Cacheoutput : first version : easy method to cache the HTML pages

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@1567 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

cacheoutput.php

@@ -0,0 +1,62 @@
+<?php
+/** This class permit to cache the ouptut of a code. If the cache is already
+    available, use it.
+    It resend the headers as the ouptut send them */
+class cacheoutput
+{
+  /** Record if the saving of pages is on going */
+  private $saving = false;
+  /** The called id */
+  private $id = null;
+  /** The called ttl */
+  private $ttl = null;
+  /** The cache object */
+  private $cache = null;
+  /** Current path at start due to lack of information in __destruct*/
+  private $cacheCWD = null;
+
+  /** 
+      @param string $id The cache identifier
+      @param integer|null $ttl The cache Time to Leave in seconds (3600s by
+                               default)
+      @param string|null $method The cache method to use */
+  public function __construct ($id, $ttl=60, $method="file")
+  {
+    $res = @include ("domframework/cache$method.php");
+    if ($res === false)
+      throw new Exception (sprintf (_("Unkwnown cache method : "), $method),
+                           500);
+    $this->id = $id;
+    $this->ttl = $ttl;
+    $this->cacheCWD = getcwd();
+    $cachemethod = "cache$method";
+    $this->cache = new $cachemethod ();
+    $res = $this->cache->read ($id);
+    // If there is a cache : display it
+    if ($res !== false)
+    {
+      foreach ($res["headers"] as $header)
+        @header ($header);
+      echo $res["content"];
+      exit;
+    }
+
+    ob_start ();
+    $this->saving = true;
+    // The datas are sent automatically
+  }
+
+  /** End of saving the datas in cache */
+  public function __destruct ()
+  {
+    // Force the path because it return to / in the destructor
+    chdir ($this->cacheCWD);
+    if ($this->saving === true)
+    {
+      // Do the saving of the datas
+      $datas = array ("content"=>ob_get_contents (),
+                      "headers"=>headers_list ());
+      $this->cache->write ($this->id, $datas, $this->ttl);
+    }
+  }
+}