SQLite

  TESTONLY( p->mxSavepoint = iSavepoint );
  return sqlite3Fts3PendingTermsFlush(p);
}
static int fts3ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){
  TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );
  assert( p->inTransaction );
  assert( p->mxSavepoint >= iSavepoint );
  TESTONLY( p->mxSavepoint = iSavepoint>0 ? iSavepoint-1 : 0 );
  return SQLITE_OK;
}
static int fts3RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){
  Fts3Table *p = (Fts3Table*)pVtab;
  assert( p->inTransaction );
  assert( p->mxSavepoint >= iSavepoint );
  TESTONLY( p->mxSavepoint = iSavepoint );

*/
struct VTable {
  sqlite3 *db;              /* Database connection associated with this table */
  Module *pMod;             /* Pointer to module implementation */
  sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
  int nRef;                 /* Number of pointers to this structure */
  u8 bConstraint;           /* True if constraints are supported */
  u8 bInSavepoint;          /* True if within a SAVEPOINT */
  VTable *pNext;            /* Next in linked list (see above) */
};

/*
** Each SQL table is represented in memory by an instance of the
** following structure.
**

      assert( sqlite3BtreeIsInTrans(pBt) );
      if( p->iStatement==0 ){
        assert( db->nStatement>=0 && db->nSavepoint>=0 );
        db->nStatement++; 
        p->iStatement = db->nSavepoint + db->nStatement;
      }

      rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN, p->iStatement);
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeBeginStmt(pBt, p->iStatement);
      }

      /* Store the current value of the database handles deferred constraint
      ** counter. If the statement transaction needs to be rolled back,
      ** the value of this counter needs to be restored too.  */

    }
  
    /* If eStatementOp is non-zero, then a statement transaction needs to
    ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to
    ** do so. If this operation returns an error, and the current statement
    ** error code is SQLITE_OK or SQLITE_CONSTRAINT, then promote the
    ** current statement error code.
    **
    ** Note that sqlite3VdbeCloseStatement() can only fail if eStatementOp
    ** is SAVEPOINT_ROLLBACK.  But if p->rc==SQLITE_OK then eStatementOp
    ** must be SAVEPOINT_RELEASE.  Hence the NEVER(p->rc==SQLITE_OK) in 
    ** the following code.
    */
    if( eStatementOp ){
      rc = sqlite3VdbeCloseStatement(p, eStatementOp);
      if( rc ){
        assert( eStatementOp==SAVEPOINT_ROLLBACK );
        if( NEVER(p->rc==SQLITE_OK) || p->rc==SQLITE_CONSTRAINT ){
          p->rc = rc;
          sqlite3DbFree(db, p->zErrMsg);
          p->zErrMsg = 0;
        }
        invalidateCursorsOnModifiedBtrees(db);
        sqlite3RollbackAll(db);
        sqlite3CloseSavepoints(db);

      VTable *pVTab = db->aVTrans[i];
      sqlite3_vtab *p = pVTab->pVtab;
      if( p ){
        int (*x)(sqlite3_vtab *);
        x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset);
        if( x ) x(p);
      }

      sqlite3VtabUnlock(pVTab);
    }
    sqlite3DbFree(db, db->aVTrans);
    db->nVTrans = 0;
    db->aVTrans = 0;
  }
}

** function immediately. If all calls to virtual table methods are successful,
** SQLITE_OK is returned.
*/
int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){
  int rc = SQLITE_OK;

  assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN );

  if( db->aVTrans ){
    int i;
    for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
      VTable *pVTab = db->aVTrans[i];
      const sqlite3_module *pMod = pVTab->pMod->pModule;
      if( pMod->iVersion>=2 && (pVTab->bInSavepoint || op==SAVEPOINT_BEGIN) ){
        int (*xMethod)(sqlite3_vtab *, int);
        switch( op ){
          case SAVEPOINT_BEGIN:
            xMethod = pMod->xSavepoint;
            pVTab->bInSavepoint = 1;
            break;
          case SAVEPOINT_ROLLBACK:
            xMethod = pMod->xRollbackTo;
            break;
          default:
            xMethod = pMod->xRelease;
            break;
        }

        if( xMethod ) rc = xMethod(db->aVTrans[i]->pVtab, iSavepoint);

      }
    }
  }
  return rc;
}

/*