use content hashes in URL of css/js files to do automatic, granular c…

…ache invalidation, instead of incrementing global cache_version
youngj · Jun 6, 2011 · f14492d · f14492d
1 parent 88f547e
commit f14492d
Show file tree

Hide file tree

Showing 6 changed files with 157 additions and 129 deletions.
diff --git a/config/default.php b/config/default.php
@@ -1,6 +1,5 @@
 <?php
 return array(
-    'cache_version' => 187,  // increment when css, or external js (tinymce/swfupload) changes
     'debug' => true,
 
     'dbuser' => '',
@@ -75,4 +74,6 @@
 
     'site_secret' => 'default_secret',
     'fallback_theme' => 'simple',
+
+    'cache_version' => 188,  // increment when all cached objects need to be invalidated (rare)
 );
diff --git a/engine/config.php b/engine/config.php
@@ -47,7 +47,8 @@ static function load()
         {
             static::$base_dir = dirname(__DIR__);            
             static::load_array(static::get_group('default'));                        
-            static::load_array(static::get_group('local'));                        
+            static::load_array(static::get_group('local'));
+            static::load_array(@include(static::$base_dir."/build/config.php"));
             static::init_dependent_settings();
 
             // The ENVAYA_CONFIG environment variable may define settings in a JSON string
@@ -60,11 +61,11 @@ static function load()
     }
 
     private static function load_array($settings, $overwrite = true)
-    {
-        $all_settings =& static::$settings;
-
+    {    
         if ($settings)
         {
+            $all_settings =& static::$settings;
+
             if (!$all_settings)
             {
                 $all_settings = $settings;

diff --git a/lib/util.php b/lib/util.php
@@ -80,15 +80,13 @@ function secure_url($url)
 
     function css_url($css_name)
     {
-        $cache_version = Config::get('cache_version');
-
         if (Config::get('debug'))
         {
-            return "/pg/css?name=$css_name&v=$cache_version";
+            return "/pg/css?name=$css_name&hash=" . md5(view("css/$css_name", 'default'));
         }
         else
         {
-            return "/_media/css/$css_name.css?$cache_version";
+            return "/_media/css/$css_name.css?".Config::get("hash:css:$css_name");
         }        
     }     
 

diff --git a/make.php b/make.php
@@ -13,65 +13,48 @@
 require_once "scripts/cmdline.php";
 
 class Build
-{
-    private static function module_glob()
-    {
-        return "{".implode(',',Config::get('modules'))."}";
-    }    
-
-    private static function minify($srcFile, $destFile, $type='js')
+{    
+    static function all()
     {
-        $src = file_get_contents($srcFile);
-
-        system("java -jar vendors/yuicompressor-2.4.2.jar --type $type -o ".escapeshellarg($destFile). " ".escapeshellarg($srcFile));
-
-        $compressed = file_get_contents($destFile);
-
-        echo strlen($src)." ".strlen($compressed)." $destFile\n";  
+        Build::path_cache();
+        Build::media();
+        Build::css();
+        Build::js();
     }
 
+    /*
+     * Removes all files generated by make.php
+     */
     static function clean()
     {
-        @unlink("build/lib_cache.php");
-        @unlink("build/path_cache.php");
-        @unlink("build/path_cache_info.php");
-
+        system('rm -rf build/*.php');
         system('rm -rf build/path_cache');
         system('rm -rf www/_media/*');        
     }
 
-    /*
-     * Generates a cache of all the paths of files in the lib/ directory.
-     *
-     * Uses relative paths so the same cache files work in any root directory
-     * and can be copied to different systems without needing to regenerate them.
-     */
-    static function lib_cache()
-    {
-        @unlink("build/lib_cache.php");
-
-        require_once "start.php";
-        $paths = Engine::get_lib_paths();  
-        static::write_file("build/lib_cache.php", static::get_array_php($paths));
-    }
-
     /*
      * Generates a cache of all the paths of files in the engine, themes, languages, and views
      * directories, which might be referenced via virtual paths in calls to Engine::get_real_path() .
      * This cache allows Engine::get_real_path() to work in O(1) time instead of O(num_modules) time.
      *
+     * Also generates a cache of all the paths of files in the lib/ directory.
+     *
      * Uses relative paths so the same cache files work in any root directory
      * and can be copied to different systems without needing to regenerate them.
      */    
     static function path_cache()
     {
+        // remove previous build files before including start.php
+        // so that Engine class doesn't use previous path cache when building the new path cache
+        @unlink("build/lib_cache.php");
+        @unlink("build/path_cache.php");
+        system('rm -rf build/path_cache');
+
         require_once "start.php";
-
-        if (!is_dir('build/path_cache'))
-        {
-            mkdir('build/path_cache');
-        }
-
+
+        $paths = Engine::get_lib_paths();  
+        static::write_file("build/lib_cache.php", static::get_array_php($paths));        
+
         $dir_paths = array(
             // allows us to test if the path cache actually works like it should
             'views/default/admin' => array(            
@@ -98,6 +81,7 @@ static function path_cache()
         static::add_nonexistent_view_paths($dir_paths);
 
