<?php
/*
* Sqlite3 support for zend cache backend added by Vepa Halliyev.
*/
/**
* Zend Framework
*
* LICENSE
*
* This source file is subject to the new BSD license that is bundled
* with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://framework.zend.com/license/new-bsd
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@zend.com so we can send you a copy immediately.
*
* @category Zend
* @package Zend_Cache
* @subpackage Zend_Cache_Backend
* @copyright Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
/**
* @see Zend_Cache_Backend_Interface
*/
require_once 'Zend/Cache/Backend/Interface.php';
/**
* @see Zend_Cache_Backend
*/
require_once 'Zend/Cache/Backend.php';
/**
* @package Zend_Cache
* @subpackage Zend_Cache_Backend
* @copyright Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
class Zend_Cache_Backend_Sqlite3 extends Zend_Cache_Backend implements Zend_Cache_Backend_Interface
{
/**
* Available options
*
* =====> (string) cache_db_complete_path :
* - the complete path (filename included) of the SQLITE database
*
* ====> (int) automatic_vacuum_factor :
* - Disable / Tune the automatic vacuum process
* - The automatic vacuum process defragment the database file (and make it smaller)
* when a clean() or delete() is called
* 0 => no automatic vacuum
* 1 => systematic vacuum (when delete() or clean() methods are called)
* x (integer) > 1 => automatic vacuum randomly 1 times on x clean() or delete()
*
* @var array Available options
*/
protected $_options = array(
'cache_db_complete_path' => null,
'automatic_vacuum_factor' => 10
);
/**
* DB ressource
*
* @var mixed $_db
*/
private $_db = null;
/**
* Boolean to store if the structure has benn checked or not
*
* @var boolean $_structureChecked
*/
private $_structureChecked = false;
/**
* Constructor
*
* @param array $options Associative array of options
* @throws Zend_cache_Exception
* @return void
*/
public function __construct(array $options = array())
{
parent::__construct($options);
if (is_null($this->_options['cache_db_complete_path'])) {
Zend_Cache::throwException('cache_db_complete_path option has to set');
}
/*if (!extension_loaded('sqlite')) {
Zend_Cache::throwException("Cannot use SQLite storage because the 'sqlite' extension is not loaded in the current PHP environment");
}*/
$this->_getConnection();
}
/**
* Destructor
*
* @return void
*/
public function __destruct()
{
//@sqlite_close($this->_getConnection());
}
/**
* Test if a cache is available for the given id and (if yes) return it (false else)
*
* @param string $id Cache id
* @param boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested
* @return string|false Cached datas
*/
public function load($id, $doNotTestCacheValidity = false)
{
$this->_checkAndBuildStructure();
$sql = "SELECT content FROM cache WHERE id=?";
if (!$doNotTestCacheValidity) {
$sql = $sql . " AND (expire=0 OR expire>" . time() . ')';
}
$result = $this->_query($sql,array($id));
if($result)
{
$row = $result->fetch();
if ($row) {
return $row['content'];
}
}
return false;
}
/**
* Test if a cache is available or not (for the given id)
*
* @param string $id Cache id
* @return mixed|false (a cache is not available) or "last modified" timestamp (int) of the available cache record
*/
public function test($id)
{
$this->_checkAndBuildStructure();
$sql = "SELECT lastModified FROM cache WHERE id=? AND (expire=0 OR expire>" . time() . ')';
$result = $this->_query($sql,array($id));
$row = $result->fetch();
if ($row) {
return ((int) $row['lastModified']);
}
return false;
}
/**
* Save some string datas into a cache record
*
* Note : $data is always "string" (serialization is done by the
* core not by the backend)
*
* @param string $data Datas to cache
* @param string $id Cache id
* @param array $tags Array of strings, the cache record will be tagged by each string entry
* @param int $specificLifetime If != false, set a specific lifetime for this cache record (null => infinite lifetime)
* @throws Zend_Cache_Exception
* @return boolean True if no problem
*/
public function save($data, $id, $tags = array(), $specificLifetime = false)
