SQLite

/*
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.91 2003/04/25 13:22:52 drh 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.

*/
static const char *fileBtreeGetFilename(Btree *pBt){
  assert( pBt->pPager!=0 );
  return sqlitepager_filename(pBt->pPager);
}

/*
** Copy the complete content of pBtFrom into pBtTo.  A transaction
** must be active for both files.
**
** The size of file pBtFrom may be reduced by this operation.
** If anything goes wrong, the transaction on pBtFrom is rolled back.
*/
static int fileBtreeCopyFile(Btree *pBtTo, Btree *pBtFrom){
  int rc = SQLITE_OK;
  Pgno i, nPage;

  if( !pBtTo->inTrans || !pBtFrom->inTrans ) return SQLITE_ERROR;
  if( pBtTo->needSwab!=pBtFrom->needSwab ) return SQLITE_ERROR;
  if( pBtTo->pCursor ) return SQLITE_BUSY;
  memcpy(pBtTo->page1, pBtFrom->page1, SQLITE_PAGE_SIZE);
  sqlitepager_overwrite(pBtTo->pPager, 1, pBtFrom->page1);
  nPage = sqlitepager_pagecount(pBtFrom->pPager);
  for(i=2; i<=nPage; i++){
    void *pPage;
    rc = sqlitepager_get(pBtFrom->pPager, i, &pPage);
    if( rc ) break;
    sqlitepager_overwrite(pBtTo->pPager, i, pPage);
    sqlitepager_unref(pPage);
  }
  if( !rc ) rc = sqlitepager_truncate(pBtTo->pPager, nPage);
  if( rc ){
    fileBtreeRollback(pBtTo);
  }
  return rc;  
}

/*
** The following tables contain pointers to all of the interface
** routines for this implementation of the B*Tree backend.  To
** substitute a different implemention of the backend, one has merely
** to provide pointers to alternative functions in similar tables.

    fileBtreeDropTable,
    fileBtreeClearTable,
    fileBtreeCursor,
    fileBtreeGetMeta,
    fileBtreeUpdateMeta,
    fileBtreeIntegrityCheck,
    fileBtreeGetFilename,
    fileBtreeCopyFile,
#ifdef SQLITE_TEST
    fileBtreePageDump,
    fileBtreePager
#endif
};
static BtCursorOps sqliteBtreeCursorOps = {
    fileBtreeMoveto,

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.33 2003/04/25 13:22:53 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/*
** Forward declarations of structure
*/

    int (*DropTable)(Btree*, int);
    int (*ClearTable)(Btree*, int);
    int (*Cursor)(Btree*, int iTable, int wrFlag, BtCursor **ppCur);
    int (*GetMeta)(Btree*, int*);
    int (*UpdateMeta)(Btree*, int*);
    char *(*IntegrityCheck)(Btree*, int*, int);
    const char *(*GetFilename)(Btree*);
    int (*CopyFile)(Btree*,Btree*);
#ifdef SQLITE_TEST
    int (*PageDump)(Btree*, int, int);
    struct Pager *(*Pager)(Btree*);
#endif
};

/*

                (btCOps(pCur)->Data(pCur, offset, amt, zBuf))
#define sqliteBtreeCloseCursor(pCur)      (btCOps(pCur)->CloseCursor(pCur))
#define sqliteBtreeGetMeta(pBt, aMeta)    (btOps(pBt)->GetMeta(pBt, aMeta))
#define sqliteBtreeUpdateMeta(pBt, aMeta) (btOps(pBt)->UpdateMeta(pBt, aMeta))
#define sqliteBtreeIntegrityCheck(pBt, aRoot, nRoot)\
                (btOps(pBt)->IntegrityCheck(pBt, aRoot, nRoot))
#define sqliteBtreeGetFilename(pBt)       (btOps(pBt)->GetFilename(pBt))
#define sqliteBtreeCopyFile(pBt1, pBt2)   (btOps(pBt1)->CopyFile(pBt1, pBt2))


