From b082c3e0482da9f875e82a57f9d01e7d2029562e Mon Sep 17 00:00:00 2001
From: Nazar Kanaev <nkanaev@live.com>
Date: Fri, 2 Apr 2021 17:28:41 +0100
Subject: [PATCH] gzip middleware

---
 src/server/gzip/middleware.go | 42 +++++++++++++++++++++++++++++++++++
 src/server/routes.go          |  4 +++-
 2 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 src/server/gzip/middleware.go

diff --git a/src/server/gzip/middleware.go b/src/server/gzip/middleware.go
new file mode 100644
index 0000000..ccf971b
--- /dev/null
+++ b/src/server/gzip/middleware.go
@@ -0,0 +1,42 @@
+package gzip
+
+import (
+	"compress/gzip"
+	"net/http"
+	"strings"
+
+	"github.com/nkanaev/yarr/src/server/router"
+)
+
+type gzipResponseWriter struct {
+	http.ResponseWriter
+
+	out *gzip.Writer
+	src http.ResponseWriter
+}
+
+func (rw *gzipResponseWriter) Header() http.Header {
+	return rw.src.Header()
+}
+
+func (rw *gzipResponseWriter) Write(x []byte) (int, error) {
+	return rw.out.Write(x)
+}
+
+func (rw *gzipResponseWriter) WriteHeader(statusCode int) {
+	rw.src.WriteHeader(statusCode)
+}
+
+func Middleware(c *router.Context) {
+	if strings.Contains(c.Req.Header.Get("Accept-Encoding"), "gzip") {
+		gz := &gzipResponseWriter{out: gzip.NewWriter(c.Out), src: c.Out}
+		defer gz.out.Close()
+
+		c.Out.Header().Set("Content-Encoding", "gzip")
+		c.Out = gz
+		c.Next()
+
+		return
+	}
+	c.Next()
+}
diff --git a/src/server/routes.go b/src/server/routes.go
index a184494..245feee 100644
--- a/src/server/routes.go
+++ b/src/server/routes.go
@@ -14,6 +14,7 @@ import (
 	"github.com/nkanaev/yarr/src/content/sanitizer"
 	"github.com/nkanaev/yarr/src/content/silo"
 	"github.com/nkanaev/yarr/src/server/auth"
+	"github.com/nkanaev/yarr/src/server/gzip"
 	"github.com/nkanaev/yarr/src/server/opml"
 	"github.com/nkanaev/yarr/src/server/router"
 	"github.com/nkanaev/yarr/src/storage"
@@ -23,6 +24,8 @@ import (
 func (s *Server) handler() http.Handler {
 	r := router.NewRouter(s.BasePath)
 
+	r.Use(gzip.Middleware)
+
 	if s.Username != "" && s.Password != "" {
 		a := &auth.Middleware{
 			BasePath: s.BasePath,
@@ -62,7 +65,6 @@ func (s *Server) handleIndex(c *router.Context) {
 }
 
 func (s *Server) handleStatic(c *router.Context) {
-	// TODO: gzip?
 	// don't serve templates
 	dir, name := filepath.Split(c.Vars["path"])
 	if dir == "" && strings.HasSuffix(name, ".html") {