{
$this->_checkAndBuildStructure();
$lifetime = $this->getLifetime($specificLifetime);
//$data = @sqlite_escape_string($data);
$mktime = time();
if (is_null($lifetime)) {
$expire = 0;
} else {
$expire = $mktime + $lifetime;
}
$this->_query("DELETE FROM cache WHERE id='$id'");
$sql = "INSERT INTO cache (id, content, lastModified, expire) VALUES (?, ?, $mktime, $expire)";
$res = $this->_query($sql,array($id,$data));
if (!$res) {
$this->_log("Zend_Cache_Backend_Sqlite::save() : impossible to store the cache id=$id");
return false;
}
$res = true;
foreach ($tags as $tag) {
$res = $res && $this->_registerTag($id, $tag);
}
return $res;
}
/**
* Remove a cache record
*
* @param string $id Cache id
* @return boolean True if no problem
*/
public function remove($id)
{
$this->_checkAndBuildStructure();
$res = $this->_query("SELECT COUNT(*) AS nbr FROM cache WHERE id='$id'");
$result1 = $res->fetchColumn();
$result2 = $this->_query("DELETE FROM cache WHERE id='$id'");
$result3 = $this->_query("DELETE FROM tag WHERE id='$id'");
$this->_automaticVacuum();
return ($result1 && $result2 && $result3);
}
/**
* Clean some cache records
*
* Available modes are :
* Zend_Cache::CLEANING_MODE_ALL (default) => remove all cache entries ($tags is not used)
* Zend_Cache::CLEANING_MODE_OLD => remove too old cache entries ($tags is not used)
* Zend_Cache::CLEANING_MODE_MATCHING_TAG => remove cache entries matching all given tags
* ($tags can be an array of strings or a single string)
* Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG => remove cache entries not {matching one of the given tags}
* ($tags can be an array of strings or a single string)
*
* @param string $mode Clean mode
* @param array $tags Array of tags
* @return boolean True if no problem
*/
public function clean($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array())
{
$this->_checkAndBuildStructure();
$return = $this->_clean($mode, $tags);
$this->_automaticVacuum();
return $return;
}
/**
* PUBLIC METHOD FOR UNIT TESTING ONLY !
*
* Force a cache record to expire
*
* @param string $id Cache id
*/
public function ___expire($id)
{
$time = time() - 1;
$this->_query("UPDATE cache SET lastModified=$time, expire=$time WHERE id='$id'");
}
/**
* Return the connection resource
*
* If we are not connected, the connection is made
*
* @throws Zend_Cache_Exception
* @return resource Connection resource
*/
private function _getConnection()
{
if ($this->_db) {
return $this->_db;
} else {
try{
$this->_db = new PDO('sqlite:'.$this->_options['cache_db_complete_path']);
}catch( PDOException $exception ){
ob_start();
header('HTTP/1.1 404 Not Found');
die($exception->getMessage());
}
return $this->_db;
}
}
/**
* Execute an SQL query silently
*
* @param string $query SQL query
* @return mixed|false query results
*/
private function _query($query,$values=false)
{
$db = $this->_getConnection();
if ($db) {
//$res = @sqlite_query($db, $query);
//echo '_query('.$query.','.$values.')'."\n";
if(is_array($values))
{
$res = $db->prepare($query);
if($res)
{
$res->execute($values);
}
}
else
{
$res = $db->exec($query);
}
if ($res === false) {
return false;
} else {
return $res;
}
}
return false;
}
/**
* Deal with the automatic vacuum process
*
* @return void
*/
private function _automaticVacuum()
{
if ($this->_options['automatic_vacuum_factor'] > 0) {
$rand = rand(1, $this->_options['automatic_vacuum_factor']);
if ($rand == 1) {
$this->_query('VACUUM');
//@sqlite_close($this->_getConnection());
}
}
}
/**
* Register a cache id with the given tag
*
* @param string $id Cache id
* @param string $tag Tag
* @return boolean True if no problem
*/
private function _registerTag($id, $tag) {
$res = $this->_query("DELETE FROM TAG WHERE name=? AND id=?",array($tag,$id));
$res = $this->_query("INSERT INTO tag (name, id) VALUES (?, ?)",array($tag,$id));
if (!$res) {
$this->_log("Zend_Cache_Backend_Sqlite::_registerTag() : impossible to register tag=$tag on id=$id");
return false;
}
return true;
}
/**
* Build the database structure
*
* @return false
*/
private function _buildStructure()
{
$this->_query('BEGIN');
