<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Cache
 *
 * @copyright   Copyright (C) 2005 - 2011 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

/**
 * eAccelerator cache storage handler
 *
 * @package     Joomla.Platform
 * @subpackage  Cache
 * @since       11.1
 */
class JCacheStorageEaccelerator extends JCacheStorage
{
    /**
     * Constructor
     *
     * @param array $options optional parameters
     */
    public function __construct($options = array())
    {
        parent::__construct($options);
    }

    /**
     * Get cached data by id and group
     *
     * @param   string  $id         The cache data id
     * @param   string  $group      The cache data group
     * @param   boolean $checkTime  True to verify cache time expiration threshold
     * @return  mixed   Boolean false on failure or a cached data string
     * @since   11.1
     */
    public function get($id, $group, $checkTime = true)
    {
        $cache_id = $this->_getCacheId($id, $group);
        $cache_content = eaccelerator_get($cache_id);
        if ($cache_content === null) {
            return false;
        }
        return $cache_content;
    }

     /**
     * Get all cached data
     *
     * @return  array data
     * @since   11.1
     */
    public function getAll()
    {
        parent::getAll();

        $keys = eaccelerator_list_keys();

        $secret = $this->_hash;
        $data   = array();

        foreach ($keys as $key) {
            /* Trim leading ":" to work around list_keys namespace bug in eAcc. This will still work when bug is fixed */
            $name       = ltrim($key['name'], ':');
            $namearr    = explode('-',$name);

            if ($namearr !== false && $namearr[0]==$secret &&  $namearr[1]=='cache') {
                $group = $namearr[2];

                if (!isset($data[$group])) {
                    $item = new JCacheStorageHelper($group);
                } else {
                    $item = $data[$group];
                }

                $item->updateSize($key['size']/1024);

                $data[$group] = $item;
            }
        }


        return $data;
    }

    /**
     * Store the data to by id and group
     *
     * @param   string  $id     The cache data id
     * @param   string  $group  The cache data group
     * @param   string  $data   The data to store in cache
     * @return  boolean True on success, false otherwise
     * @since   11.1
     */
    public function store($id, $group, $data)
    {
        $cache_id = $this->_getCacheId($id, $group);
        return eaccelerator_put($cache_id, $data, $this->_lifetime);
    }

    /**
     * Remove a cached data entry by id and group
     *
     * @param   string  $id     The cache data id
     * @param   string  $group  The cache data group
     * @return  boolean True on success, false otherwise
     * @since   11.1
     */
    function remove($id, $group)
    {
        $cache_id = $this->_getCacheId($id, $group);
        return eaccelerator_rm($cache_id);
    }

    /**
     * Clean cache for a group given a mode.
     *
     * group mode       : cleans all cache in the group
     * notgroup mode    : cleans all cache not in the group
     *
     * @param   string  $group  The cache data group
     * @param   string  $mode   The mode for cleaning cache [group|notgroup]
     * @return  boolean True on success, false otherwise
     * @since   11.1
     */
    public function clean($group, $mode = null)
    {
        $keys = eaccelerator_list_keys();

        $secret = $this->_hash;

        if (is_array($keys)) {
            foreach ($keys as $key) {
                /* Trim leading ":" to work around list_keys namespace bug in eAcc. This will still work when bug is fixed */
                $key['name'] = ltrim($key['name'], ':');

                if (strpos($key['name'], $secret.'-cache-'.$group.'-')===0 xor $mode != 'group') {
                    eaccelerator_rm($key['name']);
                }
            }
        }
        return true;
    }

    /**
     * Garbage collect expired cache data
     *
     * @return boolean  True on success, false otherwise.
     * @since   11.1
     */
    public function gc()
    {
        return eaccelerator_gc();
    }

    /**
     * Test to see if the cache storage is available.
     *
     * @return boolean  True on success, false otherwise.
     */
    public static function test()
    {
        return (extension_loaded('eaccelerator') && function_exists('eaccelerator_get'));
    }

    /**
     * Lock cached item
     *
     * @param   string  $id     The cache data id
     * @param   string  $group  The cache data group
     * @param   integer $locktime Cached item max lock time
     * @return  boolean True on success, false otherwise.
     * @since   11.1
     */
    public function lock($id,$group,$locktime)
    {
        $returning = new stdClass();
        $returning->locklooped = false;

        $looptime = $locktime * 10;

        $cache_id = $this->_getCacheId($id, $group);

        $data_lock = eaccelerator_lock($cache_id);

        if ($data_lock === false) {

            $lock_counter = 0;

            // loop until you find that the lock has been released.  that implies that data get from other thread has finished
            while ($data_lock === false) {

                if ($lock_counter > $looptime) {
                    $returning->locked = false;
                    $returning->locklooped = true;
                    break;
                }

                usleep(100);
                $data_lock = eaccelerator_lock($cache_id);
                $lock_counter++;
            }

        }
        $returning->locked = $data_lock;

        return $returning;
    }

    /**
     * Unlock cached item
     *
     * @param   string  $id     The cache data id
     * @param   string  $group  The cache data group
     * @return  boolean True on success, false otherwise.
     * @since   11.1
     */
    public function unlock($id, $group = null)
    {
        $cache_id = $this->_getCacheId($id, $group);
        return eaccelerator_unlock($cache_id);
    }
}