1 files changed, 41 insertions, 25 deletions

diff --git a/engine/handlers/cache_handler.php b/engine/handlers/cache_handler.php
index 557b37835..36fc665bb 100644
--- a/engine/handlers/cache_handler.php
+++ b/engine/handlers/cache_handler.php
@@ -1,15 +1,15 @@
 <?php
 /**
  * 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
  * variable in Elgg's config object.
  *
- * @see elgg_view_register_simplecache()
+ * @see elgg_register_simplecache_view()
  *
  * @package Elgg.Core
  * @subpackage Cache
@@ -28,62 +28,78 @@ if (!mysql_select_db($CONFIG->dbname, $mysql_dblink)) {
 	exit;
 }
 
-$query = "select name, value from {$CONFIG->dbprefix}datalists where name = 'dataroot'";
+$query = "select name, value from {$CONFIG->dbprefix}datalists
+		where name in ('dataroot', 'simplecache_enabled')";
+
 $result = mysql_query($query, $mysql_dblink);
 if (!$result) {
 	echo 'Cache error: unable to get the data root';
 	exit;
 }
-$row = mysql_fetch_object($result);
-$dataroot = $row->value;
-
+while ($row = mysql_fetch_object($result)) {
+	${$row->name} = $row->value;
+}
+mysql_free_result($result);
 
 
 $dirty_request = $_GET['request'];
 // only alphanumeric characters plus /, ., and _ and no '..'
 $filter = array("options" => array("regexp" => "/^(\.?[_a-zA-Z0-9\/]+)+$/"));
 $request = filter_var($dirty_request, FILTER_VALIDATE_REGEXP, $filter);
-if (!$request) {
+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");
+
+	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;