SQLite

      }else{
        rc = sqlite3Fts5StorageConfigValue(pTab->pStorage, z, pVal);
      }
    }
  }
  return rc;
}

static int fts5SpecialDelete(
  Fts5Table *pTab, 
  sqlite3_value **apVal, 
  sqlite3_int64 *piRowid
){
  int rc = SQLITE_OK;
  int eType1 = sqlite3_value_type(apVal[1]);
  if( eType1==SQLITE_INTEGER ){
    sqlite3_int64 iDel = sqlite3_value_int64(apVal[1]);
    rc = sqlite3Fts5StorageSpecialDelete(pTab->pStorage, iDel, &apVal[2]);
  }
  return rc;
}

/* 
** This function is the implementation of the xUpdate callback used by 
** FTS3 virtual tables. It is invoked by SQLite each time a row is to be
** inserted, updated or deleted.
*/
static int fts5UpdateMethod(

  **   1. The "old" rowid, or NULL.
  **   2. The "new" rowid.
  **   3. Values for each of the nCol matchable columns.
  **   4. Values for the two hidden columns (<tablename> and "rank").
  */
  assert( nArg==1 || nArg==(2 + pConfig->nCol + 2) );

  if( nArg>1 ){
    sqlite3_value *pCmd = sqlite3_value_type(apVal[2 + pConfig->nCol]);
    if( SQLITE_NULL!=sqlite3_value_type(pCmd) ){
      const char *z = sqlite3_value_text(pCmd);
      if( pConfig->bExternalContent && sqlite3_stricmp("delete", z) ){
        return fts5SpecialDelete(pTab, apVal, pRowid);
      }else{
        return fts5SpecialInsert(pTab, pCmd, apVal[2 + pConfig->nCol + 1]);

      }
    }
  }

  eType0 = sqlite3_value_type(apVal[0]);
  eConflict = sqlite3_vtab_on_conflict(pConfig->db);

  assert( eType0==SQLITE_INTEGER || eType0==SQLITE_NULL );
  assert( pVtab->zErrMsg==0 );

  if( rc==SQLITE_OK && eType0==SQLITE_INTEGER ){
    i64 iDel = sqlite3_value_int64(apVal[0]);    /* Rowid to delete */
    rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel);
  }

  if( rc==SQLITE_OK && nArg>1 ){
    rc = sqlite3Fts5StorageInsert(pTab->pStorage, apVal, eConflict, pRowid);
  }

  sqlite3 *db;                    /* Database handle */
  char *zDb;                      /* Database holding FTS index (e.g. "main") */
  char *zName;                    /* Name of FTS index */
  int nCol;                       /* Number of columns */
  char **azCol;                   /* Column names */
  int nPrefix;                    /* Number of prefix indexes */
  int *aPrefix;                   /* Sizes in bytes of nPrefix prefix indexes */
  int bExternalContent;           /* Content is external */
  char *zContent;                 /* "content=" option value (or NULL) */ 
  char *zContentRowid;            /* "content_rowid=" option value (or NULL) */ 
  Fts5Tokenizer *pTok;
  fts5_tokenizer *pTokApi;

  /* Values loaded from the %_config table */
  int iCookie;                    /* Incremented when %_config is modified */
  int pgsz;                       /* Approximate page size used in %_data */
  int nAutomerge;                 /* 'automerge' setting */

int sqlite3Fts5StorageSize(Fts5Storage *p, int iCol, i64 *pnAvg);
int sqlite3Fts5StorageRowCount(Fts5Storage *p, i64 *pnRow);

int sqlite3Fts5StorageSync(Fts5Storage *p, int bCommit);
int sqlite3Fts5StorageRollback(Fts5Storage *p);

int sqlite3Fts5StorageConfigValue(Fts5Storage *p, const char*, sqlite3_value*);

int sqlite3Fts5StorageSpecialDelete(Fts5Storage *p, i64 iDel, sqlite3_value**);

/*
** End of interface to code in fts5_storage.c.
**************************************************************************/


