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 1.495 2008/09/26 21:08:08 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

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

  }
  sqlite3PagerStmtCommit(pPager);
  if( pPager->stmtOpen && !pPager->exclusiveMode ){
    sqlite3OsClose(pPager->stfd);
    pPager->stmtOpen = 0;
  }
  if( pPager->journalOpen ){
    if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE
         && (rc = sqlite3OsTruncate(pPager->jfd, 0))==SQLITE_OK ){
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
    }else if( pPager->exclusiveMode 
     || pPager->journalMode==PAGER_JOURNALMODE_PERSIST
    ){
      rc = zeroJournalHdr(pPager, hasMaster);
      pager_error(pPager, rc);
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
    }else{
      assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE || rc );
      sqlite3OsClose(pPager->jfd);
      pPager->journalOpen = 0;
      if( rc==SQLITE_OK && !pPager->tempFile ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }
    sqlite3BitvecDestroy(pPager->pInJournal);

  if( eMode>=0 && !pPager->tempFile ){
    pPager->exclusiveMode = eMode;
  }
  return (int)pPager->exclusiveMode;
}

/*
** Get/set the journal-mode for this pager. Parameter eMode must be one of:
**
**    PAGER_JOURNALMODE_QUERY
**    PAGER_JOURNALMODE_DELETE
**    PAGER_JOURNALMODE_TRUNCATE
**    PAGER_JOURNALMODE_PERSIST
**    PAGER_JOURNALMODE_OFF
**
** If the parameter is not _QUERY, then the journal-mode is set to the
** value specified.
**

** The returned indicate the current (possibly updated)
** journal-mode.
*/
int sqlite3PagerJournalMode(Pager *pPager, int eMode){
  assert( eMode==PAGER_JOURNALMODE_QUERY
            || eMode==PAGER_JOURNALMODE_DELETE
            || eMode==PAGER_JOURNALMODE_TRUNCATE
            || eMode==PAGER_JOURNALMODE_PERSIST
            || eMode==PAGER_JOURNALMODE_OFF );
  assert( PAGER_JOURNALMODE_QUERY<0 );

  if( eMode>=0 ){
    pPager->journalMode = eMode;
  }else{
    assert( eMode==PAGER_JOURNALMODE_QUERY );
  }
  return (int)pPager->journalMode;
}

/*
** Get/set the size-limit used for persistent journal files.
*/

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.84 2008/09/26 21:08:08 drh Exp $
*/

#ifndef _PAGER_H_
#define _PAGER_H_

/*
** If defined as non-zero, auto-vacuum is enabled by default. Otherwise

/*
** Valid values for the second argument to sqlite3PagerJournalMode().
*/
#define PAGER_JOURNALMODE_QUERY      -1
#define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
#define PAGER_JOURNALMODE_PERSIST     1   /* Commit by zeroing journal header */
#define PAGER_JOURNALMODE_OFF         2   /* Journal omitted.  */
#define PAGER_JOURNALMODE_TRUNCATE    3   /* Commit by truncating journal */

/*
** See source code comments for a detailed description of the following
** routines:
*/
int sqlite3PagerOpen(sqlite3_vfs *, Pager **ppPager, const char*, void(*)(DbPage*), int,int,int);
void sqlite3PagerSetBusyhandler(Pager*, BusyHandler *pBusyHandler);

/*
** 2003 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.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.188 2008/09/26 21:08:08 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/
#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)

  /*
  **  PRAGMA [database.]journal_mode
  **  PRAGMA [database.]journal_mode = (delete|persist|off)
  */
  if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){
    int eMode;
    static char * const azModeName[] = {"delete", "persist", "off", "truncate"};

    if( zRight==0 ){
      eMode = PAGER_JOURNALMODE_QUERY;
    }else{
      int n = strlen(zRight);
      eMode = sizeof(azModeName)/sizeof(azModeName[0]) - 1;
      while( eMode>=0 && sqlite3StrNICmp(zRight, azModeName[eMode], n)!=0 ){
        eMode--;
      }
    }
    if( pId2->n==0 && eMode==PAGER_JOURNALMODE_QUERY ){
      /* Simple "PRAGMA journal_mode;" statement. This is a query for
      ** the current default journal mode (which may be different to

