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go-micro/server/rpc_codec.go
Vasiliy Tolstov f23638c036 fix import paths for v2 release
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2020-01-30 14:44:40 +03:00

355 lines
7.5 KiB
Go

package server
import (
"bytes"
"sync"
"github.com/micro/go-micro/v2/codec"
raw "github.com/micro/go-micro/v2/codec/bytes"
"github.com/micro/go-micro/v2/codec/grpc"
"github.com/micro/go-micro/v2/codec/json"
"github.com/micro/go-micro/v2/codec/jsonrpc"
"github.com/micro/go-micro/v2/codec/proto"
"github.com/micro/go-micro/v2/codec/protorpc"
"github.com/micro/go-micro/v2/transport"
"github.com/oxtoacart/bpool"
"github.com/pkg/errors"
)
type rpcCodec struct {
socket transport.Socket
codec codec.Codec
protocol string
req *transport.Message
buf *readWriteCloser
// check if we're the first
sync.RWMutex
first chan bool
}
type readWriteCloser struct {
sync.RWMutex
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,
}
// the local buffer pool
bufferPool = bpool.NewSizedBufferPool(32, 1)
)
func (rwc *readWriteCloser) Read(p []byte) (n int, err error) {
rwc.RLock()
defer rwc.RUnlock()
return rwc.rbuf.Read(p)
}
func (rwc *readWriteCloser) Write(p []byte) (n int, err error) {
rwc.Lock()
defer rwc.Unlock()
return rwc.wbuf.Write(p)
}
func (rwc *readWriteCloser) Close() error {
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) {
set := func(v, hdr string) string {
if len(v) > 0 {
return v
}
return m.Header[hdr]
}
m.Id = set(m.Id, "Micro-Id")
m.Error = set(m.Error, "Micro-Error")
m.Endpoint = set(m.Endpoint, "Micro-Endpoint")
m.Method = set(m.Method, "Micro-Method")
m.Target = set(m.Target, "Micro-Service")
// 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)
topic := getHeader("Micro-Topic", msg.Header)
// if the protocol exists (mucp) do nothing
if len(protocol) > 0 {
return nil
}
// newer method of processing messages over transport
if len(topic) > 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: bufferPool.Get(),
wbuf: bufferPool.Get(),
}
r := &rpcCodec{
buf: rwc,
codec: c(rwc),
req: req,
socket: socket,
protocol: "mucp",
first: make(chan bool),
}
// if grpc pre-load the buffer
// TODO: remove this terrible hack
switch r.codec.String() {
case "grpc":
// write the body
rwc.rbuf.Write(req.Body)
// set the protocol
r.protocol = "grpc"
default:
// first is not preloaded
close(r.first)
}
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
select {
case <-c.first:
// not the 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
default:
// we need to lock here to prevent race conditions
// and we make use of a channel otherwise because
// this does not result in a context switch
// locking to check c.first on every call to ReadHeader
// would otherwise drastically slow the code execution
c.Lock()
// recheck before closing because the select statement
// above is not thread safe, so thread safety here is
// mandatory
select {
case <-c.first:
default:
// disable first
close(c.first)
}
// now unlock and we never need this again
c.Unlock()
}
// 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["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 {
// close the codec
c.codec.Close()
// close the socket
err := c.socket.Close()
// put back the buffers
bufferPool.Put(c.buf.rbuf)
bufferPool.Put(c.buf.wbuf)
// return the error
return err
}
func (c *rpcCodec) String() string {
return c.protocol
}