SQLite

**
*/



#include "fts5Int.h"

/*
** pSavedRow:
**   SQL statement FTS5_STMT_LOOKUP2 is a copy of FTS5_STMT_LOOKUP, it 
**   does a by-rowid lookup to retrieve a single row from the %_content 
**   table or equivalent external-content table/view.
**
**   However, FTS5_STMT_LOOKUP2 is only used when retrieving the original
**   values for a row being UPDATEd. In that case, the SQL statement is
**   not reset and pSavedRow is set to point at it. This is so that the
**   insert operation that follows the delete may access the original 
**   row values for any new values for which sqlite3_value_nochange() returns
**   true. i.e. if the user executes:
**
**        CREATE VIRTUAL TABLE ft USING fts5(a, b, c, locale=1);
**        ...
**        UPDATE fts SET a=?, b=? WHERE rowid=?;
**
**   then the value passed to the xUpdate() method of this table as the 
**   new.c value is an sqlite3_value_nochange() value. So in this case it
**   must be read from the saved row stored in Fts5Storage.pSavedRow.
**
**   This is necessary - using sqlite3_value_nochange() instead of just having
**   SQLite pass the original value back via xUpdate() - so as not to discard
**   any locale information associated with such values.
**
*/
struct Fts5Storage {
  Fts5Config *pConfig;
  Fts5Index *pIndex;
  int bTotalsValid;               /* True if nTotalRow/aTotalSize[] are valid */
  i64 nTotalRow;                  /* Total number of rows in FTS table */
  i64 *aTotalSize;                /* Total sizes of each column */ 
  sqlite3_stmt *pSavedRow;

#if FTS5_STMT_SCAN_DESC!=1 
# error "FTS5_STMT_SCAN_DESC mismatch" 
#endif
#if FTS5_STMT_LOOKUP!=2
# error "FTS5_STMT_LOOKUP mismatch" 
#endif

#define FTS5_STMT_LOOKUP2         3
#define FTS5_STMT_INSERT_CONTENT  4
#define FTS5_STMT_REPLACE_CONTENT 5
#define FTS5_STMT_DELETE_CONTENT  6
#define FTS5_STMT_REPLACE_DOCSIZE 7
#define FTS5_STMT_DELETE_DOCSIZE  8
#define FTS5_STMT_LOOKUP_DOCSIZE  9
#define FTS5_STMT_REPLACE_CONFIG 10
#define FTS5_STMT_SCAN           11

/*
** Prepare the two insert statements - Fts5Storage.pInsertContent and
** Fts5Storage.pInsertDocsize - if they have not already been prepared.
** Return SQLITE_OK if successful, or an SQLite error code if an error
** occurs.
*/

  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
  if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){
    pCtx->szCol++;
  }
  return sqlite3Fts5IndexWrite(pIdx, pCtx->iCol, pCtx->szCol-1, pToken, nToken);
}

/*
** This function is used as part of an UPDATE statement that modifies the
** rowid of a row. In that case, this function is called first to set
** Fts5Storage.pSavedRow to point to a statement that may be used to 
** access the original values of the row being deleted - iDel.
**
** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
** It is not considered an error if row iDel does not exist. In this case
** pSavedRow is not set and SQLITE_OK returned.
*/
int sqlite3Fts5StorageFindDeleteRow(Fts5Storage *p, i64 iDel){
  int rc = SQLITE_OK;
  sqlite3_stmt *pSeek = 0;

  assert( p->pSavedRow==0 );
  rc = fts5StorageGetStmt(p, FTS5_STMT_LOOKUP+1, &pSeek, 0);
  if( rc==SQLITE_OK ){

  return rc;
}

/*
** If a row with rowid iDel is present in the %_content table, add the
** delete-markers to the FTS index necessary to delete it. Do not actually
** remove the %_content row at this time though.
**
** If parameter bSaveRow is true, then Fts5Storage.pSavedRow is left
** pointing to a statement (FTS5_STMT_LOOKUP2) that may be used to access
** the original values of the row being deleted. This is used by UPDATE
** statements.
*/
static int fts5StorageDeleteFromIndex(
  Fts5Storage *p, 
  i64 iDel, 
  sqlite3_value **apVal,
  int bSaveRow                    /* True to set pSavedRow */
){
  Fts5Config *pConfig = p->pConfig;
  sqlite3_stmt *pSeek = 0;        /* SELECT to read row iDel from %_data */
  int rc = SQLITE_OK;             /* Return code */
  int rc2;                        /* sqlite3_reset() return code */
  int iCol;
  Fts5InsertCtx ctx;

  }else{
    rc2 = sqlite3_reset(pSeek);
    if( rc==SQLITE_OK ) rc = rc2;
  }
  return rc;
}

/*
** Reset any saved statement pSavedRow. Zero pSavedRow as well. This
** should be called by the xUpdate() method of the fts5 table before 
** returning from any operation that may have set Fts5Storage.pSavedRow.
*/
void sqlite3Fts5StorageReleaseDeleteRow(Fts5Storage *pStorage){
  assert( pStorage->pSavedRow==0 
       || pStorage->pSavedRow==pStorage->aStmt[FTS5_STMT_LOOKUP2] 
  );
  sqlite3_reset(pStorage->pSavedRow);
  pStorage->pSavedRow = 0;
}

/*
** This function is called to process a DELETE on a contentless_delete=1
** table. It adds the tombstone required to delete the entry with rowid 

