Add capability to send pre-compressed js & css files if the browser can accept them

- save a gzipped version of js & css files at the same time as the uncompressed version is cache
- basic content negotiation to send the compressed files
- uses sendfile (for compressed or uncompressed versions) if config indicates its available

darcs-hash:20090118184354-f07c6-66c5b465ab147d83de409708bab2c47d1dafcf8d.gz

1 files changed, 22 insertions, 0 deletions

diff --git a/inc/pageutils.php b/inc/pageutils.php
index 1fdb4f2d0..5fea66942 100644
--- a/inc/pageutils.php
+++ b/inc/pageutils.php
@@ -578,6 +578,9 @@ function http_conditionalRequest($timestamp){
   exit;
 }
 
+/**
+ *   common routines for handling communication with the client (browser)
+ */
 function http_sendfile($file) {
   global $conf;
 
@@ -596,4 +599,23 @@ function http_sendfile($file) {
   return false;
 }
 
+function http_accepts_gzip() {
+  return !empty($_SERVER['HTTP_ACCEPT_ENCODING']) && (strpos($_SERVER['HTTP_ACCEPT_ENCODING'],'gzip') !== false);
+}
+
+function http_accepts_deflate() {
+  return !empty($_SERVER['HTTP_ACCEPT_ENCODING']) && (strpos($_SERVER['HTTP_ACCEPT_ENCODING'],'deflate') !== false);    
+}
+/**
+ * return true if there exists a gzip version of the uncompressed file (samepath/samefilename.sameext.gz)
+ * created after the uncompressed file
+ */
+function http_gzip_valid($uncompressed_file) {
+  $gzip = $uncompressed_file.'.gz';
+  if (filemtime($gzip) < filemtime($uncompressed_file)) {    // filemtime returns false (0) if file doesn't exist
+    return copy($uncompressed_file, 'compress.zlib://'.$gzip);
+  }
+
+  return true;
+}
 //Setup VIM: ex: et ts=2 enc=utf-8 :