peer.go

// Copyright 2015 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 ptn

import (
	"errors"
	"fmt"
	"strings"
	"sync"
	"time"

	set "github.com/deckarep/golang-set"
	"github.com/palletone/go-palletone/common"
	"github.com/palletone/go-palletone/common/log"
	"github.com/palletone/go-palletone/common/p2p"
	"github.com/palletone/go-palletone/consensus/jury"
	"github.com/palletone/go-palletone/dag/modules"
	"sort"
)

var (
	errClosed            = errors.New("peer set is closed")
	errAlreadyRegistered = errors.New("peer is already registered")
	errNotRegistered     = errors.New("peer is not registered")

	//ID_LENGTH = 32
	//PTNCOIN   = [ID_LENGTH]byte{'p', 't', 'n', 'c', 'o', 'i', 'n'}
)

const (
	maxKnownTxs    = 32768 // Maximum transactions hashes to keep in the known list (prevent DOS)
	maxKnownBlocks = 1024  // Maximum block hashes to keep in the known list (prevent DOS)
	//maxKnownVsss     = 25    // Maximum Vss hashes to keep in the known list (prevent DOS)
	handshakeTimeout = 5 * time.Second

	//transitionStep1  = 1 //All transition mediator each other connected to star vss
	//transitionStep2  = 2 //vss success
	//transitionCancel = 3 //retranstion

	maxKnownVSSDeal     = 21 * 20
	maxKnownVSSResponse = 21 * 20
	maxKnownSigShare    = 21 * 2
	maxKnownGroupSign   = 21 * 15
)

// PeerInfo represents a short summary of the PalletOne sub-protocol metadata known
// about a connected peer.
type PeerInfo struct {
	Version int `json:"version"` // PalletOne protocol version negotiated
	//Difficulty uint64 `json:"difficulty"` // Total difficulty of the peer's blockchain
	Index uint64 `json:"index"` // Total difficulty of the peer's blockchain
	Head  string `json:"head"`  // SHA3 hash of the peer's best owned block
}

type peerMsg struct {
	head         common.Hash
	number       *modules.ChainIndex
	stableNumber *modules.ChainIndex
}

type peer struct {
	id string

	*p2p.Peer
	rw p2p.MsgReadWriter

	version int // Protocol version negotiated
	//forkDrop *time.Timer // Timed connection dropper if forks aren't validated in time

	peermsg map[modules.AssetId]peerMsg
	lock    sync.RWMutex

	//lightpeermsg map[modules.AssetId]peerMsg
	//lightlock    sync.RWMutex

	knownTxs          set.Set // Set of transaction hashes known to be known by this peer
	knownBlocks       set.Set // Set of block hashes known to be known by this peer
	knownLightHeaders set.Set
	knownGroupSig     set.Set

	knownVSSDeal     set.Set
	knownVSSResponse set.Set
	knownSigShare    set.Set
}

func newPeer(version int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {

	id := p.ID()
	return &peer{
		Peer:              p,
		rw:                rw,
		version:           version,
		id:                id.TerminalString(),
		knownTxs:          set.NewSet(),
		knownBlocks:       set.NewSet(),
		knownLightHeaders: set.NewSet(),
		knownGroupSig:     set.NewSet(),
		peermsg:           map[modules.AssetId]peerMsg{},
		//lightpeermsg:      map[modules.AssetId]peerMsg{},

		knownVSSDeal:     set.NewSet(),
		knownVSSResponse: set.NewSet(),
		knownSigShare:    set.NewSet(),
	}
}

// Info gathers and returns a collection of metadata known about a peer.
func (p *peer) Info(protocol string) *PeerInfo {
	asset, err := modules.NewAsset(strings.ToUpper(protocol), modules.AssetType_FungibleToken,
		8, []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, modules.UniqueIdType_Null, modules.UniqueId{})
	if err != nil {
		log.Error("peer info asset err", err)
		return &PeerInfo{}
	}
	var (
		hash  = common.Hash{}
		index = uint64(0)
	)
	if ha, number := p.Head(asset.AssetId); number != nil {
		hash = ha
		index = number.Index
	}

	return &PeerInfo{
		Version: p.version,
		Index:   index,
		Head:    hash.Hex(),
	}
}

func (p *peer) StableIndex(assetID modules.AssetId) (stableIndex *modules.ChainIndex) {
	p.lock.RLock()
	defer p.lock.RUnlock()

	msg, ok := p.peermsg[assetID]
	if ok {
		stableIndex = msg.stableNumber
	}
	return stableIndex
}

