
  int nFrom, nTo;            /* Length of the zFrom and zTo strings */
  char *zFrom;               /* Transform from */

  char zTo[4];               /* Transform to (extra space appended) */
};

/*
** A stem object is used to generate variants.  It is also used to record
** previously generated outputs.
**
** Every stem is added to a hash table as it is output.  Generation of
................................................................................
**
** Active stems (those that might generate new outputs) are kepts on a linked
** list sorted by increasing cost.  The cost is the sum of rBaseCost and
** pRule->rCost.
*/
struct fuzzer_stem {
  char *zBasis;              /* Word being fuzzed */
  int nBasis;                /* Length of the zBasis string */
  const fuzzer_rule *pRule;  /* Current rule to apply */

  int n;                     /* Apply pRule at this character offset */
  fuzzer_cost rBaseCost;     /* Base cost of getting to zBasis */
  fuzzer_cost rCostX;        /* Precomputed rBaseCost + pRule->rCost */
  fuzzer_stem *pNext;        /* Next stem in rCost order */
  fuzzer_stem *pHash;        /* Next stem with same hash on zBasis */
};

/* 
** A fuzzer virtual-table object 
*/
struct fuzzer_vtab {
  sqlite3_vtab base;         /* Base class - must be first */
  char *zClassName;          /* Name of this class.  Default: "fuzzer" */
  fuzzer_rule *pRule;        /* All active rules in this fuzzer */
  fuzzer_rule *pNewRule;     /* New rules to add when last cursor expires */
  int nCursor;               /* Number of active cursors */
};

#define FUZZER_HASH  4001    /* Hash table size */
#define FUZZER_NQUEUE  20    /* Number of slots on the stem queue */

/* A fuzzer cursor object */
................................................................................
  fuzzer_stem *pStem;        /* Stem with smallest rCostX */
  fuzzer_stem *pDone;        /* Stems already processed to completion */
  fuzzer_stem *aQueue[FUZZER_NQUEUE];  /* Queue of stems with higher rCostX */
  int mxQueue;               /* Largest used index in aQueue[] */
  char *zBuf;                /* Temporary use buffer */
  int nBuf;                  /* Bytes allocated for zBuf */
  int nStem;                 /* Number of stems allocated */

  fuzzer_rule nullRule;      /* Null rule used first */
  fuzzer_stem *apHash[FUZZER_HASH]; /* Hash of previously generated terms */
};

/* Methods for the fuzzer module */
static int fuzzerConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  fuzzer_vtab *pNew;
  int n;
  if( strcmp(argv[1],"temp")!=0 ){
    *pzErr = sqlite3_mprintf("%s virtual tables must be TEMP", argv[0]);
    return SQLITE_ERROR;
  }
  n = strlen(argv[0]) + 1;
  pNew = sqlite3_malloc( sizeof(*pNew) + n );
  if( pNew==0 ) return SQLITE_NOMEM;
  pNew->zClassName = (char*)&pNew[1];
  memcpy(pNew->zClassName, argv[0], n);
  sqlite3_declare_vtab(db, "CREATE TABLE x(word,distance,cFrom,cTo,cost)");
  memset(pNew, 0, sizeof(*pNew));
  *ppVtab = &pNew->base;
  return SQLITE_OK;
}
/* Note that for this virtual table, the xCreate and xConnect
** methods are identical. */

static int fuzzerDisconnect(sqlite3_vtab *pVtab){
  fuzzer_vtab *p = (fuzzer_vtab*)pVtab;
  assert( p->nCursor==0 );
  do{
    while( p->pRule ){
      fuzzer_rule *pRule = p->pRule;
      p->pRule = pRule->pNext;
      sqlite3_free(pRule);
    }
    p->pRule = p->pNewRule;
    p->pNewRule = 0;
  }while( p->pRule );
  sqlite3_free(p);
  return SQLITE_OK;
}
/* The xDisconnect and xDestroy methods are also the same */

/*
** The two input rule lists are both sorted in order of increasing
** cost.  Merge them together into a single list, sorted by cost, and
** return a pointer to the head of that list.
*/
static fuzzer_rule *fuzzerMergeRules(fuzzer_rule *pA, fuzzer_rule *pB){
  fuzzer_rule head;
................................................................................
    pTail->pNext = pB;
  }else{
    pTail->pNext = pA;
  }
  return head.pNext;
}


/*

** Open a new fuzzer cursor.





*/
static int fuzzerOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  fuzzer_vtab *p = (fuzzer_vtab*)pVTab;
  fuzzer_cursor *pCur;














































  pCur = sqlite3_malloc( sizeof(*pCur) );

  if( pCur==0 ) return SQLITE_NOMEM;

  memset(pCur, 0, sizeof(*pCur));
  pCur->pVtab = p;
  *ppCursor = &pCur->base;
  if( p->nCursor==0 && p->pNewRule ){






























































    unsigned int i;
    fuzzer_rule *pX;
    fuzzer_rule *a[15];
    for(i=0; i<sizeof(a)/sizeof(a[0]); i++) a[i] = 0;
    while( (pX = p->pNewRule)!=0 ){
      p->pNewRule = pX->pNext;
      pX->pNext = 0;
      for(i=0; a[i] && i<sizeof(a)/sizeof(a[0])-1; i++){
        pX = fuzzerMergeRules(a[i], pX);
        a[i] = 0;
      }
      a[i] = fuzzerMergeRules(a[i], pX);
    }
    for(pX=a[0], i=1; i<sizeof(a)/sizeof(a[0]); i++){
      pX = fuzzerMergeRules(a[i], pX);
    }
    p->pRule = fuzzerMergeRules(p->pRule, pX);






  }


































































































































  p->nCursor++;
  return SQLITE_OK;
}

/*
** Free all stems in a list.
*/
................................................................................
*/
static int fuzzerRender(
  fuzzer_stem *pStem,   /* The stem to be rendered */
  char **pzBuf,         /* Write results into this buffer.  realloc if needed */
  int *pnBuf            /* Size of the buffer */
){
  const fuzzer_rule *pRule = pStem->pRule;
  int n;
  char *z;

  n = pStem->nBasis + pRule->nTo - pRule->nFrom;
  if( (*pnBuf)<n+1 ){
    (*pzBuf) = sqlite3_realloc((*pzBuf), n+100);
    if( (*pzBuf)==0 ) return SQLITE_NOMEM;
    (*pnBuf) = n+100;
  }
................................................................................
    memcpy(z, pStem->zBasis, pStem->nBasis+1);
  }else{
    memcpy(z, pStem->zBasis, n);
    memcpy(&z[n], pRule->zTo, pRule->nTo);
    memcpy(&z[n+pRule->nTo], &pStem->zBasis[n+pRule->nFrom], 
           pStem->nBasis-n-pRule->nFrom+1);
  }


  return SQLITE_OK;
}

/*
** Compute a hash on zBasis.
*/
static unsigned int fuzzerHash(const char *z){
................................................................................
  fuzzer_stem *pLookup;

  if( fuzzerRender(pStem, &pCur->zBuf, &pCur->nBuf)==SQLITE_NOMEM ){
    return -1;
  }
  h = fuzzerHash(pCur->zBuf);
  pLookup = pCur->apHash[h];
    while( pLookup && strcmp(pLookup->zBasis, pCur->zBuf)!=0 ){
    pLookup = pLookup->pHash;
  }
  return pLookup!=0;
}




















/*
** Advance a fuzzer_stem to its next value.   Return 0 if there are
** no more values that can be generated by this fuzzer_stem.  Return
** -1 on a memory allocation failure.
*/
static int fuzzerAdvance(fuzzer_cursor *pCur, fuzzer_stem *pStem){
  const fuzzer_rule *pRule;
  while( (pRule = pStem->pRule)!=0 ){

    while( pStem->n < pStem->nBasis - pRule->nFrom ){
      pStem->n++;
      if( pRule->nFrom==0
       || memcmp(&pStem->zBasis[pStem->n], pRule->zFrom, pRule->nFrom)==0
      ){
        /* Found a rewrite case.  Make sure it is not a duplicate */
        int rc = fuzzerSeen(pCur, pStem);
................................................................................
        if( rc==0 ){
          fuzzerCost(pStem);
          return 1;
        }
      }
    }
    pStem->n = -1;

    pStem->pRule = pRule->pNext;


    if( pStem->pRule && fuzzerCost(pStem)>pCur->rLimit ) pStem->pRule = 0;
  }
  return 0;
}

/*
** The two input stem lists are both sorted in order of increasing
** rCostX.  Merge them together into a single list, sorted by rCostX, and
................................................................................
*/
static fuzzer_stem *fuzzerNewStem(
  fuzzer_cursor *pCur,
  const char *zWord,
  fuzzer_cost rBaseCost
){
  fuzzer_stem *pNew;

  unsigned int h;

  pNew = sqlite3_malloc( sizeof(*pNew) + strlen(zWord) + 1 );
  if( pNew==0 ) return 0;
  memset(pNew, 0, sizeof(*pNew));
  pNew->zBasis = (char*)&pNew[1];
  pNew->nBasis = strlen(zWord);
  memcpy(pNew->zBasis, zWord, pNew->nBasis+1);
  pNew->pRule = pCur->pVtab->pRule;




  pNew->n = -1;
  pNew->rBaseCost = pNew->rCostX = rBaseCost;
  h = fuzzerHash(pNew->zBasis);
  pNew->pHash = pCur->apHash[h];
  pCur->apHash[h] = pNew;
  pCur->nStem++;
  return pNew;
................................................................................
    }
  }

  /* Adjust the priority queue so that the first element of the
  ** stem list is the next lowest cost word.
  */
  while( (pStem = pCur->pStem)!=0 ){
    if( fuzzerAdvance(pCur, pStem) ){



      pCur->pStem = 0;
      pStem = fuzzerInsert(pCur, pStem);
      if( (rc = fuzzerSeen(pCur, pStem))!=0 ){
        if( rc<0 ) return SQLITE_NOMEM;
        continue;
      }
      return SQLITE_OK;  /* New word found */
................................................................................
*/
static int fuzzerFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  fuzzer_cursor *pCur = (fuzzer_cursor *)pVtabCursor;
  const char *zWord = 0;
  fuzzer_stem *pStem;


  fuzzerClearCursor(pCur, 1);
  pCur->rLimit = 2147483647;
  if( idxNum==1 ){
    zWord = (const char*)sqlite3_value_text(argv[0]);
  }else if( idxNum==2 ){
    pCur->rLimit = (fuzzer_cost)sqlite3_value_int(argv[0]);
  }else if( idxNum==3 ){
    zWord = (const char*)sqlite3_value_text(argv[0]);
    pCur->rLimit = (fuzzer_cost)sqlite3_value_int(argv[1]);
  }
  if( zWord==0 ) zWord = "";
  pCur->pStem = pStem = fuzzerNewStem(pCur, zWord, (fuzzer_cost)0);
  if( pStem==0 ) return SQLITE_NOMEM;


  pCur->nullRule.pNext = pCur->pVtab->pRule;
  pCur->nullRule.rCost = 0;
  pCur->nullRule.nFrom = 0;
  pCur->nullRule.nTo = 0;
  pCur->nullRule.zFrom = "";








  pStem->pRule = &pCur->nullRule;
  pStem->n = pStem->nBasis;
  pCur->iRowid = 1;




  return SQLITE_OK;
}

/*
** Only the word and distance columns have values.  All other columns
** return NULL
*/
................................................................................
  fuzzer_cursor *pCur = (fuzzer_cursor*)cur;
  return pCur->rLimit<=(fuzzer_cost)0;
}

/*
** Search for terms of these forms:
**
**       word MATCH $str
**       distance < $value
**       distance <= $value

**
** The distance< and distance<= are both treated as distance<=.
** The query plan number is as follows:
**
**   0:    None of the terms above are found
**   1:    There is a "word MATCH" term with $str in filter.argv[0].
**   2:    There is a "distance<" term with $value in filter.argv[0].
**   3:    Both "word MATCH" and "distance<" with $str in argv[0] and
**         $value in argv[1].






*/
static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int iPlan = 0;
  int iDistTerm = -1;

  int i;
  const struct sqlite3_index_constraint *pConstraint;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( (iPlan & 1)==0 
     && pConstraint->iColumn==0
................................................................................
     && pConstraint->iColumn==1
     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
    ){
      iPlan |= 2;
      iDistTerm = i;
    }







  }

  if( iPlan==2 ){
    pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = 1;

  }else if( iPlan==3 ){



    pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = 2;
  }
  pIdxInfo->idxNum = iPlan;
  if( pIdxInfo->nOrderBy==1
   && pIdxInfo->aOrderBy[0].iColumn==1
   && pIdxInfo->aOrderBy[0].desc==0
  ){
    pIdxInfo->orderByConsumed = 1;
  }
  pIdxInfo->estimatedCost = (double)10000;
   
  return SQLITE_OK;
}

/*
** Disallow all attempts to DELETE or UPDATE.  Only INSERTs are allowed.
**
** On an insert, the cFrom, cTo, and cost columns are used to construct
** a new rule.   All other columns are ignored.  The rule is ignored
** if cFrom and cTo are identical.  A NULL value for cFrom or cTo is
** interpreted as an empty string.  The cost must be positive.
*/
static int fuzzerUpdate(
  sqlite3_vtab *pVTab,
  int argc,
  sqlite3_value **argv,
  sqlite_int64 *pRowid
){
  fuzzer_vtab *p = (fuzzer_vtab*)pVTab;
  fuzzer_rule *pRule;
  const char *zFrom;
  int nFrom;
  const char *zTo;
  int nTo;
  fuzzer_cost rCost;
  if( argc!=7 ){
    sqlite3_free(pVTab->zErrMsg);
    pVTab->zErrMsg = sqlite3_mprintf("cannot delete from a %s virtual table",
                                     p->zClassName);
    return SQLITE_CONSTRAINT;
  }
  if( sqlite3_value_type(argv[0])!=SQLITE_NULL ){
    sqlite3_free(pVTab->zErrMsg);
    pVTab->zErrMsg = sqlite3_mprintf("cannot update a %s virtual table",
                                     p->zClassName);
    return SQLITE_CONSTRAINT;
  }
  zFrom = (char*)sqlite3_value_text(argv[4]);
  if( zFrom==0 ) zFrom = "";
  zTo = (char*)sqlite3_value_text(argv[5]);
  if( zTo==0 ) zTo = "";
  if( strcmp(zFrom,zTo)==0 ){
    /* Silently ignore null transformations */
    return SQLITE_OK;
  }
  rCost = sqlite3_value_int(argv[6]);
  if( rCost<=0 ){
    sqlite3_free(pVTab->zErrMsg);
    pVTab->zErrMsg = sqlite3_mprintf("cost must be positive");
    return SQLITE_CONSTRAINT;    
  }
  nFrom = strlen(zFrom);
  nTo = strlen(zTo);
  pRule = sqlite3_malloc( sizeof(*pRule) + nFrom + nTo );
  if( pRule==0 ){
    return SQLITE_NOMEM;
  }
  pRule->zFrom = &pRule->zTo[nTo+1];
  pRule->nFrom = nFrom;
  memcpy(pRule->zFrom, zFrom, nFrom+1);
  memcpy(pRule->zTo, zTo, nTo+1);
  pRule->nTo = nTo;
  pRule->rCost = rCost;
  pRule->pNext = p->pNewRule;
  p->pNewRule = pRule;
  return SQLITE_OK;
}

/*
** A virtual table module that provides read-only access to a
** Tcl global variable namespace.
*/
static sqlite3_module fuzzerModule = {
  0,                           /* iVersion */
  fuzzerConnect,
................................................................................
  fuzzerOpen,                  /* xOpen - open a cursor */
  fuzzerClose,                 /* xClose - close a cursor */
  fuzzerFilter,                /* xFilter - configure scan constraints */
  fuzzerNext,                  /* xNext - advance a cursor */
  fuzzerEof,                   /* xEof - check for end of scan */
  fuzzerColumn,                /* xColumn - read data */
  fuzzerRowid,                 /* xRowid - read data */
  fuzzerUpdate,                /* xUpdate - INSERT */
  0,                           /* xBegin */
  0,                           /* xSync */
  0,                           /* xCommit */
  0,                           /* xRollback */
  0,                           /* xFindMethod */
  0,                           /* xRename */
};
................................................................................
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3 *db;
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  fuzzer_register(db);
  return TCL_OK;
}


/*
** Register commands with the TCL interpreter.

**
**    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.
**
*************************************************************************
**
** Code for a demonstration virtual table that generates variations
** on an input word at increasing edit distances from the original.
**
** A fuzzer virtual table is created like this:
**
**     CREATE VIRTUAL TABLE f USING fuzzer(<fuzzer-data-table>);
**
** When it is created, the new fuzzer table must be supplied with the
** name of a "fuzzer data table", which must reside in the same database
** file as the new fuzzer table. The fuzzer data table contains the various
** transformations and their costs that the fuzzer logic uses to generate
** variations.
**
** The fuzzer data table must contain exactly four columns (more precisely,
** the statement "SELECT * FROM <fuzzer_data_table>" must return records
** that consist of four columns). It does not matter what the columns are
** named. 
**

** Each row in the fuzzer data table represents a single character
** transformation. The left most column of the row (column 0) contains an
** integer value - the identifier of the ruleset to which the transformation
** rule belongs (see "MULTIPLE RULE SETS" below). The second column of the
** row (column 0) contains the input character or characters. The third 
** column contains the output character or characters. And the fourth column
** contains the integer cost of making the transformation. For example:
**
**    CREATE TABLE f_data(ruleset, cFrom, cTo, Cost);
**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, '', 'a', 100);
**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, 'b', '', 87);
**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, 'o', 'oe', 38);
**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, 'oe', 'o', 40);
**
** The first row inserted into the fuzzer data table by the SQL script
** above indicates that the cost of inserting a letter 'a' is 100.  (All 
** costs are integers.  We recommend that costs be scaled so that the 
** average cost is around 100.) The second INSERT statement creates a rule



** saying that the cost of deleting a single letter 'b' is 87.  The third






** and fourth INSERT statements mean that the cost of transforming a
** single letter "o" into the two-letter sequence "oe" is 38 and that the
** cost of transforming "oe" back into "o" is 40.
**

** The contents of the fuzzer data table are loaded into main memory when
** a fuzzer table is first created, and may be internally reloaded by the
** system at any subsequent time. Therefore, the fuzzer data table should be 
** populated before the fuzzer table is created and not modified thereafter.
** If you do need to modify the contents of the fuzzer data table, it is
** recommended that the associated fuzzer table be dropped, the fuzzer data
** table edited, and the fuzzer table recreated within a single transaction.
** Alternatively, the fuzzer data table can be edited then the database
** connection can be closed and reopened.
**
** Once it has been created, the fuzzer table can be queried as follows:
**
**    SELECT word, distance FROM f
**     WHERE word MATCH 'abcdefg'
**       AND distance<200;
**
** This first query outputs the string "abcdefg" and all strings that
** can be derived from that string by appling the specified transformations.
** The strings are output together with their total transformation cost
** (called "distance") and appear in order of increasing cost.  No string
** is output more than once.  If there are multiple ways to transform the
** target string into the output string then the lowest cost transform is
** the one that is returned.  In the example, the search is limited to 
** strings with a total distance of less than 200.
**
** The fuzzer is a read-only table.  Any attempt to DELETE, INSERT, or
** UPDATE on a fuzzer table will throw an error.
**
** It is important to put some kind of a limit on the fuzzer output.  This
** can be either in the form of a LIMIT clause at the end of the query,
** or better, a "distance<NNN" constraint where NNN is some number.  The
** running time and memory requirement is exponential in the value of NNN 
** so you want to make sure that NNN is not too big.  A value of NNN that
** is about twice the average transformation cost seems to give good results.
................................................................................
**    WHERE f.word MATCH $prefix
**      AND f.distance<=200
**      AND vocabulary.w BETWEEN f.word AND (f.word || x'F7BFBFBF')
**    LIMIT 50
**
** This last query will show up to 50 words out of the vocabulary that
** match or nearly match the $prefix.
**
** MULTIPLE RULE SETS
**
** Normally, the "ruleset" value associated with all character transformations
** in the fuzzer data table is zero. However, if required, the fuzzer table
** allows multiple rulesets to be defined. Each query uses only a single
** ruleset. This allows, for example, a single fuzzer table to support 
** multiple languages.
**
** By default, only the rules from ruleset 0 are used. To specify an 
** alternative ruleset, a "ruleset = ?" expression must be added to the
** WHERE clause of a SELECT, where ? is the identifier of the desired 
** ruleset. For example:
**
**   SELECT vocabulary.w FROM f, vocabulary
**    WHERE f.word MATCH $word
**      AND f.distance<=200
**      AND f.word=vocabulary.w
**      AND f.ruleset=1  -- Specify the ruleset to use here
**    LIMIT 20
**
** If no "ruleset = ?" constraint is specified in the WHERE clause, ruleset 
** 0 is used.
**
** LIMITS
**
** The maximum ruleset number is 2147483647.  The maximum length of either
** of the strings in the second or third column of the fuzzer data table
** is 50 bytes.  The maximum cost on a rule is 1000.
*/

/* If SQLITE_DEBUG is not defined, disable assert statements. */
#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
# define NDEBUG
#endif

#include "sqlite3.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
typedef struct fuzzer_vtab fuzzer_vtab;
typedef struct fuzzer_cursor fuzzer_cursor;
typedef struct fuzzer_rule fuzzer_rule;
typedef struct fuzzer_seen fuzzer_seen;
typedef struct fuzzer_stem fuzzer_stem;

/*
** Various types.
**
** fuzzer_cost is the "cost" of an edit operation.