/*
** Remove a row from the FTS table.
*/
int sqlite3Fts5StorageDelete(
  Fts5Storage *p,                 /* Storage object */
  i64 iDel,                       /* Rowid to delete from table */
  sqlite3_value **apVal,          /* Optional - values to remove from index */
  int bSaveRow                    /* If true, set pSavedRow for deleted row */
){
  Fts5Config *pConfig = p->pConfig;
  int rc;
  sqlite3_stmt *pDel = 0;

  assert( pConfig->eContent!=FTS5_CONTENT_NORMAL || apVal==0 );
  rc = fts5StorageLoadTotals(p, 1);

    i64 iRowid = sqlite3_column_int64(pScan, 0);

    sqlite3Fts5BufferZero(&buf);
    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 0, iRowid);
    for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){
      ctx.szCol = 0;
      if( pConfig->abUnindexed[ctx.iCol]==0 ){
        int bReset = 0;           /* True if tokenizer locale must be reset */
        int nText = 0;            /* Size of pText in bytes */
        const char *pText = 0;    /* Pointer to buffer containing text value */

        sqlite3_value *pVal = sqlite3_column_value(pScan, ctx.iCol+1);


        rc = sqlite3Fts5ExtractText(pConfig, pVal, 1, &bReset, &pText, &nText);
        if( rc==SQLITE_OK ){
          rc = sqlite3Fts5Tokenize(pConfig, 
              FTS5_TOKENIZE_DOCUMENT,
              pText, nText,
              (void*)&ctx,
              fts5StorageInsertCallback
          );

  }else{
    sqlite3_stmt *pInsert = 0;    /* Statement to write %_content table */
    int i;                        /* Counter variable */
    rc = fts5StorageGetStmt(p, FTS5_STMT_INSERT_CONTENT, &pInsert, 0);
    for(i=1; rc==SQLITE_OK && i<=pConfig->nCol+1; i++){
      sqlite3_value *pVal = apVal[i];
      if( sqlite3_value_nochange(pVal) && p->pSavedRow ){
        /* This is an UPDATE statement, and column (i-2) was not modified.
        ** Retrieve the value from Fts5Storage.pSavedRow instead. */
        pVal = sqlite3_column_value(p->pSavedRow, i-1);
      }else if( sqlite3_value_subtype(pVal)==FTS5_LOCALE_SUBTYPE ){
        if( pConfig->bLocale==0 ){
          sqlite3Fts5ConfigErrmsg(pConfig, 
              "fts5_locale() may not be used without locale=1"
          );
          rc = SQLITE_ERROR;

          sqlite3_bind_text(pInsert, i, pText, nText, SQLITE_TRANSIENT);
          continue;
        }
      }else if( pConfig->bLocale 
       && sqlite3_value_type(pVal)==SQLITE_BLOB 
       && i>=2 && pConfig->abUnindexed[i-2]==0
      ){
        /* Inserting a blob into a normal content table with locale=1. 
        ** Add the 4 0x00 byte header.  */
        int n = sqlite3_value_bytes(pVal);
        u8 *pBlob = sqlite3Fts5MallocZero(&rc, n+4);
        if( pBlob ){
          memcpy(&pBlob[4], sqlite3_value_blob(pVal), n);
          rc = sqlite3_bind_blob(pInsert, i, pBlob, n+4, SQLITE_TRANSIENT);
          sqlite3_free(pBlob);
        }

  if( rc==SQLITE_OK ){
    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 0, iRowid);
  }
  for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){
    ctx.szCol = 0;
    if( pConfig->abUnindexed[ctx.iCol]==0 ){
      int bReset = 0;             /* True if tokenizer locale must be reset */
      int nText = 0;              /* Size of pText in bytes */
      const char *pText = 0;      /* Pointer to buffer containing text value */
      sqlite3_value *pVal = apVal[ctx.iCol+2];
      int bDisk = 0;
      if( p->pSavedRow && sqlite3_value_nochange(pVal) ){
        pVal = sqlite3_column_value(p->pSavedRow, ctx.iCol+1);
        bDisk = 1;
      }
      rc = sqlite3Fts5ExtractText(pConfig, pVal, bDisk, &bReset, &pText,&nText);
      if( rc==SQLITE_OK ){
        assert( bReset==0 || pConfig->bLocale );





        rc = sqlite3Fts5Tokenize(pConfig, 
            FTS5_TOKENIZE_DOCUMENT, pText, nText, (void*)&ctx,
            fts5StorageInsertCallback
        );

        if( bReset ) sqlite3Fts5ClearLocale(pConfig);
      }
    }
    sqlite3Fts5BufferAppendVarint(&rc, &buf, ctx.szCol);
    p->aTotalSize[ctx.iCol] += (i64)ctx.szCol;
  }
  p->nTotalRow++;

          if( pConfig->abUnindexed[i] ) continue;
          ctx.iCol = i;
          ctx.szCol = 0;
          if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
            rc = sqlite3Fts5TermsetNew(&ctx.pTermset);
          }
          if( rc==SQLITE_OK ){
            int bReset = 0;        /* True if tokenizer locale must be reset */
            int nText = 0;         /* Size of pText in bytes */
            const char *pText = 0; /* Pointer to buffer containing text value */

            rc = sqlite3Fts5ExtractText(pConfig, 
                sqlite3_column_value(pScan, i+1), 1, &bReset, &pText, &nText
            );

            if( rc==SQLITE_OK ){
              rc = sqlite3Fts5Tokenize(pConfig, 
                  FTS5_TOKENIZE_DOCUMENT,
                  pText, nText,
                  (void*)&ctx,
                  fts5StorageIntegrityCallback
              );