unistack-org/micro
3
0
Fork 3
Code Issues 14 Pull Requests 2 Actions Packages Projects Releases 242 Wiki Activity

Pull rpcplus in local for the time being. We need to modify it for server side middleware

Browse Source
This commit is contained in:
Asim 2015-12-01 23:32:23 +00:00
parent 8825b5c0a8
commit 0c9f8411bb
7 changed files with 805 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
client/rpc_client.go
View File

@ -12,7 +12,6 @@ import (
"github.com/micro/go-micro/registry"
"github.com/micro/go-micro/transport"
rpc "github.com/youtube/vitess/go/rpcplus"
"golang.org/x/net/context"
)
@ -94,7 +93,7 @@ func (r *rpcClient) call(ctx context.Context, address string, request Request, r
}
defer c.Close()
client := rpc.NewClientWithCodec(newRpcPlusCodec(msg, c, cf))
client := newClientWithCodec(newRpcPlusCodec(msg, c, cf))
err = client.Call(ctx, request.Method(), request.Request(), response)
if err != nil {
return err
@ -126,7 +125,7 @@ func (r *rpcClient) stream(ctx context.Context, address string, request Request,
return nil, errors.InternalServerError("go.micro.client", fmt.Sprintf("Error sending request: %v", err))
}
client := rpc.NewClientWithCodec(newRpcPlusCodec(msg, c, cf))
client := newClientWithCodec(newRpcPlusCodec(msg, c, cf))
call := client.StreamGo(request.Method(), request.Request(), responseChan)
return &rpcStream{

5
client/rpc_codec.go
View File

@ -7,7 +7,6 @@ import (
"github.com/micro/go-micro/codec/jsonrpc"
"github.com/micro/go-micro/codec/protorpc"
"github.com/micro/go-micro/transport"
rpc "github.com/youtube/vitess/go/rpcplus"
)
type rpcPlusCodec struct {
@ -63,7 +62,7 @@ func newRpcPlusCodec(req *transport.Message, client transport.Client, c codec.Ne
return r
}
func (c *rpcPlusCodec) WriteRequest(req *rpc.Request, body interface{}) error {
func (c *rpcPlusCodec) WriteRequest(req *request, body interface{}) error {
m := &codec.Message{
Id: req.Seq,
Method: req.ServiceMethod,
@ -76,7 +75,7 @@ func (c *rpcPlusCodec) WriteRequest(req *rpc.Request, body interface{}) error {
return c.client.Send(c.req)
}
func (c *rpcPlusCodec) ReadResponseHeader(r *rpc.Response) error {
func (c *rpcPlusCodec) ReadResponseHeader(r *response) error {
var m transport.Message
if err := c.client.Recv(&m); err != nil {
return err

8
client/rpc_stream.go
View File

@ -1,13 +1,9 @@
package client
import (
rpc "github.com/youtube/vitess/go/rpcplus"
)
type rpcStream struct {
request Request
call *rpc.Call
client *rpc.Client
call *call
client *client
}
func (r *rpcStream) Request() Request {

