Merge pull request bnb-chain#4 from Loverush/develop

[WIP]Fast Finality: p2p protocol

Author: pythonberg1997

core/events.go

@@ -21,7 +21,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
-// NewTxsEvent is posted when a batch of transactions enter the transaction pool.
+// NewTxsEvent is posted when a batch of transactions enters the transaction pool.
 type NewTxsEvent struct{ Txs []*types.Transaction }
 
 // ReannoTxsEvent is posted when a batch of local pending transactions exceed a specified duration.
@@ -33,6 +33,9 @@ type NewMinedBlockEvent struct{ Block *types.Block }
 // RemovedLogsEvent is posted when a reorg happens
 type RemovedLogsEvent struct{ Logs []*types.Log }
 
+// NewVotesEvent is posted when a batch of votes enters the vote pool.
+type NewVotesEvent struct{ Votes []*types.VoteEnvelope }
+
 type ChainEvent struct {
 	Block *types.Block
 	Hash  common.Hash

core/types/vote.go

@@ -0,0 +1,51 @@
+package types
+
+import (
+	"sync/atomic"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+const (
+	BLSPublicKeyLength = 48
+	BLSSignatureLength = 96
+)
+
+type BLSPublicKey [BLSPublicKeyLength]byte
+type BLSSignature [BLSSignatureLength]byte
+
+type VoteData struct {
+	BlockNumber uint64
+	BlockHash   common.Hash
+}
+
+type VoteEnvelope struct {
+	VoteAddress BLSPublicKey
+	Signature   BLSSignature
+	Data        VoteData
+
+	// caches
+	hash atomic.Value
+}
+
+type VoteEnvelopes []*VoteEnvelope
+
+// Hash returns the vote hash.
+func (v *VoteEnvelope) Hash() common.Hash {
+	if hash := v.hash.Load(); hash != nil {
+		return hash.(common.Hash)
+	}
+
+	h := v.calcVoteHash()
+	v.hash.Store(h)
+	return h
+}
+
+func (v *VoteEnvelope) calcVoteHash() common.Hash {
+	voteData := struct {
+		VoteAddress BLSPublicKey
+		Signature   BLSSignature
+		Data        VoteData
+	}{v.VoteAddress, v.Signature, v.Data}
+	return rlpHash(voteData)
+}

eth/fetcher/tx_fetcher.go

@@ -260,7 +260,7 @@ func (f *TxFetcher) Notify(peer string, hashes []common.Hash) error {
 // Enqueue imports a batch of received transaction into the transaction pool
 // and the fetcher. This method may be called by both transaction broadcasts and
 // direct request replies. The differentiation is important so the fetcher can
-// re-shedule missing transactions as soon as possible.
+// re-schedule missing transactions as soon as possible.
 func (f *TxFetcher) Enqueue(peer string, txs []*types.Transaction, direct bool) error {
 	// Keep track of all the propagated transactions
 	if direct {

eth/handler.go

@@ -45,7 +45,8 @@ import (
 const (
 	// txChanSize is the size of channel listening to NewTxsEvent.
 	// The number is referenced from the size of tx pool.
-	txChanSize = 4096
+	txChanSize   = 256
+	voteChanSize = 4096
 )
 
 var (
@@ -79,12 +80,25 @@ type txPool interface {
 	SubscribeReannoTxsEvent(chan<- core.ReannoTxsEvent) event.Subscription
 }
 
+// votePool defines the methods needed from a votes pool implementation to
+// support all the operations needed by the Ethereum chain protocols.
+type votePool interface {
+	PutVote(vote *types.VoteEnvelope) error
+	Get(hash common.Hash) *types.VoteEnvelope
+	GetVotes() types.VoteEnvelopes
+
+	// SubscribeNewVotesEvent should return an event subscription of
+	// NewVotesEvent and send events to the given channel.
+	SubscribeNewVotesEvent(chan<- core.NewVotesEvent) event.Subscription
+}
+
 // handlerConfig is the collection of initialization parameters to create a full
 // node network handler.
 type handlerConfig struct {
 	Database               ethdb.Database            // Database for direct sync insertions
 	Chain                  *core.BlockChain          // Blockchain to serve data from
 	TxPool                 txPool                    // Transaction pool to propagate from
+	VotePool               votePool                  // Votes pool to propagate from
 	Network                uint64                    // Network identifier to adfvertise
 	Sync                   downloader.SyncMode       // Whether to fast or full sync
 	DiffSync               bool                      // Whether to diff sync
@@ -112,6 +126,7 @@ type handler struct {
 