**
** fuzzer_len is the length of a matching string.  
**
** fuzzer_ruleid is an ruleset identifier.
*/
typedef int fuzzer_cost;
typedef signed char fuzzer_len;
typedef int fuzzer_ruleid;

/*
** Limits
*/
#define FUZZER_MX_LENGTH           50   /* Maximum length of a rule string */
#define FUZZER_MX_RULEID   2147483647   /* Maximum rule ID */
#define FUZZER_MX_COST           1000   /* Maximum single-rule cost */
#define FUZZER_MX_OUTPUT_LENGTH   100   /* Maximum length of an output string */


/*
** Each transformation rule is stored as an instance of this object.
** All rules are kept on a linked list sorted by rCost.
*/
struct fuzzer_rule {
  fuzzer_rule *pNext;         /* Next rule in order of increasing rCost */
  char *zFrom;                /* Transform from */
  fuzzer_cost rCost;          /* Cost of this transformation */
  fuzzer_len nFrom, nTo;      /* Length of the zFrom and zTo strings */

  fuzzer_ruleid iRuleset;     /* The rule set to which this rule belongs */
  char zTo[4];                /* Transform to (extra space appended) */
};

/*
** A stem object is used to generate variants.  It is also used to record
** previously generated outputs.
**
** Every stem is added to a hash table as it is output.  Generation of
................................................................................
**
** Active stems (those that might generate new outputs) are kepts on a linked
** list sorted by increasing cost.  The cost is the sum of rBaseCost and
** pRule->rCost.
*/
struct fuzzer_stem {
  char *zBasis;              /* Word being fuzzed */

  const fuzzer_rule *pRule;  /* Current rule to apply */
  fuzzer_stem *pNext;        /* Next stem in rCost order */
  fuzzer_stem *pHash;        /* Next stem with same hash on zBasis */
  fuzzer_cost rBaseCost;     /* Base cost of getting to zBasis */
  fuzzer_cost rCostX;        /* Precomputed rBaseCost + pRule->rCost */
  fuzzer_len nBasis;         /* Length of the zBasis string */
  fuzzer_len n;              /* Apply pRule at this character offset */
};

/* 
** A fuzzer virtual-table object 
*/
struct fuzzer_vtab {
  sqlite3_vtab base;         /* Base class - must be first */
  char *zClassName;          /* Name of this class.  Default: "fuzzer" */
  fuzzer_rule *pRule;        /* All active rules in this fuzzer */

  int nCursor;               /* Number of active cursors */
};

#define FUZZER_HASH  4001    /* Hash table size */
#define FUZZER_NQUEUE  20    /* Number of slots on the stem queue */

/* A fuzzer cursor object */
................................................................................
  fuzzer_stem *pStem;        /* Stem with smallest rCostX */
  fuzzer_stem *pDone;        /* Stems already processed to completion */
  fuzzer_stem *aQueue[FUZZER_NQUEUE];  /* Queue of stems with higher rCostX */
  int mxQueue;               /* Largest used index in aQueue[] */
  char *zBuf;                /* Temporary use buffer */
  int nBuf;                  /* Bytes allocated for zBuf */
  int nStem;                 /* Number of stems allocated */
  int iRuleset;              /* Only process rules from this ruleset */
  fuzzer_rule nullRule;      /* Null rule used first */
  fuzzer_stem *apHash[FUZZER_HASH]; /* Hash of previously generated terms */
};













































/*
** The two input rule lists are both sorted in order of increasing
** cost.  Merge them together into a single list, sorted by cost, and
** return a pointer to the head of that list.
*/
static fuzzer_rule *fuzzerMergeRules(fuzzer_rule *pA, fuzzer_rule *pB){
  fuzzer_rule head;
................................................................................
    pTail->pNext = pB;
  }else{
    pTail->pNext = pA;
  }
  return head.pNext;
}


/*
** Statement pStmt currently points to a row in the fuzzer data table. This
** function allocates and populates a fuzzer_rule structure according to
** the content of the row.
**
** If successful, *ppRule is set to point to the new object and SQLITE_OK
** is returned. Otherwise, *ppRule is zeroed, *pzErr may be set to point
** to an error message and an SQLite error code returned.
*/



static int fuzzerLoadOneRule(
  fuzzer_vtab *p,                 /* Fuzzer virtual table handle */
  sqlite3_stmt *pStmt,            /* Base rule on statements current row */
  fuzzer_rule **ppRule,           /* OUT: New rule object */
  char **pzErr                    /* OUT: Error message */
){
  sqlite3_int64 iRuleset = sqlite3_column_int64(pStmt, 0);
  const char *zFrom = (const char *)sqlite3_column_text(pStmt, 1);
  const char *zTo = (const char *)sqlite3_column_text(pStmt, 2);
  int nCost = sqlite3_column_int(pStmt, 3);

  int rc = SQLITE_OK;             /* Return code */
  int nFrom;                      /* Size of string zFrom, in bytes */
  int nTo;                        /* Size of string zTo, in bytes */
  fuzzer_rule *pRule = 0;         /* New rule object to return */

  if( zFrom==0 ) zFrom = "";
  if( zTo==0 ) zTo = "";
  nFrom = strlen(zFrom);
  nTo = strlen(zTo);

  /* Silently ignore null transformations */
  if( strcmp(zFrom, zTo)==0 ){
    *ppRule = 0;
    return SQLITE_OK;
  }

  if( nCost<=0 || nCost>FUZZER_MX_COST ){
    *pzErr = sqlite3_mprintf("%s: cost must be between 1 and %d", 
        p->zClassName, FUZZER_MX_COST
    );
    rc = SQLITE_ERROR;
  }else
  if( nFrom>FUZZER_MX_LENGTH || nTo>FUZZER_MX_LENGTH ){
    *pzErr = sqlite3_mprintf("%s: maximum string length is %d", 
        p->zClassName, FUZZER_MX_LENGTH
    );
    rc = SQLITE_ERROR;    
  }else
  if( iRuleset<0 || iRuleset>FUZZER_MX_RULEID ){
    *pzErr = sqlite3_mprintf("%s: ruleset must be between 0 and %d", 
        p->zClassName, FUZZER_MX_RULEID
    );
    rc = SQLITE_ERROR;    
  }else{

    pRule = sqlite3_malloc( sizeof(*pRule) + nFrom + nTo );
    if( pRule==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pRule, 0, sizeof(*pRule));



      pRule->zFrom = &pRule->zTo[nTo+1];
      pRule->nFrom = nFrom;
      memcpy(pRule->zFrom, zFrom, nFrom+1);
      memcpy(pRule->zTo, zTo, nTo+1);
      pRule->nTo = nTo;
      pRule->rCost = nCost;
      pRule->iRuleset = (int)iRuleset;
    }
  }

  *ppRule = pRule;
  return rc;
}

/*
** Load the content of the fuzzer data table into memory.
*/
static int fuzzerLoadRules(
  sqlite3 *db,                    /* Database handle */
  fuzzer_vtab *p,                 /* Virtual fuzzer table to configure */
  const char *zDb,                /* Database containing rules data */
  const char *zData,              /* Table containing rules data */
  char **pzErr                    /* OUT: Error message */
){
  int rc = SQLITE_OK;             /* Return code */
  char *zSql;                     /* SELECT used to read from rules table */
  fuzzer_rule *pHead = 0;

  zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", zDb, zData);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    int rc2;                      /* finalize() return code */
    sqlite3_stmt *pStmt = 0;
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
    if( rc!=SQLITE_OK ){
      *pzErr = sqlite3_mprintf("%s: %s", p->zClassName, sqlite3_errmsg(db));
    }else if( sqlite3_column_count(pStmt)!=4 ){
      *pzErr = sqlite3_mprintf("%s: %s has %d columns, expected 4",
          p->zClassName, zData, sqlite3_column_count(pStmt)
      );
      rc = SQLITE_ERROR;
    }else{
      while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
        fuzzer_rule *pRule = 0;
        rc = fuzzerLoadOneRule(p, pStmt, &pRule, pzErr);
        if( pRule ){
          pRule->pNext = pHead;
          pHead = pRule;
        }
      }
    }
    rc2 = sqlite3_finalize(pStmt);
    if( rc==SQLITE_OK ) rc = rc2;
  }
  sqlite3_free(zSql);

  /* All rules are now in a singly linked list starting at pHead. This
  ** block sorts them by cost and then sets fuzzer_vtab.pRule to point to 
  ** point to the head of the sorted list.
  */
  if( rc==SQLITE_OK ){
    unsigned int i;
    fuzzer_rule *pX;
    fuzzer_rule *a[15];
    for(i=0; i<sizeof(a)/sizeof(a[0]); i++) a[i] = 0;
    while( (pX = pHead)!=0 ){
      pHead = pX->pNext;
      pX->pNext = 0;
      for(i=0; a[i] && i<sizeof(a)/sizeof(a[0])-1; i++){
        pX = fuzzerMergeRules(a[i], pX);
        a[i] = 0;
      }
      a[i] = fuzzerMergeRules(a[i], pX);
    }
    for(pX=a[0], i=1; i<sizeof(a)/sizeof(a[0]); i++){
      pX = fuzzerMergeRules(a[i], pX);
    }
    p->pRule = fuzzerMergeRules(p->pRule, pX);
  }else{
    /* An error has occurred. Setting p->pRule to point to the head of the
    ** allocated list ensures that the list will be cleaned up in this case.
    */
    assert( p->pRule==0 );
    p->pRule = pHead;
  }

  return rc;
}

/*
** This function converts an SQL quoted string into an unquoted string
** and returns a pointer to a buffer allocated using sqlite3_malloc() 
** containing the result. The caller should eventually free this buffer
** using sqlite3_free.
**
** Examples:
**
**     "abc"   becomes   abc
**     'xyz'   becomes   xyz
**     [pqr]   becomes   pqr
**     `mno`   becomes   mno
*/
static char *fuzzerDequote(const char *zIn){
  int nIn;                        /* Size of input string, in bytes */
  char *zOut;                     /* Output (dequoted) string */

  nIn = strlen(zIn);
  zOut = sqlite3_malloc(nIn+1);
  if( zOut ){
    char q = zIn[0];              /* Quote character (if any ) */

    if( q!='[' && q!= '\'' && q!='"' && q!='`' ){
      memcpy(zOut, zIn, nIn+1);
    }else{
      int iOut = 0;               /* Index of next byte to write to output */
      int iIn;                    /* Index of next byte to read from input */

      if( q=='[' ) q = ']';
      for(iIn=1; iIn<nIn; iIn++){
        if( zIn[iIn]==q ) iIn++;
        zOut[iOut++] = zIn[iIn];
      }
    }
    assert( strlen(zOut)<=nIn );
  }
  return zOut;
}

/*
** xDisconnect/xDestroy method for the fuzzer module.
*/
static int fuzzerDisconnect(sqlite3_vtab *pVtab){
  fuzzer_vtab *p = (fuzzer_vtab*)pVtab;
  assert( p->nCursor==0 );
  while( p->pRule ){
    fuzzer_rule *pRule = p->pRule;
    p->pRule = pRule->pNext;
    sqlite3_free(pRule);
  }
  sqlite3_free(p);
  return SQLITE_OK;
}

/*
** xConnect/xCreate method for the fuzzer module. Arguments are:
**
**   argv[0]   -> module name  ("fuzzer")
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[3]   -> fuzzer rule table name
*/
static int fuzzerConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  int rc = SQLITE_OK;             /* Return code */
  fuzzer_vtab *pNew = 0;          /* New virtual table */
  const char *zModule = argv[0];
  const char *zDb = argv[1];

  if( argc!=4 ){
    *pzErr = sqlite3_mprintf(
        "%s: wrong number of CREATE VIRTUAL TABLE arguments", zModule
    );
    rc = SQLITE_ERROR;
  }else{
    int nModule;                  /* Length of zModule, in bytes */

    nModule = strlen(zModule);
    pNew = sqlite3_malloc( sizeof(*pNew) + nModule + 1);
    if( pNew==0 ){
      rc = SQLITE_NOMEM;
    }else{
      char *zTab;                 /* Dequoted name of fuzzer data table */

      memset(pNew, 0, sizeof(*pNew));
      pNew->zClassName = (char*)&pNew[1];
      memcpy(pNew->zClassName, zModule, nModule+1);

      zTab = fuzzerDequote(argv[3]);
      if( zTab==0 ){
        rc = SQLITE_NOMEM;
      }else{
        rc = fuzzerLoadRules(db, pNew, zDb, zTab, pzErr);
        sqlite3_free(zTab);
      }

      if( rc==SQLITE_OK ){
        rc = sqlite3_declare_vtab(db, "CREATE TABLE x(word,distance,ruleset)");
      }
      if( rc!=SQLITE_OK ){
        fuzzerDisconnect((sqlite3_vtab *)pNew);
        pNew = 0;
      }
    }
  }

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

/*
** Open a new fuzzer cursor.
*/
static int fuzzerOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  fuzzer_vtab *p = (fuzzer_vtab*)pVTab;
  fuzzer_cursor *pCur;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  pCur->pVtab = p;
  *ppCursor = &pCur->base;
  p->nCursor++;
  return SQLITE_OK;
}

/*
** Free all stems in a list.
*/
................................................................................
*/
static int fuzzerRender(
  fuzzer_stem *pStem,   /* The stem to be rendered */
  char **pzBuf,         /* Write results into this buffer.  realloc if needed */
  int *pnBuf            /* Size of the buffer */
){
  const fuzzer_rule *pRule = pStem->pRule;
  int n;                          /* Size of output term without nul-term */
  char *z;                        /* Buffer to assemble output term in */

  n = pStem->nBasis + pRule->nTo - pRule->nFrom;
  if( (*pnBuf)<n+1 ){
    (*pzBuf) = sqlite3_realloc((*pzBuf), n+100);
    if( (*pzBuf)==0 ) return SQLITE_NOMEM;
    (*pnBuf) = n+100;
  }
................................................................................
    memcpy(z, pStem->zBasis, pStem->nBasis+1);
  }else{
    memcpy(z, pStem->zBasis, n);
    memcpy(&z[n], pRule->zTo, pRule->nTo);
    memcpy(&z[n+pRule->nTo], &pStem->zBasis[n+pRule->nFrom], 
           pStem->nBasis-n-pRule->nFrom+1);
  }

  assert( z[pStem->nBasis + pRule->nTo - pRule->nFrom]==0 );
  return SQLITE_OK;
}

/*
** Compute a hash on zBasis.
*/
static unsigned int fuzzerHash(const char *z){
................................................................................
  fuzzer_stem *pLookup;

  if( fuzzerRender(pStem, &pCur->zBuf, &pCur->nBuf)==SQLITE_NOMEM ){
    return -1;
  }
  h = fuzzerHash(pCur->zBuf);
  pLookup = pCur->apHash[h];
  while( pLookup && strcmp(pLookup->zBasis, pCur->zBuf)!=0 ){
    pLookup = pLookup->pHash;
  }
  return pLookup!=0;
}

/*
** If argument pRule is NULL, this function returns false.
**
** Otherwise, it returns true if rule pRule should be skipped. A rule 
** should be skipped if it does not belong to rule-set iRuleset, or if
** applying it to stem pStem would create a string longer than 
** FUZZER_MX_OUTPUT_LENGTH bytes.
*/
static int fuzzerSkipRule(
  const fuzzer_rule *pRule,       /* Determine whether or not to skip this */
  fuzzer_stem *pStem,             /* Stem rule may be applied to */
  int iRuleset                    /* Rule-set used by the current query */
){
  return pRule && (
      (pRule->iRuleset!=iRuleset)
   || (pStem->nBasis + pRule->nTo - pRule->nFrom)>FUZZER_MX_OUTPUT_LENGTH
  );
}

/*
** Advance a fuzzer_stem to its next value.   Return 0 if there are
** no more values that can be generated by this fuzzer_stem.  Return
** -1 on a memory allocation failure.
*/
static int fuzzerAdvance(fuzzer_cursor *pCur, fuzzer_stem *pStem){
  const fuzzer_rule *pRule;
  while( (pRule = pStem->pRule)!=0 ){
    assert( pRule==&pCur->nullRule || pRule->iRuleset==pCur->iRuleset );
    while( pStem->n < pStem->nBasis - pRule->nFrom ){
      pStem->n++;
      if( pRule->nFrom==0
       || memcmp(&pStem->zBasis[pStem->n], pRule->zFrom, pRule->nFrom)==0
      ){
        /* Found a rewrite case.  Make sure it is not a duplicate */
        int rc = fuzzerSeen(pCur, pStem);
................................................................................
        if( rc==0 ){
          fuzzerCost(pStem);
          return 1;
        }
      }
    }
    pStem->n = -1;
    do{
      pRule = pRule->pNext;
    }while( fuzzerSkipRule(pRule, pStem, pCur->iRuleset) );
    pStem->pRule = pRule;
    if( pRule && fuzzerCost(pStem)>pCur->rLimit ) pStem->pRule = 0;
  }
  return 0;
}

/*
** The two input stem lists are both sorted in order of increasing
** rCostX.  Merge them together into a single list, sorted by rCostX, and
................................................................................
*/
static fuzzer_stem *fuzzerNewStem(
  fuzzer_cursor *pCur,
  const char *zWord,
  fuzzer_cost rBaseCost
){
  fuzzer_stem *pNew;
  fuzzer_rule *pRule;
  unsigned int h;

  pNew = sqlite3_malloc( sizeof(*pNew) + strlen(zWord) + 1 );
  if( pNew==0 ) return 0;
  memset(pNew, 0, sizeof(*pNew));
  pNew->zBasis = (char*)&pNew[1];
  pNew->nBasis = strlen(zWord);
  memcpy(pNew->zBasis, zWord, pNew->nBasis+1);
  pRule = pCur->pVtab->pRule;
  while( fuzzerSkipRule(pRule, pNew, pCur->iRuleset) ){
    pRule = pRule->pNext;
  }
  pNew->pRule = pRule;
  pNew->n = -1;
  pNew->rBaseCost = pNew->rCostX = rBaseCost;
  h = fuzzerHash(pNew->zBasis);
  pNew->pHash = pCur->apHash[h];
  pCur->apHash[h] = pNew;
  pCur->nStem++;
  return pNew;
................................................................................
    }
  }

  /* Adjust the priority queue so that the first element of the
  ** stem list is the next lowest cost word.
  */
  while( (pStem = pCur->pStem)!=0 ){
    int res = fuzzerAdvance(pCur, pStem);
    if( res<0 ){
      return SQLITE_NOMEM;
    }else if( res>0 ){
      pCur->pStem = 0;
      pStem = fuzzerInsert(pCur, pStem);
      if( (rc = fuzzerSeen(pCur, pStem))!=0 ){
        if( rc<0 ) return SQLITE_NOMEM;
        continue;
      }
      return SQLITE_OK;  /* New word found */
................................................................................
*/
static int fuzzerFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  fuzzer_cursor *pCur = (fuzzer_cursor *)pVtabCursor;
  const char *zWord = "";
  fuzzer_stem *pStem;
  int idx;

  fuzzerClearCursor(pCur, 1);
  pCur->rLimit = 2147483647;
  idx = 0;
  if( idxNum & 1 ){
    zWord = (const char*)sqlite3_value_text(argv[0]);
    idx++;
  }
  if( idxNum & 2 ){
    pCur->rLimit = (fuzzer_cost)sqlite3_value_int(argv[idx]);
    idx++;
  }
  if( idxNum & 4 ){
    pCur->iRuleset = (fuzzer_cost)sqlite3_value_int(argv[idx]);
    idx++;
  }
  pCur->nullRule.pNext = pCur->pVtab->pRule;
  pCur->nullRule.rCost = 0;
  pCur->nullRule.nFrom = 0;
  pCur->nullRule.nTo = 0;
  pCur->nullRule.zFrom = "";
  pCur->iRowid = 1;
  assert( pCur->pStem==0 );

  /* If the query term is longer than FUZZER_MX_OUTPUT_LENGTH bytes, this
  ** query will return zero rows.  */
  if( strlen(zWord)<FUZZER_MX_OUTPUT_LENGTH ){
    pCur->pStem = pStem = fuzzerNewStem(pCur, zWord, (fuzzer_cost)0);
    if( pStem==0 ) return SQLITE_NOMEM;
    pStem->pRule = &pCur->nullRule;
    pStem->n = pStem->nBasis;

  }else{
    pCur->rLimit = 0;
  }

  return SQLITE_OK;
}

/*
** Only the word and distance columns have values.  All other columns
** return NULL
*/
................................................................................
  fuzzer_cursor *pCur = (fuzzer_cursor*)cur;
  return pCur->rLimit<=(fuzzer_cost)0;
}

/*
** Search for terms of these forms:
**
**   (A)    word MATCH $str
**   (B1)   distance < $value
**   (B2)   distance <= $value
**   (C)    ruleid == $ruleid
**
** The distance< and distance<= are both treated as distance<=.
** The query plan number is a bit vector:
**

**   bit 1:   Term of the form (A) found
**   bit 2:   Term like (B1) or (B2) found
**   bit 3:   Term like (C) found
**
** If bit-1 is set, $str is always in filter.argv[0].  If bit-2 is set
** then $value is in filter.argv[0] if bit-1 is clear and is in 
** filter.argv[1] if bit-1 is set.  If bit-3 is set, then $ruleid is
** in filter.argv[0] if bit-1 and bit-2 are both zero, is in
** filter.argv[1] if exactly one of bit-1 and bit-2 are set, and is in
** filter.argv[2] if both bit-1 and bit-2 are set.
*/
static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int iPlan = 0;
  int iDistTerm = -1;
  int iRulesetTerm = -1;
  int i;
  const struct sqlite3_index_constraint *pConstraint;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( (iPlan & 1)==0 
     && pConstraint->iColumn==0
................................................................................
     && pConstraint->iColumn==1
     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
    ){
      iPlan |= 2;
      iDistTerm = i;
    }
    if( (iPlan & 4)==0
     && pConstraint->iColumn==2
     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      iPlan |= 4;
      pIdxInfo->aConstraintUsage[i].omit = 1;
      iRulesetTerm = i;
    }
  }
  if( iPlan & 2 ){
    pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = 1+((iPlan&1)!=0);
  }
  if( iPlan & 4 ){
    int idx = 1;
    if( iPlan & 1 ) idx++;
    if( iPlan & 2 ) idx++;
    pIdxInfo->aConstraintUsage[iRulesetTerm].argvIndex = idx;
  }
  pIdxInfo->idxNum = iPlan;
  if( pIdxInfo->nOrderBy==1
   && pIdxInfo->aOrderBy[0].iColumn==1
   && pIdxInfo->aOrderBy[0].desc==0
  ){
    pIdxInfo->orderByConsumed = 1;
  }
  pIdxInfo->estimatedCost = (double)10000;
   
  return SQLITE_OK;
}

































































/*
** A virtual table module that provides read-only access to a
** Tcl global variable namespace.
*/
static sqlite3_module fuzzerModule = {
  0,                           /* iVersion */
  fuzzerConnect,
................................................................................
  fuzzerOpen,                  /* xOpen - open a cursor */
  fuzzerClose,                 /* xClose - close a cursor */
  fuzzerFilter,                /* xFilter - configure scan constraints */
  fuzzerNext,                  /* xNext - advance a cursor */
  fuzzerEof,                   /* xEof - check for end of scan */
  fuzzerColumn,                /* xColumn - read data */
  fuzzerRowid,                 /* xRowid - read data */
  0,                           /* xUpdate */
  0,                           /* xBegin */
  0,                           /* xSync */
  0,                           /* xCommit */
  0,                           /* xRollback */
  0,                           /* xFindMethod */
  0,                           /* xRename */
};
................................................................................
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3 *db;
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  getDbPointer(interp, Tcl_GetString(objv[1]), &db);
  fuzzer_register(db);
  return TCL_OK;
}


/*
** Register commands with the TCL interpreter.

