// Copyright 2017 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 (
"errors"
"fmt"
"math"
"net"
"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 simulation nodes and
// connects them using in-memory net.Pipe connections
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
// simulation nodes running any of the given services (the services to run on a
// particular node are 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 purposes
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]; exists {
return nil, fmt.Errorf("node already exists: %s", id)
}
// check the services are valid
if len(config.Services) == 0 {
return nil, errors.New("node must have at least one service")
}
for _, service := range config.Services {
if _, exists := s.services[service]; !exists {
return nil, fmt.Errorf("unknown node service %q", service)
}
}
n, err := node.New(&node.Config{
P2P: p2p.Config{
PrivateKey: config.PrivateKey,
MaxPeers: math.MaxInt32,
NoDiscovery: true,
Dialer: s,
EnableMsgEvents: true,
},
NoUSB: true,
Logger: log.New("node.id", id.String()),
})
if err != nil {
return nil, err
}
simNode := &SimNode{
ID: id,
config: config,
node: n,
adapter: s,
running: make(map[string]node.Service),
}
s.nodes[id] = simNode
return simNode, nil
}
// Dial implements the p2p.NodeDialer interface by connecting to the node using
// an in-memory net.Pipe connection
func (s *SimAdapter) Dial(dest *discover.Node) (conn net.Conn, err error) {
node, ok := s.GetNode(dest.ID)
if !ok {
return nil, fmt.Errorf("unknown node: %s", dest.ID)
}
srv := node.Server()
if srv == nil {
return nil, fmt.Errorf("node not running: %s", dest.ID)
}
pipe1, pipe2 := net.Pipe()
go srv.SetupConn(pipe1, 0, nil)
return pipe2, nil
}
// DialRPC implements the RPCDialer interface by creating an in-memory RPC
// client of the given node
func (s *SimAdapter) DialRPC(id discover.NodeID) (*rpc.Client, error) {
node, ok := s.GetNode(id)
if !ok {
return nil, fmt.Errorf("unknown node: %s", id)
}
handler, err := node.node.RPCHandler()
if err != nil {
return nil, err
}
return rpc.DialInProc(handler), 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
}
// SimNode is an in-memory simulation node which connects to other nodes using
// an in-memory net.Pipe connection (see SimAdapter.Dial), running devp2p
// protocols directly over that pipe
type SimNode struct {
lock sync.RWMutex
ID discover.NodeID
config *NodeConfig
adapter *SimAdapter
node *node.Node
running map[string]node.Service
client *rpc.Client
registerOnce sync.Once
}
// 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, net.IP{127, 0, 0, 1}, 30303, 30303)
}
// Client returns an rpc.Client which can be used to communicate with the
// underlying services (it is set once the node has started)
func (self *SimNode) Client() (*rpc.Client, error) {
self.lock.RLock()
defer self.lock.RUnlock()
if self.client == nil {
return nil, errors.New("node not started")
}
return self.client, nil
}
// ServeRPC serves RPC requests over the given connection by creating an
// in-memory client to the node's RPC server
func (self *SimNode) ServeRPC(conn net.Conn) error {
handler, err := self.node.RPCHandler()
if err != nil {
return err
}
handler.ServeCodec(rpc.NewJSONCodec(conn), rpc.OptionMethodInvocation|rpc.OptionSubscriptions)
return nil
}
// Snapshots creates snapshots of the services by calling the
// simulation_snapshot RPC method
func (self *SimNode) Snapshots() (map[string][]byte, error) {
self.lock.RLock()
services := make(map[string]node.Service, len(self.running))
for name, service := range self.running {
services[name] = service
}
self.lock.RUnlock()
if len(services) == 0 {
return nil, errors.New("no running services")
}
snapshots := make(map[string][]byte)
for name, service := range services {
if s, ok := service.(interface {
Snapshot() ([]byte, error)
}); ok {
snap, err := s.Snapshot()
if err != nil {
return nil, err
}
snapshots[name] = snap
}
}
return snapshots, nil
}
// Start registers the services and starts the underlying devp2p node
func (self *SimNode) Start(snapshots map[string][]byte) error {
newService := func(name string) func(ctx *node.ServiceContext) (node.Service, error) {
return func(nodeCtx *node.ServiceContext) (node.Service, error) {
ctx := &ServiceContext{
RPCDialer: self.adapter,
NodeContext: nodeCtx,
Config: self.config,
}
if snapshots != nil {
ctx.Snapshot = snapshots[name]
}
serviceFunc := self.adapter.services[name]
service, err := serviceFunc(ctx)
if err != nil {
return nil, err
}
self.running[name] = service
return service, nil
}
}
// ensure we only register the services once in the case of the node
// being stopped and then started again
var regErr error
self.registerOnce.Do(func() {
for _, name := range self.config.Services {
if err := self.node.Register(newService(name)); err != nil {
regErr = err
return
}
}
})
if regErr != nil {
return regErr
}
if err := self.node.Start(); err != nil {
return err
}
// create an in-process RPC client
handler, err := self.node.RPCHandler()
if err != nil {
return err
}
self.lock.Lock()
self.client = rpc.DialInProc(handler)
self.lock.Unlock()
return nil
}
// Stop closes the RPC client and stops the underlying devp2p node
func (self *SimNode) Stop() error {
self.lock.Lock()
if self.client != nil {
self.client.Close()
self.client = nil
}
self.lock.Unlock()
return self.node.Stop()
}
// Services returns a copy of the underlying services
func (self *SimNode) Services() []node.Service {
self.lock.RLock()
defer self.lock.RUnlock()
services := make([]node.Service, 0, len(self.running))
for _, service := range self.running {
services = append(services, service)
}
return services
}
// Server returns the underlying p2p.Server
func (self *SimNode) Server() *p2p.Server {
return self.node.Server()
}
// SubscribeEvents subscribes the given channel to peer events from the
// underlying p2p.Server
func (self *SimNode) SubscribeEvents(ch chan *p2p.PeerEvent) event.Subscription {
srv := self.Server()
if srv == nil {
panic("node not running")
}
return srv.SubscribeEvents(ch)
}
// NodeInfo returns information about the node
func (self *SimNode) NodeInfo() *p2p.NodeInfo {
server := self.Server()
if server == nil {
return &p2p.NodeInfo{
ID: self.ID.String(),
Enode: self.Node().String(),
}
}
return server.NodeInfo()
}