         // create a cache file for each virtual directory
+        mkdir('build/path_cache'); 
         foreach ($dir_paths as $dir => $paths)
         {
             $cache_name = str_replace('/','__', $dir);
@@ -142,6 +126,101 @@ static function path_cache()
         static::write_file("build/path_cache_info.php", 
             "<div>The path cache is enabled. ($num_default_paths default paths + $num_files files)</div>");
     }
+
+    /* 
+     * Minifies all CSS files defined in each module's views/default/css/ directory, 
+     * and copies to www/_media/css/.
+     */       
+    static function css($name = '*')
+    {    
+        require_once "start.php";
+
+        $modules = static::module_glob();
+        $css_paths = glob("{views/default/css/$name.php,mod/$modules/views/default/css/$name.php}", GLOB_BRACE);
+
+        $output_dir = 'www/_media/css';
+
+        if (!is_dir($output_dir))
+        {
+            mkdir($output_dir);
+        }
+
+        $build_config = static::get_build_config();
+
+        foreach ($css_paths as $css_path)
+        {
+            $pathinfo = pathinfo($css_path);
+            $filename = $pathinfo['filename'];
+            $css_temp = "scripts/$filename.tmp.css";
+            $raw_css = view("css/$filename");
+
+            if (preg_match('/http(s)?:[^\s\)\"\']*/', $raw_css, $matches))
+            {
+                throw new Exception("Absolute URL {$matches[0]} found in $css_path. In order to work on both dev/production without recompiling, CSS files must not contain absolute paths.");
+            }
+
+            file_put_contents($css_temp, $raw_css);
+            $compressed = static::minify($css_temp, "$output_dir/$filename.css", 'css');
+            unlink($css_temp);
+
+            $build_config["hash:css:$filename"] = static::get_content_hash($compressed);
+        }
+
+        static::write_build_config($build_config);
+    }
+
+    /* 
+     * Minifies Javascript in each module's js/ directory, and copie to www/_media/.
+     */   
+    static function js($name = '*')
+    {    
+        require_once "start.php";
+        $modules = static::module_glob();
+
+        static::js_minify_dir(".", $name);
+
+        foreach (Config::get('modules') as $module)
+        {            
+            static::js_minify_dir("mod/$module", $name);
+        }
+    }
+
+    /* 
+     * Copies static files from each module's _media/ directory to www/_media/.
+     */
+    static function media()
+    {
+        require_once "start.php";
+
+        static::system("rsync -rp _media/ www/_media/");
+
+        foreach (Config::get('modules') as $module)
+        {            
+            if (is_dir("mod/$module/_media"))
+            {
+                static::system("rsync -rp mod/$module/_media/ www/_media/");
+            }
+        }
+    }
+
+    private static function module_glob()
+    {
+        return "{".implode(',',Config::get('modules'))."}";
+    }    
+
+    private static function minify($srcFile, $destFile, $type='js')
+    {
+        $src = file_get_contents($srcFile);
+
+        system("java -jar vendors/yuicompressor-2.4.2.jar --type $type -o ".escapeshellarg($destFile). " ".escapeshellarg($srcFile));
+
+        $compressed = file_get_contents($destFile);
+
+        echo strlen($src)." ".strlen($compressed)." $destFile\n";  
+
+        return $compressed;
+    }
+
 
     private static function add_nonexistent_view_paths(&$dir_paths)
     {
@@ -228,40 +307,25 @@ private static function get_array_php($arr)
         return "<?php return ".var_export($arr, true).";";
     }
 
