SQLite

*/
static struct FaultInjector {
  int iCountdown;   /* Number of pending successes before we hit a failure */
  int nRepeat;      /* Number of times to repeat the failure */
  int nBenign;      /* Number of benign failures seen since last config */
  int nFail;        /* Number of failures seen since last config */
  u8 enable;        /* True if enabled */
  u8 benign;        /* True if next failure will be benign */
} aFault[SQLITE_FAULTINJECTOR_COUNT];

/*
** This routine configures and enables a fault injector.  After
** calling this routine, aFaultStep() will return false (zero)
** nDelay times, then it will return true nRepeat times,
** then it will again begin returning false.

** However, sometimes a fault is easily recoverable.  For example,
** if a malloc fails while resizing a hash table, this is completely
** recoverable simply by not carrying out the resize.  The hash table
** will continue to function normally.  So a malloc failure during
** a hash table resize is a benign fault.  
*/
void sqlite3FaultBenign(int id, int enable){
  if( id<0 ){
    for(id=0; id<SQLITE_FAULTINJECTOR_COUNT; id++){
      aFault[id].benign = enable;
    }
  }else{
    assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
    aFault[id].benign = enable;
  }
}

/*
** This routine exists as a place to set a breakpoint that will
** fire on any simulated fault.
*/
static void sqlite3Fault(void){

  DO_OS_MALLOC_TEST;
  return pVfs->xOpen(pVfs, zPath, pFile, flags, pFlagsOut);
}
int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  return pVfs->xDelete(pVfs, zPath, dirSync);
}
int sqlite3OsAccess(sqlite3_vfs *pVfs, const char *zPath, int flags){
  int rc;
#ifdef SQLITE_TEST
  void *pTstAlloc = sqlite3_malloc(10);
  if (!pTstAlloc) return -1;
  sqlite3_free(pTstAlloc);
#endif
  rc = pVfs->xAccess(pVfs, zPath, flags);
  assert( rc==0 || rc==1 );
  return rc;
}
int sqlite3OsGetTempname(sqlite3_vfs *pVfs, int nBufOut, char *zBufOut){
  return pVfs->xGetTempname(pVfs, nBufOut, zBufOut);
}
int sqlite3OsFullPathname(

** 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 1.421 2008/03/27 22:42:52 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*

    }
    zMasterPtr = &zMasterJournal[nMasterJournal];
    rc = sqlite3OsRead(pMaster, zMasterJournal, nMasterJournal, 0);
    if( rc!=SQLITE_OK ) goto delmaster_out;

    zJournal = zMasterJournal;
    while( (zJournal-zMasterJournal)<nMasterJournal ){
      rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS);
      if( rc!=0 && rc!=1 ){
        rc = SQLITE_IOERR_NOMEM;
        goto delmaster_out;
      }
      if( rc==1 ){
        /* One of the journals pointed to by the master journal exists.
        ** Open it and check if it points at the master journal. If
        ** so, return without deleting the master journal file.
        */
        int c;
        int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
        rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);

  /* Read the master journal name from the journal, if it is present.
  ** If a master journal file name is specified, but the file is not
  ** present on disk, then the journal is not hot and does not need to be
  ** played back.
  */
  zMaster = pPager->pTmpSpace;
  rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);

  if( rc!=SQLITE_OK 
   || (zMaster[0] && sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS)==0 ) 
  ){
    zMaster = 0;

    goto end_playback;
  }
  pPager->journalOff = 0;
  zMaster = 0;

  /* This loop terminates either when the readJournalHdr() call returns
  ** SQLITE_DONE or an IO error occurs. */

  assert( n1==n2 );
#endif

  return pPager->pDirty;
}

/*
** Return 1 if there is a hot journal on the given pager.
** A hot journal is one that needs to be played back.
**
** If the current size of the database file is 0 but a journal file
** exists, that is probably an old journal left over from a prior
** database with the same name.  Just delete the journal.
**
** Return negative if unable to determine the status of the journal.
*/
static int hasHotJournal(Pager *pPager){
  sqlite3_vfs *pVfs = pPager->pVfs;
  int rc;
  if( !pPager->useJournal ) return 0;
  if( !pPager->fd->pMethods ) return 0;
  rc = sqlite3OsAccess(pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS);
  if( rc<=0 ){
    return rc;
  }
  if( sqlite3OsCheckReservedLock(pPager->fd) ){
    return 0;
  }
  if( sqlite3PagerPagecount(pPager)==0 ){
    sqlite3OsDelete(pVfs, pPager->zJournal, 0);
    return 0;

