MM-26065: Reverts Brotli encoding. (#14834)

* MM-26065: Reverts Brotli encoding.

* MM-26065: Removes package reference.

web/static.go

@@ -9,23 +9,15 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/NYTimes/gziphandler"
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/utils"
 	"github.com/mattermost/mattermost-server/v5/utils/fileutils"
-	"github.com/mkraft/gziphandler"
 )
 
 var robotsTxt = []byte("User-agent: *\nDisallow: /\n")
 
-// the static content types that are Brotli encoded rather than gzipped.
-var brotliEncodedContent = map[string]string{
-	"js":  "application/javascript",
-	"css": "text/css",
-}
-
-var brotliContentTypes []string
-
 func (w *Web) InitStatic() {
 	if *w.ConfigService.Config().ServiceSettings.WebserverMode != "disabled" {
 		if err := utils.UpdateAssetsSubpathFromConfig(w.ConfigService.Config()); err != nil {
@@ -37,20 +29,11 @@ func (w *Web) InitStatic() {
 
 		subpath, _ := utils.GetSubpathFromConfig(w.ConfigService.Config())
 
-		staticHandler := brotliFilesHandler(staticFilesHandler(http.StripPrefix(path.Join(subpath, "static"), http.FileServer(http.Dir(staticDir)))))
+		staticHandler := staticFilesHandler(http.StripPrefix(path.Join(subpath, "static"), http.FileServer(http.Dir(staticDir))))
 		pluginHandler := staticFilesHandler(http.StripPrefix(path.Join(subpath, "static", "plugins"), http.FileServer(http.Dir(*w.ConfigService.Config().PluginSettings.ClientDirectory))))
 
 		if *w.ConfigService.Config().ServiceSettings.WebserverMode == "gzip" {
-			for _, ct := range brotliEncodedContent {
-				brotliContentTypes = append(brotliContentTypes, ct)
-			}
-
-			everythingExceptBrotliGzipHandler, err := gziphandler.GzipHandlerWithOpts(gziphandler.ContentTypeExceptions(brotliContentTypes))
-			if err != nil {
-				mlog.Error("Failed to initialize gziphandler", mlog.Err(err))
-			}
-
-			staticHandler = everythingExceptBrotliGzipHandler(staticHandler)
+			staticHandler = gziphandler.GzipHandler(staticHandler)
 			pluginHandler = gziphandler.GzipHandler(pluginHandler)
 		}
 
@@ -88,26 +71,6 @@ func root(c *Context, w http.ResponseWriter, r *http.Request) {
 	http.ServeFile(w, r, filepath.Join(staticDir, "root.html"))
 }
 
-func acceptsEncodingBrotli(r *http.Request) bool {
-	directives := strings.Fields(r.Header.Get("Accept-Encoding"))
-	for _, directive := range directives {
-		if strings.ToLower(directive) == "br" {
-			return true
-		}
-	}
-	return false
-}
-
-func requestingBrotliFileExtension(r *http.Request) (bool, string) {
-	extension := r.URL.Path[strings.LastIndex(r.URL.Path, ".")+1:]
-	for bx, ct := range brotliEncodedContent {
-		if bx == extension {
-			return true, ct
-		}
-	}
-	return false, ""
-}
-
 func staticFilesHandler(handler http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		//wrap our ResponseWriter with our no-cache 404-handler
@@ -124,21 +87,6 @@ func staticFilesHandler(handler http.Handler) http.Handler {
 	})
 }
 
-func brotliFilesHandler(handler http.Handler) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if model.BuildNumber != "dev" {
-			isRequestingBrotliFile, contentType := requestingBrotliFileExtension(r)
-			if isRequestingBrotliFile && acceptsEncodingBrotli(r) {
-				r.URL.Path = r.URL.Path + ".br"
-				w.Header().Set("Content-Encoding", "br")
-				w.Header().Set("Content-Type", contentType)
-			}
-		}
-
-		handler.ServeHTTP(w, r)
-	})
-}
-
 type notFoundNoCacheResponseWriter struct {
 	http.ResponseWriter
 }