go-ethereum/p2p/simulations/adapters/inproc.go
Lewis Marshall cdab665475 p2p/simulations: Move PeerEvents to admin RPC namespace
Signed-off-by: Lewis Marshall <lewis@lmars.net>
2017-05-08 10:51:55 +01:00

386 lines
11 KiB
Go

// Copyright 2016 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 adapters
import (
"context"
"errors"
"fmt"
"sync"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/node"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/rpc"
)
// SimAdapter is a NodeAdapter which creates in-memory nodes and connects them
// using an in-memory p2p.MsgReadWriter pipe
type SimAdapter struct {
mtx sync.RWMutex
nodes map[discover.NodeID]*SimNode
services map[string]ServiceFunc
}
// NewSimAdapter creates a SimAdapter which is capable of running in-memory
// nodes running any of the given services (the service to run on a particular
// node is passed to the NewNode function in the NodeConfig)
func NewSimAdapter(services map[string]ServiceFunc) *SimAdapter {
return &SimAdapter{
nodes: make(map[discover.NodeID]*SimNode),
services: services,
}
}
// Name returns the name of the adapter for logging purpoeses
func (s *SimAdapter) Name() string {
return "sim-adapter"
}
// NewNode returns a new SimNode using the given config
func (s *SimAdapter) NewNode(config *NodeConfig) (Node, error) {
s.mtx.Lock()
defer s.mtx.Unlock()
// check a node with the ID doesn't already exist
id := config.Id
if _, exists := s.nodes[id.NodeID]; exists {
return nil, fmt.Errorf("node already exists: %s", id)
}
// check the service is valid and initialize it
serviceFunc, exists := s.services[config.Service]
if !exists {
return nil, fmt.Errorf("unknown node service %q", config.Service)
}
service := serviceFunc(id)
// for simplicity, only support single protocol services (simulating
// multiple protocols on the same peer is extra effort, and we don't
// currently run any simulations which run multiple protocols)
if len(service.Protocols()) != 1 {
return nil, errors.New("service must have a single protocol")
}
node := &SimNode{
Id: id,
adapter: s,
service: service,
peers: make(map[discover.NodeID]MsgReadWriteCloser),
dropPeers: make(chan struct{}),
}
s.nodes[id.NodeID] = node
return node, nil
}
// GetNode returns the node with the given ID if it exists
func (s *SimAdapter) GetNode(id discover.NodeID) (*SimNode, bool) {
s.mtx.RLock()
defer s.mtx.RUnlock()
node, ok := s.nodes[id]
return node, ok
}
// MsgReadWriteCloser wraps a MsgReadWriter with the addition of a Close method
// so we can simulate the closing of a p2p connection (which usually happens by
/// closing the underlying TCP connection)
type MsgReadWriteCloser interface {
p2p.MsgReadWriter
Close() error
}
// SimNode is an in-memory node which connects to other SimNodes using an
// in-memory p2p.MsgReadWriter pipe, running an underlying service protocol
// directly over that pipe.
//
// It implements the p2p.Server interface so it can be used transparently
// by the underlying service.
type SimNode struct {
lock sync.RWMutex
Id *NodeId
adapter *SimAdapter
service node.Service
peers map[discover.NodeID]MsgReadWriteCloser
peerFeed event.Feed
client *rpc.Client
// dropPeers is used to force peer disconnects when
// the node is stopped
dropPeers chan struct{}
}
// Addr returns the node's discovery address
func (self *SimNode) Addr() []byte {
return []byte(self.Node().String())
}
// Node returns a discover.Node representing the SimNode
func (self *SimNode) Node() *discover.Node {
return discover.NewNode(self.Id.NodeID, nil, 0, 0)
}
// Client returns an rpc.Client which can be used to communicate with the
// underlying service (it is set once the node has started)
func (self *SimNode) Client() (*rpc.Client, error) {
self.lock.Lock()
defer self.lock.Unlock()
if self.client == nil {
return nil, errors.New("RPC not started")
}
return self.client, nil
}
// Start starts the RPC handler and the underlying service
func (self *SimNode) Start() error {
self.dropPeers = make(chan struct{})
if err := self.startRPC(); err != nil {
return err
}
return self.service.Start(self)
}
// Stop stops the RPC handler, stops the underlying service and disconnects
// any currently connected peers
func (self *SimNode) Stop() error {
self.stopRPC()
close(self.dropPeers)
return self.service.Stop()
}
// Running returns whether or not the service is running by checking if the
// RPC client is set
func (self *SimNode) Running() bool {
self.lock.Lock()
defer self.lock.Unlock()
return self.client != nil
}
// Service returns the underlying node.Service
func (self *SimNode) Service() node.Service {
return self.service
}
// startRPC starts an RPC server and connects to it using an in-process RPC
// client
func (self *SimNode) startRPC() error {
self.lock.Lock()
defer self.lock.Unlock()
if self.client != nil {
return errors.New("RPC already started")
}
// add SimAdminAPI so that the network can call the
// AddPeer, RemovePeer and PeerEvents RPC methods
apis := append(self.service.APIs(), []rpc.API{
{
Namespace: "admin",
Version: "1.0",
Service: &SimAdminAPI{self},
},
}...)
