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 1.215 2004/11/08 09:26:09 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

  if( rc!=SQLITE_OK ) goto autovacuum_out;
  put4byte(&pBt->pPage1->aData[32], 0);
  put4byte(&pBt->pPage1->aData[36], 0);
  if( rc!=SQLITE_OK ) goto autovacuum_out;
  *nTrunc = finSize;

autovacuum_out:



  assert( nRef==*sqlite3pager_stats(pPager) );
  if( rc!=SQLITE_OK ){
    sqlite3pager_rollback(pPager);
  }
  return rc;
}
#endif

            get4byte(&pBt->pPage1->aData[36]), "Main freelist: ");

  /* Check all the tables.
  */
  for(i=0; i<nRoot; i++){
    if( aRoot[i]==0 ) continue;
#ifndef SQLITE_OMIT_AUTOVACUUM

    if( pBt->autoVacuum && aRoot[i]>1 ){
      checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0, 0);
    }
#endif
    checkTreePage(&sCheck, aRoot[i], 0, "List of tree roots: ", 0,0,0,0);
  }

** 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 1.176 2004/11/08 09:26:10 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

/*
** Macros for troubleshooting.  Normally turned off
*/
#if 0
#define TRACE1(X)       sqlite3DebugPrintf(X)
#define TRACE2(X,Y)     sqlite3DebugPrintf(X,Y)
#define TRACE3(X,Y,Z)   sqlite3DebugPrintf(X,Y,Z)
#define TRACE4(X,Y,Z,W) sqlite3DebugPrintf(X,Y,Z,W)
#define TRACE5(X,Y,Z,W,V) sqlite3DebugPrintf(X,Y,Z,W,V)
#else
#define TRACE1(X)
#define TRACE2(X,Y)
#define TRACE3(X,Y,Z)
#define TRACE4(X,Y,Z,W)
#define TRACE5(X,Y,Z,W,V)
#endif

** A transaction must be active when this routine is called, however it is 
** illegal to call this routine if a statment transaction is active.
*/
int sqlite3pager_movepage(Pager *pPager, void *pData, Pgno pgno){
  PgHdr *pPg = DATA_TO_PGHDR(pData);
  PgHdr *pPgOld; 
  int h;
  Pgno needSyncPgno = 0;

  assert( !pPager->stmtInUse );
  assert( pPg->nRef>0 );

  TRACE5("MOVE %d page %d (needSync=%d) moves to %d\n", 
      PAGERID(pPager), pPg->pgno, pPg->needSync, pgno);

  if( pPg->needSync ){
    needSyncPgno = pPg->pgno;
    assert( pPg->inJournal );
    assert( pPg->dirty );
  }

  /* Unlink pPg from it's hash-chain */
  unlinkHashChain(pPager, pPg);

  /* If the cache contains a page with page-number pgno, remove it
  ** from it's hash chain. Also, if the PgHdr.needSync was set for 
  ** page pgno before the 'move' operation, it needs to be retained 

  }
  pPg->pNextHash = pPager->aHash[h];
  pPager->aHash[h] = pPg;
  pPg->pPrevHash = 0;

  pPg->dirty = 1;
  pPager->dirtyCache = 1;

  if( needSyncPgno ){
    /* If needSyncPgno is non-zero, then the journal file needs to be 
    ** sync()ed before any data is written to database file page needSyncPgno.
    ** Currently, no such page exists in the page-cache and the 
    ** Pager.aInJournal bit has been set. This needs to be remedied by loading
    ** the page into the pager-cache and setting the PgHdr.needSync flag.
    */
    int rc;
    void *pNeedSync;
    rc = sqlite3pager_get(pPager, needSyncPgno, &pNeedSync);
    if( rc!=SQLITE_OK ) return rc;
    DATA_TO_PGHDR(pNeedSync)->needSync = 1;
    DATA_TO_PGHDR(pNeedSync)->inJournal = 1;
    DATA_TO_PGHDR(pNeedSync)->dirty = 1;
    sqlite3pager_unref(pNeedSync);
  }

  return SQLITE_OK;
}
#endif

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
/*

# module "crashtest" compiled with the special "os_test.c" backend is used.
# The os_test.c simulates the kind of file corruption that can occur
# when writes are happening at the moment of power loss.
# 
# The special crash-test module with its os_test.c backend only works
# on Unix.
#
# $Id: crash.test,v 1.10 2004/11/08 09:26:10 danielk1977 Exp $

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

# set repeats 100
set repeats 10

# abc changes in any way, the signature should change.  
proc signature {} {
  return [db eval {SELECT count(*), md5sum(a), md5sum(b), md5sum(c) FROM abc}]
}
proc signature2 {} {
  return [db eval {SELECT count(*), md5sum(a), md5sum(b), md5sum(c) FROM abc2}]
}

# This variable is set to 1 if the databases being used support auto-vacuum.
# This is because some of the tests in this file verify file-size, which is
# slightly larger for auto-vacuum databases.
set AUTOVACUUM [db eval {pragma auto_vacuum}]

#--------------------------------------------------------------------------
# Simple crash test:
#
# crash-1.1: Create a database with a table with two rows.
# crash-1.2: Run a 'DELETE FROM abc WHERE a = 1' that crashes during
#            the first journal-sync.

