# 2007 March 24

#

# 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: cache.test,v 1.4 2007/08/22 02:56:44 drh Exp $

set testdir [file dirname $argv0]

source $testdir/tester.tcl

ifcapable {!pager_pragmas} {

  finish_test

  return

}

sqlite3_soft_heap_limit 0

proc pager_cache_size {db} {

  set bt [btree_from_db $db]

  db_enter $db

  array set stats [btree_pager_stats $bt]

  db_leave $db

  return $stats(page)

}

do_test cache-1.1 {

  pager_cache_size db

} {0}

do_test cache-1.2 {

  execsql {

    PRAGMA auto_vacuum=OFF;

    CREATE TABLE abc(a, b, c);

    INSERT INTO abc VALUES(1, 2, 3);

  }

  pager_cache_size db

} {2}

# At one point, repeatedly locking and unlocking the cache was causing

# a resource leak of one page per repetition. The page wasn't actually

# leaked, but would not be reused until the pager-cache was full (i.e. 

# 2000 pages by default).

#

# This tests that once the pager-cache is initialised, it can be locked

# and unlocked repeatedly without internally allocating any new pages.

#

set cache_size [pager_cache_size db]

for {set ii 0} {$ii < 10} {incr ii} {

  do_test cache-1.3.$ii {

    execsql {SELECT * FROM abc}

    pager_cache_size db

  } $::cache_size

}

sqlite3_soft_heap_limit $soft_limit

finish_test