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|
// 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 stream
import (
"context"
"fmt"
"math"
"reflect"
"sync"
"time"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/protocols"
"github.com/ethereum/go-ethereum/rpc"
"github.com/ethereum/go-ethereum/swarm/log"
"github.com/ethereum/go-ethereum/swarm/network"
"github.com/ethereum/go-ethereum/swarm/network/stream/intervals"
"github.com/ethereum/go-ethereum/swarm/state"
"github.com/ethereum/go-ethereum/swarm/storage"
)
const (
Low uint8 = iota
Mid
High
Top
PriorityQueue = 4 // number of priority queues - Low, Mid, High, Top
PriorityQueueCap = 4096 // queue capacity
HashSize = 32
)
// Enumerate options for syncing and retrieval
type SyncingOption int
// Syncing options
const (
// Syncing disabled
SyncingDisabled SyncingOption = iota
// Register the client and the server but not subscribe
SyncingRegisterOnly
// Both client and server funcs are registered, subscribe sent automatically
SyncingAutoSubscribe
)
// subscriptionFunc is used to determine what to do in order to perform subscriptions
// usually we would start to really subscribe to nodes, but for tests other functionality may be needed
// (see TestRequestPeerSubscriptions in streamer_test.go)
var subscriptionFunc = doRequestSubscription
// Registry registry for outgoing and incoming streamer constructors
type Registry struct {
addr enode.ID
api *API
skipCheck bool
clientMu sync.RWMutex
serverMu sync.RWMutex
peersMu sync.RWMutex
serverFuncs map[string]func(*Peer, string, bool) (Server, error)
clientFuncs map[string]func(*Peer, string, bool) (Client, error)
peers map[enode.ID]*Peer
delivery *Delivery
intervalsStore state.Store
maxPeerServers int
spec *protocols.Spec //this protocol's spec
balance protocols.Balance //implements protocols.Balance, for accounting
prices protocols.Prices //implements protocols.Prices, provides prices to accounting
quit chan struct{} // terminates registry goroutines
syncMode SyncingOption
syncUpdateDelay time.Duration
}
// RegistryOptions holds optional values for NewRegistry constructor.
type RegistryOptions struct {
SkipCheck bool
Syncing SyncingOption // Defines syncing behavior
SyncUpdateDelay time.Duration
MaxPeerServers int // The limit of servers for each peer in registry
}
// NewRegistry is Streamer constructor
func NewRegistry(localID enode.ID, delivery *Delivery, netStore *storage.NetStore, intervalsStore state.Store, options *RegistryOptions, balance protocols.Balance) *Registry {
if options == nil {
options = &RegistryOptions{}
}
if options.SyncUpdateDelay <= 0 {
options.SyncUpdateDelay = 15 * time.Second
}
quit := make(chan struct{})
streamer := &Registry{
addr: localID,
skipCheck: options.SkipCheck,
serverFuncs: make(map[string]func(*Peer, string, bool) (Server, error)),
clientFuncs: make(map[string]func(*Peer, string, bool) (Client, error)),
peers: make(map[enode.ID]*Peer),
delivery: delivery,
intervalsStore: intervalsStore,
maxPeerServers: options.MaxPeerServers,
balance: balance,
quit: quit,
syncUpdateDelay: options.SyncUpdateDelay,
syncMode: options.Syncing,
}
streamer.setupSpec()
streamer.api = NewAPI(streamer)
delivery.getPeer = streamer.getPeer
// If syncing is not disabled, the syncing functions are registered (both client and server)
if options.Syncing != SyncingDisabled {
RegisterSwarmSyncerServer(streamer, netStore)
RegisterSwarmSyncerClient(streamer, netStore)
}
return streamer
}
// This is an accounted protocol, therefore we need to provide a pricing Hook to the spec
// For simulations to be able to run multiple nodes and not override the hook's balance,
// we need to construct a spec instance per node instance
func (r *Registry) setupSpec() {
// first create the "bare" spec
r.createSpec()
// now create the pricing object
r.createPriceOracle()