304
client/rpcplus_client.go Normal file
View File

@ -0,0 +1,304 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package client
import (
"errors"
"io"
"log"
"reflect"
"sync"
"github.com/youtube/vitess/go/trace"
"golang.org/x/net/context"
)
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 = errors.New("connection is shut down")
// call represents an active RPC.
type call struct {
ServiceMethod string // The name of the service and method to call.
Args interface{} // The argument to the function (*struct).
Reply interface{} // The reply from the function (*struct for single, chan * struct for streaming).
Error error // After completion, the error status.
Done chan *call // Strobes when call is complete (nil for streaming RPCs)
Stream bool // True for a streaming RPC call, false otherwise
Subseq uint64 // The next expected subseq in the packets
}
// client represents an RPC client.
// There may be multiple outstanding calls associated
// with a single client, and a client may be used by
// multiple goroutines simultaneously.
type client struct {
mutex sync.Mutex // protects pending, seq, request
sending sync.Mutex
request request
seq uint64
codec clientCodec
pending map[uint64]*call
closing bool
shutdown bool
}
// A clientCodec implements writing of RPC requests and
// reading of RPC responses for the client side of an RPC session.
// The client calls WriteRequest to write a request to the connection
// and calls ReadResponseHeader and ReadResponseBody in pairs
// to read responses. The client calls Close when finished with the
// connection. ReadResponseBody may be called with a nil
// argument to force the body of the response to be read and then
// discarded.
type clientCodec interface {
WriteRequest(*request, interface{}) error
ReadResponseHeader(*response) error
ReadResponseBody(interface{}) error
Close() error
}
type request struct {
ServiceMethod string // format: "Service.Method"
Seq uint64 // sequence number chosen by client
next *request // for free list in Server
}
type response struct {
ServiceMethod string // echoes that of the Request
Seq uint64 // echoes that of the request
Error string // error, if any.
next *response // for free list in Server
}
func (client *client) send(call *call) {
client.sending.Lock()
defer client.sending.Unlock()
// Register this call.
client.mutex.Lock()
if client.shutdown {
call.Error = errShutdown
client.mutex.Unlock()
call.done()
return
}
seq := client.seq
client.seq++
client.pending[seq] = call
client.mutex.Unlock()
// Encode and send the request.
client.request.Seq = seq
client.request.ServiceMethod = call.ServiceMethod
err := client.codec.WriteRequest(&client.request, call.Args)
if err != nil {
client.mutex.Lock()
call = client.pending[seq]
delete(client.pending, seq)
client.mutex.Unlock()
if call != nil {
call.Error = err
call.done()
}
}
}
func (client *client) input() {
var err error
var resp response
for err == nil {
resp = response{}
err = client.codec.ReadResponseHeader(&resp)
if err != nil {
if err == io.EOF && !client.closing {
err = io.ErrUnexpectedEOF
}
break
}
seq := resp.Seq
client.mutex.Lock()
call := client.pending[seq]
client.mutex.Unlock()
switch {
case call == nil:
// We've got no pending call. That usually means that
// WriteRequest partially failed, and call was already
// removed; response is a server telling us about an
// error reading request body. We should still attempt
// to read error body, but there's no one to give it to.
err = client.codec.ReadResponseBody(nil)
if err != nil {
err = errors.New("reading error body: " + err.Error())
}
case resp.Error != "":
// We've got an error response. Give this to the request;
// any subsequent requests will get the ReadResponseBody
// error if there is one.
if !(call.Stream && resp.Error == lastStreamResponseError) {
call.Error = serverError(resp.Error)
}
err = client.codec.ReadResponseBody(nil)
if err != nil {
err = errors.New("reading error payload: " + err.Error())
}
client.done(seq)
case call.Stream:
// call.Reply is a chan *T2
// we need to create a T2 and get a *T2 back
value := reflect.New(reflect.TypeOf(call.Reply).Elem().Elem()).Interface()
err = client.codec.ReadResponseBody(value)
if err != nil {
call.Error = errors.New("reading body " + err.Error())
} else {
// writing on the channel could block forever. For
// instance, if a client calls 'close', this might block
// forever. the current suggestion is for the
// client to drain the receiving channel in that case
reflect.ValueOf(call.Reply).Send(reflect.ValueOf(value))
}
default:
err = client.codec.ReadResponseBody(call.Reply)
if err != nil {
call.Error = errors.New("reading body " + err.Error())
}
client.done(seq)
}
}
// Terminate pending calls.
client.sending.Lock()
client.mutex.Lock()
client.shutdown = true
closing := client.closing
for _, call := range client.pending {
call.Error = err
call.done()
}
client.mutex.Unlock()
client.sending.Unlock()
if err != io.EOF && !closing {
log.Println("rpc: client protocol error:", err)
}
}
func (client *client) done(seq uint64) {
client.mutex.Lock()
call := client.pending[seq]
delete(client.pending, seq)
client.mutex.Unlock()
if call != nil {
call.done()
}
}
func (call *call) done() {
if call.Stream {
// need to close the channel. client won't be able to read any more.
reflect.ValueOf(call.Reply).Close()
return
}
select {
case call.Done <- call:
// ok
default:
// We don't want to block here. It is the caller's responsibility to make
// sure the channel has enough buffer space. See comment in Go().
log.Println("rpc: discarding call reply due to insufficient Done chan capacity")
}
}
// NewclientWithCodec is like Newclient but uses the specified
// codec to encode requests and decode responses.
func newClientWithCodec(codec clientCodec) *client {
client := &client{
codec: codec,
pending: make(map[uint64]*call),
}
go client.input()
return client
}
// Close closes the client connection
func (client *client) Close() error {
client.mutex.Lock()
if client.shutdown || client.closing {
client.mutex.Unlock()
return errShutdown
}
client.closing = true
client.mutex.Unlock()
return client.codec.Close()
}
// Go invokes the function asynchronously. It returns the call structure representing
// the invocation. The done channel will signal when the call is complete by returning
// the same call object. If done is nil, Go will allocate a new channel.
// If non-nil, done must be buffered or Go will deliberately crash.
func (client *client) Go(ctx context.Context, serviceMethod string, args interface{}, reply interface{}, done chan *call) *call {
span := trace.NewSpanFromContext(ctx)
span.StartClient(serviceMethod)
defer span.Finish()
cal := new(call)
cal.ServiceMethod = serviceMethod
cal.Args = args
cal.Reply = reply
if done == nil {
done = make(chan *call, 10) // buffered.
} else {
// If caller passes done != nil, it must arrange that
// done has enough buffer for the number of simultaneous
// RPCs that will be using that channel. If the channel
// is totally unbuffered, it's best not to run at all.
if cap(done) == 0 {
log.Panic("rpc: done channel is unbuffered")
}
}
cal.Done = done
client.send(cal)
return cal
}
// StreamGo invokes the streaming function asynchronously. It returns the call structure representing
// the invocation.
func (client *client) StreamGo(serviceMethod string, args interface{}, replyStream interface{}) *call {
// first check the replyStream object is a stream of pointers to a data structure
typ := reflect.TypeOf(replyStream)
// FIXME: check the direction of the channel, maybe?
if typ.Kind() != reflect.Chan || typ.Elem().Kind() != reflect.Ptr {
log.Panic("rpc: replyStream is not a channel of pointers")
return nil
}
call := new(call)
call.ServiceMethod = serviceMethod
call.Args = args
call.Reply = replyStream
call.Stream = true
call.Subseq = 0
client.send(call)
return call
}
// call invokes the named function, waits for it to complete, and returns its error status.
func (client *client) Call(ctx context.Context, serviceMethod string, args interface{}, reply interface{}) error {
call := <-client.Go(ctx, serviceMethod, args, reply, make(chan *call, 1)).Done
return call.Error
}