#define sqlite3_mutex_enter(X)
#define sqlite3_mutex_try(X)      SQLITE_OK
#define sqlite3_mutex_leave(X)
#define sqlite3_mutex_held(X)     ((void)(X),1)
#define sqlite3_mutex_notheld(X)  ((void)(X),1)
#endif /* SQLITE_THREADSAFE==0 */




/* First chunk for rollback journal files */
#define SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET 400



/************************ Shim Definitions ******************************/

#ifndef SQLITE_MULTIPLEX_VFS_NAME
# define SQLITE_MULTIPLEX_VFS_NAME "multiplex"
#endif
................................................................................
  int nBase,                      /* Size of zBase in bytes (without \0) */
  int flags,                      /* Flags used to open file */
  int iChunk,                     /* Chunk to generate filename for */
  char *zOut                      /* Buffer to write generated name to */
){
  int n = nBase;
  memcpy(zOut, zBase, n+1);
  if( iChunk!=0 && iChunk!=SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET ){
#ifdef SQLITE_ENABLE_8_3_NAMES
    int i;
    for(i=n-1; i>0 && i>=n-4 && zOut[i]!='.'; i--){}
    if( i>=n-4 ) n = i+1;
    if( flags & SQLITE_OPEN_MAIN_JOURNAL ){
      /* The extensions on overflow files for main databases are 001, 002,
       ** 003 and so forth.  To avoid name collisions, add 400 to the 
       ** extensions of journal files so that they are 401, 402, 403, ....
       */
      iChunk += SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET;





    }
#endif
    sqlite3_snprintf(4,&zOut[n],"%03d",iChunk);
    n += 3;
  }

  assert( zOut[n]=='\0' );
................................................................................
      do{
        multiplexFilename(zName, nName, SQLITE_OPEN_MAIN_JOURNAL, ++iChunk, z);
        rc = pOrigVfs->xAccess(pOrigVfs, z, SQLITE_ACCESS_EXISTS, &bExists);
      }while( rc==SQLITE_OK && bExists );
      while( rc==SQLITE_OK && iChunk>1 ){
        multiplexFilename(zName, nName, SQLITE_OPEN_MAIN_JOURNAL, --iChunk, z);
        rc = pOrigVfs->xDelete(pOrigVfs, z, syncDir);











      }
    }
    sqlite3_free(z);
  }
  return rc;
}

#define sqlite3_mutex_enter(X)
#define sqlite3_mutex_try(X)      SQLITE_OK
#define sqlite3_mutex_leave(X)
#define sqlite3_mutex_held(X)     ((void)(X),1)
#define sqlite3_mutex_notheld(X)  ((void)(X),1)
#endif /* SQLITE_THREADSAFE==0 */

/* Maximum chunk number */
#define MX_CHUNK_NUMBER 299

/* First chunk for rollback journal files */
#define SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET 400
#define SQLITE_MULTIPLEX_WAL_8_3_OFFSET 700


/************************ Shim Definitions ******************************/

#ifndef SQLITE_MULTIPLEX_VFS_NAME
# define SQLITE_MULTIPLEX_VFS_NAME "multiplex"
#endif
................................................................................
  int nBase,                      /* Size of zBase in bytes (without \0) */
  int flags,                      /* Flags used to open file */
  int iChunk,                     /* Chunk to generate filename for */
  char *zOut                      /* Buffer to write generated name to */
){
  int n = nBase;
  memcpy(zOut, zBase, n+1);
  if( iChunk!=0 && iChunk<=MX_CHUNK_NUMBER ){
#ifdef SQLITE_ENABLE_8_3_NAMES
    int i;
    for(i=n-1; i>0 && i>=n-4 && zOut[i]!='.'; i--){}
    if( i>=n-4 ) n = i+1;
    if( flags & SQLITE_OPEN_MAIN_JOURNAL ){
      /* The extensions on overflow files for main databases are 001, 002,
      ** 003 and so forth.  To avoid name collisions, add 400 to the 
      ** extensions of journal files so that they are 401, 402, 403, ....
      */
      iChunk += SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET;
    }else if( flags & SQLITE_OPEN_WAL ){
      /* To avoid name collisions, add 700 to the 
      ** extensions of WAL files so that they are 701, 702, 703, ....
      */
      iChunk += SQLITE_MULTIPLEX_WAL_8_3_OFFSET;
    }
#endif
    sqlite3_snprintf(4,&zOut[n],"%03d",iChunk);
    n += 3;
  }

  assert( zOut[n]=='\0' );
................................................................................
      do{
        multiplexFilename(zName, nName, SQLITE_OPEN_MAIN_JOURNAL, ++iChunk, z);
        rc = pOrigVfs->xAccess(pOrigVfs, z, SQLITE_ACCESS_EXISTS, &bExists);
      }while( rc==SQLITE_OK && bExists );
      while( rc==SQLITE_OK && iChunk>1 ){
        multiplexFilename(zName, nName, SQLITE_OPEN_MAIN_JOURNAL, --iChunk, z);
        rc = pOrigVfs->xDelete(pOrigVfs, z, syncDir);
      }
      if( rc==SQLITE_OK ){
        iChunk = 0;
        do{
          multiplexFilename(zName, nName, SQLITE_OPEN_WAL, ++iChunk, z);
          rc = pOrigVfs->xAccess(pOrigVfs, z, SQLITE_ACCESS_EXISTS, &bExists);
        }while( rc==SQLITE_OK && bExists );
        while( rc==SQLITE_OK && iChunk>1 ){
          multiplexFilename(zName, nName, SQLITE_OPEN_WAL, --iChunk, z);
          rc = pOrigVfs->xDelete(pOrigVfs, z, syncDir);
        }
      }
    }
    sqlite3_free(z);
  }
  return rc;
}

}

/*
** File control method. For custom operations on an tvfs-file.
*/
static int tvfsFileControl(sqlite3_file *pFile, int op, void *pArg){
  TestvfsFd *p = tvfsGetFd(pFile);





















  return sqlite3OsFileControl(p->pReal, op, pArg);
}

/*
** Return the sector-size in bytes for an tvfs-file.
*/
static int tvfsSectorSize(sqlite3_file *pFile){

}

/*
** File control method. For custom operations on an tvfs-file.
*/
static int tvfsFileControl(sqlite3_file *pFile, int op, void *pArg){
  TestvfsFd *p = tvfsGetFd(pFile);
  if( op==SQLITE_FCNTL_PRAGMA ){
    char **argv = (char**)pArg;
    if( sqlite3_stricmp(argv[1],"error")==0 ){
      int rc = SQLITE_ERROR;
      if( argv[2] ){
        const char *z = argv[2];
        int x = atoi(z);
        if( x ){
          rc = x;
          while( sqlite3Isdigit(z[0]) ){ z++; }
          while( sqlite3Isspace(z[0]) ){ z++; }
        }
        if( z[0] ) argv[0] = sqlite3_mprintf("%s", z);
      }
      return rc;
    }
    if( sqlite3_stricmp(argv[1], "filename")==0 ){
      argv[0] = sqlite3_mprintf("%s", p->zFilename);
      return SQLITE_OK;
    }
  }
  return sqlite3OsFileControl(p->pReal, op, pArg);
}

/*
** Return the sector-size in bytes for an tvfs-file.
*/
static int tvfsSectorSize(sqlite3_file *pFile){

    case SQLITE_FCNTL_FILE_POINTER: zOp = "FILE_POINTER";       break;
    case SQLITE_FCNTL_SYNC_OMITTED: zOp = "SYNC_OMITTED";       break;
    case SQLITE_FCNTL_WIN32_AV_RETRY: zOp = "WIN32_AV_RETRY";   break;
    case SQLITE_FCNTL_PERSIST_WAL:  zOp = "PERSIST_WAL";        break;
    case SQLITE_FCNTL_OVERWRITE:    zOp = "OVERWRITE";          break;
    case SQLITE_FCNTL_VFSNAME:      zOp = "VFSNAME";            break;
    case 0xca093fa0:                zOp = "DB_UNCHANGED";       break;






    default: {
      sqlite3_snprintf(sizeof zBuf, zBuf, "%d", op);
      zOp = zBuf;
      break;
    }
  }
  vfstrace_printf(pInfo, "%s.xFileControl(%s,%s)",
................................................................................
                  pInfo->zVfsName, p->zFName, zOp);
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
    *(char**)pArg = sqlite3_mprintf("vfstrace.%s/%z",
                                    pInfo->zVfsName, *(char**)pArg);
  }




  return rc;
}

/*
** Return the sector-size in bytes for an vfstrace-file.
*/
static int vfstraceSectorSize(sqlite3_file *pFile){

    case SQLITE_FCNTL_FILE_POINTER: zOp = "FILE_POINTER";       break;
    case SQLITE_FCNTL_SYNC_OMITTED: zOp = "SYNC_OMITTED";       break;
    case SQLITE_FCNTL_WIN32_AV_RETRY: zOp = "WIN32_AV_RETRY";   break;
    case SQLITE_FCNTL_PERSIST_WAL:  zOp = "PERSIST_WAL";        break;
    case SQLITE_FCNTL_OVERWRITE:    zOp = "OVERWRITE";          break;
    case SQLITE_FCNTL_VFSNAME:      zOp = "VFSNAME";            break;
    case 0xca093fa0:                zOp = "DB_UNCHANGED";       break;
    case SQLITE_FCNTL_PRAGMA: {
      const char *const* a = (const char*const*)pArg;
      sqlite3_snprintf(sizeof(zBuf), zBuf, "PRAGMA,[%s,%s]",a[1],a[2]);
      zOp = zBuf;
      break;
    }
    default: {
      sqlite3_snprintf(sizeof zBuf, zBuf, "%d", op);
      zOp = zBuf;
      break;
    }
  }
  vfstrace_printf(pInfo, "%s.xFileControl(%s,%s)",
................................................................................
                  pInfo->zVfsName, p->zFName, zOp);
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
    *(char**)pArg = sqlite3_mprintf("vfstrace.%s/%z",
                                    pInfo->zVfsName, *(char**)pArg);
  }
  if( op==SQLITE_FCNTL_PRAGMA && rc==SQLITE_OK && *(char**)pArg ){
    vfstrace_printf(pInfo, "%s.xFileControl(%s,%s) returns %s",
                    pInfo->zVfsName, p->zFName, zOp, *(char**)pArg);
  }
  return rc;
}

/*
** Return the sector-size in bytes for an vfstrace-file.
*/
static int vfstraceSectorSize(sqlite3_file *pFile){

**
** IMPLEMENTATION-OF: R-20522-24639 The sqlite3_strnicmp() API allows
** applications and extensions to compare the contents of two buffers
** containing UTF-8 strings in a case-independent fashion, using the same
** definition of case independence that SQLite uses internally when
** comparing identifiers.
*/
int sqlite3StrICmp(const char *zLeft, const char *zRight){
  register unsigned char *a, *b;
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return UpperToLower[*a] - UpperToLower[*b];
}
int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){

**
** IMPLEMENTATION-OF: R-20522-24639 The sqlite3_strnicmp() API allows
** applications and extensions to compare the contents of two buffers
** containing UTF-8 strings in a case-independent fashion, using the same
** definition of case independence that SQLite uses internally when
** comparing identifiers.
*/
int sqlite3_stricmp(const char *zLeft, const char *zRight){
  register unsigned char *a, *b;
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return UpperToLower[*a] - UpperToLower[*b];
}
int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){

    extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
    int nKey;
    char *zKey;
    sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
    if( nKey ) db->nextPagesize = 0;
  }
#endif













  /* Do not attempt to change the page size for a WAL database */
  if( sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
                                               ==PAGER_JOURNALMODE_WAL ){
    db->nextPagesize = 0;
  }

................................................................................
  if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)
   || (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
   || NEVER(db->mallocFailed)
  ){
    rc = SQLITE_NOMEM;
    goto end_of_vacuum;
  }
  rc = execSql(db, pzErrMsg, "PRAGMA vacuum_db.synchronous=OFF");
  if( rc!=SQLITE_OK ){
    goto end_of_vacuum;
  }

#ifndef SQLITE_OMIT_AUTOVACUUM
  sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :
                                           sqlite3BtreeGetAutoVacuum(pMain));
#endif

  /* Begin a transaction */
  rc = execSql(db, pzErrMsg, "BEGIN EXCLUSIVE;");
  if( rc!=SQLITE_OK ) goto end_of_vacuum;

  /* Query the schema of the main database. Create a mirror schema
  ** in the temporary database.
  */
  rc = execExecSql(db, pzErrMsg,
      "SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14) "
      "  FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
      "   AND rootpage>0"

    extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
    int nKey;
    char *zKey;
    sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
    if( nKey ) db->nextPagesize = 0;
  }
#endif

  rc = execSql(db, pzErrMsg, "PRAGMA vacuum_db.synchronous=OFF");
  if( rc!=SQLITE_OK ) goto end_of_vacuum;

  /* Begin a transaction and take an exclusive lock on the main database
  ** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
  ** to ensure that we do not try to change the page-size on a WAL database.
  */
  rc = execSql(db, pzErrMsg, "BEGIN;");
  if( rc!=SQLITE_OK ) goto end_of_vacuum;
  rc = sqlite3BtreeBeginTrans(pMain, 2);
  if( rc!=SQLITE_OK ) goto end_of_vacuum;

  /* Do not attempt to change the page size for a WAL database */
  if( sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
                                               ==PAGER_JOURNALMODE_WAL ){
    db->nextPagesize = 0;
  }

................................................................................
  if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)
   || (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
   || NEVER(db->mallocFailed)
  ){
    rc = SQLITE_NOMEM;
    goto end_of_vacuum;
  }





#ifndef SQLITE_OMIT_AUTOVACUUM
  sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :
                                           sqlite3BtreeGetAutoVacuum(pMain));
#endif





  /* Query the schema of the main database. Create a mirror schema
  ** in the temporary database.
  */
  rc = execExecSql(db, pzErrMsg,
      "SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14) "
      "  FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
      "   AND rootpage>0"

      pSavepoint = pSavepoint->pNext
    ){
      iSavepoint++;
    }
    if( !pSavepoint ){
      sqlite3SetString(&p->zErrMsg, db, "no such savepoint: %s", zName);
      rc = SQLITE_ERROR;
    }else if( 
        db->writeVdbeCnt>0 || (p1==SAVEPOINT_ROLLBACK && db->activeVdbeCnt>1) 
    ){
      /* It is not possible to release (commit) a savepoint if there are 
      ** active write statements. It is not possible to rollback a savepoint
      ** if there are any active statements at all.
      */
      sqlite3SetString(&p->zErrMsg, db, 
        "cannot %s savepoint - SQL statements in progress",
        (p1==SAVEPOINT_ROLLBACK ? "rollback": "release")
      );
      rc = SQLITE_BUSY;
    }else{

      /* Determine whether or not this is a transaction savepoint. If so,
      ** and this is a RELEASE command, then the current transaction 
      ** is committed. 
................................................................................
          p->rc = rc = SQLITE_BUSY;
          goto vdbe_return;
        }
        db->isTransactionSavepoint = 0;
        rc = p->rc;
      }else{
        iSavepoint = db->nSavepoint - iSavepoint - 1;



        for(ii=0; ii<db->nDb; ii++){
          rc = sqlite3BtreeSavepoint(db->aDb[ii].pBt, p1, iSavepoint);
          if( rc!=SQLITE_OK ){
            goto abort_due_to_error;
          }
        }
        if( p1==SAVEPOINT_ROLLBACK && (db->flags&SQLITE_InternChanges)!=0 ){
................................................................................
  desiredAutoCommit = pOp->p1;
  iRollback = pOp->p2;
  turnOnAC = desiredAutoCommit && !db->autoCommit;
  assert( desiredAutoCommit==1 || desiredAutoCommit==0 );
  assert( desiredAutoCommit==1 || iRollback==0 );
  assert( db->activeVdbeCnt>0 );  /* At least this one VM is active */


  if( turnOnAC && iRollback && db->activeVdbeCnt>1 ){
    /* If this instruction implements a ROLLBACK and other VMs are
    ** still running, and a transaction is active, return an error indicating
    ** that the other VMs must complete first. 
    */
    sqlite3SetString(&p->zErrMsg, db, "cannot rollback transaction - "
        "SQL statements in progress");
    rc = SQLITE_BUSY;


  }else if( turnOnAC && !iRollback && db->writeVdbeCnt>0 ){
    /* If this instruction implements a COMMIT and other VMs are writing
    ** return an error indicating that the other VMs must complete first. 
    */
    sqlite3SetString(&p->zErrMsg, db, "cannot commit transaction - "
        "SQL statements in progress");
    rc = SQLITE_BUSY;
  }else if( desiredAutoCommit!=db->autoCommit ){
    if( iRollback ){
      assert( desiredAutoCommit==1 );
      sqlite3RollbackAll(db);
      db->autoCommit = 1;
    }else if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){
      goto vdbe_return;
    }else{
      db->autoCommit = (u8)desiredAutoCommit;
      if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
        p->pc = pc;
................................................................................
        }
        if( res ){
          v = 1;   /* IMP: R-61914-48074 */
        }else{
          assert( sqlite3BtreeCursorIsValid(pC->pCursor) );
          rc = sqlite3BtreeKeySize(pC->pCursor, &v);
          assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
          if( v==MAX_ROWID ){
            pC->useRandomRowid = 1;
          }else{
            v++;   /* IMP: R-29538-34987 */
          }
        }
      }

      pSavepoint = pSavepoint->pNext
    ){
      iSavepoint++;
    }
    if( !pSavepoint ){
      sqlite3SetString(&p->zErrMsg, db, "no such savepoint: %s", zName);
      rc = SQLITE_ERROR;
    }else if( db->writeVdbeCnt>0 && p1==SAVEPOINT_RELEASE ){


      /* It is not possible to release (commit) a savepoint if there are 
      ** active write statements.

