MDL-32683 fine tune theme style sheet caching

NoelDeMartin · May 5, 2012 · 2c61e7c · 2c61e7c
1 parent 8475b97
commit 2c61e7c
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Showing 2 changed files with 26 additions and 15 deletions.
diff --git a/lib/csslib.php b/lib/csslib.php
@@ -85,23 +85,28 @@ function css_store_css(theme_config $theme, $csspath, array $cssfiles) {
  *
  * @param string $themename The name of the theme we are sending CSS for.
  * @param string $rev The revision to ensure we utilise the cache.
+ * @param string $etag The revision to ensure we utilise the cache.
  * @param bool $slasharguments
  */
-function css_send_ie_css($themename, $rev, $slasharguments) {
-    $lifetime = 60*60*24*30; // 30 days
+function css_send_ie_css($themename, $rev, $etag, $slasharguments) {
+    global $CFG;
+
+    $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
+
+    $relroot = preg_replace('|^http.?://[^/]+|', '', $CFG->wwwroot);
 
     $css  = "/** Unfortunately IE6/7 does not support more than 4096 selectors in one CSS file, which means we have to use some ugly hacks :-( **/";
     if ($slasharguments) {
-        $css .= "\n@import url(styles.php/$themename/$rev/plugins);";
-        $css .= "\n@import url(styles.php/$themename/$rev/parents);";
-        $css .= "\n@import url(styles.php/$themename/$rev/theme);";
+        $css .= "\n@import url($relroot/styles.php/$themename/$rev/plugins);";
+        $css .= "\n@import url($relroot/styles.php/$themename/$rev/parents);";
+        $css .= "\n@import url($relroot/styles.php/$themename/$rev/theme);";
     } else {
-        $css .= "\n@import url(styles.php?theme=$themename&rev=$rev&type=plugins);";
-        $css .= "\n@import url(styles.php?theme=$themename&rev=$rev&type=parents);";
-        $css .= "\n@import url(styles.php?theme=$themename&rev=$rev&type=theme);";
+        $css .= "\n@import url($relroot/styles.php?theme=$themename&rev=$rev&type=plugins);";
+        $css .= "\n@import url($relroot/styles.php?theme=$themename&rev=$rev&type=parents);";
+        $css .= "\n@import url($relroot/styles.php?theme=$themename&rev=$rev&type=theme);";
     }
 
-    header('Etag: '.md5($rev));
+    header('Etag: '.$etag);
     header('Content-Disposition: inline; filename="styles.php"');
     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
@@ -122,11 +127,12 @@ function css_send_ie_css($themename, $rev, $slasharguments) {
  * request, then optimised/minified, and finally cached for serving.
  *
  * @param string $csspath The path to the CSS file we want to serve.
- * @param string $rev The revision to make sure we utilise any caches.
+ * @param string $etag The revision to make sure we utilise any caches.
  */
-function css_send_cached_css($csspath, $rev) {
-    $lifetime = 60*60*24*30; // 30 days
+function css_send_cached_css($csspath, $etag) {
+    $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 
+    header('Etag: '.$etag);
     header('Content-Disposition: inline; filename="styles.php"');
     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($csspath)) .' GMT');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');

diff --git a/theme/styles.php b/theme/styles.php
@@ -65,10 +65,11 @@
 }
 
 if ($type === 'ie') {
-    css_send_ie_css($themename, $rev, !empty($slashargument));
+    css_send_ie_css($themename, $rev, $etag, !empty($slashargument));
 }
 
 $candidatesheet = "$CFG->cachedir/theme/$themename/css/$type.css";
+$etag = sha1("$themename/$rev/$type");
 
 if (file_exists($candidatesheet)) {
     if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
@@ -79,9 +80,10 @@
         header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
         header('Cache-Control: public, max-age='.$lifetime);
         header('Content-Type: text/css; charset=utf-8');
+        header('Etag: '.$etag);
         die;
     }
-    css_send_cached_css($candidatesheet, $rev);
+    css_send_cached_css($candidatesheet, $etag);
 }
 
 //=================================================================================
@@ -95,6 +97,9 @@
 
 $theme = theme_config::load($themename);
 
+$rev = theme_get_revision();
+$etag = sha1("$themename/$rev/$type");
+
 if ($type === 'editor') {
     $cssfiles = $theme->editor_css_files();
     css_store_css($theme, $candidatesheet, $cssfiles);
@@ -119,4 +124,4 @@
     $cssfile = "$CFG->cachedir/theme/$themename/css/all.css";
     css_store_css($theme, $cssfile, $allfiles);
 }
-css_send_cached_css($candidatesheet, $rev);
+css_send_cached_css($candidatesheet, $etag);