7
server/rpc_codec.go
View File

@ -7,7 +7,6 @@ import (
"github.com/micro/go-micro/codec/jsonrpc"
"github.com/micro/go-micro/codec/protorpc"
"github.com/micro/go-micro/transport"
rpc "github.com/youtube/vitess/go/rpcplus"
)
type rpcPlusCodec struct {
@ -47,7 +46,7 @@ func (rwc *readWriteCloser) Close() error {
return nil
}
func newRpcPlusCodec(req *transport.Message, socket transport.Socket, c codec.NewCodec) rpc.ServerCodec {
func newRpcPlusCodec(req *transport.Message, socket transport.Socket, c codec.NewCodec) serverCodec {
rwc := &readWriteCloser{
rbuf: bytes.NewBuffer(req.Body),
wbuf: bytes.NewBuffer(nil),
@ -61,7 +60,7 @@ func newRpcPlusCodec(req *transport.Message, socket transport.Socket, c codec.Ne
return r
}
func (c *rpcPlusCodec) ReadRequestHeader(r *rpc.Request) error {
func (c *rpcPlusCodec) ReadRequestHeader(r *request) error {
var m codec.Message
err := c.codec.ReadHeader(&m, codec.Request)
r.ServiceMethod = m.Method
@ -73,7 +72,7 @@ func (c *rpcPlusCodec) ReadRequestBody(b interface{}) error {
return c.codec.ReadBody(b)
}
func (c *rpcPlusCodec) WriteResponse(r *rpc.Response, body interface{}, last bool) error {
func (c *rpcPlusCodec) WriteResponse(r *response, body interface{}, last bool) error {
c.buf.wbuf.Reset()
m := &codec.Message{
Method: r.ServiceMethod,

5
server/rpc_server.go
View File

@ -13,13 +13,12 @@ import (
"github.com/micro/go-micro/transport"
log "github.com/golang/glog"
rpc "github.com/youtube/vitess/go/rpcplus"
"golang.org/x/net/context"
)
type rpcServer struct {
rpc *rpc.Server
rpc *server
exit chan chan error
sync.RWMutex
@ -31,7 +30,7 @@ type rpcServer struct {
func newRpcServer(opts ...Option) Server {
return &rpcServer{
opts: newOptions(opts...),
rpc: rpc.NewServer(),
rpc: newServer(),
handlers: make(map[string]Handler),
subscribers: make(map[*subscriber][]broker.Subscriber),
exit: make(chan chan error),