#ifdef SQLITE_TEST
#define sqliteBtreePageDump(pBt, pgno, recursive)\
                (btOps(pBt)->PageDump(pBt, pgno, recursive))
#define sqliteBtreeCursorDump(pCur, aResult)\
                (btCOps(pCur)->CursorDump(pCur, aResult))
#define sqliteBtreePager(pBt)             (btOps(pBt)->Pager(pBt))
int btree_native_byte_order;
#endif /* SQLITE_TEST */


#endif /* _BTREE_H_ */

/*
** 2003 Feb 4
**
** 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_rb.c,v 1.9 2003/04/25 13:22:53 drh Exp $
**
** This file implements an in-core database using Red-Black balanced
** binary trees.
**
** It was contributed to SQLite by anonymous on 2003-Feb-04 23:24:49 UTC.
*/
#include "btree.h"

** Return the full pathname of the underlying database file.
*/
static const char *memBtreeGetFilename(Btree *pBt){
  return 0;  /* A NULL return indicates there is no underlying file */
}

/*
** The copy file function is not implemented for the in-memory database
*/
static int memBtreeCopyFile(Btree *pBt, Btree *pBt2){
  return SQLITE_INTERNAL;  /* Not implemented */
}

static BtOps sqliteBtreeOps = {
    memBtreeClose,
    memBtreeSetCacheSize,
    memBtreeSetSafetyLevel,
    memBtreeBeginTrans,

    memBtreeDropTable,
    memBtreeClearTable,
    memBtreeCursor,
    memBtreeGetMeta,
    memBtreeUpdateMeta,
    memBtreeIntegrityCheck,
    memBtreeGetFilename,
    memBtreeCopyFile,

#ifdef SQLITE_TEST
    memBtreePageDump,
    memBtreePager
#endif
};

#endif
#if OS_MAC
  return access(zFilename, 0)==0;
#endif
}


#if 0 /* NOT USED */
/*
** Change the name of an existing file.
*/
int sqliteOsFileRename(const char *zOldName, const char *zNewName){
#if OS_UNIX
  if( link(zOldName, zNewName) ){
    return SQLITE_ERROR;

  return SQLITE_OK;
#endif
#if OS_MAC
  /**** FIX ME ***/
  return SQLITE_ERROR;
#endif
}
#endif /* NOT USED */

/*
** Attempt to open a file for both reading and writing.  If that
** fails, try opening it read-only.  If the file does not exist,
** try to create it.
**
** On success, a handle for the open file is written to *id

** 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 1.82 2003/04/25 13:22:53 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>

  }
  n /= SQLITE_PAGE_SIZE;
  if( pPager->state!=SQLITE_UNLOCK ){
    pPager->dbSize = n;
  }
  return n;
}

/*
** Forward declaration
*/
static int syncAllPages(Pager*);

/*
** Truncate the file to the number of pages specified.
*/
int sqlitepager_truncate(Pager *pPager, Pgno nPage){
  int rc;
  if( pPager->dbSize<0 ) sqlitepager_pagecount(pPager);
  if( nPage>=pPager->dbSize ){
    return SQLITE_OK;
  }
  syncAllPages(pPager);
  rc = sqliteOsTruncate(&pPager->fd, SQLITE_PAGE_SIZE*(off_t)nPage);
  if( rc==SQLITE_OK ){
    pPager->dbSize = nPage;
  }
  return rc;
}

/*
** Shutdown the page cache.  Free all memory and close all files.
**
** If a transaction was in progress when this routine is called, that
** transaction is rolled back.  All outstanding pages are invalidated
** and their memory is freed.  Any attempt to use a page associated

/*
** Return the full pathname of the database file.
*/
const char *sqlitepager_filename(Pager *pPager){
  return pPager->zFilename;
}






































#ifdef SQLITE_TEST
/*
** Print a listing of all referenced pages and their ref count.
*/
void sqlitepager_refdump(Pager *pPager){
  PgHdr *pPg;
  for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
    if( pPg->nRef<=0 ) continue;
    printf("PAGE %3d addr=0x%08x nRef=%d\n", 
       pPg->pgno, (int)PGHDR_TO_DATA(pPg), pPg->nRef);
  }
}
#endif

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.23 2003/04/25 13:22:53 drh Exp $
*/

