<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Cache

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Cache.php 23154 2010-10-18 17:41:06Z mabe $

 */

/**

 * @package    Zend_Cache

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

abstract class Zend_Cache

{

    /**

     * Standard frontends

     *

     * @var array

     */

    public static $standardFrontends = array('Core', 'Output', 'Class', 'File', 'Function', 'Page');

    /**

     * Standard backends

     *

     * @var array

     */

    public static $standardBackends = array('File', 'Sqlite', 'Memcached', 'Libmemcached', 'Apc', 'ZendPlatform',

                                            'Xcache', 'TwoLevels', 'ZendServer_Disk', 'ZendServer_ShMem');

    /**

     * Standard backends which implement the ExtendedInterface

     *

     * @var array

     */

    public static $standardExtendedBackends = array('File', 'Apc', 'TwoLevels', 'Memcached', 'Libmemcached', 'Sqlite');

    /**

     * Only for backward compatibility (may be removed in next major release)

     *

     * @var array

     * @deprecated

     */

    public static $availableFrontends = array('Core', 'Output', 'Class', 'File', 'Function', 'Page');

    /**

     * Only for backward compatibility (may be removed in next major release)

     *

     * @var array

     * @deprecated

     */

    public static $availableBackends = array('File', 'Sqlite', 'Memcached', 'Libmemcached', 'Apc', 'ZendPlatform', 'Xcache', 'TwoLevels');

    /**

     * Consts for clean() method

     */

    const CLEANING_MODE_ALL              = 'all';

    const CLEANING_MODE_OLD              = 'old';

    const CLEANING_MODE_MATCHING_TAG     = 'matchingTag';

    const CLEANING_MODE_NOT_MATCHING_TAG = 'notMatchingTag';

    const CLEANING_MODE_MATCHING_ANY_TAG = 'matchingAnyTag';

    /**

     * Factory

     *

     * @param mixed  $frontend        frontend name (string) or Zend_Cache_Frontend_ object

     * @param mixed  $backend         backend name (string) or Zend_Cache_Backend_ object

     * @param array  $frontendOptions associative array of options for the corresponding frontend constructor

     * @param array  $backendOptions  associative array of options for the corresponding backend constructor

     * @param boolean $customFrontendNaming if true, the frontend argument is used as a complete class name ; if false, the frontend argument is used as the end of "Zend_Cache_Frontend_[...]" class name

     * @param boolean $customBackendNaming if true, the backend argument is used as a complete class name ; if false, the backend argument is used as the end of "Zend_Cache_Backend_[...]" class name

     * @param boolean $autoload if true, there will no require_once for backend and frontend (useful only for custom backends/frontends)

     * @throws Zend_Cache_Exception

     * @return Zend_Cache_Core|Zend_Cache_Frontend

     */

    public static function factory($frontend, $backend, $frontendOptions = array(), $backendOptions = array(), $customFrontendNaming = false, $customBackendNaming = false, $autoload = false)

    {

        if (is_string($backend)) {

            $backendObject = self::_makeBackend($backend, $backendOptions, $customBackendNaming, $autoload);

        } else {

            if ((is_object($backend)) && (in_array('Zend_Cache_Backend_Interface', class_implements($backend)))) {

                $backendObject = $backend;

            } else {

                self::throwException('backend must be a backend name (string) or an object which implements Zend_Cache_Backend_Interface');

            }

        }

        if (is_string($frontend)) {

            $frontendObject = self::_makeFrontend($frontend, $frontendOptions, $customFrontendNaming, $autoload);

        } else {

            if (is_object($frontend)) {

                $frontendObject = $frontend;

            } else {

                self::throwException('frontend must be a frontend name (string) or an object');

            }

        }

        $frontendObject->setBackend($backendObject);

        return $frontendObject;

    }

    /**

     * Backend Constructor

     *

     * @param string  $backend

     * @param array   $backendOptions

     * @param boolean $customBackendNaming

     * @param boolean $autoload

     * @return Zend_Cache_Backend

     */

    public static function _makeBackend($backend, $backendOptions, $customBackendNaming = false, $autoload = false)

    {

        if (!$customBackendNaming) {

            $backend  = self::_normalizeName($backend);

