<?php

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2019 - 2022, CodeIgniter Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package CodeIgniter
 * @author  EllisLab Dev Team
 * @copyright   Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright   Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
 * @copyright   Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
 * @license https://opensource.org/licenses/MIT MIT License
 * @link    https://codeigniter.com
 * @since   Version 2.0.0
 * @filesource
 */

defined('BASEPATH') or exit('No direct script access allowed');

/**
 * CodeIgniter APC Caching Class
 *
 * @package     CodeIgniter
 * @subpackage  Libraries
 * @category    Core
 * @author      EllisLab Dev Team
 * @link
 */
class CI_Cache_apc extends CI_Driver
{
    /**
     * Class constructor
     *
     * Only present so that an error message is logged
     * if APC is not available.
     *
     * @return  void
     */
    public function __construct()
    {
        if (! $this->is_supported()) {
            log_message('error', 'Cache: Failed to initialize APC; extension not loaded/enabled?');
        }
    }

    // ------------------------------------------------------------------------

    /**
     * Get
     *
     * Look for a value in the cache. If it exists, return the data
     * if not, return FALSE
     *
     * @param   string
     * @return  mixed   value that is stored/FALSE on failure
     */
    public function get($id)
    {
        $success = false;
        $data = apc_fetch($id, $success);

        return ($success === true) ? $data : false;
    }

    // ------------------------------------------------------------------------

    /**
     * Cache Save
     *
     * @param   string  $id Cache ID
     * @param   mixed   $data   Data to store
     * @param   int $ttl    Length of time (in seconds) to cache the data
     * @param   bool    $raw    Whether to store the raw value (unused)
     * @return  bool    TRUE on success, FALSE on failure
     */
    public function save($id, $data, $ttl = 60, $raw = false)
    {
        return apc_store($id, $data, (int) $ttl);
    }

    // ------------------------------------------------------------------------

    /**
     * Delete from Cache
     *
     * @param   mixed   unique identifier of the item in the cache
     * @return  bool    true on success/false on failure
     */
    public function delete($id)
    {
        return apc_delete($id);
    }

    // ------------------------------------------------------------------------

    /**
     * Increment a raw value
     *
     * @param   string  $id Cache ID
     * @param   int $offset Step/value to add
     * @return  mixed   New value on success or FALSE on failure
     */
    public function increment($id, $offset = 1)
    {
        return apc_inc($id, $offset);
    }

    // ------------------------------------------------------------------------

    /**
     * Decrement a raw value
     *
     * @param   string  $id Cache ID
     * @param   int $offset Step/value to reduce by
     * @return  mixed   New value on success or FALSE on failure
     */
    public function decrement($id, $offset = 1)
    {
        return apc_dec($id, $offset);
    }

    // ------------------------------------------------------------------------

    /**
     * Clean the cache
     *
     * @return  bool    false on failure/true on success
     */
    public function clean()
    {
        return apc_clear_cache('user');
    }

    // ------------------------------------------------------------------------

    /**
     * Cache Info
     *
     * @param   string  user/filehits
     * @return  mixed   array on success, false on failure
     */
    public function cache_info($type = null)
    {
        return apc_cache_info($type);
    }

    // ------------------------------------------------------------------------

    /**
     * Get Cache Metadata
     *
     * @param   mixed   key to get cache metadata on
     * @return  mixed   array on success/false on failure
     */
    public function get_metadata($id)
    {
        $cache_info = apc_cache_info('user', false);
        if (empty($cache_info) or empty($cache_info['cache_list'])) {
            return false;
        }

        foreach ($cache_info['cache_list'] as &$entry) {
            if ($entry['info'] !== $id) {
                continue;
            }

            $success  = false;
            $metadata = array(
                'expire' => ($entry['ttl'] ? $entry['mtime'] + $entry['ttl'] : 0),
                'mtime'  => $entry['ttl'],
                'data'   => apc_fetch($id, $success)
            );

            return ($success === true) ? $metadata : false;
        }

        return false;
    }

    // ------------------------------------------------------------------------

    /**
     * is_supported()
     *
     * Check to see if APC is available on this system, bail if it isn't.
     *
     * @return  bool
     */
    public function is_supported()
    {
        return (extension_loaded('apc') && ini_get('apc.enabled'));
    }
}