From bd41413d57e672049bf71b1e146c88a48b432be0 Mon Sep 17 00:00:00 2001
From: David Wu <david.wu@docker.com>
Date: Tue, 11 Sep 2018 14:19:08 -0700
Subject: [PATCH] remove closenotifier

Signed-off-by: David Wu <david.wu@docker.com>
---
 context/http.go               | 30 ------------------------------
 registry/handlers/api_test.go | 29 -----------------------------
 registry/handlers/helpers.go  |  8 +-------
 3 files changed, 1 insertion(+), 66 deletions(-)

diff --git a/context/http.go b/context/http.go
index b7447800..bc22f0bb 100644
--- a/context/http.go
+++ b/context/http.go
@@ -104,18 +104,6 @@ func GetRequestID(ctx context.Context) string {
 // WithResponseWriter returns a new context and response writer that makes
 // interesting response statistics available within the context.
 func WithResponseWriter(ctx context.Context, w http.ResponseWriter) (context.Context, http.ResponseWriter) {
-	if closeNotifier, ok := w.(http.CloseNotifier); ok {
-		irwCN := &instrumentedResponseWriterCN{
-			instrumentedResponseWriter: instrumentedResponseWriter{
-				ResponseWriter: w,
-				Context:        ctx,
-			},
-			CloseNotifier: closeNotifier,
-		}
-
-		return irwCN, irwCN
-	}
-
 	irw := instrumentedResponseWriter{
 		ResponseWriter: w,
 		Context:        ctx,
@@ -270,14 +258,6 @@ func (ctx *muxVarsContext) Value(key interface{}) interface{} {
 	return ctx.Context.Value(key)
 }
 
-// instrumentedResponseWriterCN provides response writer information in a
-// context. It implements http.CloseNotifier so that users can detect
-// early disconnects.
-type instrumentedResponseWriterCN struct {
-	instrumentedResponseWriter
-	http.CloseNotifier
-}
-
 // instrumentedResponseWriter provides response writer information in a
 // context. This variant is only used in the case where CloseNotifier is not
 // implemented by the parent ResponseWriter.
@@ -355,13 +335,3 @@ func (irw *instrumentedResponseWriter) Value(key interface{}) interface{} {
 fallback:
 	return irw.Context.Value(key)
 }
-
-func (irw *instrumentedResponseWriterCN) Value(key interface{}) interface{} {
-	if keyStr, ok := key.(string); ok {
-		if keyStr == "http.response" {
-			return irw
-		}
-	}
-
-	return irw.instrumentedResponseWriter.Value(key)
-}
diff --git a/registry/handlers/api_test.go b/registry/handlers/api_test.go
index bed0ab2c..2544efba 100644
--- a/registry/handlers/api_test.go
+++ b/registry/handlers/api_test.go
@@ -2529,35 +2529,6 @@ func TestRegistryAsCacheMutationAPIs(t *testing.T) {
 
 }
 
-// TestCheckContextNotifier makes sure the API endpoints get a ResponseWriter
-// that implements http.ContextNotifier.
-func TestCheckContextNotifier(t *testing.T) {
-	env := newTestEnv(t, false)
-	defer env.Shutdown()
-
-	// Register a new endpoint for testing
-	env.app.router.Handle("/unittest/{name}/", env.app.dispatcher(func(ctx *Context, r *http.Request) http.Handler {
-		return handlers.MethodHandler{
-			"GET": http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				if _, ok := w.(http.CloseNotifier); !ok {
-					t.Fatal("could not cast ResponseWriter to CloseNotifier")
-				}
-				w.WriteHeader(200)
-			}),
-		}
-	}))
-
-	resp, err := http.Get(env.server.URL + "/unittest/reponame/")
-	if err != nil {
-		t.Fatalf("unexpected error issuing request: %v", err)
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != 200 {
-		t.Fatalf("wrong status code - expected 200, got %d", resp.StatusCode)
-	}
-}
-
 func TestProxyManifestGetByTag(t *testing.T) {
 	truthConfig := configuration.Configuration{
 		Storage: configuration.Storage{
diff --git a/registry/handlers/helpers.go b/registry/handlers/helpers.go
index 46ad797e..b02338e9 100644
--- a/registry/handlers/helpers.go
+++ b/registry/handlers/helpers.go
@@ -27,13 +27,7 @@ func closeResources(handler http.Handler, closers ...io.Closer) http.Handler {
 // The copy will be limited to `limit` bytes, if limit is greater than zero.
 func copyFullPayload(ctx context.Context, responseWriter http.ResponseWriter, r *http.Request, destWriter io.Writer, limit int64, action string) error {
 	// Get a channel that tells us if the client disconnects
-	var clientClosed <-chan bool
-	if notifier, ok := responseWriter.(http.CloseNotifier); ok {
-		clientClosed = notifier.CloseNotify()
-	} else {
-		dcontext.GetLogger(ctx).Warnf("the ResponseWriter does not implement CloseNotifier (type: %T)", responseWriter)
-	}
-
+	clientClosed := r.Context().Done()
 	var body = r.Body
 	if limit > 0 {
 		body = http.MaxBytesReader(responseWriter, body, limit)