Add grpc codec

client/rpc_codec.go

@@ -6,8 +6,8 @@ import (
 
 	"github.com/micro/go-micro/codec"
 	"github.com/micro/go-micro/codec/json"
-	"github.com/micro/go-micro/codec/proto"
 	"github.com/micro/go-micro/codec/jsonrpc"
+	"github.com/micro/go-micro/codec/proto"
 	"github.com/micro/go-micro/codec/protorpc"
 	"github.com/micro/go-micro/errors"
 	"github.com/micro/go-micro/transport"

codec/grpc/grpc.go

@@ -0,0 +1,119 @@
+// Package grpc provides a grpc codec
+package grpc
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/micro/go-micro/codec"
+)
+
+type Codec struct {
+	Conn        io.ReadWriteCloser
+	ContentType string
+}
+
+func (c *Codec) ReadHeader(m *codec.Message, t codec.MessageType) error {
+	if ct := m.Header["Content-Type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	if ct := m.Header["content-type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	// service method
+	path := m.Header[":path"]
+	if len(path) == 0 || path[0] != '/' {
+		m.Target = m.Header["X-Micro-Service"]
+		m.Method = m.Header["X-Micro-Method"]
+	} else {
+		// [ , a.package.Foo, Bar]
+		parts := strings.Split(path, "/")
+		if len(parts) != 3 {
+			return errors.New("Unknown request path")
+		}
+		service := strings.Split(parts[1], ".")
+		m.Method = strings.Join([]string{service[len(service)-1], parts[2]}, ".")
+		m.Target = strings.Join(service[:len(service)-1], ".")
+	}
+
+	return nil
+}
+
+func (c *Codec) ReadBody(b interface{}) error {
+	// no body
+	if b == nil {
+		return nil
+	}
+
+	_, buf, err := decode(c.Conn)
+	if err != nil {
+		return err
+	}
+
+	switch c.ContentType {
+	case "application/grpc+json":
+		return json.Unmarshal(buf, b)
+	case "application/grpc+proto", "application/grpc":
+		return proto.Unmarshal(buf, b.(proto.Message))
+	}
+
+	return errors.New("Unsupported Content-Type")
+}
+
+func (c *Codec) Write(m *codec.Message, b interface{}) error {
+	var buf []byte
+	var err error
+
+	if ct := m.Header["Content-Type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	if ct := m.Header["content-type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	m.Header["Trailer"] = "grpc-status, grpc-message"
+
+	switch c.ContentType {
+	case "application/grpc+json":
+		buf, err = json.Marshal(b)
+	case "application/grpc+proto", "application/grpc":
+		pb, ok := b.(proto.Message)
+		if ok {
+			buf, err = proto.Marshal(pb)
+		}
+	default:
+		err = errors.New("Unsupported Content-Type")
+	}
+
+	if err != nil {
+		m.Header["grpc-status"] = "8"
+		m.Header["grpc-message"] = err.Error()
+		return err
+	}
+
+	m.Header["grpc-status"] = "0"
+	m.Header["grpc-message"] = ""
+
+	return encode(0, buf, c.Conn)
+}
+
+func (c *Codec) Close() error {
+	return c.Conn.Close()
+}
+
+func (c *Codec) String() string {
+	return "grpc"
+}
+
+func NewCodec(c io.ReadWriteCloser) codec.Codec {
+	return &Codec{
+		Conn:        c,
+		ContentType: "application/grpc",
+	}
+}

codec/grpc/util.go

@@ -0,0 +1,70 @@
+package grpc
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+var (
+	maxMessageSize = 1024 * 1024 * 4
+	maxInt         = int(^uint(0) >> 1)
+)
+
+func decode(r io.Reader) (uint8, []byte, error) {
+	header := make([]byte, 5)
+
+	// read the header
+	if _, err := r.Read(header[:]); err != nil {
+		return uint8(0), nil, err
+	}
+
+	// get encoding format e.g compressed
+	cf := uint8(header[0])
+
+	// get message length
+	length := binary.BigEndian.Uint32(header[1:])
+
+	// no encoding format
+	if length == 0 {
+		return cf, nil, nil
+	}
+
+	//
+	if int64(length) > int64(maxInt) {
+		return cf, nil, fmt.Errorf("grpc: received message larger than max length allowed on current machine (%d vs. %d)", length, maxInt)
+	}
+	if int(length) > maxMessageSize {
+		return cf, nil, fmt.Errorf("grpc: received message larger than max (%d vs. %d)", length, maxMessageSize)
+	}
+
+	msg := make([]byte, int(length))
+
+	if _, err := r.Read(msg); err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return cf, nil, err
+	}
+
+	return cf, msg, nil
+}
+
+func encode(cf uint8, buf []byte, w io.Writer) error {
+	header := make([]byte, 5)
+
+	// set compression
+	header[0] = byte(cf)
+
+	// write length as header
+	binary.BigEndian.PutUint32(header[1:], uint32(len(buf)))
+
+	// read the header
+	if _, err := w.Write(header[:]); err != nil {
+		return err
+	}
+
+	// write the buffer
+	_, err := w.Write(buf)
+	return err
+}

server/rpc_codec.go

@@ -4,9 +4,10 @@ import (
 	"bytes"
 
 	"github.com/micro/go-micro/codec"
+	"github.com/micro/go-micro/codec/grpc"
 	"github.com/micro/go-micro/codec/json"
-        "github.com/micro/go-micro/codec/proto"
 	"github.com/micro/go-micro/codec/jsonrpc"
+	"github.com/micro/go-micro/codec/proto"
 	"github.com/micro/go-micro/codec/protorpc"
 	"github.com/micro/go-micro/transport"
 	"github.com/pkg/errors"
@@ -27,6 +28,9 @@ type readWriteCloser struct {
 
 var (
 	defaultCodecs = map[string]codec.NewCodec{
+		"application/grpc":         grpc.NewCodec,
+		"application/grpc+json":    grpc.NewCodec,
+		"application/grpc+proto":   grpc.NewCodec,
 		"application/json":         json.NewCodec,
 		"application/json-rpc":     jsonrpc.NewCodec,
 		"application/protobuf":     proto.NewCodec,

transport/http_transport.go

@@ -245,6 +245,9 @@ func (h *httpTransportSocket) Recv(m *Message) error {
 			}
 		}
 
+		// set path
+		m.Header[":path"] = h.r.URL.Path
+
 		// return early early
 		return nil
 	}
@@ -276,6 +279,9 @@ func (h *httpTransportSocket) Recv(m *Message) error {
 		}
 	}
 
+	// set path
+	m.Header[":path"] = h.r.URL.Path
+
 	return nil
 }