  }
  execsql { COMMIT }
  set ::sig [signature]
  execsql { SELECT sum(a), sum(b), sum(c) from abc }
} {499500.0 999000.0 1498500.0}
do_test crash-2.2 {
  expr [file size test.db] / 1024
} [expr $AUTOVACUUM ? 20 : 19]
do_test crash-2.3 {
  crashsql 2 test.db-journal {
    DELETE FROM abc WHERE a < 800;
  }
} {1 {child process exited abnormally}}
do_test crash-2.4 {
  signature

    INSERT INTO abc SELECT * FROM abc;
    INSERT INTO abc SELECT * FROM abc;
    INSERT INTO abc SELECT * FROM abc;
    INSERT INTO abc SELECT * FROM abc;
    INSERT INTO abc SELECT * FROM abc;
  }
  expr [file size test.db] / 1024
} [expr $AUTOVACUUM ? 557 : 554]
for {set i 1} {$i < $repeats} {incr i} {
  set sig [signature]
  do_test crash-3.$i.1 {
     crashsql [expr $i%5 + 1] test.db-journal "
       BEGIN;
       SELECT random() FROM abc LIMIT $i;
       INSERT INTO abc VALUES(randstr(10,10), 0, 0);

  do_test crash-4.3.$i.2 {
    signature
  } $sig
  do_test crash-4.3.$i.3 {
    signature2
  } $sig2
}

#--------------------------------------------------------------------------
# The following test cases - crash-5.* - exposes a bug that existed in the
# sqlite3pager_movepage() API used by auto-vacuum databases.
# database when a crash occurs during a multi-file transaction. See comments
# in test crash-5.3 for details.
#
db close
file delete -force test.db
sqlite3 db test.db
do_test crash-5.1 {
  execsql {
    CREATE TABLE abc(a, b, c);                          -- Root page 3
    INSERT INTO abc VALUES(randstr(1500,1500), 0, 0);   -- Overflow page 4
    INSERT INTO abc SELECT * FROM abc;
    INSERT INTO abc SELECT * FROM abc;
    INSERT INTO abc SELECT * FROM abc;
  }
} {}
do_test crash-5.2 {
  expr [file size test.db] / 1024
} [expr $AUTOVACUUM ? 11 : 10]
set sig [signature]
do_test crash-5.3 {
# The SQL below is used to expose a bug that existed in
# sqlite3pager_movepage() during development of the auto-vacuum feature. It
# functions as follows:
# 
# 1: Begin a transaction.
# 2: Put page 4 on the free-list (was the overflow page for the row deleted).
# 3: Write data to page 4 (it becomes the overflow page for the row inserted).
#    The old page 4 data has been written to the journal file, but the
#    journal file has not been sync()hronized.
# 4: Create a table, which calls sqlite3pager_movepage() to move page 4
#    to the end of the database (page 12) to make room for the new root-page.
# 5: Put pressure on the pager-cache. This results in page 4 being written
#    to the database file to make space in the cache to load a new page. The
#    bug was that page 4 was written to the database file before the journal
#    is sync()hronized.
# 6: Commit. A crash occurs during the sync of the journal file.
#
# End result: Before the bug was fixed, data has been written to page 4 of the
# database file and the journal file does not contain trustworthy rollback
# data for this page.
#
  crashsql 1 test.db-journal {
    BEGIN;                                             -- 1
    DELETE FROM abc WHERE oid = 1;                     -- 2
    INSERT INTO abc VALUES(randstr(1500,1500), 0, 0);  -- 3
    CREATE TABLE abc2(a, b, c);                        -- 4
    SELECT * FROM abc;                                 -- 5
    COMMIT;                                            -- 6
  }
} {1 {child process exited abnormally}}
integrity_check crash-5.4
do_test crash-5.5 {
  signature
} $sig

# 2001 September 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.
#
#***********************************************************************
# This file runs all tests.
#
# $Id: quick.test,v 1.32 2004/11/08 09:26:10 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
rename finish_test really_finish_test
proc finish_test {} {}
set ISQUICK 1

  corrupt.test
  crash.test
  malloc.test
  memleak.test
  misuse.test
  quick.test
  utf16.test

  autovacuum_crash.test
}

if {[sqlite3 -has-codec]} {
  # lappend EXCLUDE \
  #  conflict.test
}