-    /* 
-     * Minifies all CSS files defined in each module's views/default/css/ directory, 
-     * and copies to www/_media/css/.
-     */       
-    static function css($name = '*')
+    private static function get_build_config()
+    {
+        return @include("build/config.php") ?: array();
+    }
+
+    private static function write_build_config($build_config)
+    {
+        static::write_file("build/config.php", static::get_array_php($build_config));
+    }
+
+    /*
+     * Returns a short hash code that can be used as part of a file's URL, to ensure that
+     * browser/proxy caches are invalidated automatically whenever the content is changed.
+     */
+    private static function get_content_hash($content)
     {    
-        require_once "start.php";
-
-        $modules = static::module_glob();
-        $css_paths = glob("{views/default/css/$name.php,mod/$modules/views/default/css/$name.php}", GLOB_BRACE);
-
-        $output_dir = 'www/_media/css';
-
-        if (!is_dir($output_dir))
-        {
-            mkdir($output_dir);
-        }
-
-        foreach ($css_paths as $css_path)
-        {
-            $pathinfo = pathinfo($css_path);
-            $filename = $pathinfo['filename'];
-            $css_temp = "scripts/$filename.tmp.css";
-            $raw_css = view("css/$filename");
-
-            if (preg_match('/http(s)?:[^\s\)\"\']*/', $raw_css, $matches))
-            {
-                throw new Exception("Absolute URL {$matches[0]} found in $css_path. In order to work on both dev/production without recompiling, CSS files must not contain absolute paths.");
-            }
-
-            file_put_contents($css_temp, $raw_css);
-            static::minify($css_temp, "$output_dir/$filename.css", 'css');
-            unlink($css_temp);
-        }
+        // 16^10 hash values should be enough to avoid collisions within an Expires timeout of 1 year    
+        // (not important to avoid intentional collisions)
+        return substr(md5($content), 0, 10);            
     }
 
     private static function js_minify_dir($base, $name = '*', $dir = '')
@@ -270,7 +334,15 @@ private static function js_minify_dir($base, $name = '*', $dir = '')
         foreach ($js_src_files as $js_src_file)
         {
             $basename = pathinfo($js_src_file,  PATHINFO_BASENAME);
-            static::minify($js_src_file, "www/_media/{$dir}{$basename}");
+            $compressed = static::minify($js_src_file, "www/_media/{$dir}{$basename}");
+
+            if ($dir != 'inline/') // inline JS does not need content hashes because it is never loaded by URL
+            {
+                $filename = pathinfo($js_src_file, PATHINFO_FILENAME);
+                $build_config = static::get_build_config();
+                $build_config["hash:js:$filename"] = static::get_content_hash($compressed);
+                static::write_build_config($build_config);
+            }
         }
 
         $subdirs = glob("$base/js/{$dir}*", GLOB_ONLYDIR);
@@ -285,56 +357,12 @@ private static function js_minify_dir($base, $name = '*', $dir = '')
             static::js_minify_dir($base, $name, "{$dir}{$basename}/");
         }
     }
-
-    /* 
-     * Minifies Javascript in each module's js/ directory, and copie to www/_media/.
-     */   
-    static function js($name = '*')
-    {    
-        require_once "start.php";
-        $modules = static::module_glob();
-
-        static::js_minify_dir(".", $name);
-
-        foreach (Config::get('modules') as $module)
-        {            
-            static::js_minify_dir("mod/$module", $name);
-        }
-    }
 
     static function system($cmd)
     {
         echo "$cmd\n";
         return system($cmd);
-    }
-
-    /* 
-     * Copies static files from each module's _media/ directory to www/_media/.
-     */
-    static function media()
-    {
-        require_once "start.php";
-
-        static::system("rsync -rp _media/ www/_media/");
-
-        foreach (Config::get('modules') as $module)
-        {            
-            if (is_dir("mod/$module/_media"))
-            {
-                static::system("rsync -rp mod/$module/_media/ www/_media/");
-            }
-        }
-    }
-
-    static function all()
-    {
-        Build::clean();
-        Build::media();
-        Build::lib_cache();
-        Build::path_cache();
-        Build::css();
-        Build::js();
-    }
+    }    
 }
 
 $target = @$argv[1] ?: 'all';

diff --git a/views/default/input/tinymce.php b/views/default/input/tinymce.php
@@ -58,7 +58,7 @@
             echo view('js/create_modal_box');         
             echo view('js/dom'); 
         ?></script>
-        <script type='text/javascript' src='/_media/tiny_mce/tiny_mce.js?v<?php echo Config::get('cache_version'); ?>'></script>
+        <script type='text/javascript' src='/_media/tiny_mce/tiny_mce.js?v<?php echo Config::get('hash:js:tiny_mce'); ?>'></script>
         <?php                
     }