Compress HTML responses to Gzip/Deflate if supported by browser

http/response/html/html.go

@@ -7,13 +7,14 @@ package html
 import (
 	"net/http"
 
+	"github.com/miniflux/miniflux/http/response"
 	"github.com/miniflux/miniflux/logger"
 )
 
 // OK writes a standard HTML response.
-func OK(w http.ResponseWriter, b []byte) {
+func OK(w http.ResponseWriter, r *http.Request, b []byte) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	w.Write(b)
+	response.Compress(w, r, b)
 }
 
 // ServerError sends a 500 error to the browser.

http/response/response.go

@@ -5,7 +5,10 @@
 package response
 
 import (
+	"compress/flate"
+	"compress/gzip"
 	"net/http"
+	"strings"
 	"time"
 )
 
@@ -32,3 +35,23 @@ func Cache(w http.ResponseWriter, r *http.Request, mimeType, etag string, conten
 		w.Write(content)
 	}
 }
+
+// Compress the response sent to the browser.
+func Compress(w http.ResponseWriter, r *http.Request, data []byte) {
+	acceptEncoding := r.Header.Get("Accept-Encoding")
+
+	switch {
+	case strings.Contains(acceptEncoding, "gzip"):
+		w.Header().Set("Content-Encoding", "gzip")
+		gzipWriter := gzip.NewWriter(w)
+		defer gzipWriter.Close()
+		gzipWriter.Write(data)
+	case strings.Contains(acceptEncoding, "deflate"):
+		w.Header().Set("Content-Encoding", "deflate")
+		flateWriter, _ := flate.NewWriter(w, -1)
+		defer flateWriter.Close()
+		flateWriter.Write(data)
+	default:
+		w.Write(data)
+	}
+}