 	database ethdb.Database
 	txpool   txPool
+	votepool votePool
 	chain    *core.BlockChain
 	maxPeers int
 
@@ -127,6 +142,8 @@ type handler struct {
 	reannoTxsCh   chan core.ReannoTxsEvent
 	reannoTxsSub  event.Subscription
 	minedBlockSub *event.TypeMuxSubscription
+	votesCh       chan core.NewVotesEvent
+	votesSub      event.Subscription
 
 	whitelist map[uint64]common.Hash
 
@@ -152,6 +169,7 @@ func newHandler(config *handlerConfig) (*handler, error) {
 		eventMux:               config.EventMux,
 		database:               config.Database,
 		txpool:                 config.TxPool,
+		votepool:               config.VotePool,
 		chain:                  config.Chain,
 		peers:                  newPeerSet(),
 		whitelist:              config.Whitelist,
@@ -332,9 +350,10 @@ func (h *handler) runEthPeer(peer *eth.Peer, handler eth.Handler) error {
 	}
 	h.chainSync.handlePeerEvent(peer)
 
-	// Propagate existing transactions. new transactions appearing
+	// Propagate existing transactions and votes. new transactions and votes appearing
 	// after this will be sent via broadcasts.
 	h.syncTransactions(peer)
+	h.syncVotes(peer)
 
 	// If we have a trusted CHT, reject all peers below that (avoid fast sync eclipse)
 	if h.checkpointHash != (common.Hash{}) {
@@ -438,6 +457,12 @@ func (h *handler) Start(maxPeers int) {
 	h.txsSub = h.txpool.SubscribeNewTxsEvent(h.txsCh)
 	go h.txBroadcastLoop()
 
+	// broadcast votes
+	h.wg.Add(1)
+	h.votesCh = make(chan core.NewVotesEvent, voteChanSize)
+	h.votesSub = h.votepool.SubscribeNewVotesEvent(h.votesCh)
+	go h.voteBroadcastLoop()
+
 	// announce local pending transactions again
 	h.wg.Add(1)
 	h.reannoTxsCh = make(chan core.ReannoTxsEvent, txChanSize)
@@ -510,7 +535,7 @@ func (h *handler) BroadcastBlock(block *types.Block, propagate bool) {
 		log.Trace("Propagated block", "hash", hash, "recipients", len(transfer), "duration", common.PrettyDuration(time.Since(block.ReceivedAt)))
 		return
 	}
-	// Otherwise if the block is indeed in out own chain, announce it
+	// Otherwise if the block is indeed in our own chain, announce it
 	if h.chain.HasBlock(hash, block.NumberU64()) {
 		for _, peer := range peers {
 			peer.AsyncSendNewBlockHash(block)
@@ -580,6 +605,33 @@ func (h *handler) ReannounceTransactions(txs types.Transactions) {
 		"announce packs", peersCount, "announced hashes", peersCount*uint(len(hashes)))
 }
 