        }

        if (in_array($backend, Zend_Cache::$standardBackends)) {

            // we use a standard backend

            $backendClass = 'Zend_Cache_Backend_' . $backend;

            // security controls are explicit

            require_once str_replace('_', DIRECTORY_SEPARATOR, $backendClass) . '.php';

        } else {

            // we use a custom backend

            if (!preg_match('~^[\w]+$~D', $backend)) {

                Zend_Cache::throwException("Invalid backend name [$backend]");

            }

            if (!$customBackendNaming) {

                // we use this boolean to avoid an API break

                $backendClass = 'Zend_Cache_Backend_' . $backend;

            } else {

                $backendClass = $backend;

            }

            if (!$autoload) {

                $file = str_replace('_', DIRECTORY_SEPARATOR, $backendClass) . '.php';

                if (!(self::_isReadable($file))) {

                    self::throwException("file $file not found in include_path");

                }

                require_once $file;

            }

        }

        return new $backendClass($backendOptions);

    }

    /**

     * Frontend Constructor

     *

     * @param string  $frontend

     * @param array   $frontendOptions

     * @param boolean $customFrontendNaming

     * @param boolean $autoload

     * @return Zend_Cache_Core|Zend_Cache_Frontend

     */

    public static function _makeFrontend($frontend, $frontendOptions = array(), $customFrontendNaming = false, $autoload = false)

    {

        if (!$customFrontendNaming) {

            $frontend = self::_normalizeName($frontend);

        }

        if (in_array($frontend, self::$standardFrontends)) {

            // we use a standard frontend

            // For perfs reasons, with frontend == 'Core', we can interact with the Core itself

            $frontendClass = 'Zend_Cache_' . ($frontend != 'Core' ? 'Frontend_' : '') . $frontend;

            // security controls are explicit

            require_once str_replace('_', DIRECTORY_SEPARATOR, $frontendClass) . '.php';

        } else {

            // we use a custom frontend

            if (!preg_match('~^[\w]+$~D', $frontend)) {

                Zend_Cache::throwException("Invalid frontend name [$frontend]");

            }

            if (!$customFrontendNaming) {

                // we use this boolean to avoid an API break

                $frontendClass = 'Zend_Cache_Frontend_' . $frontend;

            } else {

                $frontendClass = $frontend;

            }

            if (!$autoload) {

                $file = str_replace('_', DIRECTORY_SEPARATOR, $frontendClass) . '.php';

                if (!(self::_isReadable($file))) {

                    self::throwException("file $file not found in include_path");

                }

                require_once $file;

            }

        }

        return new $frontendClass($frontendOptions);

    }

    /**

     * Throw an exception

     *

     * Note : for perf reasons, the "load" of Zend/Cache/Exception is dynamic

     * @param  string $msg  Message for the exception

     * @throws Zend_Cache_Exception

     */

    public static function throwException($msg, Exception $e = null)

    {

        // For perfs reasons, we use this dynamic inclusion

        require_once 'Zend/Cache/Exception.php';

        throw new Zend_Cache_Exception($msg, 0, $e);

    }

    /**

     * Normalize frontend and backend names to allow multiple words TitleCased

     *

     * @param  string $name  Name to normalize

     * @return string

     */

    protected static function _normalizeName($name)

    {

        $name = ucfirst(strtolower($name));

        $name = str_replace(array('-', '_', '.'), ' ', $name);

        $name = ucwords($name);

        $name = str_replace(' ', '', $name);

        if (stripos($name, 'ZendServer') === 0) {

            $name = 'ZendServer_' . substr($name, strlen('ZendServer'));

        }

        return $name;

    }

    /**

     * Returns TRUE if the $filename is readable, or FALSE otherwise.

     * This function uses the PHP include_path, where PHP's is_readable()

     * does not.

     *

     * Note : this method comes from Zend_Loader (see #ZF-2891 for details)

     *

     * @param string   $filename

     * @return boolean

     */

    private static function _isReadable($filename)

    {

        if (!$fh = @fopen($filename, 'r', true)) {

            return false;

        }

        @fclose($fh);

        return true;

    }

}