From f02730dc6b062243963dd26dfd49c02aed997101 Mon Sep 17 00:00:00 2001
From: Jeremy Baxter <jeremy@baxters.nz>
Date: Mon, 5 Jan 2026 01:17:57 +1300
Subject: [PATCH 1/4] server: set Content-Length for tarballs

---
 server/server.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/server/server.go b/server/server.go
index fc95364..606649e 100644
--- a/server/server.go
+++ b/server/server.go
@@ -1,6 +1,7 @@
 package server
 
 import (
+	"fmt"
 	"log"
 	"os"
 	"regexp"
@@ -171,6 +172,8 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 				}
 				w.Header().Set("Content-Disposition", `attachment; filename="` +
 					strings.ReplaceAll(album.Name, `"`, `'`) + `.tar.gz"`)
+				w.Header().Set("Content-Length",
+					fmt.Sprintf("%d", album.TarballSize))
 				w.Write(contents)
 				return
 			}

From 06f296639edc176881c62eaf4888f822dbada4b6 Mon Sep 17 00:00:00 2001
From: Jeremy Baxter <jeremy@baxters.nz>
Date: Mon, 5 Jan 2026 01:23:47 +1300
Subject: [PATCH 2/4] util: DoChunks: accept custom chunk sizes

---
 server/server.go | 2 +-
 util/util.go     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/server/server.go b/server/server.go
index 606649e..f5059b9 100644
--- a/server/server.go
+++ b/server/server.go
@@ -108,7 +108,7 @@ func serveMediaDirectory(w http.ResponseWriter, req *http.Request) {
 		http.Error(w, "not found", http.StatusNotFound)
 		return
 	}
-	util.DoChunks(f, func (buf []byte) { w.Write(buf) })
+	util.DoChunks(f, 4, func (buf []byte) { w.Write(buf) })
 }
 
 func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
diff --git a/util/util.go b/util/util.go
index 79c32f6..55d3667 100644
--- a/util/util.go
+++ b/util/util.go
@@ -39,11 +39,11 @@ func Dirents(dir string) (entries []string, err error) {
 	return
 }
 
-func DoChunks(f io.Reader, fun func (buf []byte)) (err error) {
+func DoChunks(f io.Reader, kib uint, fun func (buf []byte)) (err error) {
 	err = nil
 	bytes, chunks := int64(0), int64(0)
 	r := bufio.NewReader(f)
-	buf := make([]byte, 0, 4*1024)
+	buf := make([]byte, 0, kib * 1024)
 
 	for {
 		var n int

From 58b6b1618d54c4d4cbff8780357fa57b7848aaf1 Mon Sep 17 00:00:00 2001
From: Jeremy Baxter <jeremy@baxters.nz>
Date: Mon, 5 Jan 2026 01:28:24 +1300
Subject: [PATCH 3/4] add missing File.Close() calls

---
 server/server.go | 2 ++
 util/util.go     | 1 +
 2 files changed, 3 insertions(+)

diff --git a/server/server.go b/server/server.go
index f5059b9..f4f8000 100644
--- a/server/server.go
+++ b/server/server.go
@@ -103,11 +103,13 @@ func serveMediaDirectory(w http.ResponseWriter, req *http.Request) {
 		http.Error(w, "is a directory; maybe you are looking for " + path, http.StatusForbidden)
 		return
 	}
+
 	f, err := os.Open(filePath)
 	if err != nil {
 		http.Error(w, "not found", http.StatusNotFound)
 		return
 	}
+	defer f.Close()
 	util.DoChunks(f, 4, func (buf []byte) { w.Write(buf) })
 }
 
diff --git a/util/util.go b/util/util.go
index 55d3667..77149eb 100644
--- a/util/util.go
+++ b/util/util.go
@@ -26,6 +26,7 @@ func Dirents(dir string) (entries []string, err error) {
 	if err != nil {
 		return nil, errors.New(err.Error())
 	}
+	defer d.Close()
 
 	names, err := d.Readdirnames(0)
 	if err != nil {

From cf8959b1d738ecf47b8cc86bbaef41ac5c358045 Mon Sep 17 00:00:00 2001
From: Jeremy Baxter <jeremy@baxters.nz>
Date: Mon, 5 Jan 2026 01:32:55 +1300
Subject: [PATCH 4/4] server: write tarball in 4 MiB chunks

---
 server/server.go | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/server/server.go b/server/server.go
index f4f8000..ea8040d 100644
--- a/server/server.go
+++ b/server/server.go
@@ -166,17 +166,19 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 		if musicindex.ArtistExists(artist) {
 			album, ok := musicindex.FindArtist(artist).Albums[albumName]
 			if ok {
-				contents, err := os.ReadFile(album.Tarball)
-
+				f, err := os.Open(album.Tarball)
 				if err != nil {
-					http.Error(w, err.Error(), http.StatusNotFound)
+					http.Error(w, "internal server error: " + err.Error(),
+						http.StatusInternalServerError)
 					return
 				}
+				defer f.Close()
+
 				w.Header().Set("Content-Disposition", `attachment; filename="` +
 					strings.ReplaceAll(album.Name, `"`, `'`) + `.tar.gz"`)
 				w.Header().Set("Content-Length",
 					fmt.Sprintf("%d", album.TarballSize))
-				w.Write(contents)
+				util.DoChunks(f, 4 * 1024, func (buf []byte) { w.Write(buf) })
 				return
 			}
 		}