      */
      sqlite3SetString(&p->zErrMsg, db, 
        "cannot release savepoint - SQL statements in progress"

      );
      rc = SQLITE_BUSY;
    }else{

      /* Determine whether or not this is a transaction savepoint. If so,
      ** and this is a RELEASE command, then the current transaction 
      ** is committed. 
................................................................................
          p->rc = rc = SQLITE_BUSY;
          goto vdbe_return;
        }
        db->isTransactionSavepoint = 0;
        rc = p->rc;
      }else{
        iSavepoint = db->nSavepoint - iSavepoint - 1;
        for(ii=0; ii<db->nDb; ii++){
          sqlite3BtreeTripAllCursors(db->aDb[ii].pBt, SQLITE_ABORT);
        }
        for(ii=0; ii<db->nDb; ii++){
          rc = sqlite3BtreeSavepoint(db->aDb[ii].pBt, p1, iSavepoint);
          if( rc!=SQLITE_OK ){
            goto abort_due_to_error;
          }
        }
        if( p1==SAVEPOINT_ROLLBACK && (db->flags&SQLITE_InternChanges)!=0 ){
................................................................................
  desiredAutoCommit = pOp->p1;
  iRollback = pOp->p2;
  turnOnAC = desiredAutoCommit && !db->autoCommit;
  assert( desiredAutoCommit==1 || desiredAutoCommit==0 );
  assert( desiredAutoCommit==1 || iRollback==0 );
  assert( db->activeVdbeCnt>0 );  /* At least this one VM is active */

#if 0
  if( turnOnAC && iRollback && db->activeVdbeCnt>1 ){
    /* If this instruction implements a ROLLBACK and other VMs are
    ** still running, and a transaction is active, return an error indicating
    ** that the other VMs must complete first. 
    */
    sqlite3SetString(&p->zErrMsg, db, "cannot rollback transaction - "
        "SQL statements in progress");
    rc = SQLITE_BUSY;
  }else
#endif
  if( turnOnAC && !iRollback && db->writeVdbeCnt>0 ){
    /* If this instruction implements a COMMIT and other VMs are writing
    ** return an error indicating that the other VMs must complete first. 
    */
    sqlite3SetString(&p->zErrMsg, db, "cannot commit transaction - "
        "SQL statements in progress");
    rc = SQLITE_BUSY;
  }else if( desiredAutoCommit!=db->autoCommit ){
    if( iRollback ){
      assert( desiredAutoCommit==1 );
      sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
      db->autoCommit = 1;
    }else if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){
      goto vdbe_return;
    }else{
      db->autoCommit = (u8)desiredAutoCommit;
      if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
        p->pc = pc;
................................................................................
        }
        if( res ){
          v = 1;   /* IMP: R-61914-48074 */
        }else{
          assert( sqlite3BtreeCursorIsValid(pC->pCursor) );
          rc = sqlite3BtreeKeySize(pC->pCursor, &v);
          assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
          if( v>=MAX_ROWID ){
            pC->useRandomRowid = 1;
          }else{
            v++;   /* IMP: R-29538-34987 */
          }
        }
      }

  assert( cnt==db->activeVdbeCnt );
  assert( nWrite==db->writeVdbeCnt );
}
#else
#define checkActiveVdbeCnt(x)
#endif

/*
** For every Btree that in database connection db which 
** has been modified, "trip" or invalidate each cursor in
** that Btree might have been modified so that the cursor
** can never be used again.  This happens when a rollback
*** occurs.  We have to trip all the other cursors, even
** cursor from other VMs in different database connections,
** so that none of them try to use the data at which they
** were pointing and which now may have been changed due
** to the rollback.
**
** Remember that a rollback can delete tables complete and
** reorder rootpages.  So it is not sufficient just to save
** the state of the cursor.  We have to invalidate the cursor
** so that it is never used again.
*/
static void invalidateCursorsOnModifiedBtrees(sqlite3 *db){
  int i;
  for(i=0; i<db->nDb; i++){
    Btree *p = db->aDb[i].pBt;
    if( p && sqlite3BtreeIsInTrans(p) ){
      sqlite3BtreeTripAllCursors(p, SQLITE_ABORT);
    }
  }
}

/*
** If the Vdbe passed as the first argument opened a statement-transaction,
** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the 
** statement transaction is commtted.
**
................................................................................
      if( !p->readOnly || mrc!=SQLITE_INTERRUPT ){
        if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL) && p->usesStmtJournal ){
          eStatementOp = SAVEPOINT_ROLLBACK;
        }else{
          /* We are forced to roll back the active transaction. Before doing
          ** so, abort any other statements this handle currently has active.
          */
          invalidateCursorsOnModifiedBtrees(db);
          sqlite3RollbackAll(db);
          sqlite3CloseSavepoints(db);
          db->autoCommit = 1;
        }
      }
    }

    /* Check for immediate foreign key violations. */
................................................................................
          rc = vdbeCommit(db, p);
        }
        if( rc==SQLITE_BUSY && p->readOnly ){
          sqlite3VdbeLeave(p);
          return SQLITE_BUSY;
        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db);
        }else{
          db->nDeferredCons = 0;
          sqlite3CommitInternalChanges(db);
        }
      }else{
        sqlite3RollbackAll(db);
      }
      db->nStatement = 0;
    }else if( eStatementOp==0 ){
      if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){
        eStatementOp = SAVEPOINT_RELEASE;
      }else if( p->errorAction==OE_Abort ){
        eStatementOp = SAVEPOINT_ROLLBACK;
      }else{
        invalidateCursorsOnModifiedBtrees(db);
        sqlite3RollbackAll(db);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;
      }
    }
  
    /* If eStatementOp is non-zero, then a statement transaction needs to
    ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to
................................................................................
      rc = sqlite3VdbeCloseStatement(p, eStatementOp);
      if( rc ){
        if( p->rc==SQLITE_OK || p->rc==SQLITE_CONSTRAINT ){
          p->rc = rc;
          sqlite3DbFree(db, p->zErrMsg);
          p->zErrMsg = 0;
        }
        invalidateCursorsOnModifiedBtrees(db);
        sqlite3RollbackAll(db);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;
      }
    }
  
    /* If this was an INSERT, UPDATE or DELETE and no statement transaction
    ** has been rolled back, update the database connection change-counter. 

  assert( cnt==db->activeVdbeCnt );
  assert( nWrite==db->writeVdbeCnt );
}
#else
#define checkActiveVdbeCnt(x)
#endif



























/*
** If the Vdbe passed as the first argument opened a statement-transaction,
** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the 
** statement transaction is commtted.
**
................................................................................
      if( !p->readOnly || mrc!=SQLITE_INTERRUPT ){
        if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL) && p->usesStmtJournal ){
          eStatementOp = SAVEPOINT_ROLLBACK;
        }else{
          /* We are forced to roll back the active transaction. Before doing
          ** so, abort any other statements this handle currently has active.
          */

          sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
          sqlite3CloseSavepoints(db);
          db->autoCommit = 1;
        }
      }
    }

    /* Check for immediate foreign key violations. */
................................................................................
          rc = vdbeCommit(db, p);
        }
        if( rc==SQLITE_BUSY && p->readOnly ){
          sqlite3VdbeLeave(p);
          return SQLITE_BUSY;
        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db, SQLITE_OK);
        }else{
          db->nDeferredCons = 0;
          sqlite3CommitInternalChanges(db);
        }
      }else{
        sqlite3RollbackAll(db, SQLITE_OK);
      }
      db->nStatement = 0;
    }else if( eStatementOp==0 ){
      if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){
        eStatementOp = SAVEPOINT_RELEASE;
      }else if( p->errorAction==OE_Abort ){
        eStatementOp = SAVEPOINT_ROLLBACK;
      }else{

        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;
      }
    }
  
    /* If eStatementOp is non-zero, then a statement transaction needs to
    ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to
................................................................................
      rc = sqlite3VdbeCloseStatement(p, eStatementOp);
      if( rc ){
        if( p->rc==SQLITE_OK || p->rc==SQLITE_CONSTRAINT ){
          p->rc = rc;
          sqlite3DbFree(db, p->zErrMsg);
          p->zErrMsg = 0;
        }

        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;
      }
    }
  
    /* If this was an INSERT, UPDATE or DELETE and no statement transaction
    ** has been rolled back, update the database connection change-counter. 

    sz = pWal->hdr.szPage;
    sz = (sz&0xfe00) + ((sz&0x0001)<<16);
    testcase( sz<=32768 );
    testcase( sz>=65536 );
    iOffset = walFrameOffset(iRead, sz) + WAL_FRAME_HDRSIZE;
    *pInWal = 1;
    /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
    return sqlite3OsRead(pWal->pWalFd, pOut, nOut, iOffset);
  }

  *pInWal = 0;
  return SQLITE_OK;
}


................................................................................
** Return true if the argument is non-NULL and the WAL module is using
** heap-memory for the wal-index. Otherwise, if the argument is NULL or the
** WAL module is using shared-memory, return false. 
*/
int sqlite3WalHeapMemory(Wal *pWal){
  return (pWal && pWal->exclusiveMode==WAL_HEAPMEMORY_MODE );
}













#endif /* #ifndef SQLITE_OMIT_WAL */

    sz = pWal->hdr.szPage;
    sz = (sz&0xfe00) + ((sz&0x0001)<<16);
    testcase( sz<=32768 );
    testcase( sz>=65536 );
    iOffset = walFrameOffset(iRead, sz) + WAL_FRAME_HDRSIZE;
    *pInWal = 1;
    /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
    return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset);
  }

  *pInWal = 0;
  return SQLITE_OK;
}


................................................................................
** Return true if the argument is non-NULL and the WAL module is using
** heap-memory for the wal-index. Otherwise, if the argument is NULL or the
** WAL module is using shared-memory, return false. 
*/
int sqlite3WalHeapMemory(Wal *pWal){
  return (pWal && pWal->exclusiveMode==WAL_HEAPMEMORY_MODE );
}

#ifdef SQLITE_ENABLE_ZIPVFS
/*
** If the argument is not NULL, it points to a Wal object that holds a
** read-lock. This function returns the database page-size if it is known,
** or zero if it is not (or if pWal is NULL).
*/
int sqlite3WalFramesize(Wal *pWal){
  assert( pWal==0 || pWal->readLock>=0 );
  return (pWal ? pWal->szPage : 0);
}
#endif

#endif /* #ifndef SQLITE_OMIT_WAL */

# define sqlite3WalSavepoint(y,z)
# define sqlite3WalSavepointUndo(y,z)            0
# define sqlite3WalFrames(u,v,w,x,y,z)           0
# define sqlite3WalCheckpoint(r,s,t,u,v,w,x,y,z) 0
# define sqlite3WalCallback(z)                   0
# define sqlite3WalExclusiveMode(y,z)            0
# define sqlite3WalHeapMemory(z)                 0

#else

#define WAL_SAVEPOINT_NDATA 4

/* Connection to a write-ahead log (WAL) file. 
** There is one object of this type for each pager. 
*/
................................................................................
int sqlite3WalExclusiveMode(Wal *pWal, int op);

/* Return true if the argument is non-NULL and the WAL module is using
** heap-memory for the wal-index. Otherwise, if the argument is NULL or the
** WAL module is using shared-memory, return false. 
*/
int sqlite3WalHeapMemory(Wal *pWal);








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

# define sqlite3WalSavepoint(y,z)
# define sqlite3WalSavepointUndo(y,z)            0
# define sqlite3WalFrames(u,v,w,x,y,z)           0
# define sqlite3WalCheckpoint(r,s,t,u,v,w,x,y,z) 0
# define sqlite3WalCallback(z)                   0
# define sqlite3WalExclusiveMode(y,z)            0
# define sqlite3WalHeapMemory(z)                 0
# define sqlite3WalFramesize(z)                  0
#else

#define WAL_SAVEPOINT_NDATA 4

/* Connection to a write-ahead log (WAL) file. 
** There is one object of this type for each pager. 
*/
................................................................................
int sqlite3WalExclusiveMode(Wal *pWal, int op);

/* Return true if the argument is non-NULL and the WAL module is using
** heap-memory for the wal-index. Otherwise, if the argument is NULL or the
** WAL module is using shared-memory, return false. 
*/
int sqlite3WalHeapMemory(Wal *pWal);

#ifdef SQLITE_ENABLE_ZIPVFS
/* If the WAL file is not empty, return the number of bytes of content
** stored in each frame (i.e. the db page-size when the WAL was created).
*/
int sqlite3WalFramesize(Wal *pWal);
#endif

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

      wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_ORDERBY;
      wsFlags |= (rev ? WHERE_REVERSE : 0);
    }

    /* If there is a DISTINCT qualifier and this index will scan rows in
    ** order of the DISTINCT expressions, clear bDist and set the appropriate
    ** flags in wsFlags. */
    if( isDistinctIndex(pParse, pWC, pProbe, iCur, pDistinct, nEq) ){


      bDist = 0;
      wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_DISTINCT;
    }

    /* If currently calculating the cost of using an index (not the IPK
    ** index), determine if all required column data may be obtained without 
    ** using the main table (i.e. if the index is a covering

      wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_ORDERBY;
      wsFlags |= (rev ? WHERE_REVERSE : 0);
    }

    /* If there is a DISTINCT qualifier and this index will scan rows in
    ** order of the DISTINCT expressions, clear bDist and set the appropriate
    ** flags in wsFlags. */
    if( isDistinctIndex(pParse, pWC, pProbe, iCur, pDistinct, nEq)
     && (wsFlags & WHERE_COLUMN_IN)==0
    ){
      bDist = 0;
      wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_DISTINCT;
    }

    /* If currently calculating the cost of using an index (not the IPK
    ** index), determine if all required column data may be obtained without 
    ** using the main table (i.e. if the index is a covering

#***********************************************************************
#
# $Id: cache.test,v 1.4 2007/08/22 02:56:44 drh Exp $

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

ifcapable {!pager_pragmas} {
  finish_test
  return
}
sqlite3_soft_heap_limit 0

proc pager_cache_size {db} {
  set bt [btree_from_db $db]

#***********************************************************************
#
# $Id: cache.test,v 1.4 2007/08/22 02:56:44 drh Exp $

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

ifcapable !pager_pragmas||!compound {
  finish_test
  return
}
sqlite3_soft_heap_limit 0

proc pager_cache_size {db} {
  set bt [btree_from_db $db]

do_test capi3-11.9.1 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3-11.9.2 {
  catchsql {
    ROLLBACK;
  }
} {1 {cannot rollback transaction - SQL statements in progress}}
do_test capi3-11.9.3 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3-11.10 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3-11.11 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3-11.12 {

  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3-11.14 {
  execsql {
    SELECT a FROM t2;
  }
} {1 2 3}
do_test capi3-11.14.1 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3-11.15 {
  catchsql {
    ROLLBACK;
  }
} {0 {}}
do_test capi3-11.15.1 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3-11.16 {
  execsql {
    SELECT a FROM t2;
  }

do_test capi3-11.9.1 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3-11.9.2 {
  catchsql {
    ROLLBACK;
  }
} {0 {}}
do_test capi3-11.9.3 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3-11.10 {
  sqlite3_step $STMT
} {SQLITE_ERROR}
do_test capi3-11.11 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3-11.12 {
  sqlite3_step $STMT
  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3-11.14 {
  execsql {
    SELECT a FROM t2;
  }
} {1 2}
do_test capi3-11.14.1 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3-11.15 {
  catchsql {
    ROLLBACK;
  }
} {1 {cannot rollback - no transaction is active}}
do_test capi3-11.15.1 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3-11.16 {
  execsql {
    SELECT a FROM t2;
  }

do_test capi3c-11.9.1 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3c-11.9.2 {
  catchsql {
    ROLLBACK;
  }
} {1 {cannot rollback transaction - SQL statements in progress}}
do_test capi3c-11.9.3 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3c-11.10 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3c-11.11 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3c-11.12 {

  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3c-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3c-11.14 {
  execsql {
    SELECT a FROM t2;
  }
} {1 2 3}
do_test capi3c-11.14.1 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3c-11.15 {
  catchsql {
    ROLLBACK;
  }
} {0 {}}
do_test capi3c-11.15.1 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3c-11.16 {
  execsql {
    SELECT a FROM t2;
  }

do_test capi3c-11.9.1 {
  sqlite3_get_autocommit $DB
} 0
do_test capi3c-11.9.2 {
  catchsql {
    ROLLBACK;
  }
} {0 {}}
do_test capi3c-11.9.3 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3c-11.10 {
  sqlite3_step $STMT
} {SQLITE_ABORT}
do_test capi3c-11.11 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3c-11.12 {
  sqlite3_step $STMT
  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3c-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3c-11.14 {
  execsql {
    SELECT a FROM t2;
  }
} {1 2}
do_test capi3c-11.14.1 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3c-11.15 {
  catchsql {
    ROLLBACK;
  }
} {1 {cannot rollback - no transaction is active}}
do_test capi3c-11.15.1 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3c-11.16 {
  execsql {
    SELECT a FROM t2;
  }

#***********************************************************************
#
# Tests for the sqlite3_db_status() function
#

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






# Memory statistics must be enabled for this test.
db close
sqlite3_shutdown
sqlite3_config_memstatus 1
sqlite3_initialize
sqlite3 db test.db

#***********************************************************************
#
# Tests for the sqlite3_db_status() function
#

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

ifcapable !compound {
  finish_test
  return
}

# Memory statistics must be enabled for this test.
db close
sqlite3_shutdown
sqlite3_config_memstatus 1
sqlite3_initialize
sqlite3 db test.db

#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is the DISTINCT modifier.
#

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






set testprefix distinct


proc is_distinct_noop {sql} {
  set sql1 $sql
  set sql2 [string map {DISTINCT ""} $sql]

#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is the DISTINCT modifier.
#

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

ifcapable !compound {
  finish_test
  return
}

set testprefix distinct


proc is_distinct_noop {sql} {
  set sql1 $sql
  set sql2 [string map {DISTINCT ""} $sql]

#***********************************************************************
#
# This file implements tests to verify that the "testable statements" in 
# the lang_delete.html document are correct.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl






proc do_delete_tests {args} {
  uplevel do_select_tests $args
}

do_execsql_test e_delete-0.0 {
  CREATE TABLE t1(a, b);

#***********************************************************************
#
# This file implements tests to verify that the "testable statements" in 
# the lang_delete.html document are correct.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !compound {
  finish_test
  return
}

proc do_delete_tests {args} {
  uplevel do_select_tests $args
}

do_execsql_test e_delete-0.0 {
  CREATE TABLE t1(a, b);

# the lang_expr.html document are correct.
#

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






proc do_expr_test {tn expr type value} {
  uplevel do_execsql_test $tn [list "SELECT typeof($expr), $expr"] [
    list [list $type $value]
  ]
}

# the lang_expr.html document are correct.
#

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

ifcapable !compound {
  finish_test
  return
}

proc do_expr_test {tn expr type value} {
  uplevel do_execsql_test $tn [list "SELECT typeof($expr), $expr"] [
    list [list $type $value]
  ]
}

    INSERT INTO parent VALUES(1);
    INSERT INTO child VALUES(1);
  }
} {}
do_test e_fkey-51.2 {
  execsql {
    UPDATE parent SET x = 22;
    SELECT * FROM parent UNION ALL SELECT 'xxx' UNION ALL SELECT a FROM child;
  }
} {22 21 23 xxx 22}
do_test e_fkey-51.3 {
  execsql {
    DELETE FROM child;
    DELETE FROM parent;
    INSERT INTO parent VALUES(-1);
    INSERT INTO child VALUES(-1);
    UPDATE parent SET x = 22;
    SELECT * FROM parent UNION ALL SELECT 'xxx' UNION ALL SELECT a FROM child;
  }
} {22 23 21 xxx 23}


#-------------------------------------------------------------------------
# Verify that ON UPDATE actions only actually take place if the parent key
# is set to a new value that is distinct from the old value. The default

    INSERT INTO parent VALUES(1);
    INSERT INTO child VALUES(1);
  }
} {}
do_test e_fkey-51.2 {
  execsql {
    UPDATE parent SET x = 22;
    SELECT * FROM parent ; SELECT 'xxx' ; SELECT a FROM child;
  }
} {22 21 23 xxx 22}
do_test e_fkey-51.3 {
  execsql {
    DELETE FROM child;
    DELETE FROM parent;
    INSERT INTO parent VALUES(-1);
    INSERT INTO child VALUES(-1);
    UPDATE parent SET x = 22;
    SELECT * FROM parent ; SELECT 'xxx' ; SELECT a FROM child;
  }
} {22 23 21 xxx 23}


#-------------------------------------------------------------------------
# Verify that ON UPDATE actions only actually take place if the parent key
# is set to a new value that is distinct from the old value. The default

# statements" in the lang_insert.html document are correct.
#
# Also, it contains tests to verify the statements in (the very short)
# lang_replace.html.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl






# Organization of tests:
#
#   e_insert-0.*: Test the syntax diagram.
#
#   e_insert-1.*: Test statements of the form "INSERT ... VALUES(...)".
#   

# statements" in the lang_insert.html document are correct.
#
# Also, it contains tests to verify the statements in (the very short)
# lang_replace.html.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !compound {
  finish_test
  return
}

# Organization of tests:
#
#   e_insert-0.*: Test the syntax diagram.
#
#   e_insert-1.*: Test statements of the form "INSERT ... VALUES(...)".
#   

#
# This file implements tests to verify that the "testable statements" in 
# the lang_select.html document are correct.
#

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






do_execsql_test e_select-1.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES('a', 'one');
  INSERT INTO t1 VALUES('b', 'two');
  INSERT INTO t1 VALUES('c', 'three');

#
# This file implements tests to verify that the "testable statements" in 
# the lang_select.html document are correct.
#

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

ifcapable !compound {
  finish_test
  return
}

do_execsql_test e_select-1.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES('a', 'one');
  INSERT INTO t1 VALUES('b', 'two');
  INSERT INTO t1 VALUES('c', 'three');

# attached is in the TEMP database, then the unqualified name of the
# table being updated is resolved in the same way as it is for a
# top-level statement (by searching first the TEMP database, then the
# main database, then any other databases in the order they were
# attached).
#
do_execsql_test e_update-2.3.0 {
  SELECT 'main', tbl_name FROM main.sqlite_master WHERE type = 'table'
    UNION ALL
  SELECT 'temp', tbl_name FROM sqlite_temp_master WHERE type = 'table'
    UNION ALL
  SELECT 'aux', tbl_name FROM aux.sqlite_master WHERE type = 'table'
} [list {*}{
    main t1
    main t2
    main t3
    main t6
    temp t4
    temp t6

# attached is in the TEMP database, then the unqualified name of the
# table being updated is resolved in the same way as it is for a
# top-level statement (by searching first the TEMP database, then the
# main database, then any other databases in the order they were
# attached).
#
do_execsql_test e_update-2.3.0 {
  SELECT 'main', tbl_name FROM main.sqlite_master WHERE type = 'table';

  SELECT 'temp', tbl_name FROM sqlite_temp_master WHERE type = 'table';

  SELECT 'aux', tbl_name FROM aux.sqlite_master WHERE type = 'table';
} [list {*}{
    main t1
    main t2
    main t3
    main t6
    temp t4
    temp t6

#
#   e_vacuum-1.2.1 - Perform many INSERT, UPDATE and DELETE ops on table t1.
#   e_vacuum-1.2.2 - Verify that t1 and its indexes are now quite fragmented.
#   e_vacuum-1.2.3 - Run VACUUM.
#   e_vacuum-1.2.4 - Verify that t1 and its indexes are now much 
#                    less fragmented.
#
ifcapable vtab {
  create_db 
  register_dbstat_vtab db
  do_execsql_test e_vacuum-1.2.1 {
    DELETE FROM t1 WHERE a%2;
    INSERT INTO t1 SELECT b, a FROM t2 WHERE a%2;
    UPDATE t1 SET b=randomblob(600) WHERE (a%2)==0;
  } {}

#
#   e_vacuum-1.2.1 - Perform many INSERT, UPDATE and DELETE ops on table t1.
#   e_vacuum-1.2.2 - Verify that t1 and its indexes are now quite fragmented.
#   e_vacuum-1.2.3 - Run VACUUM.
#   e_vacuum-1.2.4 - Verify that t1 and its indexes are now much 
#                    less fragmented.
#
ifcapable vtab&&compound {
  create_db 
  register_dbstat_vtab db
  do_execsql_test e_vacuum-1.2.1 {
    DELETE FROM t1 WHERE a%2;
    INSERT INTO t1 SELECT b, a FROM t2 WHERE a%2;
    UPDATE t1 SET b=randomblob(600) WHERE (a%2)==0;
  } {}

#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

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






set testprefix eqp

#-------------------------------------------------------------------------
#
# eqp-1.*:        Assorted tests.
# eqp-2.*:        Tests for single select statements.