// if balance is nil, this node has been started without swap support (swapEnabled flag is false)
if r.balance != nil && !reflect.ValueOf(r.balance).IsNil() {
// swap is enabled, so setup the hook
r.spec.Hook = protocols.NewAccounting(r.balance, r.prices)
}
}
// RegisterClient registers an incoming streamer constructor
func (r *Registry) RegisterClientFunc(stream string, f func(*Peer, string, bool) (Client, error)) {
r.clientMu.Lock()
defer r.clientMu.Unlock()
r.clientFuncs[stream] = f
}
// RegisterServer registers an outgoing streamer constructor
func (r *Registry) RegisterServerFunc(stream string, f func(*Peer, string, bool) (Server, error)) {
r.serverMu.Lock()
defer r.serverMu.Unlock()
r.serverFuncs[stream] = f
}
// GetClient accessor for incoming streamer constructors
func (r *Registry) GetClientFunc(stream string) (func(*Peer, string, bool) (Client, error), error) {
r.clientMu.RLock()
defer r.clientMu.RUnlock()
f := r.clientFuncs[stream]
if f == nil {
return nil, fmt.Errorf("stream %v not registered", stream)
}
return f, nil
}
// GetServer accessor for incoming streamer constructors
func (r *Registry) GetServerFunc(stream string) (func(*Peer, string, bool) (Server, error), error) {
r.serverMu.RLock()
defer r.serverMu.RUnlock()
f := r.serverFuncs[stream]
if f == nil {
return nil, fmt.Errorf("stream %v not registered", stream)
}
return f, nil
}
func (r *Registry) RequestSubscription(peerId enode.ID, s Stream, h *Range, prio uint8) error {
// check if the stream is registered
if _, err := r.GetServerFunc(s.Name); err != nil {
return err
}
peer := r.getPeer(peerId)
if peer == nil {
return fmt.Errorf("peer not found %v", peerId)
}
if _, err := peer.getServer(s); err != nil {
if e, ok := err.(*notFoundError); ok && e.t == "server" {
// request subscription only if the server for this stream is not created
log.Debug("RequestSubscription ", "peer", peerId, "stream", s, "history", h)
return peer.Send(context.TODO(), &RequestSubscriptionMsg{
Stream: s,
History: h,
Priority: prio,
})
}
return err
}
log.Trace("RequestSubscription: already subscribed", "peer", peerId, "stream", s, "history", h)
return nil
}
// Subscribe initiates the streamer
func (r *Registry) Subscribe(peerId enode.ID, s Stream, h *Range, priority uint8) error {
// check if the stream is registered
if _, err := r.GetClientFunc(s.Name); err != nil {
return err
}
peer := r.getPeer(peerId)
if peer == nil {
return fmt.Errorf("peer not found %v", peerId)
}
var to uint64
if !s.Live && h != nil {
to = h.To
}
err := peer.setClientParams(s, newClientParams(priority, to))
if err != nil {
return err
}
if s.Live && h != nil {
if err := peer.setClientParams(
getHistoryStream(s),
newClientParams(getHistoryPriority(priority), h.To),
); err != nil {
return err
}
}
msg := &SubscribeMsg{
Stream: s,
History: h,
Priority: priority,
}
log.Debug("Subscribe ", "peer", peerId, "stream", s, "history", h)
return peer.Send(context.TODO(), msg)
}
func (r *Registry) Unsubscribe(peerId enode.ID, s Stream) error {
peer := r.getPeer(peerId)
if peer == nil {
return fmt.Errorf("peer not found %v", peerId)
}
msg := &UnsubscribeMsg{
Stream: s,
}
log.Debug("Unsubscribe ", "peer", peerId, "stream", s)
if err := peer.Send(context.TODO(), msg); err != nil {
return err
}
return peer.removeClient(s)
}
// Quit sends the QuitMsg to the peer to remove the
// stream peer client and terminate the streaming.
func (r *Registry) Quit(peerId enode.ID, s Stream) error {
peer := r.getPeer(peerId)
if peer == nil {
log.Debug("stream quit: peer not found", "peer", peerId, "stream", s)
// if the peer is not found, abort the request
return nil
}
msg := &QuitMsg{
Stream: s,
}
log.Debug("Quit ", "peer", peerId, "stream", s)
return peer.Send(context.TODO(), msg)
}
func (r *Registry) Close() error {
// Stop sending neighborhood depth change and address count
// change from Kademlia that were initiated in NewRegistry constructor.