/**************************************************************************

  int n = strlen(z);
  while( n>0 && fts5_iswhitespace(z[n-1]) ){
    z[--n] = '\0';
  }
  while( fts5_iswhitespace(*z) ) z++;
  return z;
}

/*
** Duplicate the string passed as the only argument into a buffer allocated
** by sqlite3_malloc().
**
** Return 0 if an OOM error is encountered.
*/
static char *fts5Strdup(int *pRc, const char *z){
  char *pRet = 0;
  if( *pRc==SQLITE_OK ){
    pRet = sqlite3_mprintf("%s", z);
    if( pRet==0 ) *pRc = SQLITE_NOMEM;
  }
  return pRet;
}

/*
** Argument z points to a nul-terminated string containing an SQL identifier.
** This function returns a copy of the identifier enclosed in backtick 
** quotes.
*/
static char *fts5EscapeName(int *pRc, const char *z){
  char *pRet = 0;
  if( *pRc==SQLITE_OK ){
    int n = strlen(z);
    pRet = (char*)sqlite3_malloc(2 * 2*n + 1);
    if( pRet==0 ){
      *pRc = SQLITE_NOMEM;
    }else{
      int i;
      char *p = pRet;
      for(i=0; i<n; i++){
        if( z[i]=='`' ) *p++ = '`';
        *p++ = z[i];
      }
      *p++ = '`';
      *p++ = '\0';
    }
  }
  return pRet;
}

/*
** Parse the "special" CREATE VIRTUAL TABLE directive and update
** configuration object pConfig as appropriate.
**
** If successful, object pConfig is updated and SQLITE_OK returned. If
** an error occurs, an SQLite error code is returned and an error message

      }
    }

    sqlite3_free(azArg);
    sqlite3_free(pDel);
    return rc;
  }

  if( sqlite3_strnicmp("content", zCmd, nCmd)==0 ){
    int rc = SQLITE_OK;
    if( pConfig->zContent ){
      *pzErr = sqlite3_mprintf("multiple content=... directives");
      rc = SQLITE_ERROR;
    }else{
      pConfig->zContent = sqlite3_mprintf("%Q.%Q", pConfig->zDb, zArg);
      pConfig->bExternalContent = 1;
      if( pConfig->zContent==0 ) rc = SQLITE_NOMEM;
    }
    return rc;
  }

  if( sqlite3_strnicmp("content_rowid", zCmd, nCmd)==0 ){
    int rc = SQLITE_OK;
    if( pConfig->zContentRowid ){
      *pzErr = sqlite3_mprintf("multiple content_rowid=... directives");
      rc = SQLITE_ERROR;
    }else{
      pConfig->zContentRowid = fts5EscapeName(&rc, zArg);
    }
    return rc;
  }

  *pzErr = sqlite3_mprintf("unrecognized directive: \"%s\"", zCmd);
  return SQLITE_ERROR;
}
















/*
** Allocate an instance of the default tokenizer ("simple") at 
** Fts5Config.pTokenizer. Return SQLITE_OK if successful, or an SQLite error
** code if an error occurs.
*/
static int fts5ConfigDefaultTokenizer(Fts5Global *pGlobal, Fts5Config *pConfig){
  assert( pConfig->pTok==0 && pConfig->pTokApi==0 );

  /* If a tokenizer= option was successfully parsed, the tokenizer has
  ** already been allocated. Otherwise, allocate an instance of the default
  ** tokenizer (simple) now.  */
  if( rc==SQLITE_OK && pRet->pTok==0 ){
    rc = fts5ConfigDefaultTokenizer(pGlobal, pRet);
  }