#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

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

ifcapable !compound {
  finish_test
  return
}

set testprefix eqp

#-------------------------------------------------------------------------
#
# eqp-1.*:        Assorted tests.
# eqp-2.*:        Tests for single select statements.

# 2012 March 01
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#*************************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the languageid=xxx FTS4 option.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix fts4content

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts3 {
  finish_test
  return
}

set ::testprefix fts4langid

#---------------------------------------------------------------------------
# Test plan:
#
#   1.* - Warm-body tests created for specific purposes during development.
#         Passing these doesn't really prove much.
#
#   2.1.* - Test that FTS queries only ever return rows associated with
#           the requested language.
#
#   2.2.* - Same as 2.1.*, after an 'optimize' command.
#
#   2.3.* - Same as 2.1.*, after a 'rebuild' command.
#
#   3.* - Tests with content= tables. Both where there is a real 
#         underlying content table and where there is not.
#
#   4.* - Test that if one is provided, the tokenizer xLanguage method
#         is called to configure the tokenizer before tokenizing query
#         or document text.
#
#   5.* - Test the fts4aux table when the associated FTS4 table contains
#         multiple languages.
#

do_execsql_test 1.1 {
  CREATE VIRTUAL TABLE t1 USING fts4(a, b, languageid=lang_id);
}

do_execsql_test 1.2 {
  SELECT sql FROM sqlite_master WHERE name = 't1_content';
} {{CREATE TABLE 't1_content'(docid INTEGER PRIMARY KEY, 'c0a', 'c1b', langid)}}

do_execsql_test 1.3 {SELECT docid FROM t1} {}
do_execsql_test 1.4 {SELECT lang_id FROM t1} {}

do_execsql_test 1.5 {INSERT INTO t1(a, b) VALUES('aaa', 'bbb')}
do_execsql_test 1.6 {SELECT lang_id FROM t1 } {0}

do_execsql_test 1.7 {INSERT INTO t1(a, b, lang_id) VALUES('aaa', 'bbb', 4)}
do_execsql_test 1.8 {SELECT lang_id FROM t1 } {0 4}

do_execsql_test 1.9  {INSERT INTO t1(a, b, lang_id) VALUES('aaa', 'bbb', 'xyz')}
do_execsql_test 1.10 {SELECT lang_id FROM t1} {0 4 0}

do_execsql_test 1.11 {
  CREATE VIRTUAL TABLE t2 USING fts4;
  INSERT INTO t2 VALUES('abc');
} 
do_execsql_test 1.12 { SELECT rowid FROM t2 WHERE content MATCH 'abc' } 1

do_execsql_test 1.13 {
  DROP TABLE t1;
  CREATE VIRTUAL TABLE t1 USING fts4(languageid=lang_id);
  INSERT INTO t1(content)          VALUES('a b c');
  INSERT INTO t1(content, lang_id) VALUES('a b c', 1);
}

do_execsql_test 1.14 {
  SELECT rowid FROM t1 WHERE t1 MATCH 'b';
} {1}
do_execsql_test 1.15 {
  SELECT rowid FROM t1 WHERE t1 MATCH 'b' AND lang_id = 0;
} {1}

do_execsql_test 1.16 {
  SELECT rowid FROM t1 WHERE t1 MATCH 'b' AND lang_id = 1;
} {2}

do_catchsql_test 1.17 {
  INSERT INTO t1(content, lang_id) VALUES('123', -1);
} {1 {constraint failed}}

do_execsql_test 1.18 {
  DROP TABLE t1;
  CREATE VIRTUAL TABLE t1 USING fts4(languageid=lang_id);
  INSERT INTO t1(content, lang_id) VALUES('A', 13);
  INSERT INTO t1(content, lang_id) VALUES('B', 13);
  INSERT INTO t1(content, lang_id) VALUES('C', 13);
  INSERT INTO t1(content, lang_id) VALUES('D', 13);
  INSERT INTO t1(content, lang_id) VALUES('E', 13);
  INSERT INTO t1(content, lang_id) VALUES('F', 13);
  INSERT INTO t1(content, lang_id) VALUES('G', 13);
  INSERT INTO t1(content, lang_id) VALUES('H', 13);
  INSERT INTO t1(content, lang_id) VALUES('I', 13);
  INSERT INTO t1(content, lang_id) VALUES('J', 13);
  INSERT INTO t1(content, lang_id) VALUES('K', 13);
  INSERT INTO t1(content, lang_id) VALUES('L', 13);
  INSERT INTO t1(content, lang_id) VALUES('M', 13);
  INSERT INTO t1(content, lang_id) VALUES('N', 13);
  INSERT INTO t1(content, lang_id) VALUES('O', 13);
  INSERT INTO t1(content, lang_id) VALUES('P', 13);
  INSERT INTO t1(content, lang_id) VALUES('Q', 13);
  INSERT INTO t1(content, lang_id) VALUES('R', 13);
  INSERT INTO t1(content, lang_id) VALUES('S', 13);
  SELECT rowid FROM t1 WHERE t1 MATCH 'A';
} {}


#-------------------------------------------------------------------------
# Test cases 2.*
#
proc build_multilingual_db_1 {db} {
  $db eval { CREATE VIRTUAL TABLE t2 USING fts4(x, y, languageid=l) }

  set xwords [list zero one two three four five six seven eight nine ten]
  set ywords [list alpha beta gamma delta epsilon zeta eta theta iota kappa]

  for {set i 0} {$i < 1000} {incr i} {
    set iLangid [expr $i%9]
    set x ""
    set y ""

    set x [list]
    lappend x [lindex $xwords [expr ($i / 1000) % 10]]
    lappend x [lindex $xwords [expr ($i / 100)  % 10]]
    lappend x [lindex $xwords [expr ($i / 10)   % 10]]
    lappend x [lindex $xwords [expr ($i / 1)   % 10]]

    set y [list]
    lappend y [lindex $ywords [expr ($i / 1000) % 10]]
    lappend y [lindex $ywords [expr ($i / 100)  % 10]]
    lappend y [lindex $ywords [expr ($i / 10)   % 10]]
    lappend y [lindex $ywords [expr ($i / 1)   % 10]]

    $db eval { INSERT INTO t2(docid, x, y, l) VALUES($i, $x, $y, $iLangid) }
  }

  $db eval {
    CREATE TABLE data(x, y, l);
    INSERT INTO data(rowid, x, y, l) SELECT docid, x, y, l FROM t2;
  }
}

proc rowid_list_set_langid {langid} {
  set ::rowid_list_langid $langid
}
proc rowid_list {pattern} {
  set langid $::rowid_list_langid
  set res [list]
  db eval {SELECT rowid, x, y FROM data WHERE l = $langid ORDER BY rowid ASC} {
    if {[string match "*$pattern*" $x] || [string match "*$pattern*" $y]} {
      lappend res $rowid
    }
  }
  return $res
}

proc or_merge_list {list1 list2} {
  set res [list]

  set i1 0
  set i2 0

  set n1 [llength $list1]
  set n2 [llength $list2]

  while {$i1 < $n1 && $i2 < $n2} {
    set e1 [lindex $list1 $i1]
    set e2 [lindex $list2 $i2]

    if {$e1==$e2} {
      lappend res $e1
      incr i1
      incr i2
    } elseif {$e1 < $e2} {
      lappend res $e1
      incr i1
    } else {
      lappend res $e2
      incr i2
    }
  }

  concat $res [lrange $list1 $i1 end] [lrange $list2 $i2 end]
}

proc or_merge_lists {args} {
  set res [lindex $args 0]
  for {set i 1} {$i < [llength $args]} {incr i} {
    set res [or_merge_list $res [lindex $args $i]]
  }
  set res
}

proc and_merge_list {list1 list2} {
  foreach i $list2 { set a($i) 1 }
  set res [list]
  foreach i $list1 {
    if {[info exists a($i)]} {lappend res $i}
  }
  set res
}


proc and_merge_lists {args} {
  set res [lindex $args 0]
  for {set i 1} {$i < [llength $args]} {incr i} {
    set res [and_merge_list $res [lindex $args $i]]
  }
  set res
}

proc filter_list {list langid} {
  set res [list]
  foreach i $list {
    if {($i % 9) == $langid} {lappend res $i}
  }
  set res
}

do_test 2.0 { 
  reset_db
  build_multilingual_db_1 db
} {}

proc do_test_query1 {tn query res_script} {
  for {set langid 0} {$langid < 10} {incr langid} {
    rowid_list_set_langid $langid
    set res [eval $res_script]

    set actual [
      execsql {SELECT docid FROM t2 WHERE t2 MATCH $query AND l = $langid}
    ]
    do_test $tn.$langid [list set {} $actual] $res
  }
}

# Run some queries. 
do_test_query1 2.1.1  {delta}          { rowid_list delta }
do_test_query1 2.1.2  {"zero one two"} { rowid_list "zero one two" }
do_test_query1 2.1.3  {zero one two} {
  and_merge_lists [rowid_list zero] [rowid_list one] [rowid_list two]
}
do_test_query1 2.1.4  {"zero one" OR "one two"} {
  or_merge_lists [rowid_list "zero one"] [rowid_list "one two"]
}

# Now try the same tests as above, but after running the 'optimize'
# command on the FTS table.
#
do_execsql_test 2.2 {
  INSERT INTO t2(t2) VALUES('optimize');
  SELECT count(*) FROM t2_segdir;
} {9}
do_test_query1 2.2.1 {delta}          { rowid_list delta }
do_test_query1 2.2.2 {"zero one two"} { rowid_list "zero one two" }
do_test_query1 2.2.3 {zero one two} {
  and_merge_lists [rowid_list zero] [rowid_list one] [rowid_list two]
}
do_test_query1 2.2.4 {"zero one" OR "one two"} {
  or_merge_lists [rowid_list "zero one"] [rowid_list "one two"]
}

# And rebuild.
#
do_test 2.3 { 
  reset_db
  build_multilingual_db_1 db
  execsql { INSERT INTO t2(t2) VALUES('rebuild') }
} {}
do_test_query1 2.3.1 {delta}          { rowid_list delta }
do_test_query1 2.3.2 {"zero one two"} { rowid_list "zero one two" }
do_test_query1 2.3.3 {zero one two} {
  and_merge_lists [rowid_list zero] [rowid_list one] [rowid_list two]
}
do_test_query1 2.3.4 {"zero one" OR "one two"} {
  or_merge_lists [rowid_list "zero one"] [rowid_list "one two"]
}

#-------------------------------------------------------------------------
# Test cases 3.*
#
do_test 3.0 {
  reset_db
  build_multilingual_db_1 db
  execsql {
    CREATE TABLE t3_data(l, x, y);
    INSERT INTO t3_data(rowid, l, x, y) SELECT docid, l, x, y FROM t2;
    DROP TABLE t2;
  }
} {}
do_execsql_test 3.1 {
  CREATE VIRTUAL TABLE t2 USING fts4(content=t3_data, languageid=l);
  INSERT INTO t2(t2) VALUES('rebuild');
}

do_test_query1 3.1.1 {delta}          { rowid_list delta }
do_test_query1 3.1.2 {"zero one two"} { rowid_list "zero one two" }
do_test_query1 3.1.3 {zero one two} {
  and_merge_lists [rowid_list zero] [rowid_list one] [rowid_list two]
}
do_test_query1 3.1.4 {"zero one" OR "one two"} {
  or_merge_lists [rowid_list "zero one"] [rowid_list "one two"]
}

do_execsql_test 3.2.1 {
  DROP TABLE t2;
  CREATE VIRTUAL TABLE t2 USING fts4(x, y, languageid=l, content=nosuchtable);
}

do_execsql_test 3.2.2 {
  INSERT INTO t2(docid, x, y, l) SELECT rowid, x, y, l FROM t3_data;
}

do_execsql_test 3.2.3 {
  DROP TABLE t3_data;
}

do_test_query1 3.3.1 {delta}          { rowid_list delta }
do_test_query1 3.3.2 {"zero one two"} { rowid_list "zero one two" }
do_test_query1 3.3.3 {zero one two} {
  and_merge_lists [rowid_list zero] [rowid_list one] [rowid_list two]
}
do_test_query1 3.3.4 {"zero one" OR "one two"} {
  or_merge_lists [rowid_list "zero one"] [rowid_list "one two"]
}

#-------------------------------------------------------------------------
# Test cases 4.*
#
proc build_multilingual_db_2 {db} {
  $db eval {
    CREATE VIRTUAL TABLE t4 USING fts4(
        tokenize=testtokenizer, 
        languageid=lid
    );
  }
  for {set i 0} {$i < 50} {incr i} {
    execsql { 
      INSERT INTO t4(docid, content, lid) VALUES($i, 'The Quick Brown Fox', $i) 
    }
  }
}

do_test 4.1.0 {
  reset_db
  set ptr [fts3_test_tokenizer]
  execsql { SELECT fts3_tokenizer('testtokenizer', $ptr) }
  build_multilingual_db_2 db
} {}
do_execsql_test 4.1.1 {
  SELECT docid FROM t4 WHERE t4 MATCH 'quick';
} {0}
do_execsql_test 4.1.2 {
  SELECT docid FROM t4 WHERE t4 MATCH 'quick' AND lid=1;
} {}
do_execsql_test 4.1.3 {
  SELECT docid FROM t4 WHERE t4 MATCH 'Quick' AND lid=1;
} {1}
for {set i 0} {$i < 50} {incr i} {
  do_execsql_test 4.1.4.$i {
    SELECT count(*) FROM t4 WHERE t4 MATCH 'fox' AND lid=$i;
  } [expr 0==($i%2)]
}
do_catchsql_test 4.1.5 {
  INSERT INTO t4(content, lid) VALUES('hello world', 101)
} {1 {SQL logic error or missing database}}

finish_test

source $testdir/tester.tcl

ifcapable !vtab {
  finish_test
  return
}








register_fuzzer_module db



do_test fuzzer1-1.0 {
  catchsql {CREATE VIRTUAL TABLE fault1 USING fuzzer;}
} {1 {fuzzer virtual tables must be TEMP}}


do_test fuzzer1-1.1 {















  db eval {CREATE VIRTUAL TABLE temp.f1 USING fuzzer;}






















} {}

do_test fuzzer1-1.2 {
  db eval {








    INSERT INTO f1(cfrom, cto, cost) VALUES('e','a',1);
    INSERT INTO f1(cfrom, cto, cost) VALUES('a','e',10);
    INSERT INTO f1(cfrom, cto, cost) VALUES('e','o',100);
  }


} {}
























do_test fuzzer1-1.3 {
  db eval {
    SELECT word, distance FROM f1 WHERE word MATCH 'abcde'
  }





} {abcde 0 abcda 1 ebcde 10 ebcda 11 abcdo 100 ebcdo 110 obcde 110 obcda 111 obcdo 210}



































do_test fuzzer1-2.0 {
  execsql {
    CREATE VIRTUAL TABLE temp.f2 USING fuzzer;
    -- costs based on English letter frequencies

    INSERT INTO f2(cFrom,cTo,cost) VALUES('a','e',24);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('a','o',47);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('a','u',50);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('e','a',23);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('e','i',33);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('e','o',37);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('i','e',33);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('i','y',33);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('o','a',41);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('o','e',46);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('o','u',57);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('u','o',58);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('y','i',33);

    INSERT INTO f2(cFrom,cTo,cost) VALUES('t','th',70);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('th','t',66);

 
    INSERT INTO f2(cFrom,cTo,cost) VALUES('a','',84);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','b',106);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('b','',106);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','c',94);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('c','',94);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','d',89);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('d','',89);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','e',83);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('e','',83);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','f',97);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('f','',97);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','g',99);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('g','',99);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','h',86);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('h','',86);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','i',85);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('i','',85);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','j',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('j','',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','k',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('k','',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','l',89);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('l','',89);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','m',96);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('m','',96);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','n',85);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('n','',85);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','o',85);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('o','',85);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','p',100);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('p','',100);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','q',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('q','',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','r',86);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('r','',86);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','s',86);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('s','',86);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','t',84);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('t','',84);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','u',94);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('u','',94);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','v',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('v','',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','w',96);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('w','',96);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','x',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('x','',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','y',100);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('y','',100);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('','z',120);
    INSERT INTO f2(cFrom,cTo,cost) VALUES('z','',120);















    -- Street names for the 28269 ZIPCODE.
    --
    CREATE TEMP TABLE streetname(n TEXT UNIQUE);
    INSERT INTO streetname VALUES('abbotsinch');
    INSERT INTO streetname VALUES('abbottsgate');
    INSERT INTO streetname VALUES('abbywood');
................................................................................
  execsql {
    SELECT DISTINCT streetname.n FROM f2, streetname
     WHERE f2.word MATCH 'tayle'
       AND f2.distance<=200
       AND streetname.n>=f2.word AND streetname.n<=(f2.word || x'F7BFBFBF')
  }
} {{tyler finley} trailer taymouth steelewood tallia tallu talwyn thelema}

































































































































































































































































































































































finish_test

source $testdir/tester.tcl

ifcapable !vtab {
  finish_test
  return
}

set ::testprefix fuzzer1

# Test of test code. Only here to make the coverage metric better.
do_test 0.1 {
  list [catch { register_fuzzer_module a b c } msg] $msg
} {1 {wrong # args: should be "register_fuzzer_module DB"}}

register_fuzzer_module db

# Check configuration errors.
#
do_catchsql_test fuzzer1-1.1 {
  CREATE VIRTUAL TABLE f USING fuzzer;

} {1 {fuzzer: wrong number of CREATE VIRTUAL TABLE arguments}}

do_catchsql_test fuzzer1-1.2 {
  CREATE VIRTUAL TABLE f USING fuzzer(one, two);
} {1 {fuzzer: wrong number of CREATE VIRTUAL TABLE arguments}}

do_catchsql_test fuzzer1-1.3 {
  CREATE VIRTUAL TABLE f USING fuzzer(nosuchtable);
} {1 {fuzzer: no such table: main.nosuchtable}}

do_catchsql_test fuzzer1-1.4 {
  CREATE TEMP TABLE nosuchtable(a, b, c, d);
  CREATE VIRTUAL TABLE f USING fuzzer(nosuchtable);
} {1 {fuzzer: no such table: main.nosuchtable}}

do_catchsql_test fuzzer1-1.5 {
  DROP TABLE temp.nosuchtable;
  CREATE TABLE nosuchtable(a, b, c, d);
  CREATE VIRTUAL TABLE temp.f USING fuzzer(nosuchtable);
} {1 {fuzzer: no such table: temp.nosuchtable}}

do_catchsql_test fuzzer1-1.6 {
  DROP TABLE IF EXISTS f_rules;
  CREATE TABLE f_rules(a, b, c);
  CREATE VIRTUAL TABLE f USING fuzzer(f_rules);
} {1 {fuzzer: f_rules has 3 columns, expected 4}}

do_catchsql_test fuzzer1-1.7 {
  DROP TABLE IF EXISTS f_rules;
  CREATE TABLE f_rules(a, b, c, d, e);
  CREATE VIRTUAL TABLE f USING fuzzer(f_rules);
} {1 {fuzzer: f_rules has 5 columns, expected 4}}


do_execsql_test fuzzer1-2.1 {
  CREATE TABLE f1_rules(ruleset DEFAULT 0, cfrom, cto, cost);
  INSERT INTO f1_rules(cfrom, cto, cost) VALUES('e','a',1);
  INSERT INTO f1_rules(cfrom, cto, cost) VALUES('a','e',10);
  INSERT INTO f1_rules(cfrom, cto, cost) VALUES('e','o',100);

  CREATE VIRTUAL TABLE f1 USING fuzzer(f1_rules);
} {}

do_execsql_test fuzzer1-2.1 {

    SELECT word, distance FROM f1 WHERE word MATCH 'abcde'
} {
  abcde 0   abcda 1   ebcde 10 
  ebcda 11  abcdo 100 ebcdo 110 
  obcde 110 obcda 111 obcdo 210
}

do_execsql_test fuzzer1-2.4 {
  INSERT INTO f1_rules(ruleset, cfrom, cto, cost) VALUES(1,'b','x',1);
  INSERT INTO f1_rules(ruleset, cfrom, cto, cost) VALUES(1,'d','y',10);
  INSERT INTO f1_rules(ruleset, cfrom, cto, cost) VALUES(1,'y','z',100);

