Implemented a cache for documentation.

manual/new/Cache.php

+<?php
+
+class Cache
+{
+    protected $_dir;
+    protected $_ext;
+    protected $_page;
+    protected $_file; 
+    protected $_timeToLive;
+
+    public function __construct($dir, $ext, $timeToLive)
+    {
+        $this->_dir = $dir;
+        $this->_ext = $ext;
+        $this->_timeToLive = $timeToLive;
+        
+        $this->_page = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
+        $this->_file = $this->_dir . md5($this->_page) . '.' . $this->_ext;  
+    }
+    
+    /**
+     * Begins caching the output.
+     *
+     * @return A boolean value indicating whether a valid cached version of the
+     *         page was found and echoed (false), or not (true).
+     */
+    public function begin()
+    {
+        $showCache = (file_exists($this->_file) && $this->isValid());
+        clearstatcache();
+         
+        if ($showCache) {
+            readfile($this->_file);
+            return false;
+        } else {
+            ob_start();
+            return true;
+        }
+    }
+    
+    /**
+     * Ends caching the output and saves it to a cache file.
+     * 
+     */
+    public function end()
+    {
+        // Generate a new cache file
+        $fp = @fopen($this->_file, 'w');
+        
+        // Save the contents of output buffer to the file
+        @fwrite($fp, ob_get_contents());
+        @fclose($fp);
+        
+        ob_end_flush();
+    }
+
+    /**
+     * Deletes all files in the cache directory.
+     */    
+    public function clear()
+    {
+        if ($handle = opendir($this->dir)) {
+            while ($file = readdir($handle)) {
+                if ($file !== '.' && $file !== '..') {
+                    unlink($this->dir . '/' . $file);
+                }
+            }
+            closedir($handle);
+        }
+    }
+    
+    /**
+     * This method is used to check whether the cache file is valid to use.
+     * 
+     * Currently it compares the modification date of the cache file to the
+     * time-to-live value.
+     * 
+     * @return True, if cache file is valid; false otherwise.
+     */
+    protected function isValid()
+    {
+        return (time() - filemtime($this->_file)) < $this->_timeToLive;
+    }
+}
\ No newline at end of file

manual/new/index.php

@@ -7,47 +7,66 @@ set_include_path($includePath);
 
 require_once('Sensei/Sensei.php');
 require_once('DocTool.php');
+require_once('Cache.php');
 
 spl_autoload_register(array('Sensei', 'autoload'));
 
-$tool = new DocTool('docs/en/root.txt');
-// $tool->setOption('clean-url', true);
-
-$supportedLangs = array('en', 'fi');
-foreach ($supportedLangs as $language) {
-    include "lang/$language.php";
-    $tool->addLanguage($lang[$language], $language);
+// Executes the svn info command for the current directory and parses the last
+// changed date in order to calculate the time-to-live value for cache.
+$timeToLive = 0;
+exec('svn info .', $output);
+foreach ($output as $line) {
+    if (preg_match('/^Last Changed Date: (.*) \(.*\)$/', $line, $matches)) {
+        $timeToLive = time() - strtotime($matches[1]);
+        break;
+    }
 }
 
-$baseUrl = '';
-$title = 'Doctrine Manual';
-$section = null;
+$cache = new Cache('./cache/', 'cache', $timeToLive);
 
-if (isset($_GET['chapter'])) {
-    $section = $tool->findByPath($_GET['chapter']);
-    if ($tool->getOption('clean-url')) {
-        $baseUrl = '../';
-    }
-}
+if ($cache->begin()) { 
 
-if (isset($_GET['one-page'])) {
-    $tool->setOption('one-page', true);
-    $tool->setOption('max-level', 0);
-    $section = null;
+    $tool = new DocTool('docs/en/root.txt');
+    // $tool->setOption('clean-url', true);
+    
+    $supportedLangs = array('en', 'fi');
+    foreach ($supportedLangs as $language) {
+        include "lang/$language.php";
+        $tool->addLanguage($lang[$language], $language);
+    }
+    
     $baseUrl = '';
-}
-
-if ($section) {
-    while ($section->getLevel() > 1) {
-        $section = $section->getParent();
+    $title = 'Doctrine Manual';
+    $section = null;
+    
+    if (isset($_GET['chapter'])) {
+        $section = $tool->findByPath($_GET['chapter']);
+        if ($tool->getOption('clean-url')) {
+            $baseUrl = '../';
+        }
     }
-        
-    $tool->setOption('section', $section);
-    $title .= ' - Chapter ' . $section->getIndex() . ' ' . $section->getName();
-}
-
-if ($tool->getOption('clean-url')) {
-    $tool->setOption('base-url', $baseUrl);
+    
+    if (isset($_GET['one-page'])) {
+        $tool->setOption('one-page', true);
+        $tool->setOption('max-level', 0);
+        $section = null;
+        $baseUrl = '';
+    }
+    
+    if ($section) {
+        while ($section->getLevel() > 1) {
+            $section = $section->getParent();
+        }
+            
+        $tool->setOption('section', $section);
+        $title .= ' - Chapter ' . $section->getIndex() . ' ' . $section->getName();
+    }
+    
+    if ($tool->getOption('clean-url')) {
+        $tool->setOption('base-url', $baseUrl);
+    }
+    
+    include 'template.php';
+    
+    $cache->end();
 }
-
-include 'template.php';