Update and evaluate caching headers when returning buddy images.

src/app/spreed-speakfreely-server/main.go

@@ -22,6 +22,7 @@ package main
 
 import (
 	"app/spreed-speakfreely-server/sleepy"
+	"bytes"
 	"flag"
 	"fmt"
 	"github.com/gorilla/mux"
@@ -98,13 +99,16 @@ func makeImageHandler(hub *Hub, expires time.Duration) http.HandlerFunc {
 		}
 
 		w.Header().Set("Content-Type", image.mimetype)
-		w.Header().Set("Content-Length", strconv.Itoa(len(image.data)))
-		w.Header().Set("Date", time.Now().Format(time.RFC822))
+		w.Header().Set("ETag", image.lastChangeId)
+		age := time.Now().Sub(image.lastChange)
+		if age >= time.Second {
+			w.Header().Set("Age", strconv.Itoa(int(age.Seconds())))
+		}
 		if expires >= time.Second {
 			w.Header().Set("Expires", time.Now().Add(expires).Format(time.RFC1123))
-			w.Header().Set("Cache-Control", "max-age="+strconv.Itoa(int(expires.Seconds())))
+			w.Header().Set("Cache-Control", "public, no-transform, max-age="+strconv.Itoa(int(expires.Seconds())))
 		}
-		w.Write(image.data)
+		http.ServeContent(w, r, "", image.lastChange, bytes.NewReader(image.data))
 	}
 
 }
@@ -319,7 +323,7 @@ func runner(runtime phoenix.Runtime) error {
 	router := mux.NewRouter()
 	r := router.PathPrefix(basePath).Subrouter().StrictSlash(true)
 	r.HandleFunc("/", httputils.MakeGzipHandler(mainHandler))
-	r.Handle("/static/img/buddy/{flags}/{imageid}/{idx:.*}", http.StripPrefix(basePath, makeImageHandler(hub, time.Hour)))
+	r.Handle("/static/img/buddy/{flags}/{imageid}/{idx:.*}", http.StripPrefix(basePath, makeImageHandler(hub, time.Duration(24)*time.Hour)))
 	r.Handle("/static/{path:.*}", http.StripPrefix(basePath, httputils.FileStaticServer(http.Dir(rootFolder))))
 	r.Handle("/robots.txt", http.StripPrefix(basePath, http.FileServer(http.Dir(path.Join(rootFolder, "static")))))
 	r.Handle("/favicon.ico", http.StripPrefix(basePath, http.FileServer(http.Dir(path.Join(rootFolder, "static", "img")))))