Use vanilla HTTP handlers (refactoring)

http/response/response.go

@@ -0,0 +1,34 @@
+// Copyright 2018 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package response
+
+import (
+	"net/http"
+	"time"
+)
+
+// Redirect redirects the user to another location.
+func Redirect(w http.ResponseWriter, r *http.Request, path string) {
+	http.Redirect(w, r, path, http.StatusFound)
+}
+
+// NotModified sends a response with a 304 status code.
+func NotModified(w http.ResponseWriter) {
+	w.WriteHeader(http.StatusNotModified)
+}
+
+// Cache returns a response with caching headers.
+func Cache(w http.ResponseWriter, r *http.Request, mimeType, etag string, content []byte, duration time.Duration) {
+	w.Header().Set("Content-Type", mimeType)
+	w.Header().Set("ETag", etag)
+	w.Header().Set("Cache-Control", "public")
+	w.Header().Set("Expires", time.Now().Add(duration).Format(time.RFC1123))
+
+	if etag == r.Header.Get("If-None-Match") {
+		w.WriteHeader(http.StatusNotModified)
+	} else {
+		w.Write(content)
+	}
+}