490
server/rpcplus_server.go Normal file
View File

@ -0,0 +1,490 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//
// Meh, we need to get rid of this shit
package server
import (
"errors"
"io"
"log"
"reflect"
"strings"
"sync"
"unicode"
"unicode/utf8"
"golang.org/x/net/context"
)
const (
lastStreamResponseError = "EOS"
)
var (
// A value sent as a placeholder for the server's response value when the server
// receives an invalid request. It is never decoded by the client since the Response
// contains an error when it is used.
invalidRequest = struct{}{}
// Precompute the reflect type for error. Can't use error directly
// because Typeof takes an empty interface value. This is annoying.
typeOfError = reflect.TypeOf((*error)(nil)).Elem()
)
type methodType struct {
sync.Mutex // protects counters
method reflect.Method
ArgType reflect.Type
ReplyType reflect.Type
ContextType reflect.Type
stream bool
numCalls uint
}
func (m *methodType) TakesContext() bool {
return m.ContextType != nil
}
func (m *methodType) NumCalls() (n uint) {
m.Lock()
n = m.numCalls
m.Unlock()
return n
}
type service struct {
name string // name of service
rcvr reflect.Value // receiver of methods for the service
typ reflect.Type // type of the receiver
method map[string]*methodType // registered methods
}
type request struct {
ServiceMethod string // format: "Service.Method"
Seq uint64 // sequence number chosen by client
next *request // for free list in Server
}
type response struct {
ServiceMethod string // echoes that of the Request
Seq uint64 // echoes that of the request
Error string // error, if any.
next *response // for free list in Server
}
// server represents an RPC Server.
type server struct {
mu sync.Mutex // protects the serviceMap
serviceMap map[string]*service
reqLock sync.Mutex // protects freeReq
freeReq *request
respLock sync.Mutex // protects freeResp
freeResp *response
}
func newServer() *server {
return &server{serviceMap: make(map[string]*service)}
}
// Is this an exported - upper case - name?
func isExported(name string) bool {
rune, _ := utf8.DecodeRuneInString(name)
return unicode.IsUpper(rune)
}
// Is this type exported or a builtin?
func isExportedOrBuiltinType(t reflect.Type) bool {
for t.Kind() == reflect.Ptr {
t = t.Elem()
}
// PkgPath will be non-empty even for an exported type,
// so we need to check the type name as well.
return isExported(t.Name()) || t.PkgPath() == ""
}
func (server *server) Register(rcvr interface{}) error {
return server.register(rcvr, "", false)
}
// prepareMethod returns a methodType for the provided method or nil
// in case if the method was unsuitable.
func prepareMethod(method reflect.Method) *methodType {
mtype := method.Type
mname := method.Name
var replyType, argType, contextType reflect.Type
stream := false
// Method must be exported.
if method.PkgPath != "" {
return nil
}
switch mtype.NumIn() {
case 3:
// normal method
argType = mtype.In(1)
replyType = mtype.In(2)
contextType = nil
case 4:
// method that takes a context
argType = mtype.In(2)
replyType = mtype.In(3)
contextType = mtype.In(1)
default:
log.Println("method", mname, "of", mtype, "has wrong number of ins:", mtype.NumIn())
return nil
}
// First arg need not be a pointer.
if !isExportedOrBuiltinType(argType) {
log.Println(mname, "argument type not exported:", argType)
return nil
}
// the second argument will tell us if it's a streaming call
// or a regular call
if replyType.Kind() == reflect.Func {
// this is a streaming call
stream = true
if replyType.NumIn() != 1 {
log.Println("method", mname, "sendReply has wrong number of ins:", replyType.NumIn())
return nil
}
if replyType.In(0).Kind() != reflect.Interface {
log.Println("method", mname, "sendReply parameter type not an interface:", replyType.In(0))
return nil
}
if replyType.NumOut() != 1 {
log.Println("method", mname, "sendReply has wrong number of outs:", replyType.NumOut())
return nil
}
if returnType := replyType.Out(0); returnType != typeOfError {
log.Println("method", mname, "sendReply returns", returnType.String(), "not error")
return nil
}
} else if replyType.Kind() != reflect.Ptr {
log.Println("method", mname, "reply type not a pointer:", replyType)
return nil
}
// Reply type must be exported.
if !isExportedOrBuiltinType(replyType) {
