1 files changed, 27 insertions, 0 deletions
diff --git a/lib/rack/runtime.rb b/lib/rack/runtime.rb
new file mode 100644
index 00000000..1bd411fd
--- /dev/null
+++ b/lib/rack/runtime.rb
@@ -0,0 +1,27 @@
+module Rack
+  # Sets an "X-Runtime" response header, indicating the response
+  # time of the request, in seconds
+  #
+  # You can put it right before the application to see the processing
+  # time, or before all the other middlewares to include time for them,
+  # too.
+  class Runtime
+    def initialize(app, name = nil)
+      @app = app
+      @header_name = "X-Runtime"
+      @header_name << "-#{name}" if name
+    end
+
+    def call(env)
+      start_time = Time.now
+      status, headers, body = @app.call(env)
+      request_time = Time.now - start_time
+
+      if !headers.has_key?(@header_name)
+        headers[@header_name] = "%0.6f" % request_time
+      end
+
+      [status, headers, body]
+    end
+  end
+end