Serve assets as own files, use caching strategies

1 files changed, 54 insertions, 24 deletions

diff --git a/gopherproxy.go b/gopherproxy.go
index 62b7446..1fcd29f 100644
--- a/gopherproxy.go
+++ b/gopherproxy.go
@@ -2,6 +2,7 @@ package gopherproxy
 
 import (
         "bytes"
+        "crypto/md5"
         "fmt"
         "html"
         "html/template"
@@ -28,7 +29,14 @@ type Item struct {
         Text string
 }
 
-func renderDirectory(w http.ResponseWriter, tpl *template.Template, styletext string, jstext string, uri string, hostport string, d gopher.Directory) error {
+type AssetHashList struct {
+        Style  string
+        JS     string
+        FontW  string
+        FontW2 string
+}
+
+func renderDirectory(w http.ResponseWriter, tpl *template.Template, assetHashList AssetHashList, uri string, hostport string, d gopher.Directory) error {
         var title string
 
         out := make([]Item, len(d.Items))
@@ -78,13 +86,12 @@ func renderDirectory(w http.ResponseWriter, tpl *template.Template, styletext st
         }
 
         return tpl.Execute(w, struct {
-                Title   string
-                URI     string
-                Style   string
-                Script  string
-                Lines   []Item
-                RawText string
-        }{title, fmt.Sprintf("%s/%s", hostport, uri), styletext, jstext, out, ""})
+                Title         string
+                URI           string
+                AssetHashList AssetHashList
+                Lines         []Item
+                RawText       string
+        }{title, fmt.Sprintf("%s/%s", hostport, uri), assetHashList, out, ""})
 }
 
 // GopherHandler returns a Handler that proxies requests
@@ -92,7 +99,7 @@ func renderDirectory(w http.ResponseWriter, tpl *template.Template, styletext st
 // to the request path and renders the content using the provided template.
 // The optional robots parameters points to a robotstxt.RobotsData struct
 // to test user agents against a configurable robotst.txt file.
-func GopherHandler(tpl *template.Template, robotsdata *robotstxt.RobotsData, robotsdebug bool, styletext string, jstext string, uri string) http.HandlerFunc {
+func GopherHandler(tpl *template.Template, robotsdata *robotstxt.RobotsData, assetHashList AssetHashList, robotsdebug bool, uri string) http.HandlerFunc {
         return func(w http.ResponseWriter, req *http.Request) {
                 agent := req.UserAgent()
                 path := strings.TrimPrefix(req.URL.Path, "/")
@@ -141,13 +148,12 @@ func GopherHandler(tpl *template.Template, robotsdata *robotstxt.RobotsData, rob
                                 buf := new(bytes.Buffer)
                                 buf.ReadFrom(res.Body)
                                 tpl.Execute(w, struct {
-                                        Title   string
-                                        URI     string
-                                        Style   string
-                                        Script  string
-                                        RawText string
-                                        Lines   []Item
-                                }{uri, fmt.Sprintf("%s/%s", hostport, uri), styletext, jstext, buf.String(), nil})
+                                        Title         string
+                                        URI           string
+                                        AssetHashList AssetHashList
+                                        RawText       string
+                                        Lines         []Item
+                                }{uri, fmt.Sprintf("%s/%s", hostport, uri), assetHashList, buf.String(), nil})
                         } else if parts[1] == "T" {
                                 _, _, err = vips.NewTransform().
                                         Load(res.Body).
@@ -160,7 +166,7 @@ func GopherHandler(tpl *template.Template, robotsdata *robotstxt.RobotsData, rob
                                 io.Copy(w, res.Body)
                         }
                 } else {
-                        if err := renderDirectory(w, tpl, styletext, jstext, uri, hostport, res.Dir); err != nil {
+                        if err := renderDirectory(w, tpl, assetHashList, uri, hostport, res.Dir); err != nil {
                                 io.WriteString(w, fmt.Sprintf("<b>Error:</b><pre>%s</pre>", err))
                                 return
                         }
@@ -190,10 +196,27 @@ func FaviconHandler(favicondata []byte) http.HandlerFunc {
                 }
 
                 w.Header().Set("Content-Type", "image/vnd.microsoft.icon")
+                w.Header().Set("Cache-Control", "max-age=2592000")
                 w.Write(favicondata)
         }
 }
 