/*
** The size of one page
**
** You can change this value to another (reasonable) power of two
** such as 512, 2048, 4096, or 8192 and things will still work.  But

int sqlitepager_ref(void*);
int sqlitepager_unref(void*);
Pgno sqlitepager_pagenumber(void*);
int sqlitepager_write(void*);
int sqlitepager_iswriteable(void*);
int sqlitepager_overwrite(Pager *pPager, Pgno pgno, void*);
int sqlitepager_pagecount(Pager*);
int sqlitepager_truncate(Pager*,Pgno);
int sqlitepager_begin(void*);
int sqlitepager_commit(Pager*);
int sqlitepager_rollback(Pager*);
int sqlitepager_isreadonly(Pager*);
int sqlitepager_ckpt_begin(Pager*);
int sqlitepager_ckpt_commit(Pager*);
int sqlitepager_ckpt_rollback(Pager*);

**
*************************************************************************
** This file contains code used to implement the VACUUM command.
**
** Most of the code in this file may be omitted by defining the
** SQLITE_OMIT_VACUUM macro.
**
** $Id: vacuum.c,v 1.5 2003/04/25 13:22:53 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"

#define SQLITE_OMIT_VACUUM 1

/*

** become a no-op.
*/
void sqliteVacuum(Parse *pParse, Token *pTableName){
#ifdef SQLITE_OMIT_VACUUM
  const char *zFilename;  /* full pathname of the database file */
  int nFilename;          /* number of characters  in zFilename[] */
  char *zTemp = 0;        /* a temporary file in same directory as zFilename */

  sqlite *dbNew = 0;      /* The new vacuumed database */
  sqlite *db;             /* The original database */
  int rc = SQLITE_OK;     /* Return code from service routines */
  int i;                  /* Loop counter */
  char *zErrMsg = 0;      /* Error messages stored here */

  int safety = 0;         /* TRUE if safety is off */
  vacuumStruct sVac;      /* Information passed to callbacks */

  /* These are all of the pragmas that need to be transferred over
  ** to the new database */
  static const char *zPragma[] = {
     "default_synchronous",
     "default_cache_size",
     /* "default_temp_store", */

  zFilename = sqliteBtreeGetFilename(db->aDb[0].pBt);
  if( zFilename==0 ){
    /* This only happens with the in-memory database.  VACUUM is a no-op
    ** there, so just return */
    return;
  }
  nFilename = strlen(zFilename);
  zTemp = sqliteMalloc( nFilename+100 );
  if( zTemp==0 ) return;

  strcpy(zTemp, zFilename);

  for(i=0; i<10; i++){
    zTemp[nFilename] = '-';
    randomName(&zTemp[nFilename+1]);


    if( !sqliteOsFileExists(zTemp) ) break;
  }
  if( i>=10 ){
    sqliteErrorMsg(pParse, "unable to create a temporary database file "
       "in the same directory as the original database");
    goto end_of_vacuum;
  }

  
  dbNew = sqlite_open(zTemp, 0, &zErrMsg);
  if( dbNew==0 ){
    sqliteErrorMsg(pParse, "unable to open a temporary database at %s - %s",
       zTemp, zErrMsg);
    goto end_of_vacuum;
  }
  if( sqliteSafetyOff(db) ){
    sqliteErrorMsg(pParse, "library routines called out of sequence");
    goto end_of_vacuum;
  }
  safety = 1;
  if( execsql(pParse, db, "BEGIN") ) goto end_of_vacuum;
  if( execsql(pParse, dbNew, "PRAGMA synchronous=off; BEGIN") ){
    goto end_of_vacuum;
  }
  sVac.dbOld = db;
  sVac.dbNew = dbNew;
  sVac.pParse = pParse;
  for(i=0; i<sizeof(zPragma)/sizeof(zPragma[0]); i++){
    char zBuf[200];
    assert( strlen(zPragma[i])<100 );
    sprintf(zBuf, "PRAGMA %s;", zPragma[i]);
    sVac.zPragma = zPragma[i];
    rc = sqlite_exec(db, zBuf, vacuumCallback3, &sVac, &zErrMsg);
    if( rc ) goto vacuum_error;
  }
  if( rc==SQLITE_OK ){
    rc = sqlite_exec(db, "SELECT type, name, sql FROM sqlite_master "
             "WHERE sql NOT NULL", vacuumCallback1, &sVac, &zErrMsg);

