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 1.278 2007/01/02 18:41:55 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  }
  rc = sqlite3OsUnlock(pPager->fd, SHARED_LOCK);
  pPager->state = PAGER_SHARED;
  pPager->origDbSize = 0;
  pPager->setMaster = 0;
  pPager->needSync = 0;
  pPager->pFirstSynced = pPager->pFirst;
  pPager->dbSize = -1;
  return rc;
}

/*
** Compute and return a checksum for the page of data.
**
** This is not a real checksum.  It is really just the sum of the 

    return SQLITE_OK;
  }
  if( pPager->dirtyCache==0 ){
    /* Exit early (without doing the time-consuming sqlite3OsSync() calls)
    ** if there have been no changes to the database file. */
    assert( pPager->needSync==0 );
    rc = pager_unwritelock(pPager);

    return rc;
  }
  assert( pPager->journalOpen );
  rc = sqlite3pager_sync(pPager, 0, 0);
  if( rc==SQLITE_OK ){
    rc = pager_unwritelock(pPager);

  }
  return rc;
}

/*
** Rollback all changes.  The database falls back to PAGER_SHARED mode.
** All in-memory cache pages revert to their original data contents.

    pPager->stmtInUse = 0;
    pPager->state = PAGER_SHARED;
    return SQLITE_OK;
  }

  if( !pPager->dirtyCache || !pPager->journalOpen ){
    rc = pager_unwritelock(pPager);

    return rc;
  }

  if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
    if( pPager->state>=PAGER_EXCLUSIVE ){
      pager_playback(pPager);
    }

**
** 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 1.582 2007/01/02 18:41:55 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

      if( avail>=payloadSize ){
        zRec = zData;
        pC->aRow = (u8*)zData;
      }else{
        pC->aRow = 0;
      }
    }
    /* The following assert is true in all cases accept when
    ** the database file has been corrupted externally.
    **    assert( zRec!=0 || avail>=payloadSize || avail>=9 ); */
    szHdrSz = GetVarint((u8*)zData, offset);

    /* The KeyFetch() or DataFetch() above are fast and will get the entire
    ** record header in most cases.  But they will fail to get the complete
    ** record header if the record header does not fit on a single page
    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
    ** acquire the complete header text.

# 2006 June 10
#
# 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: vtab_err.test,v 1.4 2007/01/02 18:41:58 drh Exp $

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

# Only run these tests if memory debugging is turned on.
#
if {[info command sqlite_malloc_stat]==""} {
  puts "Skipping vtab_err tests: not compiled with -DSQLITE_MEMDEBUG=1"
  finish_test
  return
}

ifcapable !vtab {
  finish_test
  return
}

# Usage: do_malloc_test <test number> <options...>