SQLite

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.555 2009/01/02 21:08:09 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

    BtShared *pBt = p->pBt;
    assert( pBt->inStmt==0 );
    assert( op==SAVEPOINT_RELEASE || op==SAVEPOINT_ROLLBACK );
    assert( iSavepoint>=0 || (iSavepoint==-1 && op==SAVEPOINT_ROLLBACK) );
    sqlite3BtreeEnter(p);
    pBt->db = p->db;
    rc = sqlite3PagerSavepoint(pBt->pPager, op, iSavepoint);
    if( rc==SQLITE_OK ){
      rc = newDatabase(pBt);
    }
    sqlite3BtreeLeave(p);
  }
  return rc;
}

/*
** Create a new cursor for the BTree whose root is on the page

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.527 2009/01/02 21:08:09 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

/*
** Macros for troubleshooting.  Normally turned off
*/

  void *(*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */
  void *pCodecArg;            /* First argument to xCodec() */
#endif
  char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */
  char dbFileVers[16];        /* Changes whenever database file changes */
  i64 journalSizeLimit;       /* Size limit for persistent journal files */
  PCache *pPCache;            /* Pointer to page cache object */

  PagerSavepoint *aSavepoint; /* Array of active savepoints */
  int nSavepoint;             /* Number of elements in aSavepoint[] */
};

/*
** The following global variables hold counters used for
** testing purposes only.  These variables do not exist in
** a non-testing build.  These variables are not thread-safe.
*/

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.808 2009/01/02 21:08:09 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor

        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 ){
          sqlite3ExpirePreparedStatements(db);
          sqlite3ResetInternalSchema(db, 0);
        }
      }
  
      /* Regardless of whether this is a RELEASE or ROLLBACK, destroy all 
      ** savepoints nested inside of the savepoint being operated on. */

# 2009 January 2
#
# 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.
#
#***********************************************************************
#
# Verify that a SAVEPOINT on a new, empty database followed by a
# ROLLBACK TO that savepoint starts over again with another new
# empty database.
#
# $Id: savepoint5.test,v 1.1 2009/01/02 21:08:09 drh Exp $

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

do_test savepoint5-1.1 {
  db eval {
    SAVEPOINT sp1;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(1);
    SELECT count(*) FROM sqlite_master;
    SELECT * FROM t1;
  }
} {1 1}
do_test savepoint5-1.2 {
  db eval {
    ROLLBACK TO sp1;
    SELECT count(*) FROM sqlite_master;
  }
} {0}
do_test savepoint5-1.3 {
  db eval {
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(1);
    SELECT count(*) FROM sqlite_master;
    SELECT * FROM t1;
  }
} {1 1}


finish_test