// Head retrieves a copy of the current head hash and total difficulty of the
// peer.
//only retain the max index header.will in other mediator,not in ptn mediator.
func (p *peer) Head(assetID modules.AssetId) (hash common.Hash, number *modules.ChainIndex) {
	p.lock.RLock()
	defer p.lock.RUnlock()

	msg, ok := p.peermsg[assetID]
	if ok {
		copy(hash[:], msg.head[:])
		number = msg.number
	}
	return hash, number
}

// SetHead updates the head hash and total difficulty of the peer.
//only retain the max index header
func (p *peer) SetHead(hash common.Hash, number, index *modules.ChainIndex) {
	p.lock.Lock()
	defer p.lock.Unlock()

	msg, ok := p.peermsg[number.AssetID]
	tempstableIndex := &modules.ChainIndex{}
	if ok && index == nil {
		tempstableIndex = msg.stableNumber
	}

	if (ok && number.Index > msg.number.Index) || !ok {
		copy(msg.head[:], hash[:])
		msg.number = number
		if index != nil {
			msg.stableNumber = index
		} else {
			msg.stableNumber = tempstableIndex
		}

	}
	p.peermsg[number.AssetID] = msg
}

// MarkBlock marks a block as known for the peer, ensuring that the block will
// never be propagated to this particular peer.
func (p *peer) MarkUnit(hash common.Hash) {
	// If we reached the memory allowance, drop a previously known block hash
	for p.knownBlocks.Cardinality() >= maxKnownBlocks {
		p.knownBlocks.Pop()
	}
	p.knownBlocks.Add(hash)
}

func (p *peer) MarkGroupSig(hash common.Hash) {
	for p.knownGroupSig.Cardinality() >= maxKnownGroupSign {
		p.knownGroupSig.Pop()
	}
	p.knownGroupSig.Add(hash)
}

// MarkTransaction marks a transaction as known for the peer, ensuring that it
// will never be propagated to this particular peer.
func (p *peer) MarkTransaction(hash common.Hash) {
	// If we reached the memory allowance, drop a previously known transaction hash
	for p.knownTxs.Cardinality() >= maxKnownTxs {
		p.knownTxs.Pop()
	}
	p.knownTxs.Add(hash)
}

func (p *peer) MarkLightHeader(hash common.Hash) {
	// If we reached the memory allowance, drop a previously known transaction hash
	for p.knownLightHeaders.Cardinality() >= maxKnownTxs {
		p.knownLightHeaders.Pop()
	}
	p.knownLightHeaders.Add(hash)
}

// SendTransactions sends transactions to the peer and includes the hashes
// in its transaction hash set for future reference.
func (p *peer) SendTransactions(txs modules.Transactions) error {
	for _, tx := range txs {
		p.knownTxs.Add(tx.Hash())
	}
	return p2p.Send(p.rw, TxMsg, txs)
}

func (p *peer) SendContractTransaction(event jury.ContractEvent) error {
	return p2p.Send(p.rw, ContractMsg, event)
}

func (p *peer) SendElectionEvent(event jury.ElectionEvent) error {
	evs, err := event.ToElectionEventBytes()
	if err != nil {
		return err
	}
	return p2p.Send(p.rw, ElectionMsg, *evs)
}

func (p *peer) SendAdapterEvent(event jury.AdapterEvent) error {
	avs, err := event.ToAdapterEventBytes()
	if err != nil {
		return err
	}
	return p2p.Send(p.rw, AdapterMsg, *avs)
}

//Test SendConsensus sends consensus msg to the peer
func (p *peer) SendConsensus(msgs []byte) error {
	return p2p.Send(p.rw, NewBlockMsg, msgs)
}

// SendNewBlockHashes announces the availability of a number of blocks through
// a hash notification.
func (p *peer) SendNewUnitHashes(hashes []common.Hash, numbers []*modules.ChainIndex) error {
	for _, hash := range hashes {
		p.knownBlocks.Add(hash)
	}
	request := make(newBlockHashesData, len(hashes))
	for i := 0; i < len(hashes); i++ {
		request[i].Hash = hashes[i]
		request[i].Number = *numbers[i]
	}
	return p2p.Send(p.rw, NewBlockHashesMsg, request)
}

// SendNewBlock propagates an entire block to a remote peer.
//func (p *peer) SendNewUnit(unit *modules.Unit) error {
//	p.knownBlocks.Add(unit.UnitHash)
//	return p2p.Send(p.rw, NewBlockMsg, unit)
//}