r.delivery.Close()
close(r.quit)
return r.intervalsStore.Close()
}
func (r *Registry) getPeer(peerId enode.ID) *Peer {
r.peersMu.RLock()
defer r.peersMu.RUnlock()
return r.peers[peerId]
}
func (r *Registry) setPeer(peer *Peer) {
r.peersMu.Lock()
r.peers[peer.ID()] = peer
metrics.GetOrRegisterCounter("registry.setpeer", nil).Inc(1)
metrics.GetOrRegisterGauge("registry.peers", nil).Update(int64(len(r.peers)))
r.peersMu.Unlock()
}
func (r *Registry) deletePeer(peer *Peer) {
r.peersMu.Lock()
delete(r.peers, peer.ID())
metrics.GetOrRegisterCounter("registry.deletepeer", nil).Inc(1)
metrics.GetOrRegisterGauge("registry.peers", nil).Update(int64(len(r.peers)))
r.peersMu.Unlock()
}
func (r *Registry) peersCount() (c int) {
r.peersMu.Lock()
c = len(r.peers)
r.peersMu.Unlock()
return
}
// Run protocol run function
func (r *Registry) Run(p *network.BzzPeer) error {
sp := NewPeer(p, r)
r.setPeer(sp)
if r.syncMode == SyncingAutoSubscribe {
go sp.runUpdateSyncing()
}
defer r.deletePeer(sp)
defer close(sp.quit)
defer sp.close()
return sp.Run(sp.HandleMsg)
}
// doRequestSubscription sends the actual RequestSubscription to the peer
func doRequestSubscription(r *Registry, id enode.ID, bin uint8) error {
log.Debug("Requesting subscription by registry:", "registry", r.addr, "peer", id, "bin", bin)
// bin is always less then 256 and it is safe to convert it to type uint8
stream := NewStream("SYNC", FormatSyncBinKey(bin), true)
err := r.RequestSubscription(id, stream, NewRange(0, 0), High)
if err != nil {
log.Debug("Request subscription", "err", err, "peer", id, "stream", stream)
return err
}
return nil
}
func (r *Registry) runProtocol(p *p2p.Peer, rw p2p.MsgReadWriter) error {
peer := protocols.NewPeer(p, rw, r.spec)
bp := network.NewBzzPeer(peer)
np := network.NewPeer(bp, r.delivery.kad)
r.delivery.kad.On(np)
defer r.delivery.kad.Off(np)
return r.Run(bp)
}
// HandleMsg is the message handler that delegates incoming messages
func (p *Peer) HandleMsg(ctx context.Context, msg interface{}) error {
select {
case <-p.streamer.quit:
log.Trace("message received after the streamer is closed", "peer", p.ID())
// return without an error since streamer is closed and
// no messages should be handled as other subcomponents like
// storage leveldb may be closed
return nil
default:
}
switch msg := msg.(type) {
case *SubscribeMsg:
return p.handleSubscribeMsg(ctx, msg)
case *SubscribeErrorMsg:
return p.handleSubscribeErrorMsg(msg)
case *UnsubscribeMsg:
return p.handleUnsubscribeMsg(msg)
case *OfferedHashesMsg:
go func() {
err := p.handleOfferedHashesMsg(ctx, msg)
if err != nil {
log.Error(err.Error())
p.Drop()
}
}()
return nil
case *TakeoverProofMsg:
go func() {
err := p.handleTakeoverProofMsg(ctx, msg)
if err != nil {
log.Error(err.Error())
p.Drop()
}
}()
return nil
case *WantedHashesMsg:
go func() {
err := p.handleWantedHashesMsg(ctx, msg)
if err != nil {
log.Error(err.Error())
p.Drop()
}
}()
return nil
case *ChunkDeliveryMsgRetrieval:
// handling chunk delivery is the same for retrieval and syncing, so let's cast the msg
go func() {
err := p.streamer.delivery.handleChunkDeliveryMsg(ctx, p, ((*ChunkDeliveryMsg)(msg)))
if err != nil {
log.Error(err.Error())
p.Drop()
}
}()
return nil
case *ChunkDeliveryMsgSyncing:
// handling chunk delivery is the same for retrieval and syncing, so let's cast the msg
go func() {
err := p.streamer.delivery.handleChunkDeliveryMsg(ctx, p, ((*ChunkDeliveryMsg)(msg)))
if err != nil {
log.Error(err.Error())
p.Drop()
}
}()
return nil
case *RetrieveRequestMsg:
go func() {
err := p.streamer.delivery.handleRetrieveRequestMsg(ctx, p, msg)
if err != nil {
log.Error(err.Error())
p.Drop()
}
}()
return nil
case *RequestSubscriptionMsg:
return p.handleRequestSubscription(ctx, msg)
case *QuitMsg:
return p.handleQuitMsg(msg)
default:
return fmt.Errorf("unknown message type: %T", msg)
}
}
type server struct {
Server
stream Stream
priority uint8
currentBatch []byte
sessionIndex uint64
}
// setNextBatch adjusts passed interval based on session index and whether
// stream is live or history. It calls Server SetNextBatch with adjusted
// interval and returns batch hashes and their interval.
