plugeth/rpc/testservice_test.go
Felix Lange 245f3146c2
rpc: implement full bi-directional communication (#18471)
New APIs added:

    client.RegisterName(namespace, service) // makes service available to server
    client.Notify(ctx, method, args...)     // sends a notification
    ClientFromContext(ctx)                  // to get a client in handler method

This is essentially a rewrite of the server-side code. JSON-RPC
processing code is now the same on both server and client side. Many
minor issues were fixed in the process and there is a new test suite for
JSON-RPC spec compliance (and non-compliance in some cases).

List of behavior changes:

- Method handlers are now called with a per-request context instead of a
  per-connection context. The context is canceled right after the method
  returns.
- Subscription error channels are always closed when the connection
  ends. There is no need to also wait on the Notifier's Closed channel
  to detect whether the subscription has ended.
- Client now omits "params" instead of sending "params": null when there
  are no arguments to a call. The previous behavior was not compliant
  with the spec. The server still accepts "params": null.
- Floating point numbers are allowed as "id". The spec doesn't allow
  them, but we handle request "id" as json.RawMessage and guarantee that
  the same number will be sent back.
- Logging is improved significantly. There is now a message at DEBUG
  level for each RPC call served.
2019-02-04 13:47:34 +01:00

181 lines
4.4 KiB
Go

// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package rpc
import (
"context"
"encoding/binary"
"errors"
"sync"
"time"
)
func newTestServer() *Server {
server := NewServer()
server.idgen = sequentialIDGenerator()
if err := server.RegisterName("test", new(testService)); err != nil {
panic(err)
}
if err := server.RegisterName("nftest", new(notificationTestService)); err != nil {
panic(err)
}
return server
}
func sequentialIDGenerator() func() ID {
var (
mu sync.Mutex
counter uint64
)
return func() ID {
mu.Lock()
defer mu.Unlock()
counter++
id := make([]byte, 8)
binary.BigEndian.PutUint64(id, counter)
return encodeID(id)
}
}
type testService struct{}
type Args struct {
S string
}
type Result struct {
String string
Int int
Args *Args
}
func (s *testService) NoArgsRets() {}
func (s *testService) Echo(str string, i int, args *Args) Result {
return Result{str, i, args}
}
func (s *testService) EchoWithCtx(ctx context.Context, str string, i int, args *Args) Result {
return Result{str, i, args}
}
func (s *testService) Sleep(ctx context.Context, duration time.Duration) {
time.Sleep(duration)
}
func (s *testService) Rets() (string, error) {
return "", nil
}
func (s *testService) InvalidRets1() (error, string) {
return nil, ""
}
func (s *testService) InvalidRets2() (string, string) {
return "", ""
}
func (s *testService) InvalidRets3() (string, string, error) {
return "", "", nil
}
func (s *testService) CallMeBack(ctx context.Context, method string, args []interface{}) (interface{}, error) {
c, ok := ClientFromContext(ctx)
if !ok {
return nil, errors.New("no client")
}
var result interface{}
err := c.Call(&result, method, args...)
return result, err
}
func (s *testService) CallMeBackLater(ctx context.Context, method string, args []interface{}) error {
c, ok := ClientFromContext(ctx)
if !ok {
return errors.New("no client")
}
go func() {
<-ctx.Done()
var result interface{}
c.Call(&result, method, args...)
}()
return nil
}
func (s *testService) Subscription(ctx context.Context) (*Subscription, error) {
return nil, nil
}
type notificationTestService struct {
unsubscribed chan string
gotHangSubscriptionReq chan struct{}
unblockHangSubscription chan struct{}
}
func (s *notificationTestService) Echo(i int) int {
return i
}
func (s *notificationTestService) Unsubscribe(subid string) {
if s.unsubscribed != nil {
s.unsubscribed <- subid
}
}
func (s *notificationTestService) SomeSubscription(ctx context.Context, n, val int) (*Subscription, error) {
notifier, supported := NotifierFromContext(ctx)
if !supported {
return nil, ErrNotificationsUnsupported
}
// By explicitly creating an subscription we make sure that the subscription id is send
// back to the client before the first subscription.Notify is called. Otherwise the
// events might be send before the response for the *_subscribe method.
subscription := notifier.CreateSubscription()
go func() {
for i := 0; i < n; i++ {
if err := notifier.Notify(subscription.ID, val+i); err != nil {
return
}
}
select {
case <-notifier.Closed():
case <-subscription.Err():
}
if s.unsubscribed != nil {
s.unsubscribed <- string(subscription.ID)
}
}()
return subscription, nil
}
// HangSubscription blocks on s.unblockHangSubscription before sending anything.
func (s *notificationTestService) HangSubscription(ctx context.Context, val int) (*Subscription, error) {
notifier, supported := NotifierFromContext(ctx)
if !supported {
return nil, ErrNotificationsUnsupported
}
s.gotHangSubscriptionReq <- struct{}{}
<-s.unblockHangSubscription
subscription := notifier.CreateSubscription()
go func() {
notifier.Notify(subscription.ID, val)
}()
return subscription, nil
}