// 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 (
"encoding/json"
"errors"
"fmt"
"math"
"math/big"
"sync"
"sync/atomic"
"time"
"github.com/ava-labs/coreth/core"
"github.com/ava-labs/go-ethereum/common"
"github.com/ava-labs/go-ethereum/consensus"
"github.com/ava-labs/go-ethereum/core/types"
"github.com/ava-labs/go-ethereum/eth/downloader"
"github.com/ava-labs/go-ethereum/eth/fetcher"
"github.com/ava-labs/go-ethereum/ethdb"
"github.com/ava-labs/go-ethereum/event"
"github.com/ava-labs/go-ethereum/log"
"github.com/ava-labs/go-ethereum/p2p"
"github.com/ava-labs/go-ethereum/p2p/enode"
"github.com/ava-labs/go-ethereum/params"
"github.com/ava-labs/go-ethereum/rlp"
"github.com/ava-labs/go-ethereum/trie"
)
const (
softResponseLimit = 2 * 1024 * 1024 // Target maximum size of returned blocks, headers or node data.
estHeaderRlpSize = 500 // Approximate size of an RLP encoded block header
// txChanSize is the size of channel listening to NewTxsEvent.
// The number is referenced from the size of tx pool.
txChanSize = 4096
// minimim number of peers to broadcast new blocks to
minBroadcastPeers = 4
)
var (
syncChallengeTimeout = 15 * time.Second // Time allowance for a node to reply to the sync progress challenge
)
func errResp(code errCode, format string, v ...interface{}) error {
return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
}
type ProtocolManager struct {
networkID uint64
fastSync uint32 // Flag whether fast sync is enabled (gets disabled if we already have blocks)
acceptTxs uint32 // Flag whether we're considered synchronised (enables transaction processing)
checkpointNumber uint64 // Block number for the sync progress validator to cross reference
checkpointHash common.Hash // Block hash for the sync progress validator to cross reference
txpool txPool
blockchain *core.BlockChain
maxPeers int
downloader *downloader.Downloader
fetcher *fetcher.Fetcher
peers *peerSet
eventMux *event.TypeMux
txsCh chan core.NewTxsEvent
txsSub event.Subscription
minedBlockSub *event.TypeMuxSubscription
whitelist map[uint64]common.Hash
// channels for fetcher, syncer, txsyncLoop
newPeerCh chan *peer
txsyncCh chan *txsync
quitSync chan struct{}
noMorePeers chan struct{}
// wait group is used for graceful shutdowns during downloading
// and processing
wg sync.WaitGroup
}
// NewProtocolManager returns a new Ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
// with the Ethereum network.
func NewProtocolManager(config *params.ChainConfig, checkpoint *params.TrustedCheckpoint, mode downloader.SyncMode, networkID uint64, mux *event.TypeMux, txpool txPool, engine consensus.Engine, blockchain *core.BlockChain, chaindb ethdb.Database, cacheLimit int, whitelist map[uint64]common.Hash) (*ProtocolManager, error) {
// Create the protocol manager with the base fields
manager := &ProtocolManager{
networkID: networkID,
eventMux: mux,
txpool: txpool,
blockchain: blockchain,
peers: newPeerSet(),
whitelist: whitelist,
newPeerCh: make(chan *peer),
noMorePeers: make(chan struct{}),
txsyncCh: make(chan *txsync),
quitSync: make(chan struct{}),
}
if mode == downloader.FullSync {
// The database seems empty as the current block is the genesis. Yet the fast
// block is ahead, so fast sync was enabled for this node at a certain point.
// The scenarios where this can happen is
// * if the user manually (or via a bad block) rolled back a fast sync node
// below the sync point.
// * the last fast sync is not finished while user specifies a full sync this
// time. But we don't have any recent state for full sync.
// In these cases however it's safe to reenable fast sync.
fullBlock, fastBlock := blockchain.CurrentBlock(), blockchain.CurrentFastBlock()
if fullBlock.NumberU64() == 0 && fastBlock.NumberU64() > 0 {
manager.fastSync = uint32(1)
log.Warn("Switch sync mode from full sync to fast sync")
}
} else {
if blockchain.CurrentBlock().NumberU64() > 0 {
// Print warning log if database is not empty to run fast sync.
log.Warn("Switch sync mode from fast sync to full sync")
} else {
// If fast sync was requested and our database is empty, grant it
manager.fastSync = uint32(1)
}
}
// If we have trusted checkpoints, enforce them on the chain
if checkpoint != nil {
manager.checkpointNumber = (checkpoint.SectionIndex+1)*params.CHTFrequency - 1
manager.checkpointHash = checkpoint.SectionHead
}
// Construct the downloader (long sync) and its backing state bloom if fast
// sync is requested. The downloader is responsible for deallocating the state
// bloom when it's done.
var stateBloom *trie.SyncBloom
if atomic.LoadUint32(&manager.fastSync) == 1 {
stateBloom = trie.NewSyncBloom(uint64(cacheLimit), chaindb)
}
manager.downloader = downloader.New(manager.checkpointNumber, chaindb, stateBloom, manager.eventMux, blockchain, nil, manager.removePeer)
// Construct the fetcher (short sync)
validator := func(header *types.Header) error {
return engine.VerifyHeader(blockchain, header, true)
}
heighter := func() uint64 {
return blockchain.CurrentBlock().NumberU64()
}
inserter := func(blocks types.Blocks) (int, error) {
// If sync hasn't reached the checkpoint yet, deny importing weird blocks.
//
// Ideally we would also compare the head block's timestamp and similarly reject