1 <?php

     2 

     3 /*

     4  * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between

     5  * Version 1.1.4 (Caoineag alpha 4)

     6  * Copyright (C) 2006-2008 Dan Fuhry

     7  *

     8  * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License

     9  * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

    10  *

    11  * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied

    12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.

    13  */

    14  

    15 /**

    16  * Framework for caching arbitrary data around the site.

    17  * @package Enano

    18  * @subpackage Core

    19  * @author Dan Fuhry <dan@enanocms.org>

    20  * @license GNU General Public License

    21  */

    22 

    23 class CacheManager

    24 {

    25   /**

    26    * Fetch a cached piece of data.

    27    * @param string Cache ID. The timestamp is checked automatically.

    28    */

    29   

    30   public function fetch($cache_id)

    31   {

    32     if ( !preg_match('/^[a-z0-9_]+$/', $cache_id) )

    33     {

    34       throw new Exception('Cache ID must be letters, numbers, and underscores.');

    35     }

    36     $cache_file = ENANO_ROOT . "/cache/cache_$cache_id.php";

    37     if ( file_exists($cache_file) )

    38     {

    39       require($cache_file);

    40       if ( isset($_cache_data) && isset($_cache_ttl) && isset($_cache_timestamp) )

    41       {

    42         $cache_expire = $_cache_timestamp + ( 60 * $_cache_ttl);

    43         if ( $cache_expire >= time() || $_cache_ttl === -1 )

    44         {

    45           return $_cache_data;

    46         }

    47       }

    48     }

    49     return false;

    50   }

    51   

    52   /**

    53    * Stores an array by var_export()ing it and saving it to disk.

    54    * @param string Cache ID - human readable name for this store (letters, numbers, underscores)

    55    * @param array Data to store

    56    * @param int TTL for the cached array, in minutes. Defaults to 20. If set to -1, caches indefinitely.

    57    * @return bool True on success, false on failure

    58    */

    59   

    60   public function store($cache_id, $data, $ttl = 20)

    61   {

    62     if ( getConfig('cache_thumbs') != '1' )

    63     {

    64       // caching disabled

    65       return false;

    66     }

    67     if ( !preg_match('/^[a-z0-9_]+$/', $cache_id) )

    68     {

    69       throw new Exception('Cache ID must be letters, numbers, and underscores.');

    70     }

    71     if ( !is_int($ttl) )

    72     {

    73       throw new Exception('TTL must be an integer');

    74     }

    75     

    76     $cache_file = ENANO_ROOT . "/cache/cache_$cache_id.php";

    77     if ( file_exists($cache_file) )

    78     {

    79       @unlink($cache_file);

    80     }

    81     $fh = @fopen($cache_file, 'w');

    82     if ( !$fh )

    83     {

    84       throw new Exception('Failed to open file for writing.');

    85     }

    86     $exported = Language::var_export_string($data);

    87     $now = time();

    88     $content = <<<EOF

    89 <?php

    90 /**

    91  * Automatically generated cache file.

    92  * Do not edit this file as it will expire and be overwritten $ttl minutes from its creation.

    93  */

    94 

    95 \$_cache_ttl = $ttl;

    96 \$_cache_timestamp = $now;

    97 \$_cache_data = $exported;

    98 

    99 EOF;

   100     fwrite($fh, $content);

   101     fclose($fh);

   102     

   103     return true;

   104   }

   105   

   106   /**

   107    * Deletes a cached item.

   108    * @param string Cache ID.

   109    * @return bool true on success or if item doesn't exist, false on failure

   110    */

   111   

   112   public function purge($cache_id)

   113   {

   114     if ( !preg_match('/^[a-z0-9_]+$/', $cache_id) )

   115     {

   116       throw new Exception('Cache ID must be letters, numbers, and underscores.');

   117     }

   118     

   119     $cache_file = ENANO_ROOT . "/cache/cache_$cache_id.php";

   120     if ( file_exists($cache_file) )

   121     {

   122       if ( unlink($cache_file) )

   123       {

   124         return true;

   125       }

   126       return false;

   127     }

   128     return true;

   129   }

   130 }

   131