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 1.225 2004/11/23 09:06:56 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.

        int i;
        zeroPage(pPage, pChild->aData[0]);
        for(i=0; i<pChild->nCell; i++){
          apCell[i] = findCell(pChild,i);
          szCell[i] = cellSizePtr(pChild, apCell[i]);
        }
        assemblePage(pPage, pChild->nCell, apCell, szCell);
        /* Copy the right-pointer of the child to the parent. */
        put4byte(&pPage->aData[pPage->hdrOffset+8], 
            get4byte(&pChild->aData[pChild->hdrOffset+8]));
        freePage(pChild);
        TRACE(("BALANCE: child %d transfer to page 1\n", pChild->pgno));
      }else{
        /* The child has more information that will fit on the root.
        ** The tree is already balanced.  Do nothing. */
        TRACE(("BALANCE: child %d will not fit on page 1\n", pChild->pgno));
      }

** 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 1.178 2004/11/23 09:06:56 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  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 );
    assert( pPager->needSync );
  }

  /* 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 
  ** for the page moved there.
  */
  pPgOld = pager_lookup(pPager, pgno);
  if( pPgOld ){
    assert( pPgOld->nRef==0 );
    unlinkHashChain(pPager, pPgOld);
    pPgOld->dirty = 0;
    if( pPgOld->needSync ){
      assert( pPgOld->inJournal );
      pPg->inJournal = 1;
      pPg->needSync = 1;
      assert( pPager->needSync );
    }
  }

  /* Change the page number for pPg and insert it into the new hash-chain. */
  pPg->pgno = pgno;
  h = pager_hash(pgno);
  if( pPager->aHash[h] ){

  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.
    **
    ** The sqlite3pager_get() call may cause the journal to sync. So make
    ** sure the Pager.needSync flag is set too.
    */
    int rc;
    void *pNeedSync;
    assert( pPager->needSync );
    rc = sqlite3pager_get(pPager, needSyncPgno, &pNeedSync);
    if( rc!=SQLITE_OK ) return rc;
    pPager->needSync = 1;
    DATA_TO_PGHDR(pNeedSync)->needSync = 1;
    DATA_TO_PGHDR(pNeedSync)->inJournal = 1;
    DATA_TO_PGHDR(pNeedSync)->dirty = 1;
    sqlite3pager_unref(pNeedSync);
  }

  return SQLITE_OK;

# 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 implements regression tests for SQLite library.  The
# focus of this file is testing the CREATE TABLE statement.
#
# $Id: table.test,v 1.34 2004/11/23 09:06:56 danielk1977 Exp $

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

# Create a basic table and verify it is added to sqlite_master
#
do_test table-1.1 {

      db eval {SELECT * FROM tablet8 LIMIT 1} {} {
        db eval {DROP TABLE aux.t1;}
      }
    } msg
  ] 
  set result [list $rc $msg]
} {1 {database table is locked}}

# Create and drop 2000 tables. This is to check that the balance_shallow()
# routine works correctly on the sqlite_master table. At one point it
# contained a bug that would prevent the right-child pointer of the
# child page from being copied to the root page.
#
do_test table-15.1 {
  execsql {BEGIN}
  for {set i 0} {$i<2000} {incr i} {
    execsql "CREATE TABLE tbl$i (a, b, c)"
  }
  execsql {COMMIT}
} {}
do_test table-15.2 {
  execsql {BEGIN}
  for {set i 0} {$i<2000} {incr i} {
    execsql "DROP TABLE tbl$i"
  }
  execsql {COMMIT}
} {}

finish_test