func (s *server) setNextBatch(from, to uint64) ([]byte, uint64, uint64, *HandoverProof, error) {
if s.stream.Live {
if from == 0 {
from = s.sessionIndex
}
if to <= from || from >= s.sessionIndex {
to = math.MaxUint64
}
} else {
if (to < from && to != 0) || from > s.sessionIndex {
return nil, 0, 0, nil, nil
}
if to == 0 || to > s.sessionIndex {
to = s.sessionIndex
}
}
return s.SetNextBatch(from, to)
}
// Server interface for outgoing peer Streamer
type Server interface {
// SessionIndex is called when a server is initialized
// to get the current cursor state of the stream data.
// Based on this index, live and history stream intervals
// will be adjusted before calling SetNextBatch.
SessionIndex() (uint64, error)
SetNextBatch(uint64, uint64) (hashes []byte, from uint64, to uint64, proof *HandoverProof, err error)
GetData(context.Context, []byte) ([]byte, error)
Close()
}
type client struct {
Client
stream Stream
priority uint8
sessionAt uint64
to uint64
next chan error
quit chan struct{}
intervalsKey string
intervalsStore state.Store
}
func peerStreamIntervalsKey(p *Peer, s Stream) string {
return p.ID().String() + s.String()
}
func (c *client) AddInterval(start, end uint64) (err error) {
i := &intervals.Intervals{}
if err = c.intervalsStore.Get(c.intervalsKey, i); err != nil {
return err
}
i.Add(start, end)
return c.intervalsStore.Put(c.intervalsKey, i)
}
func (c *client) NextInterval() (start, end uint64, err error) {
i := &intervals.Intervals{}
err = c.intervalsStore.Get(c.intervalsKey, i)
if err != nil {
return 0, 0, err
}
start, end = i.Next()
return start, end, nil
}
// Client interface for incoming peer Streamer
type Client interface {
NeedData(context.Context, []byte) func(context.Context) error
BatchDone(Stream, uint64, []byte, []byte) func() (*TakeoverProof, error)
Close()
}
func (c *client) nextBatch(from uint64) (nextFrom uint64, nextTo uint64) {
if c.to > 0 && from >= c.to {
return 0, 0
}
if c.stream.Live {
return from, 0
} else if from >= c.sessionAt {
if c.to > 0 {
return from, c.to
}
return from, math.MaxUint64
}
nextFrom, nextTo, err := c.NextInterval()
if err != nil {
log.Error("next intervals", "stream", c.stream)
return
}
if nextTo > c.to {
nextTo = c.to
}
if nextTo == 0 {
nextTo = c.sessionAt
}
return
}
func (c *client) batchDone(p *Peer, req *OfferedHashesMsg, hashes []byte) error {
if tf := c.BatchDone(req.Stream, req.From, hashes, req.Root); tf != nil {
tp, err := tf()
if err != nil {
return err
}
if err := p.Send(context.TODO(), tp); err != nil {
return err
}
if c.to > 0 && tp.Takeover.End >= c.to {
return p.streamer.Unsubscribe(p.Peer.ID(), req.Stream)
}
return nil
}
return c.AddInterval(req.From, req.To)
}
func (c *client) close() {
select {
case <-c.quit:
default:
close(c.quit)
}
c.Close()
}
// clientParams store parameters for the new client
// between a subscription and initial offered hashes request handling.