  /* If no zContent option was specified, fill in the default values. */
  if( rc==SQLITE_OK && pRet->zContent==0 ){
    pRet->zContent = sqlite3_mprintf("%Q.'%q_content'", pRet->zDb, pRet->zName);
    if( pRet->zContent==0 ){
      rc = SQLITE_NOMEM;
    }else{
      sqlite3_free(pRet->zContentRowid);
      pRet->zContentRowid = 0;
    }
  }
  if( rc==SQLITE_OK && pRet->zContentRowid==0 ){
    pRet->zContentRowid = fts5Strdup(&rc, "rowid");
  }

  if( rc!=SQLITE_OK ){
    sqlite3Fts5ConfigFree(pRet);
    *ppOut = 0;
  }
  return rc;
}

    for(i=0; i<pConfig->nCol; i++){
      sqlite3_free(pConfig->azCol[i]);
    }
    sqlite3_free(pConfig->azCol);
    sqlite3_free(pConfig->aPrefix);
    sqlite3_free(pConfig->zRank);
    sqlite3_free(pConfig->zRankArgs);
    sqlite3_free(pConfig->zContent);
    sqlite3_free(pConfig->zContentRowid);
    sqlite3_free(pConfig);
  }
}

/*
** Call sqlite3_declare_vtab() based on the contents of the configuration
** object passed as the only argument. Return SQLITE_OK if successful, or

** Argument pIn points to a buffer of nIn bytes. This function allocates
** and returns a new buffer populated with a copy of (pIn/nIn) with a 
** nul-terminator byte appended to it.
**
** It is the responsibility of the caller to eventually free the returned
** buffer using sqlite3_free(). If an OOM error occurs, NULL is returned. 
*/
static char *fts5Strndup(int *pRc, const char *pIn, int nIn){
  char *zRet = 0;
  if( *pRc==SQLITE_OK ){
    zRet = (char*)sqlite3_malloc(nIn+1);
    if( zRet ){
      memcpy(zRet, pIn, nIn);
      zRet[nIn] = '\0';
    }else{
      *pRc = SQLITE_NOMEM;
    }
  }
  return zRet;
}

static int fts5ParseStringFromToken(Fts5Token *pToken, char **pz){
  int rc = SQLITE_OK;
  *pz = fts5Strndup(&rc, pToken->p, pToken->n);

  return rc;
}

/*
** Free the phrase object passed as the only argument.
*/
static void fts5ExprPhraseFree(Fts5ExprPhrase *pPhrase){
  if( pPhrase ){

  void *pContext,                 /* Pointer to Fts5InsertCtx object */
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd,                       /* End offset of token */
  int iPos                        /* Position offset of token */
){
  int rc = SQLITE_OK;
  const int SZALLOC = 8;
  TokenCtx *pCtx = (TokenCtx*)pContext;
  Fts5ExprPhrase *pPhrase = pCtx->pPhrase;
  Fts5ExprTerm *pTerm;

  if( pPhrase==0 || (pPhrase->nTerm % SZALLOC)==0 ){
    Fts5ExprPhrase *pNew;
    int nNew = SZALLOC + (pPhrase ? pPhrase->nTerm : 0);

    pNew = (Fts5ExprPhrase*)sqlite3_realloc(pPhrase, 
        sizeof(Fts5ExprPhrase) + sizeof(Fts5ExprTerm) * nNew
    );
    if( pNew==0 ) return SQLITE_NOMEM;
    if( pPhrase==0 ) memset(pNew, 0, sizeof(Fts5ExprPhrase));
    pCtx->pPhrase = pPhrase = pNew;
    pNew->nTerm = nNew - SZALLOC;
  }

  pTerm = &pPhrase->aTerm[pPhrase->nTerm++];
  memset(pTerm, 0, sizeof(Fts5ExprTerm));
  pTerm->zTerm = fts5Strndup(&rc, pToken, nToken);

  return rc;
}


/*
** Free the phrase object passed as the only argument.
*/
void sqlite3Fts5ParsePhraseFree(Fts5ExprPhrase *pPhrase){

  sqlite3_stmt **ppStmt           /* OUT: Prepared statement handle */
){
  int rc = SQLITE_OK;

  assert( eStmt>=0 && eStmt<ArraySize(p->aStmt) );
  if( p->aStmt[eStmt]==0 ){
    const char *azStmt[] = {
      "SELECT * FROM %s ORDER BY id ASC",               /* SCAN_ASC */
      "SELECT * FROM %s ORDER BY id DESC",              /* SCAN_DESC */
      "SELECT * FROM %s WHERE %s=?",                    /* LOOKUP  */

