From c7b59a5c9e73d47a154235e9a00e865623abec73 Mon Sep 17 00:00:00 2001
From: Josh Grebe <josh@shortcutsolutions.net>
Date: Fri, 11 Jul 2025 08:49:29 -0500
Subject: [PATCH] add compression

---
 go.mod  |  6 ++++--
 go.sum  |  8 ++++----
 main.go | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 6 deletions(-)

diff --git a/go.mod b/go.mod
index 165510a..bf637c6 100644
--- a/go.mod
+++ b/go.mod
@@ -1,8 +1,10 @@
 module git.teamworkapps.com/shortcut/httphere
 
-go 1.17
+go 1.24.1
 
 require (
 	git.teamworkapps.com/shortcut/enhancedfileserver v0.0.0-20230421162957-948ff8787756
-	github.com/gorilla/mux v1.8.0
+	github.com/gorilla/mux v1.8.1
 )
+
+require github.com/andybalholm/brotli v1.2.0 // indirect
diff --git a/go.sum b/go.sum
index 094654b..85509da 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,6 @@
-git.teamworkapps.com/shortcut/enhancedfileserver v0.0.0-20181107163431-49cae39a0eb7 h1:wl0faTtewN9Y0nTZpRY2mcaIhVkaR1l8k920U0rDIk0=
-git.teamworkapps.com/shortcut/enhancedfileserver v0.0.0-20181107163431-49cae39a0eb7/go.mod h1:4t5y+BFcMRTe6GkAX72YXcjrKbGkOVM7CkJMRHNZYiQ=
 git.teamworkapps.com/shortcut/enhancedfileserver v0.0.0-20230421162957-948ff8787756 h1:ViHTT1GI1JlsLrUsivl4tvg6DySn35d1C3bzXeLa8uY=
 git.teamworkapps.com/shortcut/enhancedfileserver v0.0.0-20230421162957-948ff8787756/go.mod h1:Px7gD0CL+z9WBsvFPtCuDpVEJNStJXrbFRD3q7aJwYk=
-github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
-github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
+github.com/andybalholm/brotli v1.2.0 h1:ukwgCxwYrmACq68yiUqwIWnGY0cTPox/M94sVwToPjQ=
+github.com/andybalholm/brotli v1.2.0/go.mod h1:rzTDkvFWvIrjDXZHkuS16NPggd91W3kUSvPlQ1pLaKY=
+github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
+github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
diff --git a/main.go b/main.go
index c92a398..d8ab2be 100644
--- a/main.go
+++ b/main.go
@@ -1,12 +1,16 @@
 package main
 
 import (
+	"compress/gzip"
 	"flag"
 	"fmt"
+	"io"
 	"log"
 	"net/http"
+	"strings"
 
 	"git.teamworkapps.com/shortcut/enhancedfileserver"
+	"github.com/andybalholm/brotli"
 	"github.com/gorilla/mux"
 )
 
@@ -51,6 +55,9 @@ func main() {
 		r.Use(noCache)
 	}
 
+	// Always enable compression (both brotli and gzip)
+	r.Use(compression)
+
 	if c.noindex {
 		r.PathPrefix("/").Handler(http.StripPrefix("/", enhancedfileserver.FileServerNoIndex(http.Dir("./"))))
 	} else {
@@ -92,3 +99,58 @@ func queryLog(next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
+
+// compressionWriter wraps http.ResponseWriter to provide compression
+type compressionWriter struct {
+	http.ResponseWriter
+	writer io.Writer
+}
+
+func (cw *compressionWriter) Write(b []byte) (int, error) {
+	return cw.writer.Write(b)
+}
+
+// compression middleware that supports both brotli and gzip
+func compression(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Get the Accept-Encoding header
+		acceptEncoding := r.Header.Get("Accept-Encoding")
+
+		// Check if client supports brotli (preferred)
+		if strings.Contains(acceptEncoding, "br") {
+			w.Header().Set("Content-Encoding", "br")
+			w.Header().Set("Vary", "Accept-Encoding")
+
+			bw := brotli.NewWriter(w)
+			defer bw.Close()
+
+			cw := &compressionWriter{
+				ResponseWriter: w,
+				writer:         bw,
+			}
+
+			next.ServeHTTP(cw, r)
+			return
+		}
+
+		// Check if client supports gzip
+		if strings.Contains(acceptEncoding, "gzip") {
+			w.Header().Set("Content-Encoding", "gzip")
+			w.Header().Set("Vary", "Accept-Encoding")
+
+			gw := gzip.NewWriter(w)
+			defer gw.Close()
+
+			cw := &compressionWriter{
+				ResponseWriter: w,
+				writer:         gw,
+			}
+
+			next.ServeHTTP(cw, r)
+			return
+		}
+
+		// No compression supported, serve normally
+		next.ServeHTTP(w, r)
+	})
+}