application/feed/CachedPage.php

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