  DROP TABLE f1;
  CREATE VIRTUAL TABLE f1 USING fuzzer(f1_rules);
} {}

do_execsql_test fuzzer1-2.5 {
  SELECT word, distance FROM f1 WHERE word MATCH 'abcde'
} {
  abcde 0   abcda 1   ebcde 10 
  ebcda 11  abcdo 100 ebcdo 110 
  obcde 110 obcda 111 obcdo 210
}

do_execsql_test fuzzer1-2.6 {
  SELECT word, distance FROM f1 WHERE word MATCH 'abcde' AND ruleset=0
} {
  abcde 0   abcda 1   ebcde 10 
  ebcda 11  abcdo 100 ebcdo 110 
  obcde 110 obcda 111 obcdo 210
}

do_execsql_test fuzzer1-2.7 {
  SELECT word, distance FROM f1 WHERE word MATCH 'abcde' AND ruleset=1
} {
  abcde 0 axcde 1 abcye 10 
  axcye 11 abcze 110 axcze 111
}

do_test fuzzer1-1.8 {
  db eval {
    SELECT word, distance FROM f1 WHERE word MATCH 'abcde' AND distance<100
  }
} {abcde 0 abcda 1 ebcde 10 ebcda 11}
do_test fuzzer1-1.9 {
  db eval {
    SELECT word, distance FROM f1 WHERE word MATCH 'abcde' AND distance<=100
  }
} {abcde 0 abcda 1 ebcde 10 ebcda 11 abcdo 100}
do_test fuzzer1-1.10 {
  db eval {
    SELECT word, distance FROM f1
     WHERE word MATCH 'abcde' AND distance<100 AND ruleset=0
  }
} {abcde 0 abcda 1 ebcde 10 ebcda 11}
do_test fuzzer1-1.11 {
  db eval {
    SELECT word, distance FROM f1
    WHERE word MATCH 'abcde' AND distance<=100 AND ruleset=0
  }
} {abcde 0 abcda 1 ebcde 10 ebcda 11 abcdo 100}
do_test fuzzer1-1.12 {
  db eval {
    SELECT word, distance FROM f1
     WHERE word MATCH 'abcde' AND distance<11 AND ruleset=1
  }
} {abcde 0 axcde 1 abcye 10}
do_test fuzzer1-1.13 {
  db eval {
    SELECT word, distance FROM f1
    WHERE word MATCH 'abcde' AND distance<=11 AND ruleset=1
  }
} {abcde 0 axcde 1 abcye 10 axcye 11}
do_test fuzzer1-1.14 {
  catchsql {INSERT INTO f1 VALUES(1)}
} {1 {table f1 may not be modified}}
do_test fuzzer1-1.15 {
  catchsql {DELETE FROM f1}
} {1 {table f1 may not be modified}}
do_test fuzzer1-1.16 {
  catchsql {UPDATE f1 SET rowid=rowid+10000}
} {1 {table f1 may not be modified}}


do_test fuzzer1-2.0 {
  execsql {

    -- costs based on English letter frequencies
    CREATE TEMP TABLE f2_rules(ruleset DEFAULT 0, cFrom, cTo, cost);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('a','e',24);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('a','o',47);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('a','u',50);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('e','a',23);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('e','i',33);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('e','o',37);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('i','e',33);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('i','y',33);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('o','a',41);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('o','e',46);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('o','u',57);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('u','o',58);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('y','i',33);

    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('t','th',70);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('th','t',66);
 

    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('a','',84);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','b',106);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('b','',106);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','c',94);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('c','',94);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','d',89);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('d','',89);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','e',83);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('e','',83);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','f',97);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('f','',97);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','g',99);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('g','',99);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','h',86);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('h','',86);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','i',85);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('i','',85);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','j',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('j','',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','k',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('k','',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','l',89);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('l','',89);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','m',96);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('m','',96);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','n',85);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('n','',85);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','o',85);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('o','',85);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','p',100);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('p','',100);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','q',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('q','',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','r',86);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('r','',86);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','s',86);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('s','',86);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','t',84);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('t','',84);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','u',94);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('u','',94);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','v',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('v','',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','w',96);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('w','',96);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','x',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('x','',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','y',100);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('y','',100);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('','z',120);
    INSERT INTO f2_rules(cFrom,cTo,cost) VALUES('z','',120);
    INSERT INTO f2_rules(ruleset,cFrom,cTo,cost)
      SELECT 1, cFrom, cTo, 100 FROM f2_rules WHERE ruleset=0;
    INSERT INTO f2_rules(ruleset,cFrom,cTo,cost)
      SELECT 2, cFrom, cTo, 200-cost FROM f2_rules WHERE ruleset=0;
    INSERT INTO f2_rules(ruleset,cFrom,cTo,cost)
      SELECT 3, cFrom, cTo, cost FROM f2_rules WHERE ruleset=0;
    INSERT INTO f2_rules(ruleset,cFrom,cTo,cost)
      VALUES(3, 'mallard','duck',50),
            (3, 'duck', 'mallard', 50),
            (3, 'rock', 'stone', 50),
            (3, 'stone', 'rock', 50);


    CREATE VIRTUAL TABLE temp.f2 USING fuzzer(f2_rules);

    -- Street names for the 28269 ZIPCODE.
    --
    CREATE TEMP TABLE streetname(n TEXT UNIQUE);
    INSERT INTO streetname VALUES('abbotsinch');
    INSERT INTO streetname VALUES('abbottsgate');
    INSERT INTO streetname VALUES('abbywood');
................................................................................
  execsql {
    SELECT DISTINCT streetname.n FROM f2, streetname
     WHERE f2.word MATCH 'tayle'
       AND f2.distance<=200
       AND streetname.n>=f2.word AND streetname.n<=(f2.word || x'F7BFBFBF')
  }
} {{tyler finley} trailer taymouth steelewood tallia tallu talwyn thelema}
do_test fuzzer1-2.4 {
  execsql {
    SELECT DISTINCT streetname.n
      FROM f2 JOIN streetname
        ON (streetname.n>=f2.word AND streetname.n<=(f2.word || 'zzzzzz'))
     WHERE f2.word MATCH 'duck'
       AND f2.distance<150
       AND f2.ruleset=3
     ORDER BY 1
  }
} {mallard {mallard cove} {mallard forest} {mallard grove} {mallard hill} {mallard park} {mallard ridge} {mallard view}}
do_test fuzzer1-2.5 {
  execsql {
    SELECT DISTINCT streetname.n
      FROM f2 JOIN streetname
        ON (streetname.n>=f2.word AND streetname.n<=(f2.word || 'zzzzzz'))
     WHERE f2.word MATCH 'duck'
       AND f2.distance<150
       AND f2.ruleset=2
     ORDER BY 1
  }
} {}

forcedelete test.db2
do_execsql_test fuzzer1-4.1 {
  ATTACH 'test.db2' AS aux;
  CREATE TABLE aux.f3_rules(ruleset, cfrom, cto, cost);
  INSERT INTO f3_rules(ruleset, cfrom, cto, cost) VALUES(0, 'x','y', 10);
  INSERT INTO f3_rules(ruleset, cfrom, cto, cost) VALUES(1, 'a','b', 10);
  CREATE VIRTUAL TABLE aux.f3 USING fuzzer(f3_rules);
  SELECT word FROM f3 WHERE word MATCH 'ax'
} {ax ay}

#-------------------------------------------------------------------------
#
#  1.5.1 - Check things work with a fuzzer data table name that requires
#          quoting. Also that NULL entries in the "from" column of the
#          data table are treated as zero length strings ('').
#
#  1.5.2 - Check that no-op rules (i.e. C->C) are ignored. Test NULL in
#          the "to" column of a fuzzer data table.
#  
#  1.5.3 - Test out-of-range values for the cost field of the data table.
#
#  1.5.4 - Test out-of-range values for the string fields of the data table.
#
#  1.5.5 - Test out-of-range values for the ruleset field of the data table.
#
do_execsql_test 5.1 {
  CREATE TABLE "fuzzer [x] rules table"(a, b, c, d);
  INSERT INTO "fuzzer [x] rules table" VALUES(0, NULL, 'abc', 10);
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
  SELECT word, distance FROM x WHERE word MATCH '123' LIMIT 4;
} {123 0 abc123 10 1abc23 10 12abc3 10}

do_execsql_test 5.2 {
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES(0, 'x', NULL, 20);
  INSERT INTO "fuzzer [x] rules table" VALUES(0, NULL, NULL, 10);
  INSERT INTO "fuzzer [x] rules table" VALUES(0, 'x', 'x', 10);

  DROP TABLE x;
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');

  SELECT word, distance FROM x WHERE word MATCH 'xx';
} {xx 0 x 20 {} 40}

do_execsql_test 5.3.1 {
  DROP TABLE IF EXISTS x;
  INSERT INTO "fuzzer [x] rules table" VALUES(0, 'c', 'd', 1001);
}
do_catchsql_test 5.3.2 {
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
} {1 {fuzzer: cost must be between 1 and 1000}}

do_execsql_test 5.3.3 {
  DROP TABLE IF EXISTS x;
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES(0, 'd', 'c', 0);
}
do_catchsql_test 5.3.4 {
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
} {1 {fuzzer: cost must be between 1 and 1000}}

do_execsql_test 5.3.5 {
  DROP TABLE IF EXISTS x;
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES(0, 'd', 'c', -20);
}
do_catchsql_test 5.3.6 {
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
} {1 {fuzzer: cost must be between 1 and 1000}}

do_execsql_test 5.4.1 {
  DROP TABLE IF EXISTS x;
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES(
    0, 'x', '12345678901234567890123456789012345678901234567890', 2
  );
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
  SELECT word FROM x WHERE word MATCH 'x';
} {x 12345678901234567890123456789012345678901234567890}

do_execsql_test 5.4.2 {
  DROP TABLE IF EXISTS x;
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES(
    0, 'x', '123456789012345678901234567890123456789012345678901', 2
  );
} 
do_catchsql_test 5.4.3 {
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
} {1 {fuzzer: maximum string length is 50}}

do_execsql_test 5.4.4 {
  DROP TABLE IF EXISTS x;
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES(
    0, '123456789012345678901234567890123456789012345678901', 'x', 2
  );
} 
do_catchsql_test 5.4.5 {
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
} {1 {fuzzer: maximum string length is 50}}

do_execsql_test 5.5.1 {
  DROP TABLE IF EXISTS x;
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES(-1, 'x', 'y', 2);
} 
do_catchsql_test 5.5.2 {
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
} {1 {fuzzer: ruleset must be between 0 and 2147483647}}

do_execsql_test 5.5.3 {
  DROP TABLE IF EXISTS x;
  DELETE FROM "fuzzer [x] rules table";
  INSERT INTO "fuzzer [x] rules table" VALUES((1<<32)+100, 'x', 'y', 2);
} 
do_catchsql_test 5.5.4 {
  CREATE VIRTUAL TABLE x USING fuzzer('fuzzer [x] rules table');
} {1 {fuzzer: ruleset must be between 0 and 2147483647}}

#-------------------------------------------------------------------------
# This test uses a fuzzer table with many rules. There is one rule to
# map each possible two character string, where characters are lower-case
# letters used in the English language, to all other possible two character
# strings. In total, (26^4)-(26^2) mappings (the subtracted term represents
# the no-op mappings discarded automatically by the fuzzer).
#
#
do_execsql_test 6.1.1 {
  DROP TABLE IF EXISTS x1;
  DROP TABLE IF EXISTS x1_rules;
  CREATE TABLE x1_rules(ruleset, cFrom, cTo, cost);
}
puts "This test is slow - perhaps around 7 seconds on an average pc"
do_test 6.1.2 {
  set LETTERS {a b c d e f g h i j k l m n o p q r s t u v w x y z}
  set cost 1
  db transaction {
    foreach c1 $LETTERS { 
      foreach c2 $LETTERS { 
        foreach c3 $LETTERS { 
          foreach c4 $LETTERS { 
            db eval {INSERT INTO x1_rules VALUES(0, $c1||$c2, $c3||$c4, $cost)}
            set cost [expr ($cost%1000) + 1]
          }
        }
      }
    }
    db eval {UPDATE x1_rules SET cost = 20 WHERE cost<20 AND cFrom!='xx'}
  }
} {}

do_execsql_test 6.2 {
  SELECT count(*) FROM x1_rules WHERE cTo!=cFrom;
} [expr 26*26*26*26 - 26*26]

do_execsql_test 6.2.1 {
  CREATE VIRTUAL TABLE x1 USING fuzzer(x1_rules);
  SELECT word FROM x1 WHERE word MATCH 'xx' LIMIT 10;
} {xx hw hx hy hz ia ib ic id ie}
do_execsql_test 6.2.2 {
  SELECT cTo FROM x1_rules WHERE cFrom='xx' 
  ORDER BY cost asc, rowid asc LIMIT 9;
} {hw hx hy hz ia ib ic id ie}

#-------------------------------------------------------------------------
# Test using different types of quotes with CREATE VIRTUAL TABLE 
# arguments.
#
do_execsql_test 7.1 {
  CREATE TABLE [x2 "rules] (a, b, c, d);
  INSERT INTO [x2 "rules] VALUES(0, 'a', 'b', 5);
}
foreach {tn sql} {
  1 { CREATE VIRTUAL TABLE x2 USING fuzzer( [x2 "rules] ) }
  2 { CREATE VIRTUAL TABLE x2 USING fuzzer( "x2 ""rules" ) }
  3 { CREATE VIRTUAL TABLE x2 USING fuzzer( 'x2 "rules' ) }
  4 { CREATE VIRTUAL TABLE x2 USING fuzzer( `x2 "rules` ) }
} {
  do_execsql_test 7.2.$tn.1 { DROP TABLE IF EXISTS x2 }
  do_execsql_test 7.2.$tn.2 $sql
  do_execsql_test 7.2.$tn.3 { 
    SELECT word FROM x2 WHERE word MATCH 'aaa' 
  } {aaa baa aba aab bab abb bba bbb}
}

#-------------------------------------------------------------------------
# Test using a fuzzer table in different contexts.
#
do_execsql_test 8.1 {
  CREATE TABLE x3_rules(rule_set, cFrom, cTo, cost);
  INSERT INTO x3_rules VALUES(2, 'a', 'x', 10);
  INSERT INTO x3_rules VALUES(2, 'a', 'y',  9);
  INSERT INTO x3_rules VALUES(2, 'a', 'z',  8);
  CREATE VIRTUAL TABLE x3 USING fuzzer(x3_rules);
}

do_execsql_test 8.2.1 {
  SELECT cFrom, cTo, word 
    FROM x3_rules CROSS JOIN x3 
    WHERE word MATCH 'a' AND cost=distance AND ruleset=2;
} {a x x a y y a z z}

do_execsql_test 8.2.2 {
  SELECT cFrom, cTo, word 
    FROM x3 CROSS JOIN x3_rules
    WHERE word MATCH 'a' AND cost=distance AND ruleset=2;
} {a z z a y y a x x}

do_execsql_test 8.2.3 {
  SELECT cFrom, cTo, word 
    FROM x3_rules, x3 
    WHERE word MATCH 'a' AND cost=distance AND ruleset=2;
} {a z z a y y a x x}

do_execsql_test 8.2.4 {
  SELECT cFrom, cTo, word 
    FROM x3, x3_rules
    WHERE word MATCH 'a' AND cost=distance AND ruleset=2;
} {a z z a y y a x x}

do_execsql_test 8.2.5 {
  CREATE INDEX i1 ON x3_rules(cost);
  SELECT cFrom, cTo, word 
    FROM x3_rules, x3 
    WHERE word MATCH 'a' AND cost=distance AND ruleset=2;
} {a z z a y y a x x}

do_execsql_test 8.2.5 {
  SELECT word FROM x3_rules, x3 WHERE word MATCH x3_rules.cFrom AND ruleset=2;
} {a z y x a z y x a z y x}

do_execsql_test 8.2.6 {
  SELECT word FROM x3_rules, x3 
  WHERE word MATCH x3_rules.cFrom 
    AND ruleset=2 
    AND x3_rules.cost=8;
} {a z y x}

do_execsql_test 8.2.7 {
  CREATE TABLE t1(a, b);
  CREATE INDEX i2 ON t1(b);
  SELECT word, distance FROM x3, t1 
    WHERE x3.word MATCH t1.a AND ruleset=2 AND distance=t1.b;
} {}

do_execsql_test 8.2.8 {
  INSERT INTO x3_rules VALUES(1, 'a', 't',  5);
  INSERT INTO x3_rules VALUES(1, 'a', 'u',  4);
  INSERT INTO x3_rules VALUES(1, 'a', 'v',  3);
  DROP TABLE x3;
  CREATE VIRTUAL TABLE x3 USING fuzzer(x3_rules);
  SELECT * FROM x3_rules;
} {
  2 a x 10 
  2 a y 9 
  2 a z 8 
  1 a t 5 
  1 a u 4 
  1 a v 3
}

do_catchsql_test 8.2.9 {
  SELECT word FROM x3 WHERE ruleset=2 AND word MATCH 'a' AND WORD MATCH 'b';
} {1 {unable to use function MATCH in the requested context}}

do_execsql_test 8.2.10 {
  SELECT word FROM x3 WHERE ruleset=1 AND word MATCH 'a'
} {a v u t}

# The term "ruleset<=1" is not handled by the fuzzer module. Instead, it
# is handled by SQLite, which assumes that all rows have a NULL value in
# the ruleset column. Since NULL<=1 is never true, this query returns
# no rows.
do_execsql_test 8.2.11 {
  SELECT word FROM x3 WHERE ruleset<=1 AND word MATCH 'a'
} {}

do_execsql_test 8.2.12 {
  SELECT word FROM x3 WHERE ruleset=1 AND word MATCH 'a' ORDER BY distance ASC;
} {a v u t}

do_execsql_test 8.2.13 {
  SELECT word FROM x3 WHERE ruleset=1 AND word MATCH 'a' ORDER BY distance DESC;
} {t u v a}

do_execsql_test 8.2.13 {
  SELECT word FROM x3 WHERE ruleset=1 AND word MATCH 'a' ORDER BY word ASC;
} {a t u v}

do_execsql_test 8.2.14 {
  SELECT word FROM x3 WHERE ruleset=1 AND word MATCH 'a' ORDER BY word DESC;
} {v u t a}

#-------------------------------------------------------------------------
#
do_execsql_test 9.1 {
  CREATE TABLE x4_rules(a, b, c, d);
  INSERT INTO x4_rules VALUES(0, 'a', 'b', 10);
  INSERT INTO x4_rules VALUES(0, 'a', 'c', 11);
  INSERT INTO x4_rules VALUES(0, 'bx', 'zz', 20);
  INSERT INTO x4_rules VALUES(0, 'cx', 'yy', 15);
  INSERT INTO x4_rules VALUES(0, 'zz', '!!', 50);
  CREATE VIRTUAL TABLE x4 USING fuzzer(x4_rules);
}

do_execsql_test 9.2 {
  SELECT word, distance FROM x4 WHERE word MATCH 'ax';
} {ax 0 bx 10 cx 11 yy 26 zz 30 !! 80}


do_execsql_test 10.1 {
  CREATE TABLE x5_rules(a, b, c, d);
  CREATE VIRTUAL TABLE x5 USING fuzzer(x5_rules);
}

do_execsql_test 10.2 {
  SELECT word, distance FROM x5 WHERE word MATCH 
    'aaaaaaaaaXaaaaaaaaaXaaaaaaaaaXaaaaaaaaaXaaaaaaaaa' || 
    'aaaaaaaaaXaaaaaaaaaXaaaaaaaaaXaaaaaaaaaXaaaaaaaaa' || 
    'aaaaaaaaaXaaaaaaaaaXaaaaaaaaaXaaaaaaaaaXaaaaaaaaa'
} {}

do_execsql_test 10.3 {
  INSERT INTO x5_rules VALUES(0, 'a', '0.1.2.3.4.5.6.7.8.9.a', 1);
  DROP TABLE x5;
  CREATE VIRTUAL TABLE x5 USING fuzzer(x5_rules);
  SELECT length(word) FROM x5 WHERE word MATCH 'a' LIMIT 50;
} {1 21 41 61 81}

finish_test

# 2012 February 21
#
# 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 TCL interface to the
# SQLite library. 
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable !vtab { finish_test ; return }
set ::testprefix fuzzerfault

register_fuzzer_module db

do_test 1-pre1 {
  execsql {
    CREATE TABLE x1_rules(ruleset, cFrom, cTo, cost);
    INSERT INTO x1_rules VALUES(0, 'a', 'b', 1);
    INSERT INTO x1_rules VALUES(0, 'a', 'c', 2);
    INSERT INTO x1_rules VALUES(0, 'a', 'd', 3);
  }
  faultsim_save_and_close
} {}
do_faultsim_test 1 -prep {
  faultsim_restore_and_reopen
  register_fuzzer_module db
} -body {
  execsql { 
    CREATE VIRTUAL TABLE x1 USING fuzzer(x1_rules);
    SELECT word FROM x1 WHERE word MATCH 'xax';
  }
} -test {
  faultsim_test_result {0 {xax xbx xcx xdx}}               \
                       {1 {vtable constructor failed: x1}}
}

do_test 2-pre1 {
  faultsim_delete_and_reopen
  register_fuzzer_module db
  execsql {
    CREATE TABLE x2_rules(ruleset, cFrom, cTo, cost);
    INSERT INTO x2_rules VALUES(0, 'a', 'x', 1);
    INSERT INTO x2_rules VALUES(0, 'b', 'x', 2);
    INSERT INTO x2_rules VALUES(0, 'c', 'x', 3);
    CREATE VIRTUAL TABLE x2 USING fuzzer(x2_rules);
  }
  faultsim_save_and_close
} {}

do_faultsim_test 2 -prep {
  faultsim_restore_and_reopen
  register_fuzzer_module db
} -body {
  execsql { 
    SELECT count(*) FROM x2 WHERE word MATCH 'abc';
  }
} -test {
  faultsim_test_result {0 8} {1 {vtable constructor failed: x2}}
}

do_test 3-pre1 {
  faultsim_delete_and_reopen
  execsql {
    CREATE TABLE x1_rules(ruleset, cFrom, cTo, cost);
    INSERT INTO x1_rules VALUES(0, 'a', 
      '123456789012345678901234567890a1234567890123456789', 10
    );
  }
  faultsim_save_and_close
} {}

do_faultsim_test 3 -prep {
  faultsim_restore_and_reopen
  register_fuzzer_module db
} -body {
  execsql { 
    CREATE VIRTUAL TABLE x1 USING fuzzer(x1_rules);
    SELECT count(*) FROM (SELECT * FROM x1 WHERE word MATCH 'a' LIMIT 2);
  }
} -test {
  faultsim_test_result {0 2} {1 {vtable constructor failed: x1}}
}


finish_test

    SELECT * FROM t2 WHERE a IN (
      SELECT a, b FROM t3 INTERSECT SELECT a FROM t2
    );
  }
} {1 {SELECTs to the left and right of INTERSECT do not have the same number of result columns}}
}


do_test in-12.10 {
  catchsql {
    SELECT * FROM t2 WHERE a IN (
      SELECT a FROM t3 UNION ALL SELECT a, b FROM t2
    );
  }
} {1 {only a single result allowed for a SELECT that is part of an expression}}
................................................................................
do_test in-12.13 {
  catchsql {
    SELECT * FROM t2 WHERE a IN (
      SELECT a FROM t3 INTERSECT SELECT a, b FROM t2
    );
  }
} {1 {only a single result allowed for a SELECT that is part of an expression}}



