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 1.458 2008/05/09 16:57:51 danielk1977 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"

** well-formed database file, then SQLITE_CORRUPT is returned.
** SQLITE_BUSY is returned if the database is locked.  SQLITE_NOMEM
** is returned if we run out of memory. 
*/
static int lockBtree(BtShared *pBt){
  int rc;
  MemPage *pPage1;
  int nPage;

  assert( sqlite3_mutex_held(pBt->mutex) );
  if( pBt->pPage1 ) return SQLITE_OK;
  rc = sqlite3BtreeGetPage(pBt, 1, &pPage1, 0);
  if( rc!=SQLITE_OK ) return rc;

  /* Do some checking to help insure the file we opened really is
  ** a valid database file. 
  */
  rc = SQLITE_NOTADB;
  nPage = sqlite3PagerPagecount(pBt->pPager);
  if( nPage<0 ){
    rc = SQLITE_IOERR;
    goto page1_init_failed;
  }else if( nPage>0 ){
    int pageSize;
    int usableSize;
    u8 *page1 = pPage1->aData;
    if( memcmp(page1, zMagicHeader, 16)!=0 ){
      goto page1_init_failed;
    }
    if( page1[18]>1 ){

** 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 1.444 2008/05/09 16:57:51 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*

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

  ** the error. Discard the contents of the pager-cache and treat any
  ** open journal file as a hot-journal.
  */
  if( !MEMDB && pPager->exclusiveMode && pPager->nRef==0 && pPager->errCode ){
    if( pPager->journalOpen ){
      isHot = 1;
    }

    pPager->errCode = SQLITE_OK;
    pager_reset(pPager);
  }

  /* If the pager is still in an error state, do not proceed. The error 
  ** state will be cleared at some point in the future when all page 
  ** references are dropped and the cache can be discarded.
  */
  if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){

  OS_TIME_IO(OS_WRITE, iAmt, iOfst, p->pReal->pMethods->xWrite(p->pReal, z, iAmt, iOfst));
}

/*
** Truncate an inst-file.
*/
static int instTruncate(sqlite3_file *pFile, sqlite_int64 size){
  OS_TIME_IO(OS_TRUNCATE, 0, (int)size, 
    p->pReal->pMethods->xTruncate(p->pReal, size)
  );
}

/*
** Sync an inst-file.
*/
static int instSync(sqlite3_file *pFile, int flags){
  OS_TIME_IO(OS_SYNC, flags, 0, p->pReal->pMethods->xSync(p->pReal, flags));

static void put32bits(unsigned char *p, unsigned int v){
  p[0] = v>>24;
  p[1] = v>>16;
  p[2] = v>>8;
  p[3] = v;
}

static void binarylog_flush(InstVfsBinaryLog *pLog){
  sqlite3_file *pFile = pLog->pOut;

#ifdef SQLITE_TEST
  extern int sqlite3_io_error_pending;
  extern int sqlite3_io_error_persist;
  extern int sqlite3_diskfull_pending;

  int pending = sqlite3_io_error_pending;
  int persist = sqlite3_io_error_persist;
  int diskfull = sqlite3_diskfull_pending;

  sqlite3_io_error_pending = 0;
  sqlite3_io_error_persist = 0;
  sqlite3_diskfull_pending = 0;
#endif

  pFile->pMethods->xWrite(pFile, pLog->zBuf, pLog->nBuf, pLog->iOffset);
  pLog->iOffset += pLog->nBuf;
  pLog->nBuf = 0;

#ifdef SQLITE_TEST
  sqlite3_io_error_pending = pending;
  sqlite3_io_error_persist = persist;
  sqlite3_diskfull_pending = diskfull;
#endif
}

static void binarylog_xcall(
  void *p,
  int eEvent,
  int iFileId,
  sqlite3_int64 nClick,
  int return_code,
  const char *zName,
  int flags,
  int nByte,
  sqlite3_int64 iOffset
){
  InstVfsBinaryLog *pLog = (InstVfsBinaryLog *)p;
  unsigned char *zRec;
  if( (28+pLog->nBuf)>BINARYLOG_BUFFERSIZE ){



    binarylog_flush(pLog);
  }
  zRec = (unsigned char *)&pLog->zBuf[pLog->nBuf];
  put32bits(&zRec[0], eEvent);
  put32bits(&zRec[4], (int)iFileId);
  put32bits(&zRec[8], (int)nClick);
  put32bits(&zRec[12], return_code);
  put32bits(&zRec[16], flags);
  put32bits(&zRec[20], nByte);
  put32bits(&zRec[24], (int)iOffset);
  pLog->nBuf += 28;
}

static void binarylog_xdel(void *p){
  /* Close the log file and free the memory allocated for the 
  ** InstVfsBinaryLog structure.
  */
  InstVfsBinaryLog *pLog = (InstVfsBinaryLog *)p;
  sqlite3_file *pFile = pLog->pOut;
  if( pLog->nBuf ){
    binarylog_flush(pLog);
  }
  pFile->pMethods->xClose(pFile);
  sqlite3_free(pLog->pOut);
  sqlite3_free(pLog->zBuf);
  sqlite3_free(pLog);
}

  pLog = (InstVfsBinaryLog *)pInstVfs->pClient;
  if( nBlob<0 ){
    nBlob = strlen(zBlob);
  }
  nWrite = nBlob + 28;

  if( (nWrite+pLog->nBuf)>BINARYLOG_BUFFERSIZE ){



    binarylog_flush(pLog);
  }

  zRec = (unsigned char *)&pLog->zBuf[pLog->nBuf];
  memset(zRec, 0, nWrite);
  put32bits(&zRec[0], BINARYLOG_STRING);
  put32bits(&zRec[4], (int)nBlob);
  memcpy(&zRec[28], zBlob, nBlob);