+// BroadcastVotes will propagate a batch of votes to all peers
+// which are not known to already have the given vote.
+func (h *handler) BroadcastVotes(votes types.VoteEnvelopes) {
+	var (
+		directCount int // Count of announcements made
+		directPeers int
+
+		voteset = make(map[*ethPeer][]*types.VoteEnvelope) // Set peer->hash to transfer directly
+	)
+
+	// Broadcast votes to a batch of peers not knowing about it
+	for _, vote := range votes {
+		peers := h.peers.peersWithoutVote(vote.Hash())
+		for _, peer := range peers {
+			voteset[peer] = append(voteset[peer], vote)
+		}
+	}
+
+	for peer, _votes := range voteset {
+		directPeers++
+		directCount += len(_votes)
+		peer.AsyncSendVotes(_votes)
+	}
+	log.Debug("Vote broadcast", "votes", len(votes),
+		"vote packs", directPeers, "broadcast votes", directCount)
+}
+
 // minedBroadcastLoop sends mined blocks to connected peers.
 func (h *handler) minedBroadcastLoop() {
 	defer h.wg.Done()
@@ -617,3 +669,16 @@ func (h *handler) txReannounceLoop() {
 		}
 	}
 }
+
+// voteBroadcastLoop announces new transactions to connected peers.
+func (h *handler) voteBroadcastLoop() {
+	defer h.wg.Done()
+	for {
+		select {
+		case event := <-h.votesCh:
+			h.BroadcastVotes(event.Votes)
+		case <-h.votesSub.Err():
+			return
+		}
+	}
+}

eth/handler_eth.go

@@ -40,6 +40,7 @@ type ethHandler handler
 func (h *ethHandler) Chain() *core.BlockChain     { return h.chain }
 func (h *ethHandler) StateBloom() *trie.SyncBloom { return h.stateBloom }
 func (h *ethHandler) TxPool() eth.TxPool          { return h.txpool }
+func (h *ethHandler) VotePool() eth.VotePool      { return h.votepool }
 
 // RunPeer is invoked when a peer joins on the `eth` protocol.
 func (h *ethHandler) RunPeer(peer *eth.Peer, hand eth.Handler) error {
@@ -99,6 +100,9 @@ func (h *ethHandler) Handle(peer *eth.Peer, packet eth.Packet) error {
 
 	case *eth.PooledTransactionsPacket:
 		return h.txFetcher.Enqueue(peer.ID(), *packet, true)
+
+	case *eth.VotesPacket:
+		return h.handleVotesBroadcast(peer, *packet)
 	default:
 		return fmt.Errorf("unexpected eth packet type: %T", packet)
 	}
@@ -225,3 +229,15 @@ func (h *ethHandler) handleBlockBroadcast(peer *eth.Peer, block *types.Block, td
 	}
 	return nil
 }
+
+// handleVotesBroadcast is invoked from a peer's message handler when it transmits a
+// votes broadcast for the local node to process.
+func (h *ethHandler) handleVotesBroadcast(peer *eth.Peer, votes []*types.VoteEnvelope) error {
+	// Try to put votes into votepool
+	for _, vote := range votes {
+		if err := h.votepool.PutVote(vote); err != nil {
+			return err
+		}
+	}
+	return nil
+}

eth/peerset.go

@@ -311,7 +311,7 @@ func (ps *peerSet) headPeers(num uint) []*ethPeer {
 }
 
 // peersWithoutBlock retrieves a list of peers that do not have a given block in
-// their set of known hashes so it might be propagated to them.
+// their set of known hashes, so it might be propagated to them.
 func (ps *peerSet) peersWithoutBlock(hash common.Hash) []*ethPeer {
 	ps.lock.RLock()
 	defer ps.lock.RUnlock()
@@ -340,6 +340,21 @@ func (ps *peerSet) peersWithoutTransaction(hash common.Hash) []*ethPeer {
 	return list
 }
 
+// peersWithoutVote retrieves a list of peers that do not have a given
+// vote in their set of known hashes.
+func (ps *peerSet) peersWithoutVote(hash common.Hash) []*ethPeer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	list := make([]*ethPeer, 0, len(ps.peers))
+	for _, p := range ps.peers {
+		if !p.KnownVote(hash) {
+			list = append(list, p)
+		}
+	}
+	return list
+}
+
 // len returns if the current number of `eth` peers in the set. Since the `snap`
 // peers are tied to the existence of an `eth` connection, that will always be a
 // subset of `eth`.

