0001-Pass-cache-headers-on-to-S3-and-back-to-client.patch

From 656f4c678b0c5fb7f40b758bf4d8a8cf884f2ce9 Mon Sep 17 00:00:00 2001
From: Eric Lindvall <[email protected]>
Date: Mon, 21 Sep 2009 18:33:53 -0700
Subject: [PATCH] Pass cache headers on to S3 and back to client.

This should allow varnish to serve the body of most requests after checking
freshness with the authoritative source.
---
 app/metal/hostess.rb |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/app/metal/hostess.rb b/app/metal/hostess.rb
index 1c89d36..db81d16 100644
--- a/app/metal/hostess.rb
+++ b/app/metal/hostess.rb
@@ -13,7 +13,20 @@ class Hostess < Sinatra::Default
       if redirect
         redirect File.join("http://s3.amazonaws.com", VaultObject.current_bucket, request.path_info)
       else
-        VaultObject.value(request.path_info)
+        # Query S3
+        result = VaultObject.value(request.path_info,
+                                    :if_modified_since => env['HTTP_IF_MODIFIED_SINCE'],
+                                    :if_none_match => env['HTTP_IF_NONE_MATCH'])
+
+        # These should raise a 304 if either of them match
+        last_modified(result.response['last-modified']) if result.response['last-modified']
+        etag(result.response['etag'])                   if result.response['etag']
+
+        # If we got a 304 back, let's give it back to the client
+        halt 304 if result.response.code == 304
+
+        # Otherwise return the result back
+        result
       end
     end
   end
-- 
1.6.3.2