1
0
mirror of https://github.com/go-micro/go-micro.git synced 2024-11-30 08:06:40 +02:00
go-micro/client/rpc_codec.go
2019-08-16 17:24:17 +01:00

276 lines
5.8 KiB
Go

package client
import (
"bytes"
errs "errors"
"github.com/micro/go-micro/codec"
raw "github.com/micro/go-micro/codec/bytes"
"github.com/micro/go-micro/codec/grpc"
"github.com/micro/go-micro/codec/json"
"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/registry"
"github.com/micro/go-micro/transport"
)
const (
lastStreamResponseError = "EOS"
)
// serverError represents an error that has been returned from
// the remote side of the RPC connection.
type serverError string
func (e serverError) Error() string {
return string(e)
}
// errShutdown holds the specific error for closing/closed connections
var (
errShutdown = errs.New("connection is shut down")
)
type rpcCodec struct {
client transport.Client
codec codec.Codec
req *transport.Message
buf *readWriteCloser
// signify if its a stream
stream string
}
type readWriteCloser struct {
wbuf *bytes.Buffer
rbuf *bytes.Buffer
}
var (
DefaultContentType = "application/protobuf"
DefaultCodecs = map[string]codec.NewCodec{
"application/grpc": grpc.NewCodec,
"application/grpc+json": grpc.NewCodec,
"application/grpc+proto": grpc.NewCodec,
"application/protobuf": proto.NewCodec,
"application/json": json.NewCodec,
"application/json-rpc": jsonrpc.NewCodec,
"application/proto-rpc": protorpc.NewCodec,
"application/octet-stream": raw.NewCodec,
}
// TODO: remove legacy codec list
defaultCodecs = map[string]codec.NewCodec{
"application/json": jsonrpc.NewCodec,
"application/json-rpc": jsonrpc.NewCodec,
"application/protobuf": protorpc.NewCodec,
"application/proto-rpc": protorpc.NewCodec,
"application/octet-stream": protorpc.NewCodec,
}
)
func (rwc *readWriteCloser) Read(p []byte) (n int, err error) {
return rwc.rbuf.Read(p)
}
func (rwc *readWriteCloser) Write(p []byte) (n int, err error) {
return rwc.wbuf.Write(p)
}
func (rwc *readWriteCloser) Close() error {
rwc.rbuf.Reset()
rwc.wbuf.Reset()
return nil
}
func getHeaders(m *codec.Message) {
get := func(hdr string) string {
if hd := m.Header[hdr]; len(hd) > 0 {
return hd
}
// old
return m.Header["X-"+hdr]
}
// check error in header
if len(m.Error) == 0 {
m.Error = get("Micro-Error")
}
// check endpoint in header
if len(m.Endpoint) == 0 {
m.Endpoint = get("Micro-Endpoint")
}
// check method in header
if len(m.Method) == 0 {
m.Method = get("Micro-Method")
}
if len(m.Id) == 0 {
m.Id = get("Micro-Id")
}
}
func setHeaders(m *codec.Message, stream string) {
set := func(hdr, v string) {
if len(v) == 0 {
return
}
m.Header[hdr] = v
m.Header["X-"+hdr] = v
}
set("Micro-Id", m.Id)
set("Micro-Service", m.Target)
set("Micro-Method", m.Method)
set("Micro-Endpoint", m.Endpoint)
set("Micro-Error", m.Error)
if len(stream) > 0 {
set("Micro-Stream", stream)
}
}
// setupProtocol sets up the old protocol
func setupProtocol(msg *transport.Message, node *registry.Node) codec.NewCodec {
protocol := node.Metadata["protocol"]
// got protocol
if len(protocol) > 0 {
return nil
}
// no protocol use old codecs
switch msg.Header["Content-Type"] {
case "application/json":
msg.Header["Content-Type"] = "application/json-rpc"
case "application/protobuf":
msg.Header["Content-Type"] = "application/proto-rpc"
}
// now return codec
return defaultCodecs[msg.Header["Content-Type"]]
}
func newRpcCodec(req *transport.Message, client transport.Client, c codec.NewCodec, stream string) codec.Codec {
rwc := &readWriteCloser{
wbuf: bytes.NewBuffer(nil),
rbuf: bytes.NewBuffer(nil),
}
r := &rpcCodec{
buf: rwc,
client: client,
codec: c(rwc),
req: req,
stream: stream,
}
return r
}
func (c *rpcCodec) Write(m *codec.Message, body interface{}) error {
c.buf.wbuf.Reset()
// create header
if m.Header == nil {
m.Header = map[string]string{}
}
// copy original header
for k, v := range c.req.Header {
m.Header[k] = v
}
// set the mucp headers
setHeaders(m, c.stream)
// if body is bytes Frame don't encode
if body != nil {
b, ok := body.(*raw.Frame)
if ok {
// set body
m.Body = b.Data
body = nil
}
}
if len(m.Body) == 0 {
// write to codec
if err := c.codec.Write(m, body); err != nil {
return errors.InternalServerError("go.micro.client.codec", err.Error())
}
// set body
m.Body = c.buf.wbuf.Bytes()
}
// create new transport message
msg := transport.Message{
Header: m.Header,
Body: m.Body,
}
// send the request
if err := c.client.Send(&msg); err != nil {
return errors.InternalServerError("go.micro.client.transport", err.Error())
}
return nil
}
func (c *rpcCodec) ReadHeader(m *codec.Message, r codec.MessageType) error {
var tm transport.Message
// read message from transport
if err := c.client.Recv(&tm); err != nil {
return errors.InternalServerError("go.micro.client.transport", err.Error())
}
c.buf.rbuf.Reset()
c.buf.rbuf.Write(tm.Body)
// set headers from transport
m.Header = tm.Header
// read header
err := c.codec.ReadHeader(m, r)
// get headers
getHeaders(m)
// return header error
if err != nil {
return errors.InternalServerError("go.micro.client.codec", err.Error())
}
return nil
}
func (c *rpcCodec) ReadBody(b interface{}) error {
// read body
// read raw data
if v, ok := b.(*raw.Frame); ok {
v.Data = c.buf.rbuf.Bytes()
return nil
}
if err := c.codec.ReadBody(b); err != nil {
return errors.InternalServerError("go.micro.client.codec", err.Error())
}
return nil
}
func (c *rpcCodec) Close() error {
c.buf.Close()
c.codec.Close()
if err := c.client.Close(); err != nil {
return errors.InternalServerError("go.micro.client.transport", err.Error())
}
return nil
}
func (c *rpcCodec) String() string {
return "rpc"
}