  }
  if( rc ){
    if( pParse->zErrMsg==0 ){




      sqliteErrorMsg(pParse, "unable to vacuum database - %s", zErrMsg);

    }



    goto end_of_vacuum;
  }






  rc = sqliteBtreeCopyFile(db->aDb[0].pBt, dbNew->aDb[0].pBt);

  sqlite_exec(db, "COMMIT", 0, 0, 0);


  sqliteResetInternalSchema(db, 0);

end_of_vacuum:
  sqlite_exec(db, "COMMIT", 0, 0, 0);
  if( safety ) {
    sqliteSafetyOn(db);
  }
  if( dbNew ) sqlite_close(dbNew);
  sqliteOsDelete(zTemp);
  sqliteFree(zTemp);

  sqliteFree(sVac.s1.z);
  sqliteFree(sVac.s2.z);
  if( zErrMsg ) sqlite_freemem(zErrMsg);
  return;

vacuum_error:




#endif
}

# 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 VACUUM statement.
#
# $Id: vacuum.test,v 1.9 2003/04/25 13:22:53 drh Exp $

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

proc cksum {{db db}} {
  set txt [$db eval {SELECT name, type, sql FROM sqlite_master}]\n
  foreach tbl [$db eval {SELECT name FROM sqlite_master WHERE type='table'}] {
    append txt [$db eval "SELECT * FROM $tbl"]\n
  }
  foreach prag {default_synchronous default_cache_size} {
    append txt $prag-[$db eval "PRAGMA $prag"]\n
  }



  set cksum [string length $txt]-[md5 $txt]
  puts $cksum-[file size test.db]
  return $cksum
}

do_test vacuum-1.1 {
  execsql {
    BEGIN;
    CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
    INSERT INTO t1 VALUES(NULL,randstr(10,100),randstr(5,50));

    INSERT INTO t1 SELECT NULL, b||'-'||rowid, c||'-'||rowid FROM t1;
    CREATE INDEX i1 ON t1(b,c);
    CREATE TABLE t2 AS SELECT * FROM t1;
    COMMIT;
    DROP TABLE t2;
  }
  set ::size1 [file size test.db]
  set ::cksum [cksum]
  expr {$::cksum!=""}
} {1}
do_test vacuum-1.2 {
  execsql {
    VACUUM;
  }
  cksum
} $cksum
do_test vacuum-1.3 {
  expr {[file size test.db]<$::size1}
} {1}
do_test vacuum-1.4 {
  execsql {
    BEGIN;
    CREATE TABLE t2 AS SELECT * FROM t1;
    CREATE TABLE t3 AS SELECT * FROM t1;
    CREATE VIEW v1 AS SELECT b, c FROM t3;
    CREATE TRIGGER r1 AFTER DELETE ON t2 BEGIN
      SELECT 1;
    END;
    COMMIT;
    DROP TABLE t2;
  }
  set ::size1 [file size test.db]
  set ::cksum [cksum]
  expr {$::cksum!=""}
} {1}
do_test vacuum-1.5 {
  execsql {
    VACUUM;
  }
  cksum
} $cksum
do_test vacuum-1.6 {
  expr {[file size test.db]<$::size1}
} {1}

do_test vacuum-2.1 {
  catchsql {
    BEGIN;
    VACUUM;
    COMMIT;
  }
} {1 {cannot VACUUM from within a transaction}}
catch {db eval COMMIT}
do_test vacuum-2.2 {
  sqlite db2 test.db
  execsql {
    BEGIN;
    CREATE TABLE t4 AS SELECT * FROM t1;
    CREATE TABLE t5 AS SELECT * FROM t1;
    COMMIT;
    DROP TABLE t4;
    DROP TABLE t5;
  } db2
  set ::cksum [cksum db2]
  catchsql {
    VACUUM
  }
} {1 {database schema has changed}}
do_test vacuum-2.3 {
  execsql {
    VACUUM;
  }
  cksum
} $cksum
do_test vacuum-2.4 {
  catch {db2 eval {SELECT count(*) FROM sqlite_master}}
  cksum db2
} $cksum


catch {db2 close}

# finish_test