// SendNewBlock propagates an entire block to a remote peer.
func (p *peer) SendNewRawUnit(unit *modules.Unit, data []byte) error {
	p.knownBlocks.Add(unit.Hash())
	return p2p.Send(p.rw, NewBlockMsg, data)
}

// SendLightHeader propagates an entire header to a remote partition peer.
func (p *peer) SendLightHeader(header *modules.Header) error {
	p.knownLightHeaders.Add(header.Hash())
	return p2p.Send(p.rw, NewBlockHeaderMsg, header)
}

// SendBlockHeaders sends a batch of block headers to the remote peer.
func (p *peer) SendLeafNodes(headers []*modules.Header) error {
	return p2p.Send(p.rw, LeafNodesMsg, headers)
}

// SendBlockHeaders sends a batch of block headers to the remote peer.
func (p *peer) SendUnitHeaders(headers []*modules.Header) error {
	return p2p.Send(p.rw, BlockHeadersMsg, headers)
}

// SendBlockBodies sends a batch of block contents to the remote peer.
func (p *peer) SendBlockBodies(bodies []blockBody) error {
	return p2p.Send(p.rw, BlockBodiesMsg, blockBodiesData(bodies))
}

// SendBlockBodiesRLP sends a batch of block contents to the remote peer from
// an already RLP encoded format.
func (p *peer) SendBlockBodiesRLP(bodies [][]byte /*[]rlp.RawValue*/) error {
	return p2p.Send(p.rw, BlockBodiesMsg, bodies)
}

// SendNodeDataRLP sends a batch of arbitrary internal data, corresponding to the
// hashes requested.
func (p *peer) SendNodeData(data [][]byte) error {
	return p2p.Send(p.rw, NodeDataMsg, data)
}

// SendReceiptsRLP sends a batch of transaction receipts, corresponding to the
// ones requested from an already RLP encoded format.
//func (p *peer) SendReceiptsRLP(receipts []rlp.RawValue) error {
//	return p2p.Send(p.rw, ReceiptsMsg, receipts)
//}

// RequestOneHeader is a wrapper around the header query functions to fetch a
// single header. It is used solely by the fetcher.
func (p *peer) RequestOneHeader(hash common.Hash) error {
	log.Debug("Fetching single header", "hash", hash)
	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Hash: hash},
		Amount: uint64(1), Skip: uint64(0), Reverse: false})
}

// RequestHeadersByHash fetches a batch of blocks' headers corresponding to the
// specified header query, based on the hash of an origin block.
func (p *peer) RequestHeadersByHash(origin common.Hash, amount int, skip int, reverse bool) error {
	log.Debug("Fetching batch of headers", "count", amount, "fromhash", origin, "skip", skip, "reverse", reverse)
	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Hash: origin},
		Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
}

// RequestDagHeadersByHash fetches a batch of blocks' headers corresponding to the
// specified header query, based on the hash of an origin block.
//func (p *peer) RequestDagHeadersByHash(origin common.Hash, amount int, skip int, reverse bool) error {
//	//log.Debug("Fetching batch of headers", "count", amount, "fromhash", origin, "skip", skip, "reverse", reverse)
//	return nil
//}

func (p *peer) RequestLeafNodes() error {
	//GetLeafNodes
	log.Debug("Fetching leaf nodes")
	return p2p.Send(p.rw, GetLeafNodesMsg, "")
}

// RequestHeadersByNumber fetches a batch of blocks' headers corresponding to the
// specified header query, based on the number of an origin block.
func (p *peer) RequestHeadersByNumber(origin *modules.ChainIndex, amount int, skip int, reverse bool) error {
	log.Debug("Fetching batch of headers", "count", amount, "index", origin.Index, "skip", skip, "reverse", reverse)
	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Number: *origin},
		Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
}

// RequestBodies fetches a batch of blocks' bodies corresponding to the hashes
// specified.
func (p *peer) RequestBodies(hashes []common.Hash) error {
	log.Debug("Fetching batch of block bodies", "peer id:", p.id, "count", len(hashes))
	return p2p.Send(p.rw, GetBlockBodiesMsg, hashes)
}

// RequestNodeData fetches a batch of arbitrary data from a node's known state
// data, corresponding to the specified hashes.
func (p *peer) RequestNodeData(hashes []common.Hash) error {
	log.Debug("Fetching batch of state data", "count", len(hashes))
	return p2p.Send(p.rw, GetNodeDataMsg, hashes)
}

// RequestReceipts fetches a batch of transaction receipts from a remote node.
//func (p *peer) RequestReceipts(hashes []common.Hash) error {
//	log.Debug("Fetching batch of receipts", "count", len(hashes))
//	return p2p.Send(p.rw, GetReceiptsMsg, hashes)
//}

