SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_backup_XXX() 
** API functions and the related features.
**
** $Id: backup.c,v 1.9 2009/02/09 18:55:46 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "btreeInt.h"

/* Macro to find the minimum of two numeric values.
*/
#ifndef MIN

      ((u8 *)sqlite3PagerGetExtra(pDestPg))[0] = 0;
    }
    sqlite3PagerUnref(pDestPg);
  }

  return rc;
}

/*
** If pFile is currently larger than iSize bytes, then truncate it to
** exactly iSize bytes. If pFile is not larger than iSize bytes, then
** this function is a no-op.
**
** Return SQLITE_OK if everything is successful, or an SQLite error 
** code if an error occurs.
*/
static int backupTruncateFile(sqlite3_file *pFile, i64 iSize){
  i64 iCurrent;
  int rc = sqlite3OsFileSize(pFile, &iCurrent);
  if( rc==SQLITE_OK && iCurrent>iSize ){
    rc = sqlite3OsTruncate(pFile, iSize);
  }
  return rc;
}

/*
** Copy nPage pages from the source b-tree to the destination.
*/
int sqlite3_backup_step(sqlite3_backup *p, int nPage){
  int rc;

      }
    }
  
    if( rc==SQLITE_DONE ){
      const int nSrcPagesize = sqlite3BtreeGetPageSize(p->pSrc);
      const int nDestPagesize = sqlite3BtreeGetPageSize(p->pDest);
      int nDestTruncate;


  
      /* Update the schema version field in the destination database. This
      ** is to make sure that the schema-version really does change in
      ** the case where the source and destination databases have the
      ** same schema version.
      */
      sqlite3BtreeUpdateMeta(p->pDest, 1, p->iDestSchema+1);

        **
        **   * The destination may need to be truncated, and
        **
        **   * Data stored on the pages immediately following the 
        **     pending-byte page in the source database may need to be
        **     copied into the destination database.
        */
        const i64 iSize = (i64)nSrcPagesize * (i64)nSrcPage;
        sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);

        assert( pFile );
        assert( (i64)nDestTruncate*(i64)nDestPagesize >= iSize );
        if( SQLITE_OK==(rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1))
         && SQLITE_OK==(rc = backupTruncateFile(pFile, iSize))
         && SQLITE_OK==(rc = sqlite3PagerSync(pDestPager))
        ){
          i64 iOff;
          i64 iEnd = MIN(PENDING_BYTE + nDestPagesize, iSize);
          for(
            iOff=PENDING_BYTE+nSrcPagesize; 
            rc==SQLITE_OK && iOff<iEnd; 

# 2009 January 30
#
# 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 sqlite3_backup_XXX API.
#
# $Id: backup.test,v 1.5 2009/02/09 18:55:46 danielk1977 Exp $

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

#---------------------------------------------------------------------
# Test organization:
#

#   * Target database does not include pending-byte page.
#
#   * Target database page-size is the same as the source, OR
#   * Target database page-size is larger than the source, OR
#   * Target database page-size is smaller than the source.
#
set iTest 1
foreach nSrcPg {10 64 65 66 100} {
foreach nDestRow {10 100} {
foreach nDestPgsz {512 1024 2048 4096} {

  catch { file delete test.db }
  catch { file delete test2.db }
  sqlite3 db test.db
  sqlite3 db2 test2.db

  # Set up the content of the two databases.
  #
  execsql { PRAGMA page_size = 1024 }
  execsql "PRAGMA page_size = $nDestPgsz" db2
  foreach db {db db2} {
    execsql {
      BEGIN; 
      CREATE TABLE t1(a, b);
      CREATE INDEX i1 ON t1(a, b);
      COMMIT;
    } $db
  }
  while {[file size test.db]/1024 < $nSrcPg} {
    execsql { INSERT INTO t1 VALUES($ii, randstr(200,200)) }
  }

  for {set ii 0} {$ii < $nDestRow} {incr ii} {
    execsql { INSERT INTO t1 VALUES($ii, randstr(1000,1000)) } db2
  }

  # Backup the source database.
  do_test backup-3.$iTest.1 {
    sqlite3_backup B db main db2 main
    while {[B step 10]=="SQLITE_OK"} {}
    B finish
  } {SQLITE_OK}