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 1.188 2004/09/05 00:33:43 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.

int sqlite3BtreeSetPageSize(Btree *pBt, int pageSize, int nReserve){
  if( pBt->pageSizeFixed ){
    return SQLITE_READONLY;
  }
  if( nReserve<0 ){
    nReserve = pBt->pageSize - pBt->usableSize;
  }
  if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE ){
    pBt->pageSize = pageSize;
    sqlite3pager_set_pagesize(pBt->pPager, pageSize);
  }
  pBt->usableSize = pBt->pageSize - nReserve;
  return SQLITE_OK;
}

  pBt->maxLeaf = pBt->usableSize - 35;
  pBt->minLeaf = (pBt->usableSize-12)*pBt->minLeafFrac/255 - 23;
  if( pBt->minLocal>pBt->maxLocal || pBt->maxLocal<0 ){
    goto page1_init_failed;
  }
  assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
  pBt->pPage1 = pPage1;

  return SQLITE_OK;

page1_init_failed:
  releasePage(pPage1);
  pBt->pPage1 = 0;
  return rc;
}

  data[19] = 1;
  data[20] = pBt->pageSize - pBt->usableSize;
  data[21] = pBt->maxEmbedFrac;
  data[22] = pBt->minEmbedFrac;
  data[23] = pBt->minLeafFrac;
  memset(&data[24], 0, 100-24);
  zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );
  pBt->pageSizeFixed = 1;
  return SQLITE_OK;
}

/*
** Attempt to start a new transaction. A write-transaction
** is started if the second argument is true, otherwise a read-
** transaction.

**
*************************************************************************
** 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 1.30 2004/09/05 00:33:43 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"

#if !defined(SQLITE_OMIT_VACUUM) || SQLITE_OMIT_VACUUM
/*
** Generate a random name of 20 character in length.

int sqlite3RunVacuum(char **pzErrMsg, sqlite *db){
  int rc = SQLITE_OK;     /* Return code from service routines */
#if !defined(SQLITE_OMIT_VACUUM) || 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 */
  int i;                  /* Loop counter */
  Btree *pMain;           /* The database being vacuumed */
  Btree *pTemp;
  char *zSql = 0;

  if( !db->autoCommit ){
    sqlite3SetString(pzErrMsg, "cannot VACUUM from within a transaction", 
       (char*)0);
    rc = SQLITE_ERROR;
    goto end_of_vacuum;
  }

  /* Get the full pathname of the database file and create a
  ** temporary filename in the same directory as the original file.
  */
  pMain = db->aDb[0].pBt;
  zFilename = sqlite3BtreeGetFilename(pMain);
  assert( zFilename );
  if( zFilename[0]=='\0' ){
    /* The in-memory database. Do nothing. Return directly to avoid causing
    ** an error trying to DETACH the vacuum_db (which never got attached)
    ** in the exit-handler.
    */
    return SQLITE_OK;

    rc = SQLITE_NOMEM;
    goto end_of_vacuum;
  }
  rc = execSql(db, zSql);
  sqliteFree(zSql);
  zSql = 0;
  if( rc!=SQLITE_OK ) goto end_of_vacuum;
  assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
  pTemp = db->aDb[db->nDb-1].pBt;
  sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), 0);
  assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
  execSql(db, "PRAGMA vacuum_db.synchronous=OFF");

  /* Begin a transaction */
  rc = execSql(db, "BEGIN;");
  if( rc!=SQLITE_OK ) goto end_of_vacuum;

  /* Query the schema of the main database. Create a mirror schema
  ** in the temporary database.

