xP

From 71e1a744c5521e54da333c78802cf5c57f4598db Mon Sep 17 00:00:00 2001 From: Přemysl Eric Janouch Date: Wed, 9 Jul 2025 21:53:19 +0200 Subject: xP: embed web resources, tame browser caching --- xP/xP.go | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 63 insertions(+), 11 deletions(-) (limited to 'xP/xP.go') diff --git a/xP/xP.go b/xP/xP.go index 188fd5d..7e0c386 100644 --- a/xP/xP.go +++ b/xP/xP.go @@ -1,4 +1,4 @@ -// Copyright (c) 2022, Přemysl Eric Janouch +// Copyright (c) 2022 - 2025, Přemysl Eric Janouch // SPDX-License-Identifier: 0BSD package main @@ -6,12 +6,16 @@ package main import ( "bufio" "context" + "crypto/sha1" + "embed" "encoding/binary" + "encoding/hex" "encoding/json" "flag" "fmt" "html/template" "io" + "io/fs" "log" "net" "net/http" @@ -23,7 +27,12 @@ import ( ) var ( - debug = flag.Bool("debug", false, "enable debug output") + debug = flag.Bool("debug", false, "enable debug output") + webRoot = flag.String("webroot", "", "override bundled web resources") + + //go:embed public/* + webResources embed.FS + webResourcesHash string addressBind string addressConnect string @@ -240,21 +249,20 @@ func handleWS(w http.ResponseWriter, r *http.Request) { // ----------------------------------------------------------------------------- -var staticHandler = http.FileServer(http.Dir(".")) - var page = template.Must(template.New("/").Parse(` xP + @@ -262,20 +270,49 @@ var page = template.Must(template.New("/").Parse(` `)) func handleDefault(w http.ResponseWriter, r *http.Request) { - if r.URL.Path != "/" { - staticHandler.ServeHTTP(w, r) - return - } - wsURI := addressWS if wsURI == "" { wsURI = fmt.Sprintf("ws://%s/ws", r.Host) } - if err := page.Execute(w, wsURI); err != nil { + + args := struct { + Root string + Proxy string + }{ + Root: webResourcesHash, + Proxy: wsURI, + } + if err := page.Execute(w, &args); err != nil { log.Println("Template execution failed: " + err.Error()) } } +func hashFS(root fs.FS) []byte { + hasher := sha1.New() + callback := func(path string, d fs.DirEntry, err error) error { + if err != nil { + return err + } + + // Note that this can be fooled. + fmt.Fprintln(hasher, path) + + if !d.IsDir() { + file, err := root.Open(path) + if err != nil { + return err + } + defer file.Close() + io.Copy(hasher, file) + } + return nil + } + if err := fs.WalkDir(root, ".", callback); err != nil { + log.Fatalln(err) + } + return hasher.Sum(nil) +} + func main() { flag.Usage = func() { fmt.Fprintf(flag.CommandLine.Output(), @@ -294,6 +331,21 @@ func main() { addressWS = flag.Arg(2) } + subResources, err := fs.Sub(webResources, "public") + if err != nil { + log.Fatalln(err) + } + if *webRoot != "" { + subResources = os.DirFS(*webRoot) + } + + // The simplest way of ensuring that web browsers don't use + // stale cached copies of our files. + webResourcesHash = hex.EncodeToString(hashFS(subResources)) + http.Handle("/"+webResourcesHash+"/", + http.StripPrefix("/"+webResourcesHash+"/", + http.FileServerFS(subResources))) + http.Handle("/ws", http.HandlerFunc(handleWS)) http.Handle("/", http.HandlerFunc(handleDefault)) -- cgit v1.2.3-70-g09d2