Add proto marshaller for proto-over-http (#459)

.gitignore

@@ -1 +1,2 @@
 _output/
+.idea

runtime/marshal_proto.go

@@ -0,0 +1,62 @@
+package runtime
+
+import (
+	"io"
+
+	"errors"
+	"github.com/golang/protobuf/proto"
+	"io/ioutil"
+)
+
+// ProtoMarshaller is a Marshaller which marshals/unmarshals into/from serialize proto bytes
+type ProtoMarshaller struct{}
+
+// ContentType always returns "application/octet-stream".
+func (*ProtoMarshaller) ContentType() string {
+	return "application/octet-stream"
+}
+
+// Marshal marshals "value" into Proto
+func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error) {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return nil, errors.New("unable to marshal non proto field")
+	}
+	return proto.Marshal(message)
+}
+
+// Unmarshal unmarshals proto "data" into "value"
+func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return errors.New("unable to unmarshal non proto field")
+	}
+	return proto.Unmarshal(data, message)
+}
+
+// NewDecoder returns a Decoder which reads proto stream from "reader".
+func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder {
+	return DecoderFunc(func(value interface{}) error {
+		buffer, err := ioutil.ReadAll(reader)
+		if err != nil {
+			return err
+		}
+		return marshaller.Unmarshal(buffer, value)
+	})
+}
+
+// NewEncoder returns an Encoder which writes proto stream into "writer".
+func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder {
+	return EncoderFunc(func(value interface{}) error {
+		buffer, err := marshaller.Marshal(value)
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write(buffer)
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+}

runtime/marshal_proto_test.go

@@ -0,0 +1,91 @@
+package runtime_test
+
+import (
+	"reflect"
+	"testing"
+
+	"bytes"
+	"github.com/golang/protobuf/ptypes/timestamp"
+	"github.com/grpc-ecosystem/grpc-gateway/examples/examplepb"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+)
+
+var message = &examplepb.ABitOfEverything{
+	SingleNested:        &examplepb.ABitOfEverything_Nested{},
+	RepeatedStringValue: nil,
+	MappedStringValue:   nil,
+	MappedNestedValue:   nil,
+    RepeatedEnumValue:   nil,
+	TimestampValue:      &timestamp.Timestamp{},
+	Uuid:                "6EC2446F-7E89-4127-B3E6-5C05E6BECBA7",
+	Nested: []*examplepb.ABitOfEverything_Nested{
+		{
+			Name:   "foo",
+			Amount: 12345,
+		},
+	},
+	Uint64Value: 0xFFFFFFFFFFFFFFFF,
+    EnumValue:   examplepb.NumericEnum_ONE,
+	OneofValue: &examplepb.ABitOfEverything_OneofString{
+		OneofString: "bar",
+	},
+    MapValue: map[string]examplepb.NumericEnum{
+		"a": examplepb.NumericEnum_ONE,
+		"b": examplepb.NumericEnum_ZERO,
+	},
+}
+
+func TestProtoMarshalUnmarshal(t *testing.T) {
+	marshaller := runtime.ProtoMarshaller{}
+
+	// Marshal
+	buffer, err := marshaller.Marshal(message)
+	if err != nil {
+		t.Fatalf("Marshalling returned error: %s", err.Error())
+	}
+
+	// Unmarshal
+	unmarshalled := &examplepb.ABitOfEverything{}
+	err = marshaller.Unmarshal(buffer, unmarshalled)
+	if err != nil {
+		t.Fatalf("Unmarshalling returned error: %s", err.Error())
+	}
+
+	if !reflect.DeepEqual(unmarshalled, message) {
+		t.Errorf(
+			"Unmarshalled didn't match original message: (original = %v) != (unmarshalled = %v)",
+			unmarshalled,
+			message,
+		)
+	}
+}
+
+func TestProtoEncoderDecodert(t *testing.T) {
+	marshaller := runtime.ProtoMarshaller{}
+
+	var buf bytes.Buffer
+
+	encoder := marshaller.NewEncoder(&buf)
+	decoder := marshaller.NewDecoder(&buf)
+
+	// Encode
+	err := encoder.Encode(message)
+	if err != nil {
+		t.Fatalf("Encoding returned error: %s", err.Error())
+	}
+
+	// Decode
+	unencoded := &examplepb.ABitOfEverything{}
+	err = decoder.Decode(unencoded)
+	if err != nil {
+		t.Fatalf("Unmarshalling returned error: %s", err.Error())
+	}
+
+	if !reflect.DeepEqual(unencoded, message) {
+		t.Errorf(
+			"Unencoded didn't match original message: (original = %v) != (unencoded = %v)",
+			unencoded,
+			message,
+		)
+	}
+}