type clientParams struct {
priority uint8
to uint64
// signal when the client is created
clientCreatedC chan struct{}
}
func newClientParams(priority uint8, to uint64) *clientParams {
return &clientParams{
priority: priority,
to: to,
clientCreatedC: make(chan struct{}),
}
}
func (c *clientParams) waitClient(ctx context.Context) error {
select {
case <-ctx.Done():
return ctx.Err()
case <-c.clientCreatedC:
return nil
}
}
func (c *clientParams) clientCreated() {
close(c.clientCreatedC)
}
// GetSpec returns the streamer spec to callers
// This used to be a global variable but for simulations with
// multiple nodes its fields (notably the Hook) would be overwritten
func (r *Registry) GetSpec() *protocols.Spec {
return r.spec
}
func (r *Registry) createSpec() {
// Spec is the spec of the streamer protocol
var spec = &protocols.Spec{
Name: "stream",
Version: 8,
MaxMsgSize: 10 * 1024 * 1024,
Messages: []interface{}{
UnsubscribeMsg{},
OfferedHashesMsg{},
WantedHashesMsg{},
TakeoverProofMsg{},
SubscribeMsg{},
RetrieveRequestMsg{},
ChunkDeliveryMsgRetrieval{},
SubscribeErrorMsg{},
RequestSubscriptionMsg{},
QuitMsg{},
ChunkDeliveryMsgSyncing{},
},
}
r.spec = spec
}
// An accountable message needs some meta information attached to it
// in order to evaluate the correct price
type StreamerPrices struct {
priceMatrix map[reflect.Type]*protocols.Price
registry *Registry
}
// Price implements the accounting interface and returns the price for a specific message
func (sp *StreamerPrices) Price(msg interface{}) *protocols.Price {
t := reflect.TypeOf(msg).Elem()
return sp.priceMatrix[t]
}
// Instead of hardcoding the price, get it
// through a function - it could be quite complex in the future
func (sp *StreamerPrices) getRetrieveRequestMsgPrice() uint64 {
return uint64(1)
}
// Instead of hardcoding the price, get it
// through a function - it could be quite complex in the future
func (sp *StreamerPrices) getChunkDeliveryMsgRetrievalPrice() uint64 {
return uint64(1)
}
// createPriceOracle sets up a matrix which can be queried to get
// the price for a message via the Price method
func (r *Registry) createPriceOracle() {
sp := &StreamerPrices{
registry: r,
}
sp.priceMatrix = map[reflect.Type]*protocols.Price{
reflect.TypeOf(ChunkDeliveryMsgRetrieval{}): {
Value: sp.getChunkDeliveryMsgRetrievalPrice(), // arbitrary price for now
PerByte: true,
Payer: protocols.Receiver,
},
reflect.TypeOf(RetrieveRequestMsg{}): {
Value: sp.getRetrieveRequestMsgPrice(), // arbitrary price for now
PerByte: false,
Payer: protocols.Sender,
},
}
r.prices = sp
}
func (r *Registry) Protocols() []p2p.Protocol {
return []p2p.Protocol{
{
Name: r.spec.Name,
Version: r.spec.Version,
Length: r.spec.Length(),
Run: r.runProtocol,
},
}
}
func (r *Registry) APIs() []rpc.API {
return []rpc.API{
{
Namespace: "stream",
Version: "3.0",
Service: r.api,
Public: false,
},
}
}
func (r *Registry) Start(server *p2p.Server) error {
log.Info("Streamer started")
return nil
}
func (r *Registry) Stop() error {
return nil
}
type Range struct {
From, To uint64
}
func NewRange(from, to uint64) *Range {
return &Range{
From: from,
To: to,
}
}
func (r *Range) String() string {
return fmt.Sprintf("%v-%v", r.From, r.To)
}
func getHistoryPriority(priority uint8) uint8 {
if priority == 0 {
return 0
}
return priority - 1
}
func getHistoryStream(s Stream) Stream {
return NewStream(s.Name, s.Key, false)
}
type API struct {
streamer *Registry
}
func NewAPI(r *Registry) *API {
return &API{
streamer: r,
}
}
func (api *API) SubscribeStream(peerId enode.ID, s Stream, history *Range, priority uint8) error {
return api.streamer.Subscribe(peerId, s, history, priority)
}
func (api *API) UnsubscribeStream(peerId enode.ID, s Stream) error {
return api.streamer.Unsubscribe(peerId, s)
}
/*
GetPeerServerSubscriptions is a API function which allows to query a peer for stream subscriptions it has.
It can be called via RPC.
It returns a map of node IDs with an array of string representations of Stream objects.
*/
func (api *API) GetPeerServerSubscriptions() map[string][]string {
pstreams := make(map[string][]string)
api.streamer.peersMu.RLock()
defer api.streamer.peersMu.RUnlock()
for id, p := range api.streamer.peers {
var streams []string
//every peer has a map of stream servers
//every stream server represents a subscription
p.serverMu.RLock()
for s := range p.servers {
//append the string representation of the stream
//to the list for this peer
streams = append(streams, s.String())
}
p.serverMu.RUnlock()
//set the array of stream servers to the map
pstreams[id.String()] = streams
}
return pstreams
}
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