+func StyleHandler(styledata []byte) http.HandlerFunc {
+        return func(w http.ResponseWriter, req *http.Request) {
+                w.Header().Set("Content-Type", "text/css")
+                w.Header().Set("Cache-Control", "max-age=2592000")
+                w.Write(styledata)
+        }
+}
+
+func JavaScriptHandler(jsdata []byte) http.HandlerFunc {
+        return func(w http.ResponseWriter, req *http.Request) {
+                w.Header().Set("Content-Type", "text/javascript")
+                w.Header().Set("Cache-Control", "max-age=2592000")
+                w.Write(jsdata)
+        }
+}
+
 func FontHandler(woff2 bool, fontdata []byte) http.HandlerFunc {
         return func(w http.ResponseWriter, req *http.Request) {
                 if fontdata == nil {
@@ -206,6 +229,7 @@ func FontHandler(woff2 bool, fontdata []byte) http.HandlerFunc {
                 } else {
                         w.Header().Set("Content-Type", "font/woff")
                 }
+                w.Header().Set("Cache-Control", "max-age=2592000")
 
                 w.Write(fontdata)
         }
@@ -242,21 +266,25 @@ func ListenAndServe(bind, robotsfile string, robotsdebug bool, uri string) error
         if err != nil {
                 fontdataw = []byte{}
         }
+        fontwhash := fmt.Sprintf("%x", md5.Sum(fontdataw))
 
         fontdataw2, err := box.Find("iosevka-term-ss03-regular.woff2")
         if err != nil {
                 fontdataw2 = []byte{}
         }
+        fontw2hash := fmt.Sprintf("%x", md5.Sum(fontdataw2))
 
-        styletext, err := box.FindString("style.css")
+        styledata, err := box.Find("style.css")
         if err != nil {
-                styletext = ""
+                styledata = []byte{}
         }
+        stylehash := fmt.Sprintf("%x", md5.Sum(styledata))
 
-        jstext, err := box.FindString("main.js")
+        jsdata, err := box.Find("main.js")
         if err != nil {
-                jstext = ""
+                jsdata = []byte{}
         }
+        jshash := fmt.Sprintf("%x", md5.Sum(jsdata))
 
         favicondata, err := box.Find("favicon.ico")
         if err != nil {
@@ -304,11 +332,13 @@ func ListenAndServe(bind, robotsfile string, robotsdebug bool, uri string) error
                 ConcurrencyLevel: 2,
         })
 
-        http.HandleFunc("/", GopherHandler(tpl, robotsdata, robotsdebug, styletext, jstext, uri))
+        http.HandleFunc("/", GopherHandler(tpl, robotsdata, AssetHashList{stylehash, jshash, fontwhash, fontw2hash}, robotsdebug, uri))
         http.HandleFunc("/robots.txt", RobotsTxtHandler(robotstxtdata))
         http.HandleFunc("/favicon.ico", FaviconHandler(favicondata))
-        http.HandleFunc("/iosevka-term-ss03-regular.woff", FontHandler(false, fontdataw))
-        http.HandleFunc("/iosevka-term-ss03-regular.woff2", FontHandler(true, fontdataw2))
+        http.HandleFunc("/style-"+stylehash+".css", StyleHandler(styledata))
+        http.HandleFunc("/main-"+jshash+".js", JavaScriptHandler(jsdata))
+        http.HandleFunc("/iosevka-term-ss03-regular-"+fontwhash+".woff", FontHandler(false, fontdataw))
+        http.HandleFunc("/iosevka-term-ss03-regular-"+fontw2hash+".woff2", FontHandler(true, fontdataw2))
         //http.Handle("/assets/", http.StripPrefix("/assets/", http.FileServer(http.Dir("assets/"))))
 
         return http.ListenAndServe(bind, nil)