log.Println("method", mname, "reply type not exported:", replyType)
return nil
}
// Method needs one out.
if mtype.NumOut() != 1 {
log.Println("method", mname, "has wrong number of outs:", mtype.NumOut())
return nil
}
// The return type of the method must be error.
if returnType := mtype.Out(0); returnType != typeOfError {
log.Println("method", mname, "returns", returnType.String(), "not error")
return nil
}
return &methodType{method: method, ArgType: argType, ReplyType: replyType, ContextType: contextType, stream: stream}
}
func (server *server) register(rcvr interface{}, name string, useName bool) error {
server.mu.Lock()
defer server.mu.Unlock()
if server.serviceMap == nil {
server.serviceMap = make(map[string]*service)
}
s := new(service)
s.typ = reflect.TypeOf(rcvr)
s.rcvr = reflect.ValueOf(rcvr)
sname := reflect.Indirect(s.rcvr).Type().Name()
if useName {
sname = name
}
if sname == "" {
log.Fatal("rpc: no service name for type", s.typ.String())
}
if !isExported(sname) && !useName {
s := "rpc Register: type " + sname + " is not exported"
log.Print(s)
return errors.New(s)
}
if _, present := server.serviceMap[sname]; present {
return errors.New("rpc: service already defined: " + sname)
}
s.name = sname
s.method = make(map[string]*methodType)
// Install the methods
for m := 0; m < s.typ.NumMethod(); m++ {
method := s.typ.Method(m)
if mt := prepareMethod(method); mt != nil {
s.method[method.Name] = mt
}
}
if len(s.method) == 0 {
s := "rpc Register: type " + sname + " has no exported methods of suitable type"
log.Print(s)
return errors.New(s)
}
server.serviceMap[s.name] = s
return nil
}
func (server *server) sendResponse(sending *sync.Mutex, req *request, reply interface{}, codec serverCodec, errmsg string, last bool) (err error) {
resp := server.getResponse()
// Encode the response header
resp.ServiceMethod = req.ServiceMethod
if errmsg != "" {
resp.Error = errmsg
reply = invalidRequest
}
resp.Seq = req.Seq
sending.Lock()
err = codec.WriteResponse(resp, reply, last)
if err != nil {
log.Println("rpc: writing response:", err)
}
sending.Unlock()
server.freeResponse(resp)
return err
}
func (s *service) call(ctx context.Context, server *server, sending *sync.Mutex, mtype *methodType, req *request, argv, replyv reflect.Value, codec serverCodec) {
mtype.Lock()
mtype.numCalls++
mtype.Unlock()
function := mtype.method.Func
var returnValues []reflect.Value
if !mtype.stream {
// Invoke the method, providing a new value for the reply.
if mtype.TakesContext() {
returnValues = function.Call([]reflect.Value{s.rcvr, mtype.prepareContext(ctx), argv, replyv})
} else {
returnValues = function.Call([]reflect.Value{s.rcvr, argv, replyv})
}
// The return value for the method is an error.
errInter := returnValues[0].Interface()
errmsg := ""
if errInter != nil {
errmsg = errInter.(error).Error()
}
server.sendResponse(sending, req, replyv.Interface(), codec, errmsg, true)
server.freeRequest(req)
return
}
// declare a local error to see if we errored out already
// keep track of the type, to make sure we return
// the same one consistently
var lastError error
var firstType reflect.Type
sendReply := func(oneReply interface{}) error {
// we already triggered an error, we're done
if lastError != nil {
return lastError
}
// check the oneReply has the right type using reflection
typ := reflect.TypeOf(oneReply)
if firstType == nil {
firstType = typ
} else {
if firstType != typ {
log.Println("passing wrong type to sendReply",
firstType, "!=", typ)
lastError = errors.New("rpc: passing wrong type to sendReply")
return lastError
}
}
lastError = server.sendResponse(sending, req, oneReply, codec, "", false)
if lastError != nil {
return lastError
}
// we manage to send, we're good
return nil
}
// Invoke the method, providing a new value for the reply.
if mtype.TakesContext() {
returnValues = function.Call([]reflect.Value{s.rcvr, mtype.prepareContext(ctx), argv, reflect.ValueOf(sendReply)})
} else {
returnValues = function.Call([]reflect.Value{s.rcvr, argv, reflect.ValueOf(sendReply)})
}
errInter := returnValues[0].Interface()
errmsg := ""
if errInter != nil {
// the function returned an error, we use that
errmsg = errInter.(error).Error()
} else if lastError != nil {
// we had an error inside sendReply, we use that
