bcit-ci/CodeIgniter

<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2019, British Columbia Institute of Technology
 *
 * 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/)
 * @license    https://opensource.org/licenses/MIT    MIT License
 * @link    https://codeigniter.com
 * @since    Version 3.2.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * CodeIgniter APCu Caching Class
 *
 * @package        CodeIgniter
 * @subpackage    Libraries
 * @category    Core
 * @author        CodeIgniter Dev team
 */
class CI_Cache_apcu extends CI_Driver {

    /**
     * Class constructor
     *
     * Only present so that an error message is logged
     * if APCu is not available.
     *
     * @return    void
     */
    public function __construct()
    {
        if ( ! $this->is_supported())
        {
            log_message('error', 'Cache: Failed to initialize APCu; 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;
        $data = apcu_fetch($id, $success);

        if ($success === TRUE)
        {
            return is_array($data)
                ? $data[0]
                : $data;
        }

        return 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    $raw    Whether to store the raw value
     * @return    bool    TRUE on success, FALSE on failure
     */
    public function save($id, $data, $ttl = 60, $raw = FALSE)
    {
        $ttl = (int) $ttl;

        return apcu_store(
            $id,
            ($raw === TRUE ? $data : array($data, time(), $ttl)),
            $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($id)
    {
        return apcu_delete($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, $offset = 1)
    {
        return apcu_inc($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, $offset = 1)
    {
        return apcu_dec($id, $offset);
    }

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

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

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

    /**
     * Cache Info
     *
     * @return    mixed    array on success, false on failure
     */
    public function cache_info()
    {
        return apcu_cache_info();
    }

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

    /**
     * Get Cache Metadata
     *
     * @param    mixed    key to get cache metadata on
     * @return    mixed    array on success/false on failure
     */
    public function get_metadata($id)
    {
        $success = FALSE;
        $stored = apcu_fetch($id, $success);

        if ($success === FALSE OR count($stored) !== 3)
        {
            return FALSE;
        }

        list($data, $time, $ttl) = $stored;

        return array(
            'expire'  => $time + $ttl,
            'mtime'   => $time,
            'data'    => $data
        );
    }

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

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