      "INSERT INTO %Q.'%q_content' VALUES(%s)",         /* INSERT_CONTENT  */
      "REPLACE INTO %Q.'%q_content' VALUES(%s)",        /* REPLACE_CONTENT */
      "DELETE FROM %Q.'%q_content' WHERE id=?",         /* DELETE_CONTENT  */
      "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",       /* REPLACE_DOCSIZE  */
      "DELETE FROM %Q.'%q_docsize' WHERE id=?",         /* DELETE_DOCSIZE  */

      "SELECT sz FROM %Q.'%q_docsize' WHERE id=?",      /* LOOKUP_DOCSIZE  */

      "REPLACE INTO %Q.'%q_config' VALUES(?,?)",        /* REPLACE_CONFIG */
    };
    Fts5Config *pC = p->pConfig;
    char *zSql = 0;

    switch( eStmt ){
      case FTS5_STMT_SCAN_ASC:
      case FTS5_STMT_SCAN_DESC:
        zSql = sqlite3_mprintf(azStmt[eStmt], pC->zContent);
        break;

      case FTS5_STMT_LOOKUP:
        zSql = sqlite3_mprintf(azStmt[eStmt], pC->zContent, pC->zContentRowid);
        break;

      case FTS5_STMT_INSERT_CONTENT: 
      case FTS5_STMT_REPLACE_CONTENT: {
        int nCol = pC->nCol + 1;
        char *zBind;
        int i;

        zBind = sqlite3_malloc(1 + nCol*2);
        if( zBind ){
          for(i=0; i<nCol; i++){
            zBind[i*2] = '?';
            zBind[i*2 + 1] = ',';
          }
          zBind[i*2-1] = '\0';
          zSql = sqlite3_mprintf(azStmt[eStmt], pC->zDb, pC->zName, zBind);
          sqlite3_free(zBind);
        }
        break;
      }

      default:
        zSql = sqlite3_mprintf(azStmt[eStmt], pC->zDb, pC->zName);
        break;
    }

    if( zSql==0 ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare_v2(pC->db, zSql, -1, &p->aStmt[eStmt], 0);
      sqlite3_free(zSql);
    }
  }

  *ppStmt = p->aStmt[eStmt];
  return rc;
}

  memset(p, 0, nByte);
  p->aTotalSize = (i64*)&p[1];
  p->pConfig = pConfig;
  p->pIndex = pIndex;

  if( bCreate ){
    if( pConfig->bExternalContent==0 ){
      char *zDefn = sqlite3_malloc(32 + pConfig->nCol * 10);
      if( zDefn==0 ){
        rc = SQLITE_NOMEM;
      }else{
        int i;
        int iOff = sprintf(zDefn, "id INTEGER PRIMARY KEY");
        for(i=0; i<pConfig->nCol; i++){
          iOff += sprintf(&zDefn[iOff], ", c%d", i);
        }
        rc = sqlite3Fts5CreateTable(pConfig, "content", zDefn, 0, pzErr);
      }
      sqlite3_free(zDefn);
    }

    if( rc==SQLITE_OK ){
      rc = sqlite3Fts5CreateTable(
          pConfig, "docsize", "id INTEGER PRIMARY KEY, sz BLOB", 0, pzErr
      );
    }
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts5CreateTable(

  /* Write the averages record */
  if( rc==SQLITE_OK ){
    rc = fts5StorageSaveTotals(p);
  }

  return rc;
}

int sqlite3Fts5StorageSpecialDelete(
  Fts5Storage *p, 
  i64 iDel, 
  sqlite3_value **apVal
){
  Fts5Config *pConfig = p->pConfig;
  int rc;
  sqlite3_stmt *pDel;

  assert( p->pConfig->bExternalContent );
  rc = fts5StorageLoadTotals(p, 1);

