application/feed/CachedPage.php

   1 <?php
   2
   3 namespace Shaarli\Feed;
   4
   5 /**
   6  * Simple cache system, mainly for the RSS/ATOM feeds
   7  */
   8 class CachedPage
   9 {
  10     // Directory containing page caches
  11     private $cacheDir;
  12
  13     // Should this URL be cached (boolean)?
  14     private $shouldBeCached;
  15
  16     // Name of the cache file for this URL
  17     private $filename;
  18
  19     /**
  20      * Creates a new CachedPage
  21      *
  22      * @param string $cacheDir       page cache directory
  23      * @param string $url            page URL
  24      * @param bool   $shouldBeCached whether this page needs to be cached
  25      */
  26     public function __construct($cacheDir, $url, $shouldBeCached)
  27     {
  28         // TODO: check write access to the cache directory
  29         $this->cacheDir = $cacheDir;
  30         $this->filename = $this->cacheDir . '/' . sha1($url) . '.cache';
  31         $this->shouldBeCached = $shouldBeCached;
  32     }
  33
  34     /**
  35      * Returns the cached version of a page, if it exists and should be cached
  36      *
  37      * @return string a cached version of the page if it exists, null otherwise
  38      */
  39     public function cachedVersion()
  40     {
  41         if (!$this->shouldBeCached) {
  42             return null;
  43         }
  44         if (is_file($this->filename)) {
  45             return file_get_contents($this->filename);
  46         }
  47         return null;
  48     }
  49
  50     /**
  51      * Puts a page in the cache
  52      *
  53      * @param string $pageContent XML content to cache
  54      */
  55     public function cache($pageContent)
  56     {
  57         if (!$this->shouldBeCached) {
  58             return;
  59         }
  60         file_put_contents($this->filename, $pageContent);
  61     }
  62 }