<?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

 * @subpackage Zend_Cache_Backend

 * @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: Backend.php 20880 2010-02-03 18:18:32Z matthew $

 */

/**

 * @package    Zend_Cache

 * @subpackage Zend_Cache_Backend

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

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

 */

class Zend_Cache_Backend

{

    /**

     * Frontend or Core directives

     *

     * =====> (int) lifetime :

     * - Cache lifetime (in seconds)

     * - If null, the cache is valid forever

     *

     * =====> (int) logging :

     * - if set to true, a logging is activated throw Zend_Log

     *

     * @var array directives

     */

    protected $_directives = array(

        'lifetime' => 3600,

        'logging'  => false,

        'logger'   => null

    );

    /**

     * Available options

     *

     * @var array available options

     */

    protected $_options = array();

    /**

     * Constructor

     *

     * @param  array $options Associative array of options

     * @throws Zend_Cache_Exception

     * @return void

     */

    public function __construct(array $options = array())

    {

        while (list($name, $value) = each($options)) {

            $this->setOption($name, $value);

        }

    }

    /**

     * Set the frontend directives

     *

     * @param  array $directives Assoc of directives

     * @throws Zend_Cache_Exception

     * @return void

     */

    public function setDirectives($directives)

    {

        if (!is_array($directives)) Zend_Cache::throwException('Directives parameter must be an array');

        while (list($name, $value) = each($directives)) {

            if (!is_string($name)) {

                Zend_Cache::throwException("Incorrect option name : $name");

            }

            $name = strtolower($name);

            if (array_key_exists($name, $this->_directives)) {

                $this->_directives[$name] = $value;

            }

        }

        $this->_loggerSanity();

    }

    /**

     * Set an option

     *

     * @param  string $name

     * @param  mixed  $value

     * @throws Zend_Cache_Exception

     * @return void

     */

    public function setOption($name, $value)

    {

        if (!is_string($name)) {

            Zend_Cache::throwException("Incorrect option name : $name");

        }

        $name = strtolower($name);

        if (array_key_exists($name, $this->_options)) {

            $this->_options[$name] = $value;

        }

    }

    /**

     * Get the life time

     *

     * if $specificLifetime is not false, the given specific life time is used

     * else, the global lifetime is used

     *

     * @param  int $specificLifetime

     * @return int Cache life time

     */

    public function getLifetime($specificLifetime)

    {

        if ($specificLifetime === false) {

            return $this->_directives['lifetime'];

        }

        return $specificLifetime;

    }

    /**

     * Return true if the automatic cleaning is available for the backend

     *

     * DEPRECATED : use getCapabilities() instead

     *

     * @deprecated

     * @return boolean

     */

    public function isAutomaticCleaningAvailable()

    {

        return true;

    }

    /**

     * Determine system TMP directory and detect if we have read access

     *

     * inspired from Zend_File_Transfer_Adapter_Abstract

     *

     * @return string

     * @throws Zend_Cache_Exception if unable to determine directory

     */

    public function getTmpDir()

    {

        $tmpdir = array();

        foreach (array($_ENV, $_SERVER) as $tab) {

            foreach (array('TMPDIR', 'TEMP', 'TMP', 'windir', 'SystemRoot') as $key) {

                if (isset($tab[$key])) {

                    if (($key == 'windir') or ($key == 'SystemRoot')) {

                        $dir = realpath($tab[$key] . '\\temp');

                    } else {

                        $dir = realpath($tab[$key]);

                    }

                    if ($this->_isGoodTmpDir($dir)) {

                        return $dir;

                    }

                }

            }

        }

        $upload = ini_get('upload_tmp_dir');

        if ($upload) {

            $dir = realpath($upload);

            if ($this->_isGoodTmpDir($dir)) {

                return $dir;

            }

        }

        if (function_exists('sys_get_temp_dir')) {

            $dir = sys_get_temp_dir();

            if ($this->_isGoodTmpDir($dir)) {

                return $dir;

            }

        }

        // Attemp to detect by creating a temporary file

        $tempFile = tempnam(md5(uniqid(rand(), TRUE)), '');

        if ($tempFile) {

            $dir = realpath(dirname($tempFile));

            unlink($tempFile);

            if ($this->_isGoodTmpDir($dir)) {

                return $dir;

            }

        }

        if ($this->_isGoodTmpDir('/tmp')) {

            return '/tmp';

        }

        if ($this->_isGoodTmpDir('\\temp')) {

            return '\\temp';

        }

        Zend_Cache::throwException('Could not determine temp directory, please specify a cache_dir manually');

    }

    /**

     * Verify if the given temporary directory is readable and writable

     *

     * @param $dir temporary directory

     * @return boolean true if the directory is ok

     */

    protected function _isGoodTmpDir($dir)

    {

        if (is_readable($dir)) {

            if (is_writable($dir)) {

                return true;

            }

        }

        return false;

    }

    /**

     * Make sure if we enable logging that the Zend_Log class

     * is available.

     * Create a default log object if none is set.

     *

     * @throws Zend_Cache_Exception

     * @return void

     */

    protected function _loggerSanity()

    {

        if (!isset($this->_directives['logging']) || !$this->_directives['logging']) {

            return;

        }

        if (isset($this->_directives['logger'])) {

            if ($this->_directives['logger'] instanceof Zend_Log) {

                return;

            }

            Zend_Cache::throwException('Logger object is not an instance of Zend_Log class.');

        }

        // Create a default logger to the standard output stream

        require_once 'Zend/Log.php';

        require_once 'Zend/Log/Writer/Stream.php';

        $logger = new Zend_Log(new Zend_Log_Writer_Stream('php://output'));

        $this->_directives['logger'] = $logger;

    }

    /**

     * Log a message at the WARN (4) priority.

     *

     * @param  string $message

     * @throws Zend_Cache_Exception

     * @return void

     */

    protected function _log($message, $priority = 4)

    {

        if (!$this->_directives['logging']) {

            return;

        }

        if (!isset($this->_directives['logger'])) {

            Zend_Cache::throwException('Logging is enabled but logger is not set.');

        }

        $logger = $this->_directives['logger'];

        if (!$logger instanceof Zend_Log) {

            Zend_Cache::throwException('Logger object is not an instance of Zend_Log class.');

        }

        $logger->log($message, $priority);

    }

}