eliminated an allocation on each connection by generating Accept-Encoding string only once

Author: flrdv

internal/codecutil/cache.go

@@ -1,10 +1,9 @@
 package codecutil
 
 import (
-	"iter"
+	"strings"
 
 	"github.com/indigo-web/indigo/http/codec"
-	"github.com/indigo-web/indigo/internal/strutil"
 )
 
 type Cache struct {
@@ -13,10 +12,9 @@ type Cache struct {
 	instances []codec.Instance
 }
 
-func NewCache(codecs []codec.Codec) Cache {
+func NewCache(codecs []codec.Codec, acceptString string) Cache {
 	return Cache{
-		// TODO: we're still allocating a string on every connection. Which we actually can avoid.
-		accept:    acceptEncodings(codecs),
+		accept:    acceptString,
 		codecs:    codecs,
 		instances: make([]codec.Instance, len(codecs)),
 	}
@@ -51,20 +49,18 @@ func (c Cache) AcceptEncoding() string {
 	return c.accept
 }
 
-func acceptEncodings(codecs []codec.Codec) string {
+func AcceptEncoding(codecs []codec.Codec) string {
 	if len(codecs) == 0 {
 		return "identity"
 	}
 
-	return strutil.Join(traverseTokens(codecs), ", ")
-}
+	var b strings.Builder
 
-func traverseTokens(codecs []codec.Codec) iter.Seq[string] {
-	return func(yield func(string) bool) {
-		for _, c := range codecs {
-			if !yield(c.Token()) {
-				break
-			}
-		}
+	b.WriteString(codecs[0].Token())
+	for _, c := range codecs[1:] {
+		b.WriteString(", ")
+		b.WriteString(c.Token())
 	}
+
+	return b.String()
 }

internal/httptest/parse/parse.go

@@ -12,7 +12,7 @@ import (
 func HTTP11Request(data string) (*http.Request, error) {
 	client := dummy.NewMockClient([]byte(data))
 	request := construct.Request(config.Default(), client)
-	suit := http1.New(config.Default(), nil, client, request, codecutil.NewCache(nil))
+	suit := http1.New(config.Default(), nil, client, request, codecutil.NewCache(nil, "identity"))
 	request.Body = http.NewBody(suit)
 
 	for {

internal/protocol/http1/serializer_test.go

@@ -26,7 +26,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-var noCodecs = codecutil.NewCache(nil)
+var noCodecs = codecutil.NewCache(nil, "identity")
 
 func BenchmarkSerializer(b *testing.B) {
 	getRequest := func(cfg *config.Config, m method.Method) *http.Request {
@@ -37,7 +37,8 @@ func BenchmarkSerializer(b *testing.B) {
 
 	getSerializer := func(cfg *config.Config, m method.Method, codecs ...codec.Codec) *serializer {
 		buff := make([]byte, 0, cfg.NET.WriteBufferSize.Default)
-		return newSerializer(cfg, getRequest(cfg, method.GET), new(dummy.NopClient), codecutil.NewCache(codecs), buff)
+		cache := codecutil.NewCache(codecs, codecutil.AcceptEncoding(codecs))
+		return newSerializer(cfg, getRequest(cfg, method.GET), new(dummy.NopClient), cache, buff)
 	}
 
 	getResponseWithHeaders := func(n int) *http.Response {
@@ -354,7 +355,7 @@ func TestSerializer(t *testing.T) {
 
 	t.Run("streams", func(t *testing.T) {
 		request := newRequest(method.GET)
-		codecs := codecutil.NewCache([]codec.Codec{codec.NewGZIP()})
+		codecs := codecutil.NewCache([]codec.Codec{codec.NewGZIP()}, codec.NewGZIP().Token())
 		s, w := getSerializer(nil, request, codecs)
 
 		testSized := func(t *testing.T, method string, contentLength int, body string, contentEncoding ...string) {

internal/protocol/http1/suit_test.go

@@ -164,7 +164,7 @@ func getSuit(client transport.Client, codecs ...codec.Codec) (*Suit, *http.Reque
 	cfg := config.Default()
 	r := getInbuiltRouter()
 	req := construct.Request(cfg, client)
-	suit := New(cfg, r, client, req, codecutil.NewCache(codecs))
+	suit := New(cfg, r, client, req, codecutil.NewCache(codecs, codecutil.AcceptEncoding(codecs)))
 	req.Body = http.NewBody(suit)
 
 	return suit, req

internal/strutil/join.go

@@ -33,8 +33,10 @@ func TCP() Transport {
 	return Transport{
 		inner: transport.NewTCP(),
 		spawnCallback: func(cfg *config.Config, r router.Router, c []codec.Codec) func(net.Conn) {
+			acceptString := codecutil.AcceptEncoding(c)
+
 			return func(conn net.Conn) {
-				serve.HTTP1(cfg, conn, 0, r, codecutil.NewCache(c))
+				serve.HTTP1(cfg, conn, 0, r, codecutil.NewCache(c, acceptString))
 			}
 		},
 	}
@@ -105,9 +107,11 @@ func newTLSTransport(cfg *tls.Config) Transport {
 	return Transport{
 		inner: transport.NewTLS(cfg),
 		spawnCallback: func(cfg *config.Config, r router.Router, c []codec.Codec) func(net.Conn) {
+			acceptString := codecutil.AcceptEncoding(c)
+
 			return func(conn net.Conn) {
 				ver := conn.(*tls.Conn).ConnectionState().Version
-				serve.HTTP1(cfg, conn, ver, r, codecutil.NewCache(c))
+				serve.HTTP1(cfg, conn, ver, r, codecutil.NewCache(c, acceptString))
 			}
 		},
 	}