Get the metadata from Redis on a HEAD request

No need to hit the storage backend, we can set the response headers from
the data in Redis

lib/remote_storage/rest_provider.rb

@@ -36,23 +36,30 @@ module RemoteStorage
     end
 
     def get_head(user, directory, key)
-      url = url_for_key(user, directory, key)
+      none_match = (server.env["HTTP_IF_NONE_MATCH"] || "").split(",")
+                                                           .map(&:strip)
+                                                           .map { |s| s.gsub(/^"?W\//, "") }
+      metadata = redis.hgetall redis_metadata_object_key(user, directory, key)
 
-      res = do_head_request(url)
+      server.halt 404 if metadata.empty?
 
-      set_response_headers(res)
-    rescue RestClient::ResourceNotFound
-      server.halt 404
+      # Set the response headers for a 304 or 200 response
+      server.headers["ETag"]           = %Q("#{metadata["e"]}")
+      server.headers["Last-Modified"]  = Time.at(metadata["m"].to_i / 1000).httpdate
+
+      if none_match.include? %Q("#{metadata["e"]}")
+        server.halt 304
+      end
     end
 
     def get_data(user, directory, key)
       none_match = (server.env["HTTP_IF_NONE_MATCH"] || "").split(",")
                                                            .map(&:strip)
                                                            .map { |s| s.gsub(/^"?W\//, "") }
-      existing_metadata = redis.hgetall redis_metadata_object_key(user, directory, key)
-      if none_match.include? %Q("#{existing_metadata["e"]}")
-        server.headers["ETag"]           = %Q("#{existing_metadata["e"]}")
-        server.headers["Last-Modified"]  = Time.at(existing_metadata["m"].to_i / 1000).httpdate
+      metadata = redis.hgetall redis_metadata_object_key(user, directory, key)
+      if none_match.include? %Q("#{metadata["e"]}")
+        server.headers["ETag"]           = %Q("#{metadata["e"]}")
+        server.headers["Last-Modified"]  = Time.at(metadata["m"].to_i / 1000).httpdate
         server.halt 304
       end
 

spec/s3/app_spec.rb

@@ -815,7 +815,7 @@ describe "App" do
         header "Authorization", "Bearer amarillo"
 
         put_stub = OpenStruct.new(headers: {
-          etag: "bla"
+          etag: "0815etag"
         })
 
         RestClient.stub :put, put_stub do
@@ -838,20 +838,45 @@ describe "App" do
       end
 
       describe "documents" do
-        it "returns a 404 when the document doesn't exist" do
-          raises_exception = ->(url, headers) { raise RestClient::ResourceNotFound.new }
-          RestClient.stub :head, raises_exception do
+        context "when the document doesn't exist" do
+          it "returns a 404" do
             head "/phil/food/steak"
-          end
 
             last_response.status.must_equal 404
             last_response.body.must_be_empty
           end
         end
 
+        context "when the document exists" do
+          it "returns the required response headers" do
+            head "/phil/food/aguacate"
+
+            last_response.status.must_equal 200
+            last_response.headers["ETag"].must_equal "\"0815etag\""
+            last_response.headers["Cache-Control"].must_equal "no-cache"
           end
 
+          it "responds with 304 when IF_NONE_MATCH header contains the ETag" do
+            header "If-None-Match", "\"0815etag\""
+
+            head "/phil/food/aguacate"
+
+            last_response.status.must_equal 304
+            last_response.headers["ETag"].must_equal "\"0815etag\""
+            last_response.headers["Last-Modified"].must_equal "Fri, 04 Mar 2016 12:20:18 GMT"
           end
 
-end
+          it "responds with 304 when IF_NONE_MATCH header contains weak ETAG matching the current ETag" do
+            header "If-None-Match", "W/\"0815etag\""
 
+            head "/phil/food/aguacate"
+
+            last_response.status.must_equal 304
+            last_response.headers["ETag"].must_equal "\"0815etag\""
+            last_response.headers["Last-Modified"].must_equal "Fri, 04 Mar 2016 12:20:18 GMT"
+          end
+        end
+      end
+    end
+  end
+end

spec/swift/app_spec.rb

@@ -773,7 +773,7 @@ describe "App" do
         header "Authorization", "Bearer amarillo"
 
         put_stub = OpenStruct.new(headers: {
-          etag: "bla",
+          etag: "0815etag",
           last_modified: "Fri, 04 Mar 2016 12:20:18 GMT"
         })
 
@@ -795,20 +795,46 @@ describe "App" do
       end
 
       describe "documents" do
-        it "returns a 404 when the document doesn't exist" do
-          raises_exception = ->(url, headers) { raise RestClient::ResourceNotFound.new }
-          RestClient.stub :head, raises_exception do
+        context "when the document doesn't exist" do
+          it "returns a 404" do
             head "/phil/food/steak"
-          end
 
             last_response.status.must_equal 404
             last_response.body.must_be_empty
           end
         end
 
+        context "when the document exists" do
+          it "returns the required response headers" do
+            head "/phil/food/aguacate"
+
+            last_response.status.must_equal 200
+            last_response.headers["ETag"].must_equal "\"0815etag\""
+            last_response.headers["Cache-Control"].must_equal "no-cache"
           end
 
+          it "responds with 304 when IF_NONE_MATCH header contains the ETag" do
+            header "If-None-Match", "\"0815etag\""
+
+            head "/phil/food/aguacate"
+
+            last_response.status.must_equal 304
+            last_response.headers["ETag"].must_equal "\"0815etag\""
+            last_response.headers["Last-Modified"].must_equal "Fri, 04 Mar 2016 12:20:18 GMT"
           end
 
+          it "responds with 304 when IF_NONE_MATCH header contains weak ETAG matching the current ETag" do
+            header "If-None-Match", "W/\"0815etag\""
+
+            head "/phil/food/aguacate"
+
+            last_response.status.must_equal 304
+            last_response.headers["ETag"].must_equal "\"0815etag\""
+            last_response.headers["Last-Modified"].must_equal "Fri, 04 Mar 2016 12:20:18 GMT"
+          end
+        end
+      end
+    end
+  end
 end