// start the RPC handler
handler := rpc.NewServer()
for _, api := range apis {
if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
return fmt.Errorf("error registering RPC: %s", err)
}
}
// create an in-process RPC client
self.client = rpc.DialInProc(handler)
return nil
}
// stopRPC closes the node's RPC client
func (self *SimNode) stopRPC() {
self.lock.Lock()
defer self.lock.Unlock()
if self.client != nil {
self.client.Close()
self.client = nil
}
}
// RemovePeer removes the given node as a peer by looking up the corresponding
// p2p.MsgReadWriter pipe and closing it (which will cause both the local
// and peer Protocol.Run functions to exit)
func (self *SimNode) RemovePeer(peer *discover.Node) {
self.lock.Lock()
defer self.lock.Unlock()
peerRW, exists := self.peers[peer.ID]
if !exists {
return
}
peerRW.Close()
delete(self.peers, peer.ID)
log.Trace(fmt.Sprintf("dropped peer %v", peer.ID))
}
// AddPeer adds the given node as a peer by creating a p2p.MsgReadWriter pipe
// and running both the local and peer's Protocol.Run function over the pipe
func (self *SimNode) AddPeer(peer *discover.Node) {
self.lock.Lock()
defer self.lock.Unlock()
if _, exists := self.peers[peer.ID]; exists {
return
}
peerNode, exists := self.adapter.GetNode(peer.ID)
if !exists {
panic(fmt.Sprintf("unknown peer: %s", peer.ID))
}
if !peerNode.Running() {
return
}
p1, p2 := p2p.MsgPipe()
localRW := p2p.NewMsgEventer(p1, &self.peerFeed, peer.ID)
peerRW := p2p.NewMsgEventer(p2, &self.peerFeed, self.Id.NodeID)
self.peers[peer.ID] = peerRW
peerNode.RunProtocol(self, peerRW)
self.RunProtocol(peerNode, localRW)
}
// SubscribeEvents subscribes the given channel to p2p peer events
func (self *SimNode) SubscribeEvents(ch chan *p2p.PeerEvent) event.Subscription {
return self.peerFeed.Subscribe(ch)
}
// PeerCount returns the number of currently connected peers
func (self *SimNode) PeerCount() int {
self.lock.Lock()
defer self.lock.Unlock()
return len(self.peers)
}
// NodeInfo returns information about the node
func (self *SimNode) NodeInfo() *p2p.NodeInfo {
info := &p2p.NodeInfo{
ID: self.Id.String(),
Enode: self.Node().String(),
Protocols: make(map[string]interface{}),
}
for _, proto := range self.service.Protocols() {
nodeInfo := interface{}("unknown")
if query := proto.NodeInfo; query != nil {
nodeInfo = proto.NodeInfo()
}
info.Protocols[proto.Name] = nodeInfo
}
return info
}
// PeersInfo is a stub so that SimNode implements p2p.Server
func (self *SimNode) PeersInfo() (info []*p2p.PeerInfo) {
return nil
}
// RunProtocol runs the underlying service's protocol with the peer using the
// given MsgReadWriteCloser, emitting peer add / drop events for peer event
// subscribers
func (self *SimNode) RunProtocol(peer *SimNode, rw MsgReadWriteCloser) {
// close the rw if the node is stopped to disconnect the peer
go func() {
<-self.dropPeers
log.Trace("dropping peer", "self.id", self.Id, "peer.id", peer.Id)
rw.Close()
}()
id := peer.Id
log.Trace(fmt.Sprintf("protocol starting on peer %v (connection with %v)", self.Id, id))
protocol := self.service.Protocols()[0]
p := p2p.NewPeer(id.NodeID, id.Label(), []p2p.Cap{})
go func() {
// emit peer add event
self.peerFeed.Send(&p2p.PeerEvent{
Type: p2p.PeerEventTypeAdd,
Peer: id.NodeID,
})
// run the protocol
err := protocol.Run(p, rw)
// remove the peer
self.RemovePeer(peer.Node())
log.Trace(fmt.Sprintf("protocol quit on peer %v (connection with %v broken: %v)", self.Id, id, err))
// emit peer drop event
self.peerFeed.Send(&p2p.PeerEvent{
Type: p2p.PeerEventTypeDrop,
Peer: id.NodeID,
Error: err.Error(),
})
}()
}
// SimAdminAPI implements the AddPeer and RemovePeer RPC methods (API
// compatible with node.PrivateAdminAPI)
type SimAdminAPI struct {
*SimNode
}
func (api *SimAdminAPI) AddPeer(url string) (bool, error) {
node, err := discover.ParseNode(url)
if err != nil {
return false, fmt.Errorf("invalid enode: %v", err)
}
api.SimNode.AddPeer(node)
return true, nil
}
func (api *SimAdminAPI) RemovePeer(url string) (bool, error) {
node, err := discover.ParseNode(url)
if err != nil {
return false, fmt.Errorf("invalid enode: %v", err)
}
api.SimNode.RemovePeer(node)
return true, nil
}
// PeerEvents creates an RPC subscription which receives peer events from the
// underlying p2p.Server
func (api *SimAdminAPI) PeerEvents(ctx context.Context) (*rpc.Subscription, error) {
notifier, supported := rpc.NotifierFromContext(ctx)
if !supported {
return &rpc.Subscription{}, rpc.ErrNotificationsUnsupported
}
rpcSub := notifier.CreateSubscription()
go func() {
events := make(chan *p2p.PeerEvent)
sub := api.SubscribeEvents(events)
defer sub.Unsubscribe()
for {
select {
case event := <-events:
notifier.Notify(rpcSub.ID, event)
case <-sub.Err():
return
case <-rpcSub.Err():
return
case <-notifier.Closed():
return
}
}
}()
return rpcSub, nil
}