bcit-ci/CodeIgniter

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system/libraries/Cache/drivers/Cache_memcached.php

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<?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
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * CodeIgniter Memcached Caching Class
 *
 * @package        CodeIgniter
 * @subpackage    Libraries
 * @category    Core
 * @author        EllisLab Dev Team
 * @link
 */
class CI_Cache_memcached extends CI_Driver {

    /**
     * Holds the memcached object
     *
     * @var object
     */
    protected $_memcached;

    /**
     * Memcached configuration
     *
     * @var array
     */
    protected $_config = array(
        'default' => array(
            'host'        => '127.0.0.1',
            'port'        => 11211,
            'weight'    => 1
        )
    );

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

    /**
     * Class constructor
     *
     * Setup Memcache(d)
     *
     * @return    void
     */
    public function __construct()
    {
        // Try to load memcached server info from the config file.
        $CI =& get_instance();
        $defaults = $this->_config['default'];

        if ($CI->config->load('memcached', TRUE, TRUE))
        {
            $this->_config = $CI->config->config['memcached'];
        }

        if (class_exists('Memcached', FALSE))
        {
            $this->_memcached = new Memcached();
        }
        elseif (class_exists('Memcache', FALSE))
        {
            $this->_memcached = new Memcache();
        }
        else
        {
            log_message('error', 'Cache: Failed to create Memcache(d) object; extension not loaded?');
            return;
        }

        foreach ($this->_config as $cache_name => $cache_server)
        {
            if ( ! isset($cache_server['hostname']))
            {
                log_message('debug', 'Cache: Memcache(d) configuration "'.$cache_name.'" doesn\'t include a hostname; ignoring.');
                continue;
            }
            elseif ($cache_server['hostname'][0] === '/')
            {
                $cache_server['port'] = 0;
            }
            elseif (empty($cache_server['port']))
            {
                $cache_server['port'] = $defaults['port'];
            }

            isset($cache_server['weight']) OR $cache_server['weight'] = $defaults['weight'];

            if ($this->_memcached instanceof Memcache)
            {
                // Third parameter is persistence and defaults to TRUE.
                $this->_memcached->addServer(
                    $cache_server['hostname'],
                    $cache_server['port'],
                    TRUE,
                    $cache_server['weight']
                );
            }
            elseif ($this->_memcached instanceof Memcached)
            {
                $this->_memcached->addServer(
                    $cache_server['hostname'],
                    $cache_server['port'],
                    $cache_server['weight']
                );
            }
        }
    }

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

    /**
     * Fetch from cache
     *
     * @param    string    $id    Cache ID
     * @return    mixed    Data on success, FALSE on failure
     */
    public function get($id)
    {
        $data = $this->_memcached->get($id);

        return is_array($data) ? $data[0] : $data;
    }

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

    /**
     * Save
     *
     * @param    string    $id    Cache ID
     * @param    mixed    $data    Data being cached
     * @param    int    $ttl    Time to live
     * @param    bool    $raw    Whether to store the raw value
     * @return    bool    TRUE on success, FALSE on failure
     */
    public function save($id, $data, $ttl = 60, $raw = FALSE)
    {
        if ($raw !== TRUE)
        {
            $data = array($data, time(), $ttl);
        }

        if ($this->_memcached instanceof Memcached)
        {
            return $this->_memcached->set($id, $data, $ttl);
        }
        elseif ($this->_memcached instanceof Memcache)
        {
            return $this->_memcached->set($id, $data, 0, $ttl);
        }

        return FALSE;
    }

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

    /**
     * Delete from Cache
     *
     * @param    mixed    $id    key to be deleted.
     * @return    bool    true on success, false on failure
     */
    public function delete($id)
    {
        return $this->_memcached->delete($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, $offset = 1)
    {
        if (($result = $this->_memcached->increment($id, $offset)) === FALSE)
        {
            return $this->_memcached->add($id, $offset) ? $offset : FALSE;
        }

        return $result;
    }

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

    /**
     * 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, $offset = 1)
    {
        if (($result = $this->_memcached->decrement($id, $offset)) === FALSE)
        {
            return $this->_memcached->add($id, 0) ? 0 : FALSE;
        }

        return $result;
    }

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

    /**
     * Clean the Cache
     *
     * @return    bool    false on failure/true on success
     */
    public function clean()
    {
        return $this->_memcached->flush();
    }

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

    /**
     * Cache Info
     *
     * @return    mixed    array on success, false on failure
     */
    public function cache_info()
    {
        return $this->_memcached->getStats();
    }

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

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

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

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

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

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

    /**
     * Is supported
     *
     * Returns FALSE if memcached is not supported on the system.
     * If it is, we setup the memcached object & return TRUE
     *
     * @return    bool
     */
    public function is_supported()
    {
        return (extension_loaded('memcached') OR extension_loaded('memcache'));
    }

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

    /**
     * Class destructor
     *
     * Closes the connection to Memcache(d) if present.
     *
     * @return    void
     */
    public function __destruct()
    {
        if ($this->_memcached instanceof Memcache)
        {
            $this->_memcached->close();
        }
        elseif ($this->_memcached instanceof Memcached && method_exists($this->_memcached, 'quit'))
        {
            $this->_memcached->quit();
        }
    }
}