// Handshake executes the ptn protocol handshake, negotiating version number,
// network IDs, difficulties, head and genesis blocks.
func (p *peer) Handshakev103(network uint64, index *modules.ChainIndex, genesis common.Hash, headHash common.Hash,
	stable *modules.ChainIndex) error {
	// Send out own handshake in a new thread
	errc := make(chan error, 2)
	var status statusDatav103 // safe to read after two values have been received from errc

	go func() {
		errc <- p2p.Send(p.rw, StatusMsg, &statusDatav103{
			ProtocolVersion: uint32(p.version),
			NetworkId:       network,
			Index:           index,
			GenesisUnit:     genesis,
			CurrentHeader:   headHash,
			StableIndex:     stable,
		})
	}()
	go func() {
		errc <- p.readStatus(network, &status, genesis)
	}()
	timeout := time.NewTimer(handshakeTimeout)
	defer timeout.Stop()
	for i := 0; i < 2; i++ {
		select {
		case err := <-errc:
			if err != nil {
				return err
			}
		case <-timeout.C:
			return p2p.DiscReadTimeout
		}
	}
	//stableIndex :=&modules.ChainIndex{Index:uint64(1085100)}
	//stableIndex := &modules.ChainIndex{AssetID: modules.PTNCOIN, Index: uint64(1)}
	log.Debug("peer Handshakev103", "p.id", p.id, "index", status.Index, "stable", status.StableIndex)
	p.SetHead(status.CurrentHeader, status.Index, status.StableIndex)
	return nil
}

func (p *peer) Handshake(network uint64, index *modules.ChainIndex, genesis common.Hash, headHash common.Hash,
	stable *modules.ChainIndex) error {
	// Send out own handshake in a new thread
	errc := make(chan error, 2)
	var status statusData // safe to read after two values have been received from errc

	go func() {
		errc <- p2p.Send(p.rw, StatusMsg, &statusData{
			ProtocolVersion: uint32(p.version),
			NetworkId:       network,
			Index:           index,
			GenesisUnit:     genesis,
			CurrentHeader:   headHash,
			//StableIndex:     stable,
		})
	}()
	go func() {
		errc <- p.readStatus(network, &status, genesis)
	}()
	timeout := time.NewTimer(handshakeTimeout)
	defer timeout.Stop()
	for i := 0; i < 2; i++ {
		select {
		case err := <-errc:
			if err != nil {
				return err
			}
		case <-timeout.C:
			return p2p.DiscReadTimeout
		}
	}

	log.Debug("peer Handshake", "p.id", p.id, "index", status.Index, "stable", stable.Index)
	p.SetHead(status.CurrentHeader, status.Index, stable)
	return nil
}

func (p *peer) readStatus(network uint64, status interface{}, genesis common.Hash) (err error) {
	msg, err := p.rw.ReadMsg()
	if err != nil {
		return err
	}
	if msg.Code != StatusMsg {
		return errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
	}
	if msg.Size > ProtocolMaxMsgSize {
		return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
	}
	if status1, ok := status.(*statusData); ok {
		// Decode the handshake and make sure everything matches
		if err := msg.Decode(&status1); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}

		if status1.GenesisUnit != genesis {
			return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", status1.GenesisUnit[:8], genesis[:8])
		}
		if status1.NetworkId != network {
			return errResp(ErrNetworkIdMismatch, "%d (!= %d)", status1.NetworkId, network)
		}
		if int(status1.ProtocolVersion) != p.version {
			return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", status1.ProtocolVersion, p.version)
		}
	}

	if status103, ok := status.(*statusDatav103); ok {
		// Decode the handshake and make sure everything matches
		if err := msg.Decode(&status103); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}

		if status103.GenesisUnit != genesis {
			return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", status103.GenesisUnit[:8], genesis[:8])
		}
		if status103.NetworkId != network {
			return errResp(ErrNetworkIdMismatch, "%d (!= %d)", status103.NetworkId, network)
		}
		if int(status103.ProtocolVersion) != p.version {
			return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", status103.ProtocolVersion, p.version)
		}
	}

	return nil
}

// String implements fmt.Stringer.
func (p *peer) String() string {
	return fmt.Sprintf("Peer %s [%s]", p.id,
		fmt.Sprintf("ptn/%2d", p.version),
	)
}

// peerSet represents the collection of active peers currently participating in
// the PalletOne sub-protocol.
type peerSet struct {
	peers  map[string]*peer
	lock   sync.RWMutex
	closed bool
}