eth/protocols/eth/broadcast.go

@@ -200,3 +200,24 @@ func (p *Peer) announceTransactions() {
 		}
 	}
 }
+
+// broadcastVotes is a write loop that schedules votes broadcasts
+// to the remote peer. The goal is to have an async writer that does not lock up
+// node internals and at the same time rate limits queued data.
+func (p *Peer) broadcastVotes() {
+	for {
+		select {
+		case votes := <-p.voteBroadcast:
+			if err := p.SendVotes(votes); err != nil {
+				return
+			}
+			p.Log().Trace("Sent votes", "count", len(votes))
+
+		case <-p.voteTerm:
+			return
+
+		case <-p.term:
+			return
+		}
+	}
+}

eth/protocols/eth/handler.go

@@ -79,6 +79,9 @@ type Backend interface {
 	// or if inbound transactions should simply be dropped.
 	AcceptTxs() bool
 
+	// VotePool retrieves the votes pool object to serve data.
+	VotePool() VotePool
+
 	// RunPeer is invoked when a peer joins on the `eth` protocol. The handler
 	// should do any peer maintenance work, handshakes and validations. If all
 	// is passed, control should be given back to the `handler` to process the
@@ -96,10 +99,15 @@ type Backend interface {
 
 // TxPool defines the methods needed by the protocol handler to serve transactions.
 type TxPool interface {
-	// Get retrieves the the transaction from the local txpool with the given hash.
+	// Get retrieves the transaction from the local txpool with the given hash.
 	Get(hash common.Hash) *types.Transaction
 }
 
+type VotePool interface {
+	// Get retrieves the vote from the local votepool with the given hash.
+	Get(hash common.Hash) *types.VoteEnvelope
+}
+
 // MakeProtocols constructs the P2P protocol definitions for `eth`.
 func MakeProtocols(backend Backend, network uint64, dnsdisc enode.Iterator) []p2p.Protocol {
 	protocols := make([]p2p.Protocol, len(ProtocolVersions))
@@ -111,7 +119,7 @@ func MakeProtocols(backend Backend, network uint64, dnsdisc enode.Iterator) []p2
 			Version: version,
 			Length:  protocolLengths[version],
 			Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
-				peer := NewPeer(version, p, rw, backend.TxPool())
+				peer := NewPeer(version, p, rw, backend.TxPool(), backend.VotePool())
 				defer peer.Close()
 
 				return backend.RunPeer(peer, func(peer *Peer) error {
@@ -206,6 +214,26 @@ var eth66 = map[uint64]msgHandler{
 	PooledTransactionsMsg:    handlePooledTransactions66,
 }
 
+var eth68 = map[uint64]msgHandler{
+	NewBlockHashesMsg:             handleNewBlockhashes,
+	NewBlockMsg:                   handleNewBlock,
+	TransactionsMsg:               handleTransactions,
+	NewPooledTransactionHashesMsg: handleNewPooledTransactionHashes,
+	// eth66 messages with request-id
+	GetBlockHeadersMsg:       handleGetBlockHeaders66,
+	BlockHeadersMsg:          handleBlockHeaders66,
+	GetBlockBodiesMsg:        handleGetBlockBodies66,
+	BlockBodiesMsg:           handleBlockBodies66,
+	GetNodeDataMsg:           handleGetNodeData66,
+	NodeDataMsg:              handleNodeData66,
+	GetReceiptsMsg:           handleGetReceipts66,
+	ReceiptsMsg:              handleReceipts66,
+	GetPooledTransactionsMsg: handleGetPooledTransactions66,
+	PooledTransactionsMsg:    handlePooledTransactions66,
+	// eth68 messages
+	VotesMsg: handleVotes,
+}
+
 // handleMessage is invoked whenever an inbound message is received from a remote
 // peer. The remote connection is torn down upon returning any error.
 func handleMessage(backend Backend, peer *Peer) error {
@@ -220,7 +248,9 @@ func handleMessage(backend Backend, peer *Peer) error {
 	defer msg.Discard()
 
 	var handlers = eth65
-	if peer.Version() >= ETH66 {
+	if peer.Version() >= ETH68 {
+		handlers = eth68
+	} else if peer.Version() >= ETH66 {
 		handlers = eth66
 	}
 	// Track the amount of time it takes to serve the request and run the handler