  p->zOut = (char *)&p[1];
  p->pOut = (sqlite3_file *)sqlite3_malloc(pParent->szOsFile);
  pParent->xFullPathname(pParent, zLog, pParent->mxPathname, p->zOut);
  flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_MASTER_JOURNAL;
  pParent->xDelete(pParent, p->zOut, 0);
  rc = pParent->xOpen(pParent, p->zOut, p->pOut, flags, &flags);
  if( rc==SQLITE_OK ){
    memcpy(p->zBuf, "sqlite_ostrace1.....", 20);
    p->iOffset = 0;
    p->nBuf = 20;
  }
  if( rc ){
    binarylog_xdel(p);
    return 0;
  }

  pVfs = sqlite3_instvfs_create(zVfs, zParentVfs);

      }
      Tcl_SetObjResult(interp, objv[2]);
      break;
    }
    case IV_BINARYLOG: {
      char *zName = 0;
      char *zLog = 0;
      char *zParent = 0;
      sqlite3_vfs *p;
      int isDefault = 0;
      int argbase = 2;

      if( objc>2 && 0==strcmp("-default", Tcl_GetString(objv[argbase])) ){
        isDefault = 1;
        argbase++;
      }
      if( objc>(argbase+1) 
       && 0==strcmp("-parent", Tcl_GetString(objv[argbase])) 
      ){
        zParent = Tcl_GetString(objv[argbase+1]);
        argbase += 2;
      }

      if( (objc-argbase)!=2 ){
        Tcl_WrongNumArgs(
            interp, 2, objv, "?-default? ?-parent VFS? NAME LOGFILE"
        );
        return TCL_ERROR;
      }
      zName = Tcl_GetString(objv[argbase]);
      zLog = Tcl_GetString(objv[argbase+1]);
      p = sqlite3_instvfs_binarylog(zName, zParent, zLog);
      if( !p ){
        Tcl_AppendResult(interp, "error creating vfs ", 0);
        return TCL_ERROR;
      }
      if( isDefault ){
        sqlite3_vfs_register(p, 1);
      }

# This file implements regression tests for SQLite library.  The
# focus of this file is testing for correct handling of I/O errors
# such as writes failing because the disk is full.
# 
# The tests in this file use special facilities that are only
# available in the SQLite test fixture.
#
# $Id: incrvacuum_ioerr.test,v 1.4 2008/05/09 16:57:51 danielk1977 Exp $

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

# If this build of the library does not support auto-vacuum, omit this
# whole file.
ifcapable {!autovacuum} {
  finish_test
  return
}

if 0 {

do_ioerr_test incrvacuum-ioerr-1 -cksum 1 -sqlprep {
  PRAGMA auto_vacuum = 'incremental';
  CREATE TABLE abc(a);
  INSERT INTO abc VALUES(randstr(1500,1500));
} -sqlbody {
  BEGIN;

  PRAGMA incremental_vacuum(5);
} -cleanup {
  sqlite3 db test.db
  integrity_check incrvacuum-ioerr-2.$n.integritycheck
  db close
}

}


ifcapable shared_cache {

  catch { db close }
  file delete -force test.db
  set ::enable_shared_cache [sqlite3_enable_shared_cache 1]
  
  # Create two connections to a single shared-cache:
  #
  sqlite3 db1 test.db
  sqlite3 db2 test.db
  
  # Create a database with around 20 free pages.
  #
  do_test incrvacuum-ioerr-4.0 {
    execsql {
      PRAGMA page_size = 1024;
      PRAGMA locking_mode = exclusive;
      PRAGMA auto_vacuum = 'incremental';
      BEGIN;
      CREATE TABLE a(i integer, b blob);
    } db1
    for {set ii 0} {$ii < 20} {incr ii} {
      execsql { INSERT INTO a VALUES($ii, randstr(800,1500)); } db1
    }
    execsql COMMIT db1
    execsql {DELETE FROM a WHERE oid} db1
  } {}
  
  set ::rc 1
  for {set iTest 1} {$::rc && $iTest<2000} {incr iTest} {
  
    # Figure out how big the database is and how many free pages it
    # has before running incremental-vacuum.
    #
    set nPage [expr {[file size test.db]/1024}]
    set nFree [execsql {pragma freelist_count} db1]
  
    # Now run incremental-vacuum to vacuum 5 pages from the db file.
    # The iTest'th I/O call is set to fail.
    #
    set ::sqlite_io_error_pending $iTest
    set ::sqlite_io_error_persist 1
    do_test incrvacuum-ioerr-4.$iTest.1 {
      set ::rc [catch {execsql {pragma incremental_vacuum(5)} db1} msg]
      expr {$::rc==0 || $msg eq "disk I/O error"}
    } {1}
  
    set ::sqlite_io_error_pending 0
    set ::sqlite_io_error_persist 0
    set ::sqlite_io_error_hit 0
    set ::sqlite_io_error_hardhit 0
  
    set nFree2 [execsql {pragma freelist_count} db1]
    set nPage2 [expr {[file size test.db]/1024}]
  
    do_test incrvacuum-ioerr-4.$iTest.2 {
      set shrink [expr {$nPage-$nPage2}]
      expr {$shrink==0 || $shrink==5}
    } {1}
  
    do_test incrvacuum-ioerr-4.$iTest.3 {
      expr {$nPage - $nPage2}
    } [expr {$nFree - $nFree2}]
  }
  
  # Close the two database connections and restore the default
  # shared-cache mode setting.
  #
  db1 close
  db2 close
  sqlite3_enable_shared_cache $::enable_shared_cache
}

finish_test