        }
        assert( pPager->state>=SHARED_LOCK );
      }
  
      /* If a journal file exists, and there is no RESERVED lock on the
      ** database file, then it either needs to be played back or deleted.
      */
      rc = hasHotJournal(pPager);
      if( rc<0 ){
        return pager_error(pPager, SQLITE_IOERR_NOMEM);
      }
      if( rc==1 || isHot ){
        /* Get an EXCLUSIVE lock on the database file. At this point it is
        ** important that a RESERVED lock is not obtained on the way to the
        ** EXCLUSIVE lock. If it were, another process might open the
        ** database file, detect the RESERVED lock, and conclude that the
        ** database is safe to read while this process is still rolling it 
        ** back.
        ** 

        ** exclusive-access mode the file descriptor will be kept open and
        ** possibly used for a transaction later on. On some systems, the
        ** OsTruncate() call used in exclusive-access mode also requires
        ** a read/write file handle.
        */
        if( !isHot ){
          rc = SQLITE_BUSY;
          if( sqlite3OsAccess(pVfs, pPager->zJournal,SQLITE_ACCESS_EXISTS)==1 ){
            int fout = 0;
            int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
            assert( !pPager->tempFile );
            rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
            assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
            if( fout&SQLITE_OPEN_READONLY ){
              rc = SQLITE_BUSY;

/*
** 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 1.174 2008/03/27 22:42:52 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)

        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
            "temp_store_directory", P4_STATIC);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
      }
    }else{
      if( zRight[0] 
       && sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE)==0 
      ){
        sqlite3ErrorMsg(pParse, "not a writable directory");
        goto pragma_out;
      }
      if( TEMP_STORE==0
       || (TEMP_STORE==1 && db->temp_store<=1)
       || (TEMP_STORE==2 && db->temp_store==1)

**
** 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 1.720 2008/03/27 22:42:52 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

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

  p->rc = SQLITE_OK;
  assert( p->explain==0 );
  p->pResultSet = 0;
  db->busyHandler.nBusy = 0;
  CHECK_FOR_INTERRUPT;
  sqlite3VdbeIOTraceSql(p);
#ifdef SQLITE_DEBUG
  sqlite3FaultBenign(-1, 1);
  if( p->pc==0 && ((p->db->flags & SQLITE_VdbeListing)!=0
    || sqlite3OsAccess(db->pVfs, "vdbe_explain", SQLITE_ACCESS_EXISTS)==1 )
  ){
    int i;
    printf("VDBE Program Listing:\n");
    sqlite3VdbePrintSql(p);
    for(i=0; i<p->nOp; i++){
      sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
    }
  }
  if( sqlite3OsAccess(db->pVfs, "vdbe_trace", SQLITE_ACCESS_EXISTS)==1 ){
    p->trace = stdout;
  }
  sqlite3FaultBenign(-1, 0);
#endif
  for(pc=p->pc; rc==SQLITE_OK; pc++){
    assert( pc>=0 && pc<p->nOp );
    if( db->mallocFailed ) goto no_mem;
#ifdef VDBE_PROFILE
    origPc = pc;
    start = hwtime();
#endif
    pOp = &p->aOp[pc];

    /* Only allow tracing if SQLITE_DEBUG is defined.
    */
#ifdef SQLITE_DEBUG
    if( p->trace ){
      if( pc==0 ){
        printf("VDBE Execution Trace:\n");
        sqlite3VdbePrintSql(p);
      }
      sqlite3VdbePrintOp(p->trace, pc, pOp);
    }
    if( p->trace==0 && pc==0 ){
      sqlite3FaultBenign(-1, 1);
      if( sqlite3OsAccess(db->pVfs, "vdbe_sqltrace", SQLITE_ACCESS_EXISTS)==1 ){
        sqlite3VdbePrintSql(p);
      }
      sqlite3FaultBenign(-1, 0);
    }
#endif
      

    /* Check to see if we need to simulate an interrupt.  This only happens
    ** if we have a special test build.
    */

      u32 random;
      sqlite3_free(zMaster);
      sqlite3_randomness(sizeof(random), &random);
      zMaster = sqlite3MPrintf(db, "%s-mj%08X", zMainFile, random&0x7fffffff);
      if( !zMaster ){
        return SQLITE_NOMEM;
      }
      rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS);
    }while( rc==1 );
    if( rc!=0 ){
      rc = SQLITE_IOERR_NOMEM;
    }else{
      /* Open the master journal. */
      rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster, 
          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
          SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0
      );
    }
    if( rc!=SQLITE_OK ){
      sqlite3_free(zMaster);
      return rc;
    }
 
    /* Write the name of each database file in the transaction into the new
    ** master journal file. If an error occurs at this point close