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go-micro/server/rpc_codec.go
2019-08-26 12:33:59 +01:00

320 lines
6.6 KiB
Go

package server
import (
"bytes"
"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/transport"
"github.com/pkg/errors"
)
type rpcCodec struct {
socket transport.Socket
codec codec.Codec
first bool
protocol string
req *transport.Message
buf *readWriteCloser
}
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/json": json.NewCodec,
"application/json-rpc": jsonrpc.NewCodec,
"application/protobuf": proto.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 getHeader(hdr string, md map[string]string) string {
if hd := md[hdr]; len(hd) > 0 {
return hd
}
return md["X-"+hdr]
}
func getHeaders(m *codec.Message) {
get := func(hdr, v string) string {
if len(v) > 0 {
return v
}
if hd := m.Header[hdr]; len(hd) > 0 {
return hd
}
// old
return m.Header["X-"+hdr]
}
m.Id = get("Micro-Id", m.Id)
m.Error = get("Micro-Error", m.Error)
m.Endpoint = get("Micro-Endpoint", m.Endpoint)
m.Method = get("Micro-Method", m.Method)
m.Target = get("Micro-Service", m.Target)
// TODO: remove this cruft
if len(m.Endpoint) == 0 {
m.Endpoint = m.Method
}
}
func setHeaders(m, r *codec.Message) {
set := func(hdr, v string) {
if len(v) == 0 {
return
}
m.Header[hdr] = v
m.Header["X-"+hdr] = v
}
// set headers
set("Micro-Id", r.Id)
set("Micro-Service", r.Target)
set("Micro-Method", r.Method)
set("Micro-Endpoint", r.Endpoint)
set("Micro-Error", r.Error)
}
// setupProtocol sets up the old protocol
func setupProtocol(msg *transport.Message) codec.NewCodec {
service := getHeader("Micro-Service", msg.Header)
method := getHeader("Micro-Method", msg.Header)
endpoint := getHeader("Micro-Endpoint", msg.Header)
protocol := getHeader("Micro-Protocol", msg.Header)
target := getHeader("Micro-Target", msg.Header)
// if the protocol exists (mucp) do nothing
if len(protocol) > 0 {
return nil
}
// if no service/method/endpoint then it's the old protocol
if len(service) == 0 && len(method) == 0 && len(endpoint) == 0 {
return defaultCodecs[msg.Header["Content-Type"]]
}
// old target method specified
if len(target) > 0 {
return defaultCodecs[msg.Header["Content-Type"]]
}
// no method then set to endpoint
if len(method) == 0 {
msg.Header["Micro-Method"] = endpoint
}
// no endpoint then set to method
if len(endpoint) == 0 {
msg.Header["Micro-Endpoint"] = method
}
return nil
}
func newRpcCodec(req *transport.Message, socket transport.Socket, c codec.NewCodec) codec.Codec {
rwc := &readWriteCloser{
rbuf: bytes.NewBuffer(nil),
wbuf: bytes.NewBuffer(nil),
}
r := &rpcCodec{
buf: rwc,
codec: c(rwc),
req: req,
socket: socket,
protocol: "mucp",
}
// if grpc pre-load the buffer
// TODO: remove this terrible hack
switch r.codec.String() {
case "grpc":
// set as first
r.first = true
// write the body
rwc.rbuf.Write(req.Body)
// set the protocol
r.protocol = "grpc"
}
return r
}
func (c *rpcCodec) ReadHeader(r *codec.Message, t codec.MessageType) error {
// the initial message
m := codec.Message{
Header: c.req.Header,
Body: c.req.Body,
}
// first message could be pre-loaded
if !c.first {
var tm transport.Message
// read off the socket
if err := c.socket.Recv(&tm); err != nil {
return err
}
// reset the read buffer
c.buf.rbuf.Reset()
// write the body to the buffer
if _, err := c.buf.rbuf.Write(tm.Body); err != nil {
return err
}
// set the message header
m.Header = tm.Header
// set the message body
m.Body = tm.Body
// set req
c.req = &tm
}
// disable first
c.first = false
// set some internal things
getHeaders(&m)
// read header via codec
if err := c.codec.ReadHeader(&m, codec.Request); err != nil {
return err
}
// fallback for 0.14 and older
if len(m.Endpoint) == 0 {
m.Endpoint = m.Method
}
// set message
*r = m
return nil
}
func (c *rpcCodec) ReadBody(b interface{}) error {
// don't read empty body
if len(c.req.Body) == 0 {
return nil
}
// read raw data
if v, ok := b.(*raw.Frame); ok {
v.Data = c.req.Body
return nil
}
// decode the usual way
return c.codec.ReadBody(b)
}
func (c *rpcCodec) Write(r *codec.Message, b interface{}) error {
c.buf.wbuf.Reset()
// create a new message
m := &codec.Message{
Target: r.Target,
Method: r.Method,
Endpoint: r.Endpoint,
Id: r.Id,
Error: r.Error,
Type: r.Type,
Header: r.Header,
}
if m.Header == nil {
m.Header = map[string]string{}
}
setHeaders(m, r)
// the body being sent
var body []byte
// is it a raw frame?
if v, ok := b.(*raw.Frame); ok {
body = v.Data
// if we have encoded data just send it
} else if len(r.Body) > 0 {
body = r.Body
// write the body to codec
} else if err := c.codec.Write(m, b); err != nil {
c.buf.wbuf.Reset()
// write an error if it failed
m.Error = errors.Wrapf(err, "Unable to encode body").Error()
m.Header["X-Micro-Error"] = m.Error
m.Header["Micro-Error"] = m.Error
// no body to write
if err := c.codec.Write(m, nil); err != nil {
return err
}
} else {
// set the body
body = c.buf.wbuf.Bytes()
}
// Set content type if theres content
if len(body) > 0 {
m.Header["Content-Type"] = c.req.Header["Content-Type"]
}
// send on the socket
return c.socket.Send(&transport.Message{
Header: m.Header,
Body: body,
})
}
func (c *rpcCodec) Close() error {
c.buf.Close()
c.codec.Close()
return c.socket.Close()
}
func (c *rpcCodec) String() string {
return c.protocol
}