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 1.156 2004/08/18 15:58:23 drh Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

        PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
        TRACE3("JOURNAL %d page %d\n", pPager->fd.h, pPg->pgno);
        assert( pHist->pOrig==0 );
        pHist->pOrig = sqliteMallocRaw( pPager->pageSize );
        if( pHist->pOrig ){
          memcpy(pHist->pOrig, PGHDR_TO_DATA(pPg), pPager->pageSize);
        }
        pPg->inJournal = 1;
      }else{
        u32 cksum;
        CODEC(pPager, pData, pPg->pgno, 7);
        cksum = pager_cksum(pPager, pPg->pgno, pData);
        saved = *(u32*)PGHDR_TO_EXTRA(pPg, pPager);
        store32bits(cksum, pPg, pPager->pageSize);
        szPg = pPager->pageSize+8;

          pPager->errMask |= PAGER_ERR_FULL;
          return rc;
        }
        pPager->nRec++;
        assert( pPager->aInJournal!=0 );
        pPager->aInJournal[pPg->pgno/8] |= 1<<(pPg->pgno&7);
        pPg->needSync = !pPager->noSync;
        pPg->inJournal = 1;
        if( pPager->stmtInUse ){
          pPager->aInStmt[pPg->pgno/8] |= 1<<(pPg->pgno&7);
          page_add_to_stmt_list(pPg);
        }
      }
    }else{
      pPg->needSync = !pPager->journalStarted && !pPager->noSync;
      TRACE4("APPEND %d page %d needSync=%d\n",
              pPager->fd.h, pPg->pgno, pPg->needSync);
    }
    if( pPg->needSync ){
      pPager->needSync = 1;
    }

  }

  /* If the statement journal is open and the page is not in it,
  ** then write the current page to the statement journal.  Note that
  ** the statement journal format differs from the standard journal format
  ** in that it omits the checksums and the header.
  */

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the ATTACH and DETACH commands
# and related functionality.
#
# $Id: attach2.test,v 1.24 2004/08/18 15:58:24 drh Exp $
#

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


# Ticket #354

  catchsql {
    ATTACH 'test2.db' AS t2;
  }
} {0 {}}
do_test attach2-2.2 {
  # make sure test2.db did get attached.
  db_list db
} {0 main 1 temp 2 t2}
db2 eval {COMMIT}

do_test attach2-2.5 {
  # Make sure we can read test2.db from db
  catchsql {
    SELECT name FROM t2.sqlite_master;
  }