Started ETag support

senchalabs · Sep 13, 2010 · 181c63d · 181c63d
1 parent 4b2b8d1
commit 181c63d
Showing 1 changed file with 32 additions and 6 deletions.
diff --git a/lib/connect/middleware/staticProvider.js b/lib/connect/middleware/staticProvider.js
@@ -85,7 +85,7 @@ module.exports = function staticProvider(options){
                 res.writeHead(200, hit.headers);
                 res.end(hit.body);
             } else {
-                notModified(res);
+                notModified(res, hit.headers);
             }
             return;
         }
@@ -112,12 +112,13 @@ module.exports = function staticProvider(options){
                     "Content-Type": utils.mime.type(filename),
                     "Content-Length": stat.size,
                     "Last-Modified": stat.mtime.toUTCString(),
-                    "Cache-Control": "public max-age=" + maxAge
+                    "Cache-Control": "public max-age=" + maxAge,
+                    "ETag": etag(stat)
                 };
 
                 // Conditional GET
                 if (!modified(req, headers)) {
-                    return notModified(res);
+                    return notModified(res, headers);
                 }
 
                 res.writeHead(200, headers);
@@ -154,7 +155,9 @@ module.exports = function staticProvider(options){
 
 function modified(req, headers) {
     var modifiedSince = req.headers['if-modified-since'],
-        lastModified = headers['Last-Modified'];
+        lastModified = headers['Last-Modified'],
+        noneMatch = req.headers['if-none-match'],
+        etag = headers['ETag'];
 
     // Check If-Modified-Since
     if (modifiedSince && lastModified) {
@@ -165,19 +168,42 @@ function modified(req, headers) {
             if (lastModified <= modifiedSince) return false;
         }
     }
+
+    // Check If-None-Match
+    if (noneMatch && etag && noneMatch == etag) {
+        return false;
+    }
 
     return true;
 }
 
+/**
+ * Return an ETag in the form of size-mtime.
+ *
+ * @param {Object} stat
+ * @return {String}
+ * @api private
+ */
+
+function etag(stat) {
+    return stat.size + '-' + Number(stat.mtime);
+}
+
 /**
  * Respond with 304 "Not Modified".
  *
  * @param {ServerResponse} res
+ * @param {Object} headers
  * @api private
  */
 
-function notModified(res) {
-    res.writeHead(304);
+function notModified(res, headers) {
+    Object.keys(headers).forEach(function(field){
+        if (0 == field.indexOf('Content')) {
+            delete headers[field];
+        }
+    });
+    res.writeHead(304, headers);
     res.end();
 }