  ** transaction open on the vacuum database, but not on the main database.
  ** Open a btree level transaction on the main database. This allows a
  ** call to sqlite3BtreeCopyFile(). The main database btree level
  ** transaction is then committed, so the SQL level never knows it was
  ** opened for writing. This way, the SQL transaction used to create the
  ** temporary database never needs to be committed.
  */

  if( sqlite3BtreeIsInTrans(pTemp) ){

    u32 meta;

    assert( 0==sqlite3BtreeIsInTrans(pMain) );
    rc = sqlite3BtreeBeginTrans(pMain, 1);
    if( rc!=SQLITE_OK ) goto end_of_vacuum;

    /* Copy Btree meta values 3 and 4. These correspond to SQL layer meta 

# 2004 September 2
#
# 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.
# This file implements tests for the page_size PRAGMA.
#
# $Id: pagesize.test,v 1.3 2004/09/05 00:33:44 drh Exp $


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

do_test pagesize-1.1 {
  execsql {PRAGMA page_size}
} 1024
do_test pagesize-1.2 {
  catch {execsql {EXPLAIN PRAGMA page_size}}
} 0
do_test pagesize-1.3 {
  execsql {
    CREATE TABLE t1(a);
    PRAGMA page_size=2048;
    PRAGMA page_size;
  }
} 1024

do_test pagesize-1.4 {
  db close
  file delete -force test.db
  sqlite3 db test.db
  execsql {
    PRAGMA page_size=511;
    PRAGMA page_size;
  }
} 1024
do_test pagesize-1.5 {
  execsql {
    PRAGMA page_size=512;
    PRAGMA page_size;
  }
} 512
do_test pagesize-1.6 {
  execsql {
    PRAGMA page_size=8192;
    PRAGMA page_size;
  }
} 8192
do_test pagesize-1.7 {
  execsql {
    PRAGMA page_size=65537;
    PRAGMA page_size;
  }
} 8192
  


foreach PGSZ {512 2000 2048 3000 4096} {
  do_test pagesize-2.$PGSZ.1 {
    db close
    file delete -force test.db
    sqlite3 db test.db
    execsql "PRAGMA page_size=$PGSZ"
    execsql {
      CREATE TABLE t1(x);
      PRAGMA page_size;
    }
  } $PGSZ
  do_test pagesize-2.$PGSZ.2 {
    db close
    sqlite3 db test.db
    execsql {
      PRAGMA page_size
    }
  } $PGSZ
  do_test pagesize-2.$PGSZ.3 {
    file size test.db
  } [expr {$PGSZ*2}]
  do_test pagesize-2.$PGSZ.4 {
    execsql {VACUUM}
  } {}
  integrity_check pagesize-2.$PGSZ.5
  do_test pagesize-2.$PGSZ.6 {
    db close
    sqlite3 db test.db
    execsql {PRAGMA page_size}
  } $PGSZ
  do_test pagesize-2.$PGSZ.7 {
    execsql {
      INSERT INTO t1 VALUES(randstr(10,9000));
      INSERT INTO t1 VALUES(randstr(10,9000));
      INSERT INTO t1 VALUES(randstr(10,9000));
      BEGIN;
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      SELECT count(*) FROM t1;
    }
  } 48
  do_test pagesize-2.$PGSZ.8 {
    execsql {
      ROLLBACK;
      SELECT count(*) FROM t1;
    }
  } 3
  integrity_check pagesize-2.$PGSZ.9
  do_test pagesize-2.$PGSZ.10 {
    db close
    sqlite3 db test.db
    execsql {PRAGMA page_size}
  } $PGSZ
  do_test pagesize-2.$PGSZ.11 {
    execsql {
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      INSERT INTO t1 SELECT x||x FROM t1;
      SELECT count(*) FROM t1;
    }
  } 192
  do_test pagesize-2.$PGSZ.12 {
    execsql {
      BEGIN;
      DELETE FROM t1 WHERE rowid%5!=0;
      SELECT count(*) FROM t1;
    }
  } 38
  do_test pagesize-2.$PGSZ.13 {
    execsql {
      ROLLBACK;
      SELECT count(*) FROM t1;
    }
  } 192
  integrity_check pagesize-2.$PGSZ.14
  do_test pagesize-2.$PGSZ.15 {
    execsql {
      DELETE FROM t1 WHERE rowid%5!=0;
      VACUUM;
      SELECT count(*) FROM t1;
    }
  } 38
  do_test pagesize-2.$PGSZ.16 {
    execsql {
      DROP TABLE t1;
      VACUUM;
    }
  } {}
  integrity_check pagesize-2.$PGSZ.17
}

finish_test