improved static file handling and caching

web/cachedfs.go

@@ -0,0 +1,24 @@
+package web
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+)
+
+func CachedServeFunc(h http.HandlerFunc) http.HandlerFunc {
+	var etag = fmt.Sprintf(`"%d"`, time.Now().UnixMicro())
+	return func(w http.ResponseWriter, r *http.Request) {
+		if match := r.Header.Get("If-None-Match"); match != "" {
+			if strings.Contains(match, etag) {
+				w.WriteHeader(http.StatusNotModified)
+				return
+			}
+		}
+
+		w.Header().Set("Cache-Control", "max-age=60")
+		w.Header().Set("ETag", etag)
+		h.ServeHTTP(w, r)
+	}
+}

web/serve.go

@@ -23,7 +23,16 @@ func Serve(ctx *app.App) {
 	mux := http.NewServeMux()
 
 	// static files
-	mux.Handle("/", http.FileServer(getFileSystem(ctx.Config.Webdev, public.Files)))
+	if ctx.Config.Webdev {
+		logrus.Print("using live mode")
+		fs := http.FileServer(http.FS(os.DirFS("public")))
+		mux.HandleFunc("/", fs.ServeHTTP)
+
+	} else {
+		logrus.Print("using embed mode")
+		fs := http.FileServer(http.FS(public.Files))
+		mux.HandleFunc("/", CachedServeFunc(fs.ServeHTTP))
+	}
 
 	tiles := &Tiles{ctx: ctx}
 	tiles.Init()