micro/client/mucp/mucp_codec.go
Asim Aslam 563768b58a
v3 refactor (#1868)
* Move to v3

Co-authored-by: Ben Toogood <bentoogood@gmail.com>
2020-07-27 13:22:00 +01:00

268 lines
5.8 KiB
Go

package mucp
import (
"bytes"
errs "errors"
"github.com/micro/go-micro/v3/codec"
raw "github.com/micro/go-micro/v3/codec/bytes"
"github.com/micro/go-micro/v3/codec/grpc"
"github.com/micro/go-micro/v3/codec/json"
"github.com/micro/go-micro/v3/codec/jsonrpc"
"github.com/micro/go-micro/v3/codec/proto"
"github.com/micro/go-micro/v3/codec/protorpc"
"github.com/micro/go-micro/v3/errors"
"github.com/micro/go-micro/v3/registry"
"github.com/micro/go-micro/v3/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) {
set := func(v, hdr string) string {
if len(v) > 0 {
return v
}
return m.Header[hdr]
}
// check error in header
m.Error = set(m.Error, "Micro-Error")
// check endpoint in header
m.Endpoint = set(m.Endpoint, "Micro-Endpoint")
// check method in header
m.Method = set(m.Method, "Micro-Method")
// set the request id
m.Id = set(m.Id, "Micro-Id")
}
func setHeaders(m *codec.Message, stream string) {
set := func(hdr, v string) {
if len(v) == 0 {
return
}
m.Header[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 {
// get the protocol from node metadata
if protocol := node.Metadata["protocol"]; len(protocol) > 0 {
return nil
}
// processing topic publishing
if len(msg.Header["Micro-Topic"]) > 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 {
if b, ok := body.(*raw.Frame); ok {
// set body
m.Body = b.Data
} else {
// 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"
}