#------------------------------------------------------------------------
# The following tests check that NULL is handled correctly when it 
# appears as part of a set of values on the right-hand side of an
# IN or NOT IN operator.
#

    SELECT * FROM t2 WHERE a IN (
      SELECT a, b FROM t3 INTERSECT SELECT a FROM t2
    );
  }
} {1 {SELECTs to the left and right of INTERSECT do not have the same number of result columns}}
}

ifcapable compound {
do_test in-12.10 {
  catchsql {
    SELECT * FROM t2 WHERE a IN (
      SELECT a FROM t3 UNION ALL SELECT a, b FROM t2
    );
  }
} {1 {only a single result allowed for a SELECT that is part of an expression}}
................................................................................
do_test in-12.13 {
  catchsql {
    SELECT * FROM t2 WHERE a IN (
      SELECT a FROM t3 INTERSECT SELECT a, b FROM t2
    );
  }
} {1 {only a single result allowed for a SELECT that is part of an expression}}
}; #ifcapable compound


#------------------------------------------------------------------------
# The following tests check that NULL is handled correctly when it 
# appears as part of a set of values on the right-hand side of an
# IN or NOT IN operator.
#

  } {10}
  do_test incrblob-6.9 {
    seek $::blob 0
    puts -nonewline $::blob "invocation"
    flush $::blob
  } {}
  
  # At this point rollback should be illegal (because 
  # there is an open blob channel).  But commit is also illegal because
  # the open blob is read-write.
  #
  do_test incrblob-6.10 {
    catchsql {
      ROLLBACK;
    } db2
  } {1 {cannot rollback transaction - SQL statements in progress}}
  do_test incrblob-6.11 {
    catchsql {
      COMMIT;
    } db2
  } {1 {cannot commit transaction - SQL statements in progress}}
  
  do_test incrblob-6.12 {

  } {10}
  do_test incrblob-6.9 {
    seek $::blob 0
    puts -nonewline $::blob "invocation"
    flush $::blob
  } {}
  
  # At this point commit should be illegal (because 
  # there is an open blob channel).

  #





  do_test incrblob-6.11 {
    catchsql {
      COMMIT;
    } db2
  } {1 {cannot commit transaction - SQL statements in progress}}
  
  do_test incrblob-6.12 {

    INSERT INTO t6 SELECT nullif(y*2+10,14), y+100 FROM t6;
    SELECT x, y FROM t6;
  }
} {1 1 2 2 3 3 12 101 13 102 16 103}

# Multiple VALUES clauses
#

do_test insert-10.1 {
  execsql {
    CREATE TABLE t10(a,b,c);
    INSERT INTO t10 VALUES(1,2,3), (4,5,6), (7,8,9);
    SELECT * FROM t10;
  }
} {1 2 3 4 5 6 7 8 9}
do_test insert-10.2 {
  catchsql {
    INSERT INTO t10 VALUES(11,12,13), (14,15);
  }
} {1 {all VALUES must have the same number of terms}}


integrity_check insert-99.0

finish_test

    INSERT INTO t6 SELECT nullif(y*2+10,14), y+100 FROM t6;
    SELECT x, y FROM t6;
  }
} {1 1 2 2 3 3 12 101 13 102 16 103}

# Multiple VALUES clauses
#
ifcapable compound {
  do_test insert-10.1 {
    execsql {
      CREATE TABLE t10(a,b,c);
      INSERT INTO t10 VALUES(1,2,3), (4,5,6), (7,8,9);
      SELECT * FROM t10;
    }
  } {1 2 3 4 5 6 7 8 9}
  do_test insert-10.2 {
    catchsql {
      INSERT INTO t10 VALUES(11,12,13), (14,15);
    }
  } {1 {all VALUES must have the same number of terms}}
}

integrity_check insert-99.0

finish_test

} {1 91 92 3 93 5 93}
do_test join6-3.6 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 JOIN t3 USING(z);
  }
} {1 91 92 3 93 5 91 2 93 94 4 95 6 99}


do_test join6-4.1 {
  execsql {
    SELECT * FROM
       (SELECT 1 AS a, 91 AS x, 92 AS y UNION SELECT 2, 93, 94)
       NATURAL JOIN t2 NATURAL JOIN t3
  }
} {1 91 92 3 93 5}
do_test join6-4.2 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN
       (SELECT 3 AS b, 92 AS y, 93 AS z UNION SELECT 4, 94, 95)
       NATURAL JOIN t3
  }
} {1 91 92 3 93 5}
do_test join6-4.3 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 NATURAL JOIN
       (SELECT 5 AS c, 91 AS x, 93 AS z UNION SELECT 6, 99, 95)
  }
} {1 91 92 3 93 5}












finish_test

} {1 91 92 3 93 5 93}
do_test join6-3.6 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 JOIN t3 USING(z);
  }
} {1 91 92 3 93 5 91 2 93 94 4 95 6 99}

ifcapable compound {
  do_test join6-4.1 {
    execsql {
      SELECT * FROM
         (SELECT 1 AS a, 91 AS x, 92 AS y UNION SELECT 2, 93, 94)
         NATURAL JOIN t2 NATURAL JOIN t3
    }
  } {1 91 92 3 93 5}
  do_test join6-4.2 {
    execsql {
      SELECT * FROM t1 NATURAL JOIN
         (SELECT 3 AS b, 92 AS y, 93 AS z UNION SELECT 4, 94, 95)
         NATURAL JOIN t3
    }
  } {1 91 92 3 93 5}
  do_test join6-4.3 {
    execsql {
      SELECT * FROM t1 NATURAL JOIN t2 NATURAL JOIN
         (SELECT 5 AS c, 91 AS x, 93 AS z UNION SELECT 6, 99, 95)
    }
  } {1 91 92 3 93 5}
}











finish_test

#-------------------------------------------------------------------------
# If a connection is required to create a journal file, it creates it with 
# the same file-system permissions as the database file itself. Test this.
#
if {$::tcl_platform(platform) == "unix" && ![path_is_dos "."]} {



  set umask [exec /bin/sh -c umask]
  faultsim_delete_and_reopen
  do_test journal3-1.1 { execsql { CREATE TABLE tx(y, z) } } {}

  foreach {tn permissions} {
   1 00644
   2 00666
   3 00600
   4 00755
  } {
    db close
    set effective [format %.5o [expr $permissions & ~$umask]]

    do_test journal3-1.2.$tn.1 {
      catch { forcedelete test.db-journal }
      file attributes test.db -permissions $permissions
      file attributes test.db -permissions
    } $permissions
    do_test journal3-1.2.$tn.2 { file exists test.db-journal } {0}
    do_test journal3-1.2.$tn.3 {

#-------------------------------------------------------------------------
# If a connection is required to create a journal file, it creates it with 
# the same file-system permissions as the database file itself. Test this.
#
if {$::tcl_platform(platform) == "unix" && ![path_is_dos "."]} {

  # Changed on 2012-02-13:  umask is deliberately ignored for -wal, -journal,
  # and -shm files.
  #set umask [exec /bin/sh -c umask]
  faultsim_delete_and_reopen
  do_test journal3-1.1 { execsql { CREATE TABLE tx(y, z) } } {}

  foreach {tn permissions} {
   1 00644
   2 00666
   3 00600
   4 00755
  } {
    db close
    #set effective [format %.5o [expr $permissions & ~$umask]]
    set effective $permissions
    do_test journal3-1.2.$tn.1 {
      catch { forcedelete test.db-journal }
      file attributes test.db -permissions $permissions
      file attributes test.db -permissions
    } $permissions
    do_test journal3-1.2.$tn.2 { file exists test.db-journal } {0}
    do_test journal3-1.2.$tn.3 {

#
# Demonstration that the value returned for p is on the same row as 
# the maximum q.
#

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






do_test minmax4-1.1 {
  db eval {
    CREATE TABLE t1(p,q);
    SELECT p, max(q) FROM t1;
  }
} {{} {}}

#
# Demonstration that the value returned for p is on the same row as 
# the maximum q.
#

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

ifcapable !compound {
  finish_test
  return
}

do_test minmax4-1.1 {
  db eval {
    CREATE TABLE t1(p,q);
    SELECT p, max(q) FROM t1;
  }
} {{} {}}

    foreach f [glob -nocomplain test.*] {forcecopy $f "xx_$f"}
    sqlite3 db2 file:xx_test.db?8_3_names=1
    execsql {SELECT md5sum(a, b) FROM t1 ORDER BY a} db2
  } $::cksum1

  db2 close
}






























catch { db close }




sqlite3_multiplex_shutdown
finish_test

    foreach f [glob -nocomplain test.*] {forcecopy $f "xx_$f"}
    sqlite3 db2 file:xx_test.db?8_3_names=1
    execsql {SELECT md5sum(a, b) FROM t1 ORDER BY a} db2
  } $::cksum1

  db2 close
}
catch { db close }


do_test 3.0 { setup_and_save_db } {}
do_faultsim_test 3 -faults ioerr-trans* -prep {

  forcedelete test2.db
  set fd [open test2.wal w]
  seek $fd 4095
  puts -nonewline $fd x
  close $fd

  multiplex_restore_db
  sqlite3 db file:test.db?8_3_names=1
  sqlite3 db2 file:test2.db?8_3_names=1
  sqlite3_multiplex_control db main chunk_size [expr 256*1024]
  sqlite3_multiplex_control db2 main chunk_size [expr 256*1024]
} -body {
  sqlite3_backup B db2 main db main
  B step 100000
  set rc [B finish]
  if { [string match SQLITE_IOERR_* $rc] } {error "disk I/O error"}
  set rc
} -test {
  faultsim_test_result {0 SQLITE_OK}
  if {$testrc==0} {
    set cksum2 [execsql {SELECT md5sum(a, b) FROM t1 ORDER BY a} db2]
    if {$cksum2 != $::cksum1} { error "data mismatch" }
  }
  catch { B finish }
  catch { db close }
  catch { db2 close }
}

catch { db close }
sqlite3_multiplex_shutdown
finish_test

  fts3defer.test fts3defer2.test fts3e.test fts3expr.test fts3expr2.test 
  fts3near.test fts3query.test fts3shared.test fts3snippet.test 
  fts3sort.test
  fts3fault.test fts3malloc.test fts3matchinfo.test
  fts3aux1.test fts3comp1.test fts3auto.test
  fts4aa.test fts4content.test
  fts3conf.test fts3prefix.test fts3fault2.test fts3corrupt.test
  fts3corrupt2.test
  fts3first.test
}


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

  fts3defer.test fts3defer2.test fts3e.test fts3expr.test fts3expr2.test 
  fts3near.test fts3query.test fts3shared.test fts3snippet.test 
  fts3sort.test
  fts3fault.test fts3malloc.test fts3matchinfo.test
  fts3aux1.test fts3comp1.test fts3auto.test
  fts4aa.test fts4content.test
  fts3conf.test fts3prefix.test fts3fault2.test fts3corrupt.test
  fts3corrupt2.test fts3first.test fts4langid.test

}


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

    execsql "
      PRAGMA temp_store=$::temp_setting;
      PRAGMA temp_store=$::temp_setting;
      PRAGMA temp_store;
    "
  } $val
}























finish_test

    execsql "
      PRAGMA temp_store=$::temp_setting;
      PRAGMA temp_store=$::temp_setting;
      PRAGMA temp_store;
    "
  } $val
}

# The SQLITE_FCNTL_PRAGMA logic, with error handling.
#
db close
testvfs tvfs
sqlite3 db test.db -vfs tvfs
do_test pragma-19.1 {
  catchsql {PRAGMA error}
} {1 {SQL logic error or missing database}}
do_test pragma-19.2 {
  catchsql {PRAGMA error='This is the error message'}
} {1 {This is the error message}}
do_test pragma-19.3 {
  catchsql {PRAGMA error='7 This is the error message'}
} {1 {This is the error message}}
do_test pragma-19.4 {
  catchsql {PRAGMA error=7}
} {1 {out of memory}}
do_test pragma-19.5 {
  file tail [lindex [execsql {PRAGMA filename}] 0]
} {test.db}


finish_test

# expression evaluation logic of TCL.
#
# An early version of this script is how bug #3541 was detected.
#
# $Id: randexpr1.test,v 1.1 2008/12/15 16:33:30 drh Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl






# Create test data
#
do_test randexpr1-1.1 {
  db eval {
    CREATE TABLE t1(a,b,c,d,e,f);
    INSERT INTO t1 VALUES(100,200,300,400,500,600);

# expression evaluation logic of TCL.
#
# An early version of this script is how bug #3541 was detected.
#
# $Id: randexpr1.test,v 1.1 2008/12/15 16:33:30 drh Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !compound {
  finish_test
  return
}

# Create test data
#
do_test randexpr1-1.1 {
  db eval {
    CREATE TABLE t1(a,b,c,d,e,f);
    INSERT INTO t1 VALUES(100,200,300,400,500,600);

    catchsql {RELEASE abc}
  } {1 {no such savepoint: abc}}
  
  do_test savepoint-5.3.1 {
    execsql  {SAVEPOINT abc}
    catchsql {ROLLBACK TO def}
  } {1 {no such savepoint: def}}
  do_test savepoint-5.3.2 {
    execsql  {SAVEPOINT def}
    set fd [db incrblob -readonly blobs x 1]




    catchsql {ROLLBACK TO def}
  } {1 {cannot rollback savepoint - SQL statements in progress}}





  do_test savepoint-5.3.3 {
    catchsql  {RELEASE def}
  } {0 {}}
  do_test savepoint-5.3.4 {
    close $fd
    execsql  {savepoint def}
    set fd [db incrblob blobs x 1]
................................................................................
    execsql {
      ATTACH 'test2.db' AS aux1;
      ATTACH 'test3.db' AS aux2;
      DROP TABLE t1;
      CREATE TABLE main.t1(x, y);
      CREATE TABLE aux1.t2(x, y);
      CREATE TABLE aux2.t3(x, y);
      SELECT name FROM sqlite_master 
        UNION ALL
      SELECT name FROM aux1.sqlite_master 
        UNION ALL
      SELECT name FROM aux2.sqlite_master;
    }
  } {t1 t2 t3}
  do_test savepoint-10.2.2 {
    execsql { PRAGMA lock_status }
  } [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]
  
................................................................................
    execsql { ROLLBACK TO two }
    execsql { SELECT * FROM t2 }
  } {}
  do_test savepoint-10.2.8 {
    execsql { PRAGMA lock_status }
  } [list main reserved temp $templockstate aux1 reserved aux2 reserved]
  do_test savepoint-10.2.9 {
    execsql { SELECT 'a', * FROM t1 UNION ALL SELECT 'b', * FROM t3 }
  } {a 1 2 b 3 4}
  do_test savepoint-10.2.9 {
    execsql {
      INSERT INTO t2 VALUES(5, 6);
      RELEASE one;
    }
    execsql { 

    catchsql {RELEASE abc}
  } {1 {no such savepoint: abc}}
  
  do_test savepoint-5.3.1 {
    execsql  {SAVEPOINT abc}
    catchsql {ROLLBACK TO def}
  } {1 {no such savepoint: def}}
  do_test savepoint-5.3.2.1 {
    execsql  {SAVEPOINT def}
    set fd [db incrblob -readonly blobs x 1]
    set rc [catch {seek $fd 0;read $fd} res]
    lappend rc $res
  } {0 {hellontyeight character blob}}
  do_test savepoint-5.3.2.2 {
    catchsql {ROLLBACK TO def}

  } {0 {}}
  do_test savepoint-5.3.2.3 {
    set rc [catch {seek $fd 0; read $fd} res]
    set rc
  } {1}
  do_test savepoint-5.3.3 {
    catchsql  {RELEASE def}
  } {0 {}}
  do_test savepoint-5.3.4 {
    close $fd
    execsql  {savepoint def}
    set fd [db incrblob blobs x 1]
................................................................................
    execsql {
      ATTACH 'test2.db' AS aux1;
      ATTACH 'test3.db' AS aux2;
      DROP TABLE t1;
      CREATE TABLE main.t1(x, y);
      CREATE TABLE aux1.t2(x, y);
      CREATE TABLE aux2.t3(x, y);
      SELECT name FROM sqlite_master;

      SELECT name FROM aux1.sqlite_master;

      SELECT name FROM aux2.sqlite_master;
    }
  } {t1 t2 t3}
  do_test savepoint-10.2.2 {
    execsql { PRAGMA lock_status }
  } [list main unlocked temp $templockstate aux1 unlocked aux2 unlocked]
  
................................................................................
    execsql { ROLLBACK TO two }
    execsql { SELECT * FROM t2 }
  } {}
  do_test savepoint-10.2.8 {
    execsql { PRAGMA lock_status }
  } [list main reserved temp $templockstate aux1 reserved aux2 reserved]
  do_test savepoint-10.2.9 {
    execsql { SELECT 'a', * FROM t1 ; SELECT 'b', * FROM t3 }
  } {a 1 2 b 3 4}
  do_test savepoint-10.2.9 {
    execsql {
      INSERT INTO t2 VALUES(5, 6);
      RELEASE one;
    }
    execsql { 

    execsql { DROP INDEX i1 } db2
    db2 close
  } {}
  do_test select1-15.3 {
    execsql { SELECT 2 IN (SELECT a FROM t1) }
  } {1}
}
  






finish_test

    execsql { DROP INDEX i1 } db2
    db2 close
  } {}
  do_test select1-15.3 {
    execsql { SELECT 2 IN (SELECT a FROM t1) }
  } {1}
}

# Crash bug reported on the mailing list on 2012-02-23
#
do_test select1-16.1 {
  catchsql {SELECT 1 FROM (SELECT *)}
} {1 {no tables specified}}
  
finish_test

  catchsql {
    SELECT 1 UNION SELECT 2,3 UNION SELECT 4,5 ORDER BY 1;
  } db2
} {1 {SELECTs to the left and right of UNION do not have the same number of result columns}}

} ;# ifcapable compound




















finish_test

  catchsql {
    SELECT 1 UNION SELECT 2,3 UNION SELECT 4,5 ORDER BY 1;
  } db2
} {1 {SELECTs to the left and right of UNION do not have the same number of result columns}}

} ;# ifcapable compound


# Ticket [3557ad65a076c] - Incorrect DISTINCT processing with an
# indexed query using IN.
#
do_test select4-13.1 {
  sqlite3 db test.db
  db eval {
    CREATE TABLE t13(a,b);
    INSERT INTO t13 VALUES(1,1);
    INSERT INTO t13 VALUES(2,1);
    INSERT INTO t13 VALUES(3,1);
    INSERT INTO t13 VALUES(2,2);
    INSERT INTO t13 VALUES(3,2);
    INSERT INTO t13 VALUES(4,2);
    CREATE INDEX t13ab ON t13(a,b);
    SELECT DISTINCT b from t13 WHERE a IN (1,2,3);
  }
} {1 2}

finish_test

      FROM t1
     ORDER BY x DESC
  }
} {CCC AAA AAA}

# The following query used to leak memory.  Verify that has been fixed.
#
ifcapable trigger {
  do_test selectC-2.1 {
    catchsql {
      CREATE TABLE t21a(a,b);
      INSERT INTO t21a VALUES(1,2);
      CREATE TABLE t21b(n);
      CREATE TRIGGER r21 AFTER INSERT ON t21b BEGIN
        SELECT a FROM t21a WHERE a>new.x UNION ALL

      FROM t1
     ORDER BY x DESC
  }
} {CCC AAA AAA}

# The following query used to leak memory.  Verify that has been fixed.
#
ifcapable trigger&&compound {
  do_test selectC-2.1 {
    catchsql {
      CREATE TABLE t21a(a,b);
      INSERT INTO t21a VALUES(1,2);
      CREATE TABLE t21b(n);
      CREATE TRIGGER r21 AFTER INSERT ON t21b BEGIN
        SELECT a FROM t21a WHERE a>new.x UNION ALL

