<?php

/**

 * 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) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Sqlite.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * @see Zend_Cache_Backend_Interface

 */

require_once 'Zend/Cache/Backend/ExtendedInterface.php';

/**

 * @see Zend_Cache_Backend

 */

require_once 'Zend/Cache/Backend.php';

/**

 * @package    Zend_Cache

 * @subpackage Zend_Cache_Backend

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Cache_Backend_Sqlite extends Zend_Cache_Backend implements Zend_Cache_Backend_ExtendedInterface

{

    /**

     * 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 ($this->_options['cache_db_complete_path'] === null) {

            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();

        $sql = "SELECT content FROM cache WHERE id='$id'";

        if (!$doNotTestCacheValidity) {

            $sql = $sql . " AND (expire=0 OR expire>" . time() . ')';

        }

        $result = $this->_query($sql);

        $row = @sqlite_fetch_array($result);

        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();

        $sql = "SELECT lastModified FROM cache WHERE id='$id' AND (expire=0 OR expire>" . time() . ')';

        $result = $this->_query($sql);

        $row = @sqlite_fetch_array($result);

        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 ($lifetime === null) {

            $expire = 0;

        } else {

            $expire = $mktime + $lifetime;

        }

        $this->_query("DELETE FROM cache WHERE id='$id'");

        $sql = "INSERT INTO cache (id, content, lastModified, expire) VALUES ('$id', '$data', $mktime, $expire)";

        $res = $this->_query($sql);

        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 = $this->_registerTag($id, $tag) && $res;

        }

        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'");

        $result1 = @sqlite_fetch_single($res);

        $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)

     * Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG => remove cache entries matching any 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;

    }

    /**

     * Return an array of stored cache ids

     *

     * @return array array of stored cache ids (string)

     */

    public function getIds()

    {

        $this->_checkAndBuildStructure();

        $res = $this->_query("SELECT id FROM cache WHERE (expire=0 OR expire>" . time() . ")");

        $result = array();

        while ($id = @sqlite_fetch_single($res)) {

            $result[] = $id;

        }

        return $result;

    }

    /**

     * Return an array of stored tags

     *

     * @return array array of stored tags (string)

     */

    public function getTags()

    {

        $this->_checkAndBuildStructure();

        $res = $this->_query("SELECT DISTINCT(name) AS name FROM tag");

        $result = array();

        while ($id = @sqlite_fetch_single($res)) {

            $result[] = $id;

        }

        return $result;

    }

    /**

     * Return an array of stored cache ids which match given tags

     *

     * In case of multiple tags, a logical AND is made between tags

     *

     * @param array $tags array of tags

     * @return array array of matching cache ids (string)

     */

    public function getIdsMatchingTags($tags = array())

    {

        $first = true;

        $ids = array();

        foreach ($tags as $tag) {

            $res = $this->_query("SELECT DISTINCT(id) AS id FROM tag WHERE name='$tag'");

            if (!$res) {

                return array();

            }

            $rows = @sqlite_fetch_all($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 = array();

        foreach ($ids as $id) {

            $result[] = $id;

        }

        return $result;

    }

    /**

     * Return an array of stored cache ids which don't match given tags

     *

     * In case of multiple tags, a logical OR is made between tags

     *

     * @param array $tags array of tags

     * @return array array of not matching cache ids (string)

     */

    public function getIdsNotMatchingTags($tags = array())

    {

        $res = $this->_query("SELECT id FROM cache");

        $rows = @sqlite_fetch_all($res, SQLITE_ASSOC);

        $result = array();

        foreach ($rows as $row) {

            $id = $row['id'];

            $matching = false;

            foreach ($tags as $tag) {

                $res = $this->_query("SELECT COUNT(*) AS nbr FROM tag WHERE name='$tag' AND id='$id'");

                if (!$res) {

                    return array();

                }

                $nbr = (int) @sqlite_fetch_single($res);

                if ($nbr > 0) {

                    $matching = true;

                }

            }

            if (!$matching) {

                $result[] = $id;

            }

        }

        return $result;

    }

    /**

     * Return an array of stored cache ids which match any given tags

     *

     * In case of multiple tags, a logical AND is made between tags

     *

     * @param array $tags array of tags

     * @return array array of any matching cache ids (string)

     */

    public function getIdsMatchingAnyTags($tags = array())

    {

        $first = true;

        $ids = array();

        foreach ($tags as $tag) {

            $res = $this->_query("SELECT DISTINCT(id) AS id FROM tag WHERE name='$tag'");

            if (!$res) {

                return array();

            }

            $rows = @sqlite_fetch_all($res, SQLITE_ASSOC);

            $ids2 = array();

            foreach ($rows as $row) {

                $ids2[] = $row['id'];

            }

            if ($first) {

                $ids = $ids2;

                $first = false;

            } else {

                $ids = array_merge($ids, $ids2);

            }

        }

        $result = array();

        foreach ($ids as $id) {

            $result[] = $id;

        }

        return $result;

    }

    /**

     * Return the filling percentage of the backend storage

     *

     * @throws Zend_Cache_Exception

     * @return int integer between 0 and 100

     */

    public function getFillingPercentage()

    {

        $dir = dirname($this->_options['cache_db_complete_path']);

        $free = disk_free_space($dir);

        $total = disk_total_space($dir);

        if ($total == 0) {

            Zend_Cache::throwException('can\'t get disk_total_space');

        } else {

            if ($free >= $total) {

                return 100;

            }

            return ((int) (100. * ($total - $free) / $total));

        }

    }

    /**

     * Return an array of metadatas for the given cache id

     *

     * The array must include these keys :

     * - expire : the expire timestamp

     * - tags : a string array of tags

     * - mtime : timestamp of last modification time

     *

     * @param string $id cache id

     * @return array array of metadatas (false if the cache id is not found)

     */

    public function getMetadatas($id)

    {

        $tags = array();

        $res = $this->_query("SELECT name FROM tag WHERE id='$id'");

        if ($res) {

            $rows = @sqlite_fetch_all($res, SQLITE_ASSOC);

            foreach ($rows as $row) {

                $tags[] = $row['name'];

            }

        }

        $this->_query('CREATE TABLE cache (id TEXT PRIMARY KEY, content BLOB, lastModified INTEGER, expire INTEGER)');

        $res = $this->_query("SELECT lastModified,expire FROM cache WHERE id='$id'");

        if (!$res) {

            return false;

        }

        $row = @sqlite_fetch_array($res, SQLITE_ASSOC);

        return array(

            'tags' => $tags,

            'mtime' => $row['lastModified'],

            'expire' => $row['expire']

        );

    }

    /**

     * Give (if possible) an extra lifetime to the given cache id

     *

     * @param string $id cache id

     * @param int $extraLifetime

     * @return boolean true if ok

     */

    public function touch($id, $extraLifetime)

    {

        $sql = "SELECT expire FROM cache WHERE id='$id' AND (expire=0 OR expire>" . time() . ')';

        $res = $this->_query($sql);

        if (!$res) {

            return false;

        }

        $expire = @sqlite_fetch_single($res);

        $newExpire = $expire + $extraLifetime;

        $res = $this->_query("UPDATE cache SET lastModified=" . time() . ", expire=$newExpire WHERE id='$id'");

        if ($res) {

            return true;

        } else {

            return false;

        }