application/CachedPage.php

   1 <?php
   2 /**
   3  * Simple cache system, mainly for the RSS/ATOM feeds
   4  */
   5 class CachedPage
   6 {
   7     // Directory containing page caches
   8     private $cacheDir;
   9
  10     // Should this URL be cached (boolean)?
  11     private $shouldBeCached;
  12
  13     // Name of the cache file for this URL
  14     private $filename;
  15
  16     /**
  17      * Creates a new CachedPage
  18      *
  19      * @param string $cacheDir       page cache directory
  20      * @param string $url            page URL
  21      * @param bool   $shouldBeCached whether this page needs to be cached
  22      */
  23     public function __construct($cacheDir, $url, $shouldBeCached)
  24     {
  25         // TODO: check write access to the cache directory
  26         $this->cacheDir = $cacheDir;
  27         $this->filename = $this->cacheDir.'/'.sha1($url).'.cache';
  28         $this->shouldBeCached = $shouldBeCached;
  29     }
  30
  31     /**
  32      * Returns the cached version of a page, if it exists and should be cached
  33      *
  34      * @return string a cached version of the page if it exists, null otherwise
  35      */
  36     public function cachedVersion()
  37     {
  38         if (!$this->shouldBeCached) {
  39             return null;
  40         }
  41         if (is_file($this->filename)) {
  42             return file_get_contents($this->filename);
  43         }
  44         return null;
  45     }
  46
  47     /**
  48      * Puts a page in the cache
  49      *
  50      * @param string $pageContent XML content to cache
  51      */
  52     public function cache($pageContent)
  53     {
  54         if (!$this->shouldBeCached) {
  55             return;
  56         }
  57         file_put_contents($this->filename, $pageContent);
  58     }
  59 }