protobuf: add vtproto as a supplemental marshaler

vtproto is an extra protobuf compiler that generates special methods
suffixed with `VT` that create typed and unrolled marshal and unmarshal
functions similar to gogo that can be used for performance sensitive
code. These extensions are optional for code to use but buildkit uses
them.

A codec is also included to utilize vtproto for grpc code. If the
package `github.com/moby/buildkit/util/grpcutil/encoding/proto` is
imported then vtproto will be used if it exists and otherwise it will
use the standard marshaling and unmarshaling methods.

This codec has an important difference from the default codec. The
default codec will always reset messages before unmarshaling. In most
cases, this is unnecessary and is only relevant for `RecvMsg` on
streams. In most cases, if we are passing in an existing message to this
method, we want to reuse the buffers. This codec will always merge the
message when unmarshaling instead of resetting the input message.

Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>

api/services/control/control_bench_test.go

@@ -6,7 +6,7 @@ import (
 
 	digest "github.com/opencontainers/go-digest"
 	"github.com/stretchr/testify/require"
-	"google.golang.org/protobuf/proto"
+	proto "google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
 
@@ -17,7 +17,7 @@ func BenchmarkMarshalVertex(b *testing.B) {
 	v := sampleVertex()
 	for i := 0; i < b.N; i++ {
 		var err error
-		Buf, err = proto.Marshal(v)
+		Buf, err = v.MarshalVT()
 		require.NoError(b, err)
 	}
 }
@@ -26,7 +26,7 @@ func BenchmarkMarshalVertexStatus(b *testing.B) {
 	v := sampleVertexStatus()
 	for i := 0; i < b.N; i++ {
 		var err error
-		Buf, err = proto.Marshal(v)
+		Buf, err = v.MarshalVT()
 		require.NoError(b, err)
 	}
 }
@@ -35,7 +35,7 @@ func BenchmarkMarshalVertexLog(b *testing.B) {
 	v := sampleVertexLog()
 	for i := 0; i < b.N; i++ {
 		var err error
-		Buf, err = proto.Marshal(v)
+		Buf, err = v.MarshalVT()
 		require.NoError(b, err)
 	}
 }
@@ -48,7 +48,7 @@ func BenchmarkUnmarshalVertex(b *testing.B) {
 	require.NoError(b, err)
 
 	for i := 0; i < b.N; i++ {
-		err := proto.Unmarshal(buf, &VertexOutput)
+		err := VertexOutput.UnmarshalVT(buf)
 		require.NoError(b, err)
 	}
 }
@@ -61,7 +61,7 @@ func BenchmarkUnmarshalVertexStatus(b *testing.B) {
 	require.NoError(b, err)
 
 	for i := 0; i < b.N; i++ {
-		err := proto.Unmarshal(buf, &VertexStatusOutput)
+		err := VertexStatusOutput.UnmarshalVT(buf)
 		require.NoError(b, err)
 	}
 }
@@ -74,7 +74,7 @@ func BenchmarkUnmarshalVertexLog(b *testing.B) {
 	require.NoError(b, err)
 
 	for i := 0; i < b.N; i++ {
-		err := proto.Unmarshal(buf, &VertexLogOutput)
+		err := VertexLogOutput.UnmarshalVT(buf)
 		require.NoError(b, err)
 	}
 }