SQLite

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.481 2008/04/17 20:59:38 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.

      sqlite3ErrorMsg(pParse, "unable to open a temporary database "
        "file for storing temporary tables");
      pParse->rc = rc;
      return 1;
    }
    assert( (db->flags & SQLITE_InTrans)==0 || db->autoCommit );
    assert( db->aDb[1].pSchema );
    sqlite3PagerJournalMode(sqlite3BtreePager(db->aDb[1].pBt),
                            db->dfltJournalMode);
  }
  return 0;
}

/*
** Generate VDBE code that will verify the schema cookie and start
** a read-transaction for all named database files.

** 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 1.429 2008/04/17 20:59:38 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*

  u8 needSync;                /* True if an fsync() is needed on the journal */
  u8 dirtyCache;              /* True if cached pages have changed */
  u8 alwaysRollback;          /* Disable DontRollback() for all pages */
  u8 memDb;                   /* True to inhibit all file I/O */
  u8 setMaster;               /* True if a m-j name has been written to jrnl */
  u8 doNotSync;               /* Boolean. While true, do not spill the cache */
  u8 exclusiveMode;           /* Boolean. True if locking_mode==EXCLUSIVE */
  u8 journalMode;             /* On of the PAGER_JOURNALMODE_* values */
  u8 changeCountDone;         /* Set after incrementing the change-counter */
  u32 vfsFlags;               /* Flags for sqlite3_vfs.xOpen() */
  int errCode;                /* One of several kinds of errors */
  int dbSize;                 /* Number of pages in the file */
  int origDbSize;             /* dbSize before the current change */
  int stmtSize;               /* Size of database (in pages) at stmt_begin() */
  int nRec;                   /* Number of pages written to the journal */

/*
** Execute a rollback if a transaction is active and unlock the 
** database file. If the pager has already entered the error state, 
** do not attempt the rollback.
*/
static void pagerUnlockAndRollback(Pager *p){
  /* assert( p->state>=PAGER_RESERVED || p->journalOpen==0 ); */
  if( p->errCode==SQLITE_OK && p->state>=PAGER_RESERVED ){
    sqlite3PagerRollback(p);
  }
  pager_unlock(p);
#if 0
  assert( p->errCode || !p->journalOpen || (p->exclusiveMode&&!p->journalOff) );
  assert( p->errCode || !p->stmtOpen || p->exclusiveMode );
#endif
}

/*
** This routine ends a transaction.  A transaction is ended by either
** a COMMIT or a ROLLBACK.
**
** When this routine is called, the pager has the journal file open and

  }
  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))==SQLITE_OK ){
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
    }else{
      sqlite3OsClose(pPager->jfd);
      pPager->journalOpen = 0;
      if( rc==SQLITE_OK ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);

  pPager->errCode = 0;
  pPager->exclusiveMode = 0;
  pager_reset(pPager);
  pagerUnlockAndRollback(pPager);
  enable_simulated_io_errors();
  PAGERTRACE2("CLOSE %d\n", PAGERID(pPager));
  IOTRACE(("CLOSE %p\n", pPager))

  if( pPager->journalOpen ){
    sqlite3OsClose(pPager->jfd);
  }
  sqlite3BitvecDestroy(pPager->pInJournal);
  if( pPager->stmtOpen ){
    sqlite3OsClose(pPager->stfd);
  }

static int pager_open_journal(Pager *pPager){
  sqlite3_vfs *pVfs = pPager->pVfs;
  int flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_CREATE);

  int rc;
  assert( !MEMDB );
  assert( pPager->state>=PAGER_RESERVED );

  assert( pPager->useJournal );
  assert( pPager->pInJournal==0 );
  sqlite3PagerPagecount(pPager);
  pagerLeave(pPager);
  pPager->pInJournal = sqlite3BitvecCreate(pPager->dbSize);
  pagerEnter(pPager);
  if( pPager->pInJournal==0 ){
    rc = SQLITE_NOMEM;
    goto failed_to_open_journal;
  }

  if( pPager->journalOpen==0 ){
    if( pPager->tempFile ){
      flags |= (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL);
    }else{
      flags |= (SQLITE_OPEN_MAIN_JOURNAL);
    }
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
    rc = sqlite3JournalOpen(
        pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
    );
#else
    rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
#endif
    assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
    pPager->journalOff = 0;
    pPager->setMaster = 0;
    pPager->journalHdr = 0;
    if( rc!=SQLITE_OK ){
      if( rc==SQLITE_NOMEM ){
        sqlite3OsDelete(pVfs, pPager->zJournal, 0);
      }
      goto failed_to_open_journal;
    }
  }
  pPager->journalOpen = 1;
  pPager->journalStarted = 0;
  pPager->needSync = 0;
  pPager->alwaysRollback = 0;
  pPager->nRec = 0;
  if( pPager->errCode ){

