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<?php
// +----------------------------------------------------------------------+
// | PEAR :: Cache |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2003 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Ulf Wendel <ulf.wendel@phpdoc.de> |
// | Sebastian Bergmann <sb@sebastian-bergmann.de> |
// | Chuck Hagenbuch <chuck@horde.org> |
// +----------------------------------------------------------------------+
//
// $Id: db.php 178288 2005-01-26 09:42:30Z dufuz $
require_once 'DB.php';
require_once 'Cache/Container.php';
/**
* PEAR/DB Cache Container.
*
* WARNING: Other systems might or might not support certain datatypes of
* the tables shown. As far as I know there's no large binary
* type in SQL-92 or SQL-99. Postgres seems to lack any
* BLOB or TEXT type, for MS-SQL you could use IMAGE, don't know
* about other databases. Please add sugestions for other databases to
* the inline docs.
*
* The field 'changed' has no meaning for the Cache itself. It's just there
* because it's a good idea to have an automatically updated timestamp
* field for debugging in all of your tables.
*
* For _MySQL_ you need this DB table:
*
* CREATE TABLE cache (
* id CHAR(32) NOT null DEFAULT '',
* cachegroup VARCHAR(127) NOT null DEFAULT '',
* cachedata BLOB NOT null DEFAULT '',
* userdata VARCHAR(255) NOT null DEFAULT '',
* expires INT(9) NOT null DEFAULT 0,
*
* changed TIMESTAMP(14) NOT null,
*
* INDEX (expires),
* PRIMARY KEY (id, cachegroup)
* )
*
* @author Sebastian Bergmann <sb@sebastian-bergmann.de>
* @version $Id: db.php 178288 2005-01-26 09:42:30Z dufuz $
* @package Cache
*/
class Cache_Container_db extends Cache_Container
{
/**
* Name of the DB table to store caching data
*
* @see Cache_Container_file::$filename_prefix
*/
var $cache_table = '';
/**
* PEAR DB dsn to use.
*
* @var string
*/
var $dsn = '';
/**
* PEAR DB object
*
* @var object PEAR_DB
*/
var $db;
function Cache_Container_db($options)
{
if (!is_array($options) || !isset($options['dsn'])) {
return new Cache_Error('No dsn specified!', __FILE__, __LINE__);
}
$this->setOptions($options, array_merge($this->allowed_options, array('dsn', 'cache_table')));
if (!$this->dsn) {
return new Cache_Error('No dsn specified!', __FILE__, __LINE__);
}
$this->db = DB::connect($this->dsn, true);
if (PEAR::isError($this->db)) {
return new Cache_Error('DB::connect failed: ' . DB::errorMessage($this->db), __FILE__, __LINE__);
}
$this->db->setFetchMode(DB_FETCHMODE_ASSOC);
}
function fetch($id, $group)
{
$query = sprintf("SELECT cachedata, userdata, expires FROM %s WHERE id = '%s' AND cachegroup = '%s'",
$this->cache_table,
addslashes($id),
addslashes($group)
);
$res = $this->db->query($query);
if (PEAR::isError($res)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res), __FILE__, __LINE__);
}
$row = $res->fetchRow();
if (is_array($row)) {
$data = array($row['expires'], $this->decode($row['cachedata']), $row['userdata']);
} else {
$data = array(null, null, null);
}
// last used required by the garbage collection
// WARNING: might be MySQL specific
$query = sprintf("UPDATE %s SET changed = (NOW() + 0) WHERE id = '%s' AND cachegroup = '%s'",
$this->cache_table,
addslashes($id),
addslashes($group)
);
$res = $this->db->query($query);
if (PEAR::isError($res)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res), __FILE__, __LINE__);
}
return $data;
}
/**
* Stores a dataset.
*
* WARNING: we use the SQL command REPLACE INTO this might be
* MySQL specific. As MySQL is very popular the method should
* work fine for 95% of you.
*/
function save($id, $data, $expires, $group, $userdata)
{
$this->flushPreload($id, $group);
$query = sprintf("REPLACE INTO %s (userdata, cachedata, expires, id, cachegroup) VALUES ('%s', '%s', %d, '%s', '%s')",
$this->cache_table,
addslashes($userdata),
addslashes($this->encode($data)),
$this->getExpiresAbsolute($expires) ,
addslashes($id),
addslashes($group)
);
$res = $this->db->query($query);
if (PEAR::isError($res)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res) , __FILE__, __LINE__);
}
}
function remove($id, $group)
{
$this->flushPreload($id, $group);
$query = sprintf("DELETE FROM %s WHERE id = '%s' and cachegroup = '%s'",
$this->cache_table,
addslashes($id),
addslashes($group)
);
$res = $this->db->query($query);
if (PEAR::isError($res)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res), __FILE__, __LINE__);
}
}
function flush($group = '')
{
$this->flushPreload();
if ($group) {
$query = sprintf("DELETE FROM %s WHERE cachegroup = '%s'", $this->cache_table, addslashes($group));
} else {
$query = sprintf("DELETE FROM %s", $this->cache_table);
}
$res = $this->db->query($query);
if (PEAR::isError($res))
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res), __FILE__, __LINE__);
}
function idExists($id, $group)
{
$query = sprintf("SELECT id FROM %s WHERE ID = '%s' AND cachegroup = '%s'",
$this->cache_table,
addslashes($id),
addslashes($group)
);
$res = $this->db->query($query);
if (PEAR::isError($res)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res), __FILE__, __LINE__);
}
$row = $res->fetchRow();
if (is_array($row)) {
return true;
}
return false;
}
function garbageCollection($maxlifetime)
{
$this->flushPreload();
$query = sprintf('DELETE FROM %s WHERE (expires <= %d AND expires > 0) OR changed <= %d',
$this->cache_table,
time(),
time() - $maxlifetime
);
$res = $this->db->query($query);
$query = sprintf('select sum(length(cachedata)) as CacheSize from %s',
$this->cache_table
);
$cachesize = $this->db->GetOne($query);
if (PEAR::isError($cachesize)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($cachesize), __FILE__, __LINE__);
}
//if cache is to big.
if ($cachesize > $this->highwater) {
//find the lowwater mark.
$query = sprintf('select length(cachedata) as size, changed from %s order by changed DESC',
$this->cache_table
);
$res = $this->db->query($query);
if (PEAR::isError($res)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res), __FILE__, __LINE__);
}
$numrows = $this->db->numRows($res);
$keep_size = 0;
while ($keep_size < $this->lowwater && $numrows--) {
$entry = $res->fetchRow(DB_FETCHMODE_ASSOC);
$keep_size += $entry['size'];
}
//delete all entries, which were changed before the "lowwwater mark"
$query = sprintf('delete from %s where changed <= '.($entry['changed'] ? $entry['changed'] : 0),
$this->cache_table
);
$res = $this->db->query($query);
}
if (PEAR::isError($res)) {
return new Cache_Error('DB::query failed: ' . DB::errorMessage($res), __FILE__, __LINE__);
}
}
}
?>
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