SQLite

** 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 1.517 2008/12/18 18:31:39 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

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

** to access those pages will likely result in a coredump.
*/
static void pager_reset(Pager *pPager){
  if( pPager->errCode ) return;
  sqlite3PcacheClear(pPager->pPCache);
}

/*
** Free all structures in the Pager.aSavepoint[] array and set both
** Pager.aSavepoint and Pager.nSavepoint to zero. Close the sub-journal
** if it is open and the pager is not in exclusive mode.
*/
static void releaseAllSavepoint(Pager *pPager){
  int ii;
  for(ii=0; ii<pPager->nSavepoint; ii++){
    sqlite3BitvecDestroy(pPager->aSavepoint[ii].pInSavepoint);
  }
  if( !pPager->exclusiveMode ){
    sqlite3OsClose(pPager->sjfd);
  }
  sqlite3_free(pPager->aSavepoint);
  pPager->aSavepoint = 0;
  pPager->nSavepoint = 0;
}

/*
** Set the bit number pgno in the PagerSavepoint.pInSavepoint bitvecs of
** all open savepoints.
*/
static int addToSavepointBitvecs(Pager *pPager, Pgno pgno){
  int ii;
  for(ii=0; ii<pPager->nSavepoint; ii++){
    PagerSavepoint *p = &pPager->aSavepoint[ii];
    if( pgno<=p->nOrig ){
      /* TODO: malloc() failure handling */
      sqlite3BitvecSet(p->pInSavepoint, pgno);

**
** 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 1.805 2008/12/18 18:31:39 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

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

  */
  assert( db->pSavepoint==0 || db->autoCommit==0 );
  assert( p1==SAVEPOINT_BEGIN||p1==SAVEPOINT_RELEASE||p1==SAVEPOINT_ROLLBACK );
  assert( db->pSavepoint || db->isTransactionSavepoint==0 );
  assert( checkSavepointCount(db) );

  if( p1==SAVEPOINT_BEGIN ){
    if( db->writeVdbeCnt>0 ){
      /* A new savepoint cannot be created if there are active write 
      ** statements (i.e. open read/write incremental blob handles).
      */
      sqlite3SetString(&p->zErrMsg, db, "cannot open savepoint - "
        "SQL statements in progress");
      rc = SQLITE_BUSY;
    }else{

        "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. 


      */
      int isTransaction = pSavepoint->pNext==0 && db->isTransactionSavepoint;
      if( isTransaction && p1==SAVEPOINT_RELEASE ){

        db->autoCommit = 1;
        if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
          p->pc = pc;
          db->autoCommit = 0;
          p->rc = rc = SQLITE_BUSY;
          goto vdbe_return;
        }
        db->isTransactionSavepoint = 0;
        rc = p->rc;
      }else{
        int ii;
        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;

# 2008 December 15
#
# 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: savepoint.test,v 1.2 2008/12/18 18:31:39 danielk1977 Exp $

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


#----------------------------------------------------------------------
# The following tests - savepoint-1.* - test that the SAVEPOINT, RELEASE

    INSERT INTO t3 VALUES('value');
  }
  execsql {SELECT * FROM t3}
} {value}
do_test savepoint-4.8 {
  execsql COMMIT
} {}

#------------------------------------------------------------------------
# Test some logic errors to do with the savepoint feature.
# 

do_test savepoint-5.1.1 {
  execsql {
    CREATE TABLE blobs(x);
    INSERT INTO blobs VALUES('a twentyeight character blob');
  }
  set fd [db incrblob blobs x 1]
  puts -nonewline $fd "hello"
  catchsql {SAVEPOINT abc}
} {1 {cannot open savepoint - SQL statements in progress}}
do_test savepoint-5.1.2 {
  close $fd
  catchsql {SAVEPOINT abc}
} {0 {}}

do_test savepoint-5.2 {
  execsql  {RELEASE abc}
  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]
  catchsql {release def}
} {1 {cannot release savepoint - SQL statements in progress}}
do_test savepoint-5.3.5 {
  close $fd
  execsql {release abc}
} {}

do_test savepoint-5.4.1 {
  execsql {
    SAVEPOINT main;
    INSERT INTO blobs VALUES('another blob');
  }
} {}
do_test savepoint-5.4.2 {
  sqlite3 db2 test.db
  execsql { BEGIN ; SELECT * FROM blobs } db2
  catchsql { RELEASE main }
} {1 {database is locked}}
do_test savepoint-5.4.3 {
  db2 close
  catchsql { RELEASE main }
} {0 {}}
do_test savepoint-5.4.4 {
  execsql { SELECT x FROM blobs WHERE rowid = 2 }
} {{another blob}}

finish_test

# 2008 December 15
#
# 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: savepoint2.test,v 1.2 2008/12/18 18:31:39 danielk1977 Exp $

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

# Tests in this file are quite similar to those run by trans.test and
# avtrans.test.
#

proc signature {} {
  return [db eval {SELECT count(*), md5sum(x) FROM t3}]
}



do_test savepoint2-1 {
  execsql {
    PRAGMA cache_size=10;




    BEGIN;
    CREATE TABLE t3(x TEXT);
    INSERT INTO t3 VALUES(randstr(10,400));
    INSERT INTO t3 VALUES(randstr(10,400));
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;
    INSERT INTO t3 SELECT randstr(10,400) FROM t3;

# 2008 December 15
#
# 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: savepoint3.test,v 1.1 2008/12/18 18:31:39 danielk1977 Exp $

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

source $testdir/malloc_common.tcl

do_malloc_test savepoint3-1 -sqlprep {
  CREATE TABLE t1(a, b, c);
  INSERT INTO t1 VALUES(1, 2, 3);
} -sqlbody {
  SAVEPOINT one;
    INSERT INTO t1 VALUES(4, 5, 6);
    SAVEPOINT two;
      DELETE FROM t1;
    ROLLBACK TO two;
  RELEASE one;
}

do_malloc_test savepoint3-1 -sqlprep {
  PRAGMA cache_size = 10;
  CREATE TABLE t1(a, b, c);
  INSERT INTO t1 VALUES(randstr(400,400), randstr(400,400), randstr(400,400));
  INSERT INTO t1 SELECT 
    randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
  INSERT INTO t1 
    SELECT randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
  INSERT INTO t1 
    SELECT randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
  INSERT INTO t1 
    SELECT randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
  INSERT INTO t1 
    SELECT randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
  INSERT INTO t1 
    SELECT randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
  INSERT INTO t1 
    SELECT randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
  INSERT INTO t1 
    SELECT randstr(400,400), randstr(400,400), randstr(400,400) FROM t1;
} -sqlbody {
  PRAGMA cache_size = 10;
  SAVEPOINT one;
    DELETE FROM t1 WHERE rowid < 5;
    SAVEPOINT two;
      DELETE FROM t1 WHERE rowid > 10;
    ROLLBACK TO two;
  ROLLBACK TO one;
  RELEASE one;
}

finish_test