263 lines
8.9 KiB
Go
263 lines
8.9 KiB
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 eth
|
|
|
|
import (
|
|
"math/big"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/core/rawdb"
|
|
"github.com/ethereum/go-ethereum/core/types"
|
|
"github.com/ethereum/go-ethereum/eth/downloader"
|
|
"github.com/ethereum/go-ethereum/eth/protocols/eth"
|
|
"github.com/ethereum/go-ethereum/log"
|
|
)
|
|
|
|
const (
|
|
forceSyncCycle = 10 * time.Second // Time interval to force syncs, even if few peers are available
|
|
defaultMinSyncPeers = 5 // Amount of peers desired to start syncing
|
|
)
|
|
|
|
// syncTransactions starts sending all currently pending transactions to the given peer.
|
|
func (h *handler) syncTransactions(p *eth.Peer) {
|
|
// Assemble the set of transaction to broadcast or announce to the remote
|
|
// peer. Fun fact, this is quite an expensive operation as it needs to sort
|
|
// the transactions if the sorting is not cached yet. However, with a random
|
|
// order, insertions could overflow the non-executable queues and get dropped.
|
|
//
|
|
// TODO(karalabe): Figure out if we could get away with random order somehow
|
|
var txs types.Transactions
|
|
pending, _ := h.txpool.Pending(false)
|
|
for _, batch := range pending {
|
|
txs = append(txs, batch...)
|
|
}
|
|
if len(txs) == 0 {
|
|
return
|
|
}
|
|
// The eth/65 protocol introduces proper transaction announcements, so instead
|
|
// of dripping transactions across multiple peers, just send the entire list as
|
|
// an announcement and let the remote side decide what they need (likely nothing).
|
|
hashes := make([]common.Hash, len(txs))
|
|
for i, tx := range txs {
|
|
hashes[i] = tx.Hash()
|
|
}
|
|
p.AsyncSendPooledTransactionHashes(hashes)
|
|
}
|
|
|
|
// chainSyncer coordinates blockchain sync components.
|
|
type chainSyncer struct {
|
|
handler *handler
|
|
force *time.Timer
|
|
forced bool // true when force timer fired
|
|
peerEventCh chan struct{}
|
|
doneCh chan error // non-nil when sync is running
|
|
}
|
|
|
|
// chainSyncOp is a scheduled sync operation.
|
|
type chainSyncOp struct {
|
|
mode downloader.SyncMode
|
|
peer *eth.Peer
|
|
td *big.Int
|
|
head common.Hash
|
|
}
|
|
|
|
// newChainSyncer creates a chainSyncer.
|
|
func newChainSyncer(handler *handler) *chainSyncer {
|
|
return &chainSyncer{
|
|
handler: handler,
|
|
peerEventCh: make(chan struct{}),
|
|
}
|
|
}
|
|
|
|
// handlePeerEvent notifies the syncer about a change in the peer set.
|
|
// This is called for new peers and every time a peer announces a new
|
|
// chain head.
|
|
func (cs *chainSyncer) handlePeerEvent(peer *eth.Peer) bool {
|
|
select {
|
|
case cs.peerEventCh <- struct{}{}:
|
|
return true
|
|
case <-cs.handler.quitSync:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// loop runs in its own goroutine and launches the sync when necessary.
|
|
func (cs *chainSyncer) loop() {
|
|
defer cs.handler.wg.Done()
|
|
|
|
cs.handler.blockFetcher.Start()
|
|
cs.handler.txFetcher.Start()
|
|
defer cs.handler.blockFetcher.Stop()
|
|
defer cs.handler.txFetcher.Stop()
|
|
defer cs.handler.downloader.Terminate()
|
|
|
|
// The force timer lowers the peer count threshold down to one when it fires.
|
|
// This ensures we'll always start sync even if there aren't enough peers.
|
|
cs.force = time.NewTimer(forceSyncCycle)
|
|
defer cs.force.Stop()
|
|
|
|
for {
|
|
if op := cs.nextSyncOp(); op != nil {
|
|
cs.startSync(op)
|
|
}
|
|
select {
|
|
case <-cs.peerEventCh:
|
|
// Peer information changed, recheck.
|
|
case <-cs.doneCh:
|
|
cs.doneCh = nil
|
|
cs.force.Reset(forceSyncCycle)
|
|
cs.forced = false
|
|
case <-cs.force.C:
|
|
cs.forced = true
|
|
|
|
case <-cs.handler.quitSync:
|
|
// Disable all insertion on the blockchain. This needs to happen before
|
|
// terminating the downloader because the downloader waits for blockchain
|
|
// inserts, and these can take a long time to finish.
|
|
cs.handler.chain.StopInsert()
|
|
cs.handler.downloader.Terminate()
|
|
if cs.doneCh != nil {
|
|
<-cs.doneCh
|
|
}
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// nextSyncOp determines whether sync is required at this time.
|
|
func (cs *chainSyncer) nextSyncOp() *chainSyncOp {
|
|
if cs.doneCh != nil {
|
|
return nil // Sync already running.
|
|
}
|
|
|
|
// Ensure we're at minimum peer count.