        }
        db->dfltJournalMode = eMode;
      }
      pPager = sqlite3BtreePager(pDb->pBt);
      eMode = sqlite3PagerJournalMode(pPager, eMode);
    }
    assert( eMode==PAGER_JOURNALMODE_DELETE
              || eMode==PAGER_JOURNALMODE_TRUNCATE
              || eMode==PAGER_JOURNALMODE_PERSIST
              || eMode==PAGER_JOURNALMODE_OFF );
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", P4_STATIC);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, 
           azModeName[eMode], P4_STATIC);
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

# 2008 April 17
#
# 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.
#
#***********************************************************************
# This file implements regression tests for SQLite library. The focus
# of these tests is the journal mode pragma.
#
# $Id: jrnlmode.test,v 1.6 2008/09/26 21:08:08 drh Exp $

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

ifcapable {!pager_pragmas} {
  finish_test
  return

do_test jrnlmode-1.7 {
  execsql {
    PRAGMA journal_mode;
    PRAGMA main.journal_mode;
    PRAGMA temp.journal_mode;
  } 
} {delete delete delete}
do_test jrnlmode-1.7.1 {
  execsql {
    PRAGMA journal_mode = truncate;
  } 
} {truncate}
do_test jrnlmode-1.7.2 {
  execsql {
    PRAGMA journal_mode;
    PRAGMA main.journal_mode;
    PRAGMA temp.journal_mode;
  } 
} {truncate truncate truncate}
do_test jrnlmode-1.8 {
  execsql {
    PRAGMA journal_mode = off;
    PRAGMA journal_mode = invalid;
  } 
} {off off}
ifcapable attach {
  do_test jrnlmode-1.9 {
    execsql {
      PRAGMA journal_mode = PERSIST;
      ATTACH ':memory:' as aux1;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA aux1.journal_mode;
    }
  } {persist persist}
  do_test jrnlmode-1.10 {
    execsql {
      PRAGMA main.journal_mode = OFF;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA temp.journal_mode;
      PRAGMA aux1.journal_mode;
    }
  } {off persist persist}

      PRAGMA main.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
    }
  } {off persist persist}
  do_test jrnlmode-1.11 {
    execsql {
      PRAGMA aux1.journal_mode = DELETE;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
    }
  } {off delete persist}

      PRAGMA main.journal_mode;
      PRAGMA temp.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
      PRAGMA aux3.journal_mode;
    }
  } {delete delete delete delete delete}
  do_test jrnlmode-1.14 {
    execsql {
      PRAGMA journal_mode = TRUNCATE;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA temp.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
      PRAGMA aux3.journal_mode;
    }
  } {truncate truncate truncate truncate truncate}
  
  do_test jrnlmode-1.99 {
    execsql {
      DETACH aux1;
      DETACH aux2;
      DETACH aux3;
    }

# 2008 June 21
#
# 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: permutations.test,v 1.31 2008/09/26 21:08:08 drh Exp $

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

# Argument processing.
#
#puts "PERM-DEBUG: argv=$argv"

# Run some tests in exclusive locking mode.
#
run_tests "exclusive" -description {
  Run tests in exclusive locking mode.
} -presql {
  pragma locking_mode = 'exclusive'
} -include {
  vacuum.test
  rollback.test select1.test select2.test 
  malloc.test ioerr.test
} 

# Run some tests in exclusive locking mode with truncated journals.
#
run_tests "exclusive-truncate" -description {
  Run tests in exclusive locking mode and truncate journal mode.
} -presql {
  pragma locking_mode = 'exclusive';
  pragma journal_mode = TRUNCATE;
} -include {
  delete.test delete2.test insert.test rollback.test select1.test
  select2.test update.test malloc.test ioerr.test
} 

# Run some tests in persistent journal mode.
#
run_tests "persistent_journal" -description {
  Run tests in persistent-journal mode.
} -presql {
  pragma journal_mode = persist
} -include {
  delete.test delete2.test insert.test rollback.test select1.test
  select2.test trans.test update.test vacuum.test 
}

# Run some tests in truncating journal mode.
#
run_tests "truncate_journal" -description {
  Run tests in persistent-journal mode.
} -presql {
  pragma journal_mode = truncate
} -include {
  delete.test delete2.test insert.test rollback.test select1.test
  select2.test trans.test update.test vacuum.test 
  malloc.test ioerr.test
}

# Run some error tests in persistent journal mode.
#
run_tests "persistent_journal_error" -description {
  Run malloc.test and ioerr.test in persistent-journal mode.
} -presql {
  pragma journal_mode = persist