1 files changed, 30 insertions, 19 deletions

diff --git a/engine/handlers/cache_handler.php b/engine/handlers/cache_handler.php
index 05c35171b..36fc665bb 100644
--- a/engine/handlers/cache_handler.php
+++ b/engine/handlers/cache_handler.php
@@ -3,7 +3,7 @@
  * Cache handler.
  *
  * External access to cached CSS and JavaScript views. The cached file URLS
- * should be of the form: cache/<type>/<view>/<viewtype>/<unique_id> where
+ * should be of the form: cache/<type>/<viewtype>/<name/of/view>.<unique_id>.<type> where
  * type is either css or js, view is the name of the cached view, and
  * unique_id is an identifier that is updated every time the cache is flushed.
  * The simplest way to maintain a unique identifier is to use the lastcache
@@ -50,45 +50,56 @@ if (!$request || !$simplecache_enabled) {
 	echo 'Cache error: bad request';
 	exit;
 }
-$request = explode('/', $request);
 
+// testing showed regex to be marginally faster than array / string functions over 100000 reps
+// it won't make a difference in real life and regex is easier to read.
+// <type>/<viewtype>/<name/of/view.and.dots>.<ts>.<type>
+$regex = '|([^/]+)/([^/]+)/(.+)\.([^\.]+)\.([^.]+)$|';
+preg_match($regex, $request, $matches);
 
-//cache/<type>/<view>/<viewtype>/
-$type = $request[0];
-$view = $request[1];
-$viewtype = $request[2];
+$type = $matches[1];
+$viewtype = $matches[2];
+$view = $matches[3];
+$ts = $matches[4];
+
+// If is the same ETag, content didn't changed.
+$etag = $ts;
+if (isset($_SERVER['HTTP_IF_NONE_MATCH']) && trim($_SERVER['HTTP_IF_NONE_MATCH']) == "\"$etag\"") {
+	header("HTTP/1.1 304 Not Modified");
+	exit;
+}
 
 switch ($type) {
 	case 'css':
 		header("Content-type: text/css", true);
-		header('Expires: ' . date('r', time() + 86400000), true);
-		header("Pragma: public", true);
-		header("Cache-Control: public", true);
-
 		$view = "css/$view";
 		break;
 	case 'js':
 		header('Content-type: text/javascript', true);
-		header('Expires: ' . date('r', time() + 864000000), true);
-		header("Pragma: public", true);
-		header("Cache-Control: public", true);
-
 		$view = "js/$view";
 		break;
 }
 
+header('Expires: ' . gmdate('D, d M Y H:i:s \G\M\T', strtotime("+6 months")), true);
+header("Pragma: public", true);
+header("Cache-Control: public", true);
+header("ETag: \"$etag\"");
+
 $filename = $dataroot . 'views_simplecache/' . md5($viewtype . $view);
 
 if (file_exists($filename)) {
-	$contents = file_get_contents($filename);
+	readfile($filename);
 } else {
 	// someone trying to access a non-cached file or a race condition with cache flushing
 	mysql_close($mysql_dblink);
 	require_once(dirname(dirname(__FILE__)) . "/start.php");
-	elgg_regenerate_simplecache();
+
+	global $CONFIG;
+	if (!in_array($view, $CONFIG->views->simplecache)) {
+		header("HTTP/1.1 404 Not Found");
+		exit;
+	}
 
 	elgg_set_viewtype($viewtype);
-	$contents = elgg_view($view);
+	echo elgg_view($view);
 }
-
-echo $contents;