      }
      if( rc!=SQLITE_OK ){
        pagerLeave(pPager);
        return rc;
      }
      pPager->dirtyCache = 0;
      PAGERTRACE2("TRANSACTION %d\n", PAGERID(pPager));
      if( pPager->useJournal && !pPager->tempFile
             && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
        rc = pager_open_journal(pPager);
      }
    }
  }else if( pPager->journalOpen && pPager->journalOff==0 ){
    /* This happens when the pager was in exclusive-access mode last
    ** time a (read or write) transaction was successfully concluded
    ** by this connection. Instead of deleting the journal file it was 

    */
    assert( pPager->state!=PAGER_UNLOCK );
    rc = sqlite3PagerBegin(pPg, 0);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    assert( pPager->state>=PAGER_RESERVED );
    if( !pPager->journalOpen && pPager->useJournal
          && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
      rc = pager_open_journal(pPager);
      if( rc!=SQLITE_OK ) return rc;
    }

    pPager->dirtyCache = 1;
  
    /* The transaction journal now exists and we have a RESERVED or an
    ** EXCLUSIVE lock on the main database file.  Write the current page to
    ** the transaction journal if it is not there already.
    */
    if( !pPg->inJournal && (pPager->journalOpen || MEMDB) ){
      if( (int)pPg->pgno <= pPager->origDbSize ){
        if( MEMDB ){
          PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
          PAGERTRACE3("JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
          assert( pHist->pOrig==0 );
          pHist->pOrig = sqlite3_malloc( pPager->pageSize );
          if( !pHist->pOrig ){

** The returned value is either PAGER_JOURNALMODE_DELETE or
** PAGER_JOURNALMODE_PERSIST, indicating the current (possibly updated)
** journal-mode.
*/
int sqlite3PagerJournalMode(Pager *pPager, int eMode){
  assert( eMode==PAGER_JOURNALMODE_QUERY
            || eMode==PAGER_JOURNALMODE_DELETE
            || eMode==PAGER_JOURNALMODE_PERSIST
            || eMode==PAGER_JOURNALMODE_OFF );
  assert( PAGER_JOURNALMODE_QUERY<0 );
  assert( PAGER_JOURNALMODE_DELETE>=0 && PAGER_JOURNALMODE_PERSIST>=0 );
  if( eMode>=0 ){
    pPager->journalMode = eMode;
  }
  return (int)pPager->journalMode;
}

#ifdef SQLITE_TEST
/*
** Print a listing of all referenced pages and their ref count.
*/
void sqlite3PagerRefdump(Pager *pPager){

**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
** @(#) $Id: parse.y,v 1.243 2008/04/17 20:59:38 drh Exp $
*/

// All token codes are small integers with #defines that begin with "TK_"
%token_prefix TK_

// The type of the data attached to each token is Token.  This is also the
// default type for non-terminals.

cmd ::= VACUUM nm.             {sqlite3Vacuum(pParse);}
%endif  SQLITE_OMIT_ATTACH
%endif  SQLITE_OMIT_VACUUM

///////////////////////////// The PRAGMA command /////////////////////////////
//
%ifndef SQLITE_OMIT_PRAGMA
cmd ::= PRAGMA nm(X) dbnm(Z) EQ nmnum(Y).   {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
cmd ::= PRAGMA nm(X) dbnm(Z) EQ ON(Y).      {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
cmd ::= PRAGMA nm(X) dbnm(Z) EQ DELETE(Y).  {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
cmd ::= PRAGMA nm(X) dbnm(Z) EQ minus_num(Y). {
  sqlite3Pragma(pParse,&X,&Z,&Y,1);
}
cmd ::= PRAGMA nm(X) dbnm(Z) LP nmnum(Y) RP. {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
cmd ::= PRAGMA nm(X) dbnm(Z).             {sqlite3Pragma(pParse,&X,&Z,0,0);}
nmnum(A) ::= plus_num(X).             {A = X;}
nmnum(A) ::= nm(X).                   {A = X;}

/*
** 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 1.176 2008/04/17 20:59:38 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)

        **
        ** Also, the sqlite3.dfltJournalMode variable is set so that
        ** any subsequently attached databases also use the specified
        ** journal mode.
        */
        int ii;
        assert(pDb==&db->aDb[0]);
        for(ii=1; ii<db->nDb; ii++){
          if( db->aDb[ii].pBt ){
            pPager = sqlite3BtreePager(db->aDb[ii].pBt);
            sqlite3PagerJournalMode(pPager, eMode);
          }
        }
        db->dfltJournalMode = eMode;
      }
      pPager = sqlite3BtreePager(pDb->pBt);
      eMode = sqlite3PagerJournalMode(pPager, eMode);
    }
    assert( eMode==PAGER_JOURNALMODE_DELETE