        DELETE FROM numbers;
      } db1
    }
  }
  list $a $count
} {32 64}

#---------------------------------------------------------------------------
# These tests, shared2.2.*, test the outcome when data is added to or 
# removed from a table due to a rollback while a read-uncommitted 
# cursor is scanning it.
#
do_test shared2-2.1 {
  execsql {
    INSERT INTO numbers VALUES(1, 'Medium length text field');
    INSERT INTO numbers VALUES(2, 'Medium length text field');
    INSERT INTO numbers VALUES(3, 'Medium length text field');
    INSERT INTO numbers VALUES(4, 'Medium length text field');
    BEGIN;
    DELETE FROM numbers WHERE (a%2)=0;
  } db1
  set res [list]
  db2 eval {
    SELECT a FROM numbers ORDER BY a;
  } {
    lappend res $a
    if {$a==3} {
      execsql {ROLLBACK} db1
    }
  }
  set res
} {1 3 4}
do_test shared2-2.2 {
  execsql {
    BEGIN;
    INSERT INTO numbers VALUES(5, 'Medium length text field');
    INSERT INTO numbers VALUES(6, 'Medium length text field');
  } db1
  set res [list]
  db2 eval {
    SELECT a FROM numbers ORDER BY a;
  } {
    lappend res $a
    if {$a==5} {
      execsql {ROLLBACK} db1
    }
  }
  set res
} {1 2 3 4 5}

db1 close
db2 close

do_test shared2-3.2 {
  sqlite3_enable_shared_cache 1
} {1}

        DELETE FROM numbers;
      } db1
    }
  }
  list $a $count
} {32 64}












































db1 close
db2 close

do_test shared2-3.2 {
  sqlite3_enable_shared_cache 1
} {1}

# This file implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#

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

ifcapable !vtab {
  finish_test
  return
}


set ::asc 1
proc a_string {n} { string range [string repeat [incr ::asc]. $n] 1 $n }

# This file implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#

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

ifcapable !vtab||!compound {
  finish_test
  return
}


set ::asc 1
proc a_string {n} { string range [string repeat [incr ::asc]. $n] 1 $n }

#-------------------------------------------------------------------------
# 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
} {
  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

#-------------------------------------------------------------------------
# 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 umask
} {
  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

#
# This file implements tests to verify that ticket [02a8e81d44] has been
# fixed.  
#

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






do_test tkt-02a838-1.1 {
  execsql {
    CREATE TABLE t1(a);
    INSERT INTO t1 VALUES(1);
    INSERT INTO t1 VALUES(2);
    INSERT INTO t1 VALUES(4);
    INSERT INTO t1 VALUES(5);
    SELECT * FROM (SELECT a FROM t1 LIMIT 1) UNION ALL SELECT 3;
  }
} {1 3}

finish_test

#
# This file implements tests to verify that ticket [02a8e81d44] has been
# fixed.  
#

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

ifcapable !compound {
  finish_test
  return
}

do_test tkt-02a838-1.1 {
  execsql {
    CREATE TABLE t1(a);
    INSERT INTO t1 VALUES(1);
    INSERT INTO t1 VALUES(2);
    INSERT INTO t1 VALUES(4);
    INSERT INTO t1 VALUES(5);
    SELECT * FROM (SELECT a FROM t1 LIMIT 1) UNION ALL SELECT 3;
  }
} {1 3}

finish_test

# This file implements regression tests for SQLite library. Specifically,
# it tests that ticket [38cb5df375078d3f9711482d2a1615d09f6b3f33] has
# been resolved.
#

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






do_test tkt-38cb5df375.0 {
  execsql {
    CREATE TABLE t1(a);
    INSERT INTO t1 VALUES(1);
    INSERT INTO t1 VALUES(2);
    INSERT INTO t1 SELECT a+2 FROM t1;

# This file implements regression tests for SQLite library. Specifically,
# it tests that ticket [38cb5df375078d3f9711482d2a1615d09f6b3f33] has
# been resolved.
#

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

ifcapable !compound {
  finish_test
  return
}

do_test tkt-38cb5df375.0 {
  execsql {
    CREATE TABLE t1(a);
    INSERT INTO t1 VALUES(1);
    INSERT INTO t1 VALUES(2);
    INSERT INTO t1 SELECT a+2 FROM t1;

# This file implements regression tests for SQLite library.
#
# This file implements tests to verify that ticket [3a77c9714e] has been
# fixed.  

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






set testprefix "tkt-3a77c9714e"

do_execsql_test 1.1 {
  CREATE TABLE t1(t1_id INTEGER PRIMARY KEY, t1_title TEXT);
  CREATE TABLE t2(t2_id INTEGER PRIMARY KEY, t2_title TEXT);
  CREATE TABLE t3(t3_id INTEGER PRIMARY KEY, t3_title TEXT);

# This file implements regression tests for SQLite library.
#
# This file implements tests to verify that ticket [3a77c9714e] has been
# fixed.  

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

ifcapable !compound {
  finish_test
  return
}

set testprefix "tkt-3a77c9714e"

do_execsql_test 1.1 {
  CREATE TABLE t1(t1_id INTEGER PRIMARY KEY, t1_title TEXT);
  CREATE TABLE t2(t2_id INTEGER PRIMARY KEY, t2_title TEXT);
  CREATE TABLE t3(t3_id INTEGER PRIMARY KEY, t3_title TEXT);

  INSERT INTO t3(t3_a) VALUES(2);
  INSERT INTO t3(t3_a) VALUES(3);
  SELECT * FROM t3;
} {1 I 2 II 3 III}

do_execsql_test 1.3 { DELETE FROM t3 }


do_execsql_test 1.4 {
  INSERT INTO t3(t3_a) SELECT 1 UNION SELECT 2 UNION SELECT 3;
  SELECT * FROM t3;
} {1 I 2 II 3 III}




#-------------------------------------------------------------------------
# The following test case - 2.* - is from the original bug report as 
# posted to the mailing list.
#

  INSERT INTO t3(t3_a) VALUES(2);
  INSERT INTO t3(t3_a) VALUES(3);
  SELECT * FROM t3;
} {1 I 2 II 3 III}

do_execsql_test 1.3 { DELETE FROM t3 }

ifcapable compound {
  do_execsql_test 1.4 {
    INSERT INTO t3(t3_a) SELECT 1 UNION SELECT 2 UNION SELECT 3;
    SELECT * FROM t3;
  } {1 I 2 II 3 III}
}



#-------------------------------------------------------------------------
# The following test case - 2.* - is from the original bug report as 
# posted to the mailing list.
#

do_execsql_test 303 {
  SELECT * FROM t1, t2 WHERE
    (a='A' AND d='E') OR
    (b='B' AND c IN (SELECT c FROM t1))
} {A B C D E}


do_execsql_test 304 {
  SELECT * FROM t1, t2 WHERE
    (a='A' AND d='E') OR
    (b='B' AND c IN (SELECT 'B' UNION SELECT 'C' UNION SELECT 'D'))
} {A B C D E}


do_execsql_test 305 {
  SELECT * FROM t1, t2 WHERE
    (b='B' AND c IN ('C', 'D', 'E')) OR
    (a='A' AND d='E')
} {A B C D E}

do_execsql_test 306 {
  SELECT * FROM t1, t2 WHERE
    (b='B' AND c IN (SELECT c FROM t1)) OR
    (a='A' AND d='E')
} {A B C D E}


do_execsql_test 307 {
  SELECT * FROM t1, t2 WHERE
    (b='B' AND c IN (SELECT 'B' UNION SELECT 'C' UNION SELECT 'D')) OR
    (a='A' AND d='E')
} {A B C D E}


finish_test

do_execsql_test 303 {
  SELECT * FROM t1, t2 WHERE
    (a='A' AND d='E') OR
    (b='B' AND c IN (SELECT c FROM t1))
} {A B C D E}

ifcapable compound {
  do_execsql_test 304 {
    SELECT * FROM t1, t2 WHERE
      (a='A' AND d='E') OR
      (b='B' AND c IN (SELECT 'B' UNION SELECT 'C' UNION SELECT 'D'))
  } {A B C D E}
}

do_execsql_test 305 {
  SELECT * FROM t1, t2 WHERE
    (b='B' AND c IN ('C', 'D', 'E')) OR
    (a='A' AND d='E')
} {A B C D E}

do_execsql_test 306 {
  SELECT * FROM t1, t2 WHERE
    (b='B' AND c IN (SELECT c FROM t1)) OR
    (a='A' AND d='E')
} {A B C D E}

ifcapable compound {
  do_execsql_test 307 {
    SELECT * FROM t1, t2 WHERE
      (b='B' AND c IN (SELECT 'B' UNION SELECT 'C' UNION SELECT 'D')) OR
      (a='A' AND d='E')
  } {A B C D E}
}

finish_test

#     The bug is that sqlite3ExpirePreparedStatements expires all statements.
#     Note that B was prepared after the schema change and hence is perfectly
#     valid and then is marked as expired while running.
#

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






unset -nocomplain ::STMT
proc runsql {} {
  db eval {CREATE TABLE IF NOT EXISTS t4(q)}
  sqlite3_step $::STMT
  set rc [sqlite3_column_int $::STMT 0]
  sqlite3_reset $::STMT

#     The bug is that sqlite3ExpirePreparedStatements expires all statements.
#     Note that B was prepared after the schema change and hence is perfectly
#     valid and then is marked as expired while running.
#

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

ifcapable !compound {
  finish_test
  return
}

unset -nocomplain ::STMT
proc runsql {} {
  db eval {CREATE TABLE IF NOT EXISTS t4(q)}
  sqlite3_step $::STMT
  set rc [sqlite3_column_int $::STMT 0]
  sqlite3_reset $::STMT

#
# This file implements tests to verify that ticket [d82e3f3721] has been
# fixed.  
#

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






do_test tkt-d82e3-1.1 {
  db eval {
    CREATE TABLE t1(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
    INSERT INTO t1 VALUES(null,'abc');
    INSERT INTO t1 VALUES(null,'def');
    DELETE FROM t1;

#
# This file implements tests to verify that ticket [d82e3f3721] has been
# fixed.  
#

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

ifcapable !compound {
  finish_test
  return
}

do_test tkt-d82e3-1.1 {
  db eval {
    CREATE TABLE t1(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
    INSERT INTO t1 VALUES(null,'abc');
    INSERT INTO t1 VALUES(null,'def');
    DELETE FROM t1;

#
# This file implements tests to verify that ticket [f777251dc7a] has been
# fixed.  
#

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






do_test tkt-f7772-1.1 {
  execsql {
     CREATE TEMP TABLE t1(x UNIQUE);
     INSERT INTO t1 VALUES(1);
     CREATE TABLE t2(x, y);
     INSERT INTO t2 VALUES(1, 2);
................................................................................
db function force_rollback force_rollback

do_test tkt-f7772-1.2 {
  catchsql {
    BEGIN IMMEDIATE;
    SELECT x, force_rollback(), EXISTS(SELECT 1 FROM t3 WHERE w=x) FROM t2;
  }
} {1 {callback requested query abort}}
do_test tkt-f7772-1.3 {
  sqlite3_get_autocommit db
} {1}

do_test tkt-f7772-2.1 {
  execsql {
     DROP TABLE IF EXISTS t1;

#
# This file implements tests to verify that ticket [f777251dc7a] has been
# fixed.  
#

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

ifcapable !compound {
  finish_test
  return
}

do_test tkt-f7772-1.1 {
  execsql {
     CREATE TEMP TABLE t1(x UNIQUE);
     INSERT INTO t1 VALUES(1);
     CREATE TABLE t2(x, y);
     INSERT INTO t2 VALUES(1, 2);
................................................................................
db function force_rollback force_rollback

do_test tkt-f7772-1.2 {
  catchsql {
    BEGIN IMMEDIATE;
    SELECT x, force_rollback(), EXISTS(SELECT 1 FROM t3 WHERE w=x) FROM t2;
  }
} {1 {abort due to ROLLBACK}}
do_test tkt-f7772-1.3 {
  sqlite3_get_autocommit db
} {1}

do_test tkt-f7772-2.1 {
  execsql {
     DROP TABLE IF EXISTS t1;

# This file is a verification that the bugs identified in ticket
# #3527 have been fixed.
#
# $Id: tkt3527.test,v 1.1 2008/12/08 13:42:36 drh Exp $

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






do_test tkt3527-1.1 {
  db eval {
    CREATE TABLE Element (
     Code INTEGER PRIMARY KEY,
     Name VARCHAR(60)
    );

# This file is a verification that the bugs identified in ticket
# #3527 have been fixed.
#
# $Id: tkt3527.test,v 1.1 2008/12/08 13:42:36 drh Exp $

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

ifcapable !compound {
  finish_test
  return
}

do_test tkt3527-1.1 {
  db eval {
    CREATE TABLE Element (
     Code INTEGER PRIMARY KEY,
     Name VARCHAR(60)
    );

# subquery contains an ORDER BY clause.
#
#
# $Id: tkt3773.test,v 1.1 2009/04/02 16:59:47 drh Exp $

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






do_test tkt3773-1.1 {
  db eval {
    CREATE TABLE t1(a,b);
    INSERT INTO t1 VALUES(2,1);
    INSERT INTO t1 VALUES(33,3);
    CREATE TABLE t2(x,y);

# subquery contains an ORDER BY clause.
#
#
# $Id: tkt3773.test,v 1.1 2009/04/02 16:59:47 drh Exp $

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

ifcapable !compound {
  finish_test
  return
}

do_test tkt3773-1.1 {
  db eval {
    CREATE TABLE t1(a,b);
    INSERT INTO t1 VALUES(2,1);
    INSERT INTO t1 VALUES(33,3);
    CREATE TABLE t2(x,y);

        if {[catch {db eval ROLLBACK} errmsg]} {
           set ::ecode [sqlite3_extended_errcode db]
           error $errmsg
        }
     }
  } errmsg]
  lappend x $errmsg
} {1 {cannot rollback transaction - SQL statements in progress}}
do_test trans3-1.6 {
  set ::ecode
} {SQLITE_BUSY}
do_test trans3-1.7 {
  db eval COMMIT
  db eval {SELECT * FROM t1}
} {1 2 3 4 5}
unset -nocomplain ecode

finish_test

        if {[catch {db eval ROLLBACK} errmsg]} {
           set ::ecode [sqlite3_extended_errcode db]
           error $errmsg
        }
     }
  } errmsg]
  lappend x $errmsg
} {1 {abort due to ROLLBACK}}
do_test trans3-1.6 {
  set ::ecode
} {}
do_test trans3-1.7 {

  db eval {SELECT * FROM t1}
} {1 2 3 4}
unset -nocomplain ecode

finish_test

# trig-1.12: Ensure that INSTEAD OF triggers cannot be created on tables
# trig-1.13: Ensure that AFTER triggers cannot be created on views
# trig-1.14: Ensure that BEFORE triggers cannot be created on views
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable {!trigger} {
  finish_test
  return
}

do_test trigger1-1.1.1 {
   catchsql {
     CREATE TRIGGER trig UPDATE ON no_such_table BEGIN

# trig-1.12: Ensure that INSTEAD OF triggers cannot be created on tables
# trig-1.13: Ensure that AFTER triggers cannot be created on views
# trig-1.14: Ensure that BEFORE triggers cannot be created on views
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable !trigger||!compound {
  finish_test
  return
}

do_test trigger1-1.1.1 {
   catchsql {
     CREATE TRIGGER trig UPDATE ON no_such_table BEGIN

do_test vtabD-1.5 {
  execsql { SELECT * FROM tv1 WHERE (a > 0 AND a < 5) OR (b > 15 AND b < 65) }
} {1 1 2 4 3 9 4 16 5 25 6 36 7 49 8 64}

do_test vtabD-1.6 {
  execsql { SELECT * FROM tv1 WHERE a < 500 OR b = 810000 }
} [execsql {
  SELECT * FROM t1 WHERE a < 500
    UNION ALL
  SELECT * FROM t1 WHERE b = 810000 AND NOT (a < 500)
}]

do_test vtabD-1.7 {
  execsql { SELECT * FROM tv1 WHERE a < 90000 OR b = 8100000000 }
} [execsql {
  SELECT * FROM t1 WHERE a < 90000
    UNION ALL
  SELECT * FROM t1 WHERE b = 8100000000 AND NOT (a < 90000)
}]

if {[working_64bit_int]} {
do_test vtabD-1.8 {
  execsql { SELECT * FROM tv1 WHERE a = 90001 OR b = 810000 }
} {90001 8100180001 900 810000}
}

finish_test

do_test vtabD-1.5 {
  execsql { SELECT * FROM tv1 WHERE (a > 0 AND a < 5) OR (b > 15 AND b < 65) }
} {1 1 2 4 3 9 4 16 5 25 6 36 7 49 8 64}

do_test vtabD-1.6 {
  execsql { SELECT * FROM tv1 WHERE a < 500 OR b = 810000 }
} [execsql {
  SELECT * FROM t1 WHERE a < 500;

  SELECT * FROM t1 WHERE b = 810000 AND NOT (a < 500);
}]

do_test vtabD-1.7 {
  execsql { SELECT * FROM tv1 WHERE a < 90000 OR b = 8100000000 }
} [execsql {
  SELECT * FROM t1 WHERE a < 90000;

  SELECT * FROM t1 WHERE b = 8100000000 AND NOT (a < 90000);
}]

if {[working_64bit_int]} {
do_test vtabD-1.8 {
  execsql { SELECT * FROM tv1 WHERE a = 90001 OR b = 810000 }
} {90001 8100180001 900 810000}
}

finish_test

  execsql {
    CREATE VIRTUAL TABLE t2 USING echo(t0);
    CREATE VIRTUAL TABLE t3 USING echo(t0);
  }
  execsql { SELECT * FROM t3 } db2
} {1 2 3 4 5 6}


do_test vtab_shared-1.12.1 {
  db close
  execsql { 
    SELECT * FROM t1 UNION ALL
    SELECT * FROM t2 UNION ALL
    SELECT * FROM t3 
  } db2
} {1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6}
do_test vtab_shared-1.12.2 {
  sqlite3 db test.db
  register_echo_module [sqlite3_connection_pointer db]
  execsql { 
    SELECT * FROM t1 UNION ALL
    SELECT * FROM t2 UNION ALL
    SELECT * FROM t3 
  } db
} {1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6}


# Try a rename or two.
#
ifcapable altertable {
  do_test vtab_shared-1.13.1 {
    execsql { ALTER TABLE t1 RENAME TO t4 }
    execsql { SELECT * FROM t4 } db

  execsql {
    CREATE VIRTUAL TABLE t2 USING echo(t0);
    CREATE VIRTUAL TABLE t3 USING echo(t0);
  }
  execsql { SELECT * FROM t3 } db2
} {1 2 3 4 5 6}

ifcapable compound {
  do_test vtab_shared-1.12.1 {
    db close
    execsql { 
      SELECT * FROM t1 UNION ALL
      SELECT * FROM t2 UNION ALL
      SELECT * FROM t3 
    } db2
  } {1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6}
  do_test vtab_shared-1.12.2 {
    sqlite3 db test.db
    register_echo_module [sqlite3_connection_pointer db]
    execsql { 
      SELECT * FROM t1 UNION ALL
      SELECT * FROM t2 UNION ALL
      SELECT * FROM t3 
    } db
  } {1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6}
}

# Try a rename or two.
#
ifcapable altertable {
  do_test vtab_shared-1.13.1 {
    execsql { ALTER TABLE t1 RENAME TO t4 }
    execsql { SELECT * FROM t4 } db

#-------------------------------------------------------------------------
# If a connection is required to create a WAL or SHM file, it creates 
# the new files with the same file-system permissions as the database 
# file itself. Test this.
#
if {$::tcl_platform(platform) == "unix"} {
  faultsim_delete_and_reopen

  set umask [exec /bin/sh -c umask]



  do_test wal2-12.1 {
    sqlite3 db test.db
    execsql { 
      CREATE TABLE tx(y, z);
      PRAGMA journal_mode = WAL;
    }

#-------------------------------------------------------------------------
# If a connection is required to create a WAL or SHM file, it creates 
# the new files with the same file-system permissions as the database 
# file itself. Test this.
#
if {$::tcl_platform(platform) == "unix"} {
  faultsim_delete_and_reopen
  # Changed on 2012-02-13: umask is deliberately ignored for -wal files.
  #set umask [exec /bin/sh -c umask]
  set umask 0
  

  do_test wal2-12.1 {
    sqlite3 db test.db
    execsql { 
      CREATE TABLE tx(y, z);
      PRAGMA journal_mode = WAL;
    }

# 2012 February 28
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode.
#
# Specifically, it tests the case where a connection opens an empty
# file. Then, another connection opens the same file and initializes
# the connection as a WAL database. Following this, the first connection
# executes a "PRAGMA page_size = XXX" command to set its expected page
# size, and then queries the database.
#
# This is an unusual case, as normally SQLite is able to glean the page
# size from the database file as soon as it is opened (even before the
# first read transaction is executed), and the "PRAGMA page_size = XXX"
# is a no-op.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix wal8

db close
forcedelete test.db test.db-wal

sqlite3 db test.db
sqlite3 db2 test.db

do_test 1.0 {
  execsql {
    PRAGMA journal_mode = wal;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  } db2
} {wal}

do_catchsql_test 1.1 {
  PRAGMA page_size = 4096;
  VACUUM;
} {0 {}}

db close
db2 close
forcedelete test.db test.db-wal

sqlite3 db test.db
sqlite3 db2 test.db

do_test 2.0 {
  execsql {
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
    PRAGMA journal_mode = wal;
  } db2
} {wal}

do_catchsql_test 2.1 {
  PRAGMA page_size = 4096;
  VACUUM;
} {0 {}}

db close
db2 close
forcedelete test.db test.db-wal

sqlite3 db test.db
sqlite3 db2 test.db

do_test 3.0 {
  execsql {
    PRAGMA journal_mode = wal;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  } db2
} {wal}

do_execsql_test 3.1 {
  PRAGMA page_size = 4096;
  SELECT name FROM sqlite_master;
} {t1}

finish_test

# This file implements regression tests for SQLite library.  The
# focus of this file is testing the multi-index OR clause optimizer.
#

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

ifcapable !or_opt {
  finish_test
  return
}

# Evaluate SQL.  Return the result set followed by the
# and the number of full-scan steps.
#

# This file implements regression tests for SQLite library.  The
# focus of this file is testing the multi-index OR clause optimizer.
#

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

ifcapable !or_opt||!compound {
  finish_test
  return
}

# Evaluate SQL.  Return the result set followed by the
# and the number of full-scan steps.
#