// newPeerSet creates a new peer set to track the active participants.
func newPeerSet() *peerSet {
	return &peerSet{
		peers: make(map[string]*peer),
	}
}

// Register injects a new peer into the working set, or returns an error if the
// peer is already known.
func (ps *peerSet) Register(p *peer) error {
	ps.lock.Lock()
	defer ps.lock.Unlock()

	if ps.closed {
		return errClosed
	}
	if _, ok := ps.peers[p.id]; ok {
		return errAlreadyRegistered
	}
	ps.peers[p.id] = p
	return nil
}

// Unregister removes a remote peer from the active set, disabling any further
// actions to/from that particular entity.
func (ps *peerSet) Unregister(id string) error {
	ps.lock.Lock()
	defer ps.lock.Unlock()

	if _, ok := ps.peers[id]; !ok {
		return errNotRegistered
	}
	delete(ps.peers, id)
	return nil
}

// Peer retrieves the registered peer with the given id.
func (ps *peerSet) Peer(id string) *peer {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	return ps.peers[id]
}

// Len returns if the current number of peers in the set.
func (ps *peerSet) Len() int {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	return len(ps.peers)
}

// PeersWithoutBlock retrieves a list of peers that do not have a given block in
// their set of known hashes.
func (ps *peerSet) PeersWithoutUnit(hash common.Hash) []*peer {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	list := make([]*peer, 0, len(ps.peers))
	for _, p := range ps.peers {
		if !p.knownBlocks.Contains(hash) {
			list = append(list, p)
		}
	}
	return list
}

func (ps *peerSet) PeersWithoutLightHeader(hash common.Hash) []*peer {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	list := make([]*peer, 0, len(ps.peers))
	for _, p := range ps.peers {
		if !p.knownLightHeaders.Contains(hash) {
			list = append(list, p)
		}
	}
	return list
}

func (ps *peerSet) PeersWithoutGroupSig(hash common.Hash) []*peer {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	list := make([]*peer, 0, len(ps.peers))
	for _, p := range ps.peers {
		if !p.knownGroupSig.Contains(hash) {
			list = append(list, p)
		}
	}
	return list
}

// PeersWithoutTx retrieves a list of peers that do not have a given transaction
// in their set of known hashes.
func (ps *peerSet) PeersWithoutTx(hash common.Hash) []*peer {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	list := make([]*peer, 0, len(ps.peers))
	for _, p := range ps.peers {
		if !p.knownTxs.Contains(hash) {
			list = append(list, p)
		}
	}
	return list
}

// BestPeer retrieves the known peer with the currently highest total difficulty.
func (ps *peerSet) BestPeer(assetId modules.AssetId) *peer {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	var (
		bestPeer *peer
		bestTd   uint64 //*big.Int
	)
	for _, p := range ps.peers {
		if _, number := p.Head(assetId); bestPeer == nil || number.Index > bestTd {
			if number != nil {
				bestPeer, bestTd = p, number.Index
			}
		}
	}
	return bestPeer
}

type stableIndex []uint64

func (si stableIndex) Len() int {
	return len(si)
}
func (si stableIndex) Less(i, j int) bool {
	return si[i] < si[j]
}
func (si stableIndex) Swap(i, j int) {
	si[i], si[j] = si[j], si[i]
}

func (ps *peerSet) StableIndex(assetId modules.AssetId) uint64 {
	ps.lock.RLock()
	defer ps.lock.RUnlock()

	var indexs stableIndex
	for _, p := range ps.peers {
		if stable := p.StableIndex(assetId); stable != nil {
			indexs = append(indexs, stable.Index)
		}
	}
	length := indexs.Len()
	if length == 0 {
		return 0
	}
	sort.Sort(indexs)
	if length%2 == 0 {
		return (indexs[(length/2)-1] + indexs[length/2]) / 2
	}
	return indexs[length/2]
}

// Close disconnects all peers.
// No new peers can be registered after Close has returned.
func (ps *peerSet) Close() {
	ps.lock.Lock()
	defer ps.lock.Unlock()

	for _, p := range ps.peers {
		p.Disconnect(p2p.DiscQuitting)
	}
	for id := range ps.peers {
		delete(ps.peers, id)
	}
	ps.peers = nil
	ps.closed = true
}

func (ps *peerSet) GetPeers() []*peer {
	ps.lock.RLock()
	defer ps.lock.RUnlock()
	list := make([]*peer, 0, len(ps.peers))
	for _, p := range ps.peers {
		list = append(list, p)
	}
	return list
}