|
|
minPeers := defaultMinSyncPeers
|
|
if cs.forced {
|
|
minPeers = 1
|
|
} else if minPeers > cs.handler.maxPeers {
|
|
minPeers = cs.handler.maxPeers
|
|
}
|
|
if cs.handler.peers.len() < minPeers {
|
|
return nil
|
|
}
|
|
// We have enough peers, check TD
|
|
peer := cs.handler.peers.peerWithHighestTD()
|
|
if peer == nil {
|
|
return nil
|
|
}
|
|
mode, ourTD := cs.modeAndLocalHead()
|
|
if mode == downloader.FastSync && atomic.LoadUint32(&cs.handler.snapSync) == 1 {
|
|
// Fast sync via the snap protocol
|
|
mode = downloader.SnapSync
|
|
}
|
|
op := peerToSyncOp(mode, peer)
|
|
if op.td.Cmp(ourTD) <= 0 {
|
|
return nil // We're in sync.
|
|
}
|
|
return op
|
|
}
|
|
|
|
func peerToSyncOp(mode downloader.SyncMode, p *eth.Peer) *chainSyncOp {
|
|
peerHead, peerTD := p.Head()
|
|
return &chainSyncOp{mode: mode, peer: p, td: peerTD, head: peerHead}
|
|
}
|
|
|
|
func (cs *chainSyncer) modeAndLocalHead() (downloader.SyncMode, *big.Int) {
|
|
// If we're in fast sync mode, return that directly
|
|
if atomic.LoadUint32(&cs.handler.fastSync) == 1 {
|
|
block := cs.handler.chain.CurrentFastBlock()
|
|
td := cs.handler.chain.GetTdByHash(block.Hash())
|
|
return downloader.FastSync, td
|
|
}
|
|
// We are probably in full sync, but we might have rewound to before the
|
|
// fast sync pivot, check if we should reenable
|
|
if pivot := rawdb.ReadLastPivotNumber(cs.handler.database); pivot != nil {
|
|
if head := cs.handler.chain.CurrentBlock(); head.NumberU64() < *pivot {
|
|
block := cs.handler.chain.CurrentFastBlock()
|
|
td := cs.handler.chain.GetTdByHash(block.Hash())
|
|
return downloader.FastSync, td
|
|
}
|
|
}
|
|
// Nope, we're really full syncing
|
|
head := cs.handler.chain.CurrentBlock()
|
|
td := cs.handler.chain.GetTd(head.Hash(), head.NumberU64())
|
|
return downloader.FullSync, td
|
|
}
|
|
|
|
// startSync launches doSync in a new goroutine.
|
|
func (cs *chainSyncer) startSync(op *chainSyncOp) {
|
|
cs.doneCh = make(chan error, 1)
|
|
go func() { cs.doneCh <- cs.handler.doSync(op) }()
|
|
}
|
|
|
|
// doSync synchronizes the local blockchain with a remote peer.
|
|
func (h *handler) doSync(op *chainSyncOp) error {
|
|
if op.mode == downloader.FastSync || op.mode == downloader.SnapSync {
|
|
// Before launch the fast sync, we have to ensure user uses the same
|
|
// txlookup limit.
|
|
// The main concern here is: during the fast sync Geth won't index the
|
|
// block(generate tx indices) before the HEAD-limit. But if user changes
|
|
// the limit in the next fast sync(e.g. user kill Geth manually and
|
|
// restart) then it will be hard for Geth to figure out the oldest block
|
|
// has been indexed. So here for the user-experience wise, it's non-optimal
|
|
// that user can't change limit during the fast sync. If changed, Geth
|
|
// will just blindly use the original one.
|
|
limit := h.chain.TxLookupLimit()
|
|
if stored := rawdb.ReadFastTxLookupLimit(h.database); stored == nil {
|
|
rawdb.WriteFastTxLookupLimit(h.database, limit)
|
|
} else if *stored != limit {
|
|
h.chain.SetTxLookupLimit(*stored)
|
|
log.Warn("Update txLookup limit", "provided", limit, "updated", *stored)
|
|
}
|
|
}
|
|
// Run the sync cycle, and disable fast sync if we're past the pivot block
|
|
err := h.downloader.Synchronise(op.peer.ID(), op.head, op.td, op.mode)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if atomic.LoadUint32(&h.fastSync) == 1 {
|
|
log.Info("Fast sync complete, auto disabling")
|
|
atomic.StoreUint32(&h.fastSync, 0)
|
|
}
|
|
if atomic.LoadUint32(&h.snapSync) == 1 {
|
|
log.Info("Snap sync complete, auto disabling")
|
|
atomic.StoreUint32(&h.snapSync, 0)
|
|
}
|
|
// If we've successfully finished a sync cycle and passed any required checkpoint,
|
|
// enable accepting transactions from the network.
|
|
head := h.chain.CurrentBlock()
|
|
if head.NumberU64() >= h.checkpointNumber {
|
|
// Checkpoint passed, sanity check the timestamp to have a fallback mechanism
|
|
// for non-checkpointed (number = 0) private networks.
|
|
if head.Time() >= uint64(time.Now().AddDate(0, -1, 0).Unix()) {
|
|
atomic.StoreUint32(&h.acceptTxs, 1)
|
|
}
|
|
}
|
|
if head.NumberU64() > 0 {
|
|
// We've completed a sync cycle, notify all peers of new state. This path is
|
|
// essential in star-topology networks where a gateway node needs to notify
|
|
// all its out-of-date peers of the availability of a new block. This failure
|
|
// scenario will most often crop up in private and hackathon networks with
|
|
// degenerate connectivity, but it should be healthy for the mainnet too to
|
|
// more reliably update peers or the local TD state.
|
|
h.BroadcastBlock(head, false)
|
|
}
|
|
return nil
|
|
}
|