// 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 les implements the Light Ethereum Subprotocol.
package les
import (
"encoding/binary"
"math"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/eth"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/les/flowcontrol"
"github.com/ethereum/go-ethereum/light"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
type LesServer struct {
protocolManager *ProtocolManager
fcManager *flowcontrol.ClientManager // nil if our node is client only
fcCostStats *requestCostStats
defParams *flowcontrol.ServerParams
}
func NewLesServer(eth *eth.Ethereum, config *eth.Config) (*LesServer, error) {
pm, err := NewProtocolManager(config.ChainConfig, false, config.NetworkId, eth.EventMux(), eth.Pow(), eth.BlockChain(), eth.TxPool(), eth.ChainDb(), nil, nil)
if err != nil {
return nil, err
}
pm.blockLoop()
srv := &LesServer{protocolManager: pm}
pm.server = srv
srv.defParams = &flowcontrol.ServerParams{
BufLimit: 300000000,
MinRecharge: 50000,
}
srv.fcManager = flowcontrol.NewClientManager(uint64(config.LightServ), 10, 1000000000)
srv.fcCostStats = newCostStats(eth.ChainDb())
return srv, nil
}
func (s *LesServer) Protocols() []p2p.Protocol {
return s.protocolManager.SubProtocols
}
func (s *LesServer) Start(srvr *p2p.Server) {
s.protocolManager.Start(srvr)
}
func (s *LesServer) Stop() {
s.fcCostStats.store()
s.fcManager.Stop()
go func() {
<-s.protocolManager.noMorePeers
}()
s.protocolManager.Stop()
}
type requestCosts struct {
baseCost, reqCost uint64
}
type requestCostTable map[uint64]*requestCosts
type RequestCostList []struct {
MsgCode, BaseCost, ReqCost uint64
}
func (list RequestCostList) decode() requestCostTable {
table := make(requestCostTable)
for _, e := range list {
table[e.MsgCode] = &requestCosts{
baseCost: e.BaseCost,
reqCost: e.ReqCost,
}
}
return table
}
func (table requestCostTable) encode() RequestCostList {
list := make(RequestCostList, len(table))
for idx, code := range reqList {
list[idx].MsgCode = code
list[idx].BaseCost = table[code].baseCost
list[idx].ReqCost = table[code].reqCost
}
return list
}
type linReg struct {
sumX, sumY, sumXX, sumXY float64
cnt uint64
}
const linRegMaxCnt = 100000
func (l *linReg) add(x, y float64) {
if l.cnt >= linRegMaxCnt {
sub := float64(l.cnt+1-linRegMaxCnt) / linRegMaxCnt
l.sumX -= l.sumX * sub
l.sumY -= l.sumY * sub
l.sumXX -= l.sumXX * sub
l.sumXY -= l.sumXY * sub
l.cnt = linRegMaxCnt - 1
}
l.cnt++
l.sumX += x
l.sumY += y
l.sumXX += x * x
l.sumXY += x * y
}
func (l *linReg) calc() (b, m float64) {
if l.cnt == 0 {
return 0, 0
}
cnt := float64(l.cnt)
d := cnt*l.sumXX - l.sumX*l.sumX
if d < 0.001 {
return l.sumY / cnt, 0
}
m = (cnt*l.sumXY - l.sumX*l.sumY) / d
b = (l.sumY / cnt) - (m * l.sumX / cnt)
return b, m
}
func (l *linReg) toBytes() []byte {
var arr [40]byte
binary.BigEndian.PutUint64(arr[0:8], math.Float64bits(l.sumX))
binary.BigEndian.PutUint64(arr[8:16], math.Float64bits(l.sumY))
binary.BigEndian.PutUint64(arr[16:24], math.Float64bits(l.sumXX))
binary.BigEndian.PutUint64(arr[24:32], math.Float64bits(l.sumXY))
binary.BigEndian.PutUint64(arr[32:40], l.cnt)
return arr[:]
}
func linRegFromBytes(data []byte) *linReg {
if len(data) != 40 {
return nil
}
l := &linReg{}
l.sumX = math.Float64frombits(binary.BigEndian.Uint64(data[0:8]))
l.sumY = math.Float64frombits(binary.BigEndian.Uint64(data[8:16]))
l.sumXX = math.Float64frombits(binary.BigEndian.Uint64(data[16:24]))
l.sumXY = math.Float64frombits(binary.BigEndian.Uint64(data[24:32]))
l.cnt = binary.BigEndian.Uint64(data[32:40])
return l
}
type requestCostStats struct {
lock sync.RWMutex
db ethdb.Database
stats map[uint64]*linReg
}
type requestCostStatsRlp []struct {
MsgCode uint64
Data []byte
}
var rcStatsKey = []byte("_requestCostStats")
func newCostStats(db ethdb.Database) *requestCostStats {
stats := make(map[uint64]*linReg)
for _, code := range reqList {
stats[code] = &linReg{cnt: 100}
}
if db != nil {
data, err := db.Get(rcStatsKey)
var statsRlp requestCostStatsRlp
if err == nil {
err = rlp.DecodeBytes(data, &statsRlp)
}
if err == nil {
for _, r := range statsRlp {
if stats[r.MsgCode] != nil {
if l := linRegFromBytes(r.Data); l != nil {
stats[r.MsgCode] = l
