client: deprecate CallCustomCodec and provide new version using encoding.Codec (#2556)

dialoptions.go

@@ -164,7 +164,7 @@ func WithDefaultCallOptions(cos ...CallOption) DialOption {
 // WithCodec returns a DialOption which sets a codec for message marshaling and
 // unmarshaling.
 //
-// Deprecated: use WithDefaultCallOptions(CallCustomCodec(c)) instead.
+// Deprecated: use WithDefaultCallOptions(ForceCodec(_)) instead.
 func WithCodec(c Codec) DialOption {
 	return WithDefaultCallOptions(CallCustomCodec(c))
 }

rpc_util.go

@@ -370,13 +370,13 @@ func (o CompressorCallOption) after(c *callInfo) {}
 // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
 // more details.
 //
-// If CallCustomCodec is not also used, the content-subtype will be used to
-// look up the Codec to use in the registry controlled by RegisterCodec. See
-// the documentation on RegisterCodec for details on registration. The lookup
-// of content-subtype is case-insensitive. If no such Codec is found, the call
+// If ForceCodec is not also used, the content-subtype will be used to look up
+// the Codec to use in the registry controlled by RegisterCodec. See the
+// documentation on RegisterCodec for details on registration. The lookup of
+// content-subtype is case-insensitive. If no such Codec is found, the call
 // will result in an error with code codes.Internal.
 //
-// If CallCustomCodec is also used, that Codec will be used for all request and
+// If ForceCodec is also used, that Codec will be used for all request and
 // response messages, with the content-subtype set to the given contentSubtype
 // here for requests.
 func CallContentSubtype(contentSubtype string) CallOption {
@@ -396,7 +396,7 @@ func (o ContentSubtypeCallOption) before(c *callInfo) error {
 }
 func (o ContentSubtypeCallOption) after(c *callInfo) {}
 
-// CallCustomCodec returns a CallOption that will set the given Codec to be
+// ForceCodec returns a CallOption that will set the given Codec to be
 // used for all request and response messages for a call. The result of calling
 // String() will be used as the content-subtype in a case-insensitive manner.
 //
@@ -408,12 +408,37 @@ func (o ContentSubtypeCallOption) after(c *callInfo) {}
 //
 // This function is provided for advanced users; prefer to use only
 // CallContentSubtype to select a registered codec instead.
+//
+// This is an EXPERIMENTAL API.
+func ForceCodec(codec encoding.Codec) CallOption {
+	return ForceCodecCallOption{Codec: codec}
+}
+
+// ForceCodecCallOption is a CallOption that indicates the codec used for
+// marshaling messages.
+//
+// This is an EXPERIMENTAL API.
+type ForceCodecCallOption struct {
+	Codec encoding.Codec
+}
+
+func (o ForceCodecCallOption) before(c *callInfo) error {
+	c.codec = o.Codec
+	return nil
+}
+func (o ForceCodecCallOption) after(c *callInfo) {}
+
+// CallCustomCodec behaves like ForceCodec, but accepts a grpc.Codec instead of
+// an encoding.Codec.
+//
+// Deprecated: use ForceCodec instead.
 func CallCustomCodec(codec Codec) CallOption {
 	return CustomCodecCallOption{Codec: codec}
 }
 
 // CustomCodecCallOption is a CallOption that indicates the codec used for
 // marshaling messages.
+//
 // This is an EXPERIMENTAL API.
 type CustomCodecCallOption struct {
 	Codec Codec

test/end2end_test.go

@@ -51,6 +51,7 @@ import (
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/encoding"
 	_ "google.golang.org/grpc/encoding/gzip"
 	_ "google.golang.org/grpc/grpclog/glogger"
 	"google.golang.org/grpc/health"
@@ -500,7 +501,7 @@ type test struct {
 	streamServerInt             grpc.StreamServerInterceptor
 	unknownHandler              grpc.StreamHandler
 	sc                          <-chan grpc.ServiceConfig
-	customCodec                 grpc.Codec
+	customCodec                 encoding.Codec
 	serverInitialWindowSize     int32
 	serverInitialConnWindowSize int32
 	clientInitialWindowSize     int32
@@ -632,9 +633,6 @@ func (te *test) listenAndServe(ts testpb.TestServiceServer, listen func(network,
 	case "clientTimeoutCreds":
 		sopts = append(sopts, grpc.Creds(&clientTimeoutCreds{}))
 	}
-	if te.customCodec != nil {
-		sopts = append(sopts, grpc.CustomCodec(te.customCodec))
-	}
 	if te.svrKeepAlive != nil {
 		sopts = append(sopts, grpc.KeepaliveParams(*te.svrKeepAlive))
 	}
@@ -866,7 +864,7 @@ func (te *test) configDial(opts ...grpc.DialOption) ([]grpc.DialOption, string)
 		opts = append(opts, grpc.WithPerRPCCredentials(te.perRPCCreds))
 	}
 	if te.customCodec != nil {
-		opts = append(opts, grpc.WithDefaultCallOptions(grpc.CallCustomCodec(te.customCodec)))
+		opts = append(opts, grpc.WithDefaultCallOptions(grpc.ForceCodec(te.customCodec)))
 	}
 	if !te.nonBlockingDial && te.srvAddr != "" {
 		// Only do a blocking dial if server is up.
@@ -5736,7 +5734,7 @@ func (c *errCodec) Unmarshal(data []byte, v interface{}) error {
 	return nil
 }
 
-func (c *errCodec) String() string {
+func (c *errCodec) Name() string {
 	return "Fermat's near-miss."
 }
 

vet.sh

@@ -112,6 +112,7 @@ google.golang.org/grpc/balancer_test.go:SA1019
 google.golang.org/grpc/clientconn_test.go:SA1019
 google.golang.org/grpc/balancer/roundrobin/roundrobin_test.go:SA1019
 google.golang.org/grpc/benchmark/benchmain/main.go:SA1019
+google.golang.org/grpc/benchmark/worker/benchmark_client.go:SA1019
 google.golang.org/grpc/internal/transport/handler_server.go:SA1019
 google.golang.org/grpc/internal/transport/handler_server_test.go:SA1019
 google.golang.org/grpc/stats/stats_test.go:SA1019