errmsg = lastError.Error()
} else {
// no error, we send the special EOS error
errmsg = lastStreamResponseError
}
// this is the last packet, we don't do anything with
// the error here (well sendStreamResponse will log it
// already)
server.sendResponse(sending, req, nil, codec, errmsg, true)
server.freeRequest(req)
}
func (m *methodType) prepareContext(ctx context.Context) reflect.Value {
if contextv := reflect.ValueOf(ctx); contextv.IsValid() {
return contextv
}
return reflect.Zero(m.ContextType)
}
func (server *server) ServeRequestWithContext(ctx context.Context, codec serverCodec) error {
sending := new(sync.Mutex)
service, mtype, req, argv, replyv, keepReading, err := server.readRequest(codec)
if err != nil {
if !keepReading {
return err
}
// send a response if we actually managed to read a header.
if req != nil {
server.sendResponse(sending, req, invalidRequest, codec, err.Error(), true)
server.freeRequest(req)
}
return err
}
service.call(ctx, server, sending, mtype, req, argv, replyv, codec)
return nil
}
func (server *server) getRequest() *request {
server.reqLock.Lock()
req := server.freeReq
if req == nil {
req = new(request)
} else {
server.freeReq = req.next
*req = request{}
}
server.reqLock.Unlock()
return req
}
func (server *server) freeRequest(req *request) {
server.reqLock.Lock()
req.next = server.freeReq
server.freeReq = req
server.reqLock.Unlock()
}
func (server *server) getResponse() *response {
server.respLock.Lock()
resp := server.freeResp
if resp == nil {
resp = new(response)
} else {
server.freeResp = resp.next
*resp = response{}
}
server.respLock.Unlock()
return resp
}
func (server *server) freeResponse(resp *response) {
server.respLock.Lock()
resp.next = server.freeResp
server.freeResp = resp
server.respLock.Unlock()
}
func (server *server) readRequest(codec serverCodec) (service *service, mtype *methodType, req *request, argv, replyv reflect.Value, keepReading bool, err error) {
service, mtype, req, keepReading, err = server.readRequestHeader(codec)
if err != nil {
if !keepReading {
return
}
// discard body
codec.ReadRequestBody(nil)
return
}
// Decode the argument value.
argIsValue := false // if true, need to indirect before calling.
if mtype.ArgType.Kind() == reflect.Ptr {
argv = reflect.New(mtype.ArgType.Elem())
} else {
argv = reflect.New(mtype.ArgType)
argIsValue = true
}
// argv guaranteed to be a pointer now.
if err = codec.ReadRequestBody(argv.Interface()); err != nil {
return
}
if argIsValue {
argv = argv.Elem()
}
if !mtype.stream {
replyv = reflect.New(mtype.ReplyType.Elem())
}
return
}
func (server *server) readRequestHeader(codec serverCodec) (service *service, mtype *methodType, req *request, keepReading bool, err error) {
// Grab the request header.
req = server.getRequest()
err = codec.ReadRequestHeader(req)
if err != nil {
req = nil
if err == io.EOF || err == io.ErrUnexpectedEOF {
return
}
err = errors.New("rpc: server cannot decode request: " + err.Error())
return
}
// We read the header successfully. If we see an error now,
// we can still recover and move on to the next request.
keepReading = true
serviceMethod := strings.Split(req.ServiceMethod, ".")
if len(serviceMethod) != 2 {
err = errors.New("rpc: service/method request ill-formed: " + req.ServiceMethod)
return
}
// Look up the request.
server.mu.Lock()
service = server.serviceMap[serviceMethod[0]]
server.mu.Unlock()
if service == nil {
err = errors.New("rpc: can't find service " + req.ServiceMethod)
return
}
mtype = service.method[serviceMethod[1]]
if mtype == nil {
err = errors.New("rpc: can't find method " + req.ServiceMethod)
}
return
}
// A serverCodec implements reading of RPC requests and writing of
// RPC responses for the server side of an RPC session.
// The server calls ReadRequestHeader and ReadRequestBody in pairs
// to read requests from the connection, and it calls WriteResponse to
// write a response back. The server calls Close when finished with the
// connection. ReadRequestBody may be called with a nil
// argument to force the body of the request to be read and discarded.
type serverCodec interface {
ReadRequestHeader(*request) error
ReadRequestBody(interface{}) error
WriteResponse(*response, interface{}, bool) error
Close() error
}