}
}
}
}
}
return &requestCostStats{
db: db,
stats: stats,
}
}
func (s *requestCostStats) store() {
s.lock.Lock()
defer s.lock.Unlock()
statsRlp := make(requestCostStatsRlp, len(reqList))
for i, code := range reqList {
statsRlp[i].MsgCode = code
statsRlp[i].Data = s.stats[code].toBytes()
}
if data, err := rlp.EncodeToBytes(statsRlp); err == nil {
s.db.Put(rcStatsKey, data)
}
}
func (s *requestCostStats) getCurrentList() RequestCostList {
s.lock.Lock()
defer s.lock.Unlock()
list := make(RequestCostList, len(reqList))
//fmt.Println("RequestCostList")
for idx, code := range reqList {
b, m := s.stats[code].calc()
//fmt.Println(code, s.stats[code].cnt, b/1000000, m/1000000)
if m < 0 {
b += m
m = 0
}
if b < 0 {
b = 0
}
list[idx].MsgCode = code
list[idx].BaseCost = uint64(b * 2)
list[idx].ReqCost = uint64(m * 2)
}
return list
}
func (s *requestCostStats) update(msgCode, reqCnt, cost uint64) {
s.lock.Lock()
defer s.lock.Unlock()
c, ok := s.stats[msgCode]
if !ok || reqCnt == 0 {
return
}
c.add(float64(reqCnt), float64(cost))
}
func (pm *ProtocolManager) blockLoop() {
pm.wg.Add(1)
sub := pm.eventMux.Subscribe(core.ChainHeadEvent{})
newCht := make(chan struct{}, 10)
newCht <- struct{}{}
go func() {
var mu sync.Mutex
var lastHead *types.Header
lastBroadcastTd := common.Big0
for {
select {
case ev := <-sub.Chan():
peers := pm.peers.AllPeers()
if len(peers) > 0 {
header := ev.Data.(core.ChainHeadEvent).Block.Header()
hash := header.Hash()
number := header.Number.Uint64()
td := core.GetTd(pm.chainDb, hash, number)
if td != nil && td.Cmp(lastBroadcastTd) > 0 {
var reorg uint64
if lastHead != nil {
reorg = lastHead.Number.Uint64() - core.FindCommonAncestor(pm.chainDb, header, lastHead).Number.Uint64()
}
lastHead = header
lastBroadcastTd = td
glog.V(logger.Debug).Infoln("===> ", number, hash, td, reorg)
announce := announceData{Hash: hash, Number: number, Td: td, ReorgDepth: reorg}
for _, p := range peers {
select {
case p.announceChn <- announce:
default:
pm.removePeer(p.id)
}
}
}
}
newCht <- struct{}{}
case <-newCht:
go func() {
mu.Lock()
more := makeCht(pm.chainDb)
mu.Unlock()
if more {
time.Sleep(time.Millisecond * 10)
newCht <- struct{}{}
}
}()
case <-pm.quitSync:
sub.Unsubscribe()
pm.wg.Done()
return
}
}
}()
}
var (
lastChtKey = []byte("LastChtNumber") // chtNum (uint64 big endian)
chtPrefix = []byte("cht") // chtPrefix + chtNum (uint64 big endian) -> trie root hash
chtConfirmations = light.ChtFrequency / 2
)
func getChtRoot(db ethdb.Database, num uint64) common.Hash {
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], num)
data, _ := db.Get(append(chtPrefix, encNumber[:]...))
return common.BytesToHash(data)
}
func storeChtRoot(db ethdb.Database, num uint64, root common.Hash) {
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], num)
db.Put(append(chtPrefix, encNumber[:]...), root[:])
}
func makeCht(db ethdb.Database) bool {
headHash := core.GetHeadBlockHash(db)
headNum := core.GetBlockNumber(db, headHash)
var newChtNum uint64
if headNum > chtConfirmations {
newChtNum = (headNum - chtConfirmations) / light.ChtFrequency
}
var lastChtNum uint64
data, _ := db.Get(lastChtKey)
if len(data) == 8 {
lastChtNum = binary.BigEndian.Uint64(data[:])
}
if newChtNum <= lastChtNum {
return false
}
var t *trie.Trie
if lastChtNum > 0 {
var err error
t, err = trie.New(getChtRoot(db, lastChtNum), db)
if err != nil {
lastChtNum = 0
}
}
if lastChtNum == 0 {
t, _ = trie.New(common.Hash{}, db)
}
for num := lastChtNum * light.ChtFrequency; num < (lastChtNum+1)*light.ChtFrequency; num++ {
hash := core.GetCanonicalHash(db, num)
if hash == (common.Hash{}) {
panic("Canonical hash not found")
}
td := core.GetTd(db, hash, num)
if td == nil {
panic("TD not found")
}
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], num)
var node light.ChtNode
node.Hash = hash
node.Td = td
data, _ := rlp.EncodeToBytes(node)
t.Update(encNumber[:], data)
}
root, err := t.Commit()
if err != nil {
lastChtNum = 0
} else {
lastChtNum++
glog.V(logger.Detail).Infof("cht: %d %064x", lastChtNum, root)
storeChtRoot(db, lastChtNum, root)
var data [8]byte
binary.BigEndian.PutUint64(data[:], lastChtNum)
db.Put(lastChtKey, data[:])
}
return newChtNum > lastChtNum
}
