<?php
/*
 *  $Id$
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.phpdoctrine.com>.
 */
/**
 * Doctrine_Cache_Query_Sqlite
 *
 *
 * @package     Doctrine
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @category    Object Relational Mapping
 * @link        www.phpdoctrine.com
 * @since       1.0
 * @version     $Revision$
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 */
class Doctrine_Cache_Query_Sqlite implements Countable
{
    /**
     * doctrine cache
     */
    const CACHE_TABLE = 'doctrine_query_cache';
    /**
     * @var Doctrine_Session $session       the table object this cache container belongs to
     */
    private $table;
    /**
     * @var PDO $dbh                    database handler
     */
    private $dbh;
    /**
     * constructor
     *
     * @param Doctrine_Connection|null $connection
     */
    public function __construct($connection = null)
    {
        if ( ! ($connection instanceof Doctrine_Connection)) {
            $connection = Doctrine_Manager::getInstance()->getCurrentConnection();
        }
        $this->session = $connection;
        $dir = 'cache';

        $this->path = $dir.DIRECTORY_SEPARATOR;
        $this->dbh  = new PDO("sqlite::memory:");

        try {
            if ($this->session->getAttribute(Doctrine::ATTR_CREATE_TABLES) === true) {
                $columns = array();
                $columns['query_md5']       = array('string', 32, 'notnull');
                $columns['query_result']    = array('array', 100000, 'notnull');
                $columns['expires']         = array('integer', 11, 'notnull');

                $dataDict = new Doctrine_DataDict($this->dbh);
                $dataDict->createTable(self::CACHE_TABLE, $columns);
            }
        } catch(PDOException $e) {

        }
    }
    /**
     * store
     * stores a query in cache
     *
     * @param string $query
     * @param array $result
     * @param integer $lifespan
     * @return void
     */
    public function store($query, array $result, $lifespan)
    {
        $sql    = "INSERT INTO ".self::CACHE_TABLE." (query_md5, query_result, expires) VALUES (?,?,?)";
        $stmt   = $this->dbh->prepare($sql);
        $params = array(md5($query), serialize($result), (time() + $lifespan));
        $stmt->execute($params);
    }
    /**
     * fetch
     *
     * @param string $md5
     * @return array
     */
    public function fetch($md5)
    {
        $sql    = "SELECT query_result, expires FROM ".self::CACHE_TABLE." WHERE query_md5 = ?";
        $stmt   = $this->dbh->prepare($sql);
        $params = array($md5);
        $stmt->execute($params);
        $result = $stmt->fetch(PDO::FETCH_ASSOC);
        return unserialize($result['query_result']);
    }
    /**
     * deleteAll
     * returns the number of deleted rows
     *
     * @return integer
     */
    public function deleteAll()
    {
        $sql    = "DELETE FROM ".self::CACHE_TABLE;
        $stmt   = $this->dbh->exec($sql);
        return $stmt->rowCount();
    }
    /**
     * deleteExpired
     * returns the number of deleted rows
     *
     * @return integer
     */
    public function deleteExpired()
    {
        $sql    = "DELETE FROM ".self::CACHE_TABLE." WHERE expired < ?";
        $stmt   = $this->dbh->prepare($sql);
        $stmt->execute(array(time()));
    }
    /**
     * delete
     * returns whether or not the given
     * query was succesfully deleted
     *
     * @param string $md5
     * @return boolean
     */
    public function delete($md5)
    {
        $sql    = "DELETE FROM ".self::CACHE_TABLE." WHERE query_md5 = ?";
        $stmt   = $this->dbh->prepare($sql);
        $params = array($md5);
        $stmt->execute($params);
        return $stmt->rowCount();
    }
    /**
     * count
     *
     * @return integer
     */
    public function count()
    {
        $stmt = $this->dbh->query("SELECT COUNT(*) FROM ".self::CACHE_TABLE);
        $data = $stmt->fetch(PDO::FETCH_NUM);

        // table has three columns so we have to divide the count by two
        return $data[0];
    }
}