  /* Delete the index records */
  if( rc==SQLITE_OK ){
    int iCol;
    Fts5InsertCtx ctx;
    ctx.pStorage = p;
    ctx.iCol = -1;

    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, iDel);
    for(iCol=0; rc==SQLITE_OK && iCol<pConfig->nCol; iCol++){
      rc = sqlite3Fts5Tokenize(pConfig, 
        (const char*)sqlite3_value_text(apVal[iCol]),
        sqlite3_value_bytes(apVal[iCol]),
        (void*)&ctx,
        fts5StorageInsertCallback
      );
      p->aTotalSize[iCol-1] -= (i64)ctx.szCol;
    }
    p->nTotalRow--;
  }

  /* Delete the %_docsize record */
  if( rc==SQLITE_OK ){
    rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_DOCSIZE, &pDel);
  }
  if( rc==SQLITE_OK ){
    sqlite3_bind_int64(pDel, 1, iDel);
    sqlite3_step(pDel);
    rc = sqlite3_reset(pDel);
  }

  /* Write the averages record */
  if( rc==SQLITE_OK ){
    rc = fts5StorageSaveTotals(p);
  }

  return rc;

}

/*
** Allocate a new rowid. This is used for "external content" tables when
** a NULL value is inserted into the rowid column. The new rowid is allocated
** by inserting a dummy row into the %_docsize table. The dummy will be
** overwritten later.
*/
static int fts5StorageNewRowid(Fts5Storage *p, i64 *piRowid){
  sqlite3_stmt *pReplace = 0;
  int rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_DOCSIZE, &pReplace);
  if( rc==SQLITE_OK ){
    sqlite3_bind_null(pReplace, 1);
    sqlite3_bind_null(pReplace, 2);
    sqlite3_step(pReplace);
    rc = sqlite3_reset(pReplace);
  }
  if( rc==SQLITE_OK ){
    *piRowid = sqlite3_last_insert_rowid(p->pConfig->db);
  }
  return rc;
}

/*
** Insert a new row into the FTS table.
*/
int sqlite3Fts5StorageInsert(
  Fts5Storage *p,                 /* Storage module to write to */
  sqlite3_value **apVal,          /* Array of values passed to xUpdate() */

  Fts5InsertCtx ctx;              /* Tokenization callback context object */
  Fts5Buffer buf;                 /* Buffer used to build up %_docsize blob */

  memset(&buf, 0, sizeof(Fts5Buffer));
  rc = fts5StorageLoadTotals(p, 1);

  /* Insert the new row into the %_content table. */
  if( rc==SQLITE_OK && pConfig->bExternalContent==0 ){
    if( pConfig->bExternalContent ){
      if( sqlite3_value_type(apVal[1])==SQLITE_INTEGER ){
        *piRowid = sqlite3_value_int64(apVal[1]);
      }else{
        rc = fts5StorageNewRowid(p, piRowid);
      }
    }else{
      if( eConflict==SQLITE_REPLACE ){
        eStmt = FTS5_STMT_REPLACE_CONTENT;
        if( sqlite3_value_type(apVal[1])==SQLITE_INTEGER ){
          rc = fts5StorageDeleteFromIndex(p, sqlite3_value_int64(apVal[1]));
        }
      }else{
        eStmt = FTS5_STMT_INSERT_CONTENT;
      }

      if( rc==SQLITE_OK ){
        rc = fts5StorageGetStmt(p, eStmt, &pInsert);
      }
      for(i=1; rc==SQLITE_OK && i<=pConfig->nCol+1; i++){
        rc = sqlite3_bind_value(pInsert, i, apVal[i]);
      }
      if( rc==SQLITE_OK ){
        sqlite3_step(pInsert);
        rc = sqlite3_reset(pInsert);
      }
      *piRowid = sqlite3_last_insert_rowid(pConfig->db);
    }
  }

  /* Add new entries to the FTS index */
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, *piRowid);
    ctx.pStorage = p;
  }
  for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){