$this->_query('DROP INDEX tag_id_index');
$this->_query('DROP INDEX tag_name_index');
$this->_query('DROP INDEX cache_id_expire_index');
$this->_query('DROP TABLE version');
$this->_query('DROP TABLE cache');
$this->_query('DROP TABLE tag');
$this->_query('CREATE TABLE version (num INTEGER PRIMARY KEY)');
$this->_query('CREATE TABLE cache (id TEXT PRIMARY KEY, content BLOB, lastModified INTEGER, expire INTEGER)');
$this->_query('CREATE TABLE tag (name TEXT, id TEXT)');
$this->_query('CREATE INDEX tag_id_index ON tag(id)');
$this->_query('CREATE INDEX tag_name_index ON tag(name)');
$this->_query('CREATE INDEX cache_id_expire_index ON cache(id, expire)');
$this->_query('INSERT INTO version (num) VALUES (1)');
$this->_query('COMMIT');
}
/**
* Check if the database structure is ok (with the good version)
*
* @return boolean True if ok
*/
private function _checkStructureVersion()
{
$result = $this->_query("SELECT num FROM version",array());
if (!$result) return false;
$row = $result->fetch();
if (!$row) {
return false;
}
if (((int) $row['num']) != 1) {
// old cache structure
$this->_log('Zend_Cache_Backend_Sqlite::_checkStructureVersion() : old cache structure version detected => the cache is going to be dropped');
return false;
}
return true;
}
/**
* Clean some cache records
*
* Available modes are :
* Zend_Cache::CLEANING_MODE_ALL (default) => remove all cache entries ($tags is not used)
* Zend_Cache::CLEANING_MODE_OLD => remove too old cache entries ($tags is not used)
* Zend_Cache::CLEANING_MODE_MATCHING_TAG => remove cache entries matching all given tags
* ($tags can be an array of strings or a single string)
* Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG => remove cache entries not {matching one of the given tags}
* ($tags can be an array of strings or a single string)
*
* @param string $mode Clean mode
* @param array $tags Array of tags
* @return boolean True if no problem
*/
private function _clean($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array())
{
if ($mode==Zend_Cache::CLEANING_MODE_ALL) {
$res1 = $this->_query('DELETE FROM cache');
$res2 = $this->_query('DELETE FROM tag');
return $res1 && $res2;
}
if ($mode==Zend_Cache::CLEANING_MODE_OLD) {
$mktime = time();
$res1 = $this->_query("DELETE FROM tag WHERE id IN (SELECT id FROM cache WHERE expire>0 AND expire<=$mktime)");
$res2 = $this->_query("DELETE FROM cache WHERE expire>0 AND expire<=$mktime");
return $res1 && $res2;
}
if ($mode==Zend_Cache::CLEANING_MODE_MATCHING_TAG) {
$first = true;
$ids = array();
foreach ($tags as $tag) {
$res = $this->_query("SELECT DISTINCT(id) AS id FROM tag WHERE name=?",array($tag));
if (!$res) {
return false;
}
$rows = $res->fetchAll();
//$rows = @sqlite_fetch_all($res, SQLITE_ASSOC);
$ids2 = array();
foreach ($rows as $row) {
$ids2[] = $row['id'];
}
if ($first) {
$ids = $ids2;
$first = false;
} else {
$ids = array_intersect($ids, $ids2);
}
}
$result = true;
foreach ($ids as $id) {
$result = $result && ($this->remove($id));
}
return $result;
}
if ($mode==Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG) {
$res = $this->_query("SELECT id FROM cache",array());
$rows = $res->fetchAll();
//$rows = @sqlite_fetch_all($res, SQLITE_ASSOC);
$result = true;
foreach ($rows as $row) {
$id = $row['id'];
$matching = false;
foreach ($tags as $tag) {
$res = $this->_query("SELECT COUNT(*) AS nbr FROM tag WHERE name=? AND id=?",array($tag,$id));
if (!$res) {
return false;
}
$nbr = (int) $res->fetchColumn();
if ($nbr > 0) {
$matching = true;
}
}
if (!$matching) {
$result = $result && $this->remove($id);
}
}
return $result;
}
return false;
}
/**
* Check if the database structure is ok (with the good version), if no : build it
*
* @return boolean True if ok
*/
private function _checkAndBuildStructure()
{
if (!($this->_structureChecked)) {
if (!$this->_checkStructureVersion()) {
$this->_buildStructure();
if (!$this->_checkStructureVersion()) {
Zend_Cache::throwException("Impossible to build cache structure in " . $this->_options['cache_db_complete_path']);
}
}
$this->_structureChecked = true;
}
return true;
}
}