// Copyright 2019 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 snapshot
import (
"bytes"
"encoding/binary"
"math/big"
"time"
"github.com/VictoriaMetrics/fastcache"
"github.com/ava-labs/coreth/core/rawdb"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
var (
// emptyRoot is the known root hash of an empty trie.
emptyRoot = common.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
// emptyCode is the known hash of the empty EVM bytecode.
emptyCode = crypto.Keccak256Hash(nil)
)
// generatorStats is a collection of statistics gathered by the snapshot generator
// for logging purposes.
type generatorStats struct {
wiping chan struct{} // Notification channel if wiping is in progress
origin uint64 // Origin prefix where generation started
start time.Time // Timestamp when generation started
accounts uint64 // Number of accounts indexed
slots uint64 // Number of storage slots indexed
storage common.StorageSize // Account and storage slot size
}
// Log creates an contextual log with the given message and the context pulled
// from the internally maintained statistics.
func (gs *generatorStats) Log(msg string, root common.Hash, marker []byte) {
var ctx []interface{}
if root != (common.Hash{}) {
ctx = append(ctx, []interface{}{"root", root}...)
}
// Figure out whether we're after or within an account
switch len(marker) {
case common.HashLength:
ctx = append(ctx, []interface{}{"at", common.BytesToHash(marker)}...)
case 2 * common.HashLength:
ctx = append(ctx, []interface{}{
"in", common.BytesToHash(marker[:common.HashLength]),
"at", common.BytesToHash(marker[common.HashLength:]),
}...)
}
// Add the usual measurements
ctx = append(ctx, []interface{}{
"accounts", gs.accounts,
"slots", gs.slots,
"storage", gs.storage,
"elapsed", common.PrettyDuration(time.Since(gs.start)),
}...)
// Calculate the estimated indexing time based on current stats
if len(marker) > 0 {
if done := binary.BigEndian.Uint64(marker[:8]) - gs.origin; done > 0 {
left := math.MaxUint64 - binary.BigEndian.Uint64(marker[:8])
speed := done/uint64(time.Since(gs.start)/time.Millisecond+1) + 1 // +1s to avoid division by zero
ctx = append(ctx, []interface{}{
"eta", common.PrettyDuration(time.Duration(left/speed) * time.Millisecond),
}...)
}
}
log.Info(msg, ctx...)
}
// generateSnapshot regenerates a brand new snapshot based on an existing state
// database and head block asynchronously. The snapshot is returned immediately
// and generation is continued in the background until done.
func generateSnapshot(diskdb ethdb.KeyValueStore, triedb *trie.Database, cache int, root common.Hash, wiper chan struct{}) *diskLayer {
// Wipe any previously existing snapshot from the database if no wiper is
// currently in progress.
if wiper == nil {
wiper = wipeSnapshot(diskdb, true)
}
// Create a new disk layer with an initialized state marker at zero
rawdb.WriteSnapshotRoot(diskdb, root)
base := &diskLayer{
diskdb: diskdb,
triedb: triedb,
root: root,
cache: fastcache.New(cache * 1024 * 1024),
genMarker: []byte{}, // Initialized but empty!
genPending: make(chan struct{}),
genAbort: make(chan chan *generatorStats),
}
go base.generate(&generatorStats{wiping: wiper, start: time.Now()})
return base
}
// generate is a background thread that iterates over the state and storage tries,
// constructing the state snapshot. All the arguments are purely for statistics
// gethering and logging, since the method surfs the blocks as they arrive, often
// being restarted.
func (dl *diskLayer) generate(stats *generatorStats) {
// If a database wipe is in operation, wait until it's done
if stats.wiping != nil {
stats.Log("Wiper running, state snapshotting paused", common.Hash{}, dl.genMarker)
select {
// If wiper is done, resume normal mode of operation
case <-stats.wiping:
stats.wiping = nil
stats.start = time.Now()
// If generator was aboted during wipe, return
case abort := <-dl.genAbort:
abort <- stats
return
}
}
// Create an account and state iterator pointing to the current generator marker
accTrie, err := trie.NewSecure(dl.root, dl.triedb)
if err != nil {
// The account trie is missing (GC), surf the chain until one becomes available
stats.Log("Trie missing, state snapshotting paused", dl.root, dl.genMarker)
abort := <-dl.genAbort
abort <- stats
return
}
stats.Log("Resuming state snapshot generation", dl.root, dl.genMarker)
var accMarker []byte
if len(dl.genMarker) > 0 { // []byte{} is the start, use nil for that
accMarker = dl.genMarker[:common.HashLength]
}
accIt := trie.NewIterator(accTrie.NodeIterator(accMarker))
batch := dl.diskdb.NewBatch()
// Iterate from the previous marker and continue generating the state snapshot
logged := time.Now()
for accIt.Next() {
// Retrieve the current account and flatten it into the internal format
accountHash := common.BytesToHash(accIt.Key)
var acc struct {
Nonce uint64
Balance *big.Int
Root common.Hash
CodeHash []byte
}
if err := rlp.DecodeBytes(accIt.Value, &acc); err != nil {
log.Crit("Invalid account encountered during snapshot creation", "err", err)
}
data := SlimAccountRLP(acc.Nonce, acc.Balance, acc.Root, acc.CodeHash)
// If the account is not yet in-progress, write it out
if accMarker == nil || !bytes.Equal(accountHash[:], accMarker) {
rawdb.WriteAccountSnapshot(batch, accountHash, data)
stats.storage += common.StorageSize(1 + common.HashLength + len(data))
stats.accounts++
}
// If we've exceeded our batch allowance or termination was requested, flush to disk
var abort chan *generatorStats
select {
case abort = <-dl.genAbort:
default:
}
if batch.ValueSize() > ethdb.IdealBatchSize || abort != nil {
// Only write and set the marker if we actually did something useful
if batch.ValueSize() > 0 {
batch.Write()
batch.Reset()
dl.lock.Lock()
dl.genMarker = accountHash[:]
dl.lock.Unlock()
}
if abort != nil {
stats.Log("Aborting state snapshot generation", dl.root, accountHash[:])
abort <- stats
return
}
}
// If the account is in-progress, continue where we left off (otherwise iterate all)
if acc.Root != emptyRoot {
storeTrie, err := trie.NewSecure(acc.Root, dl.triedb)
if err != nil {
log.Crit("Storage trie inaccessible for snapshot generation", "err", err)
}
var storeMarker []byte
if accMarker != nil && bytes.Equal(accountHash[:], accMarker) && len(dl.genMarker) > common.HashLength {
storeMarker = dl.genMarker[common.HashLength:]
}
storeIt := trie.NewIterator(storeTrie.NodeIterator(storeMarker))
for storeIt.Next() {
rawdb.WriteStorageSnapshot(batch, accountHash, common.BytesToHash(storeIt.Key), storeIt.Value)
stats.storage += common.StorageSize(1 + 2*common.HashLength + len(storeIt.Value))
stats.slots++
// If we've exceeded our batch allowance or termination was requested, flush to disk
var abort chan *generatorStats
select {
case abort = <-dl.genAbort:
default:
}
if batch.ValueSize() > ethdb.IdealBatchSize || abort != nil {
// Only write and set the marker if we actually did something useful
if batch.ValueSize() > 0 {
batch.Write()
batch.Reset()
dl.lock.Lock()
dl.genMarker = append(accountHash[:], storeIt.Key...)
dl.lock.Unlock()
}
if abort != nil {
stats.Log("Aborting state snapshot generation", dl.root, append(accountHash[:], storeIt.Key...))
abort <- stats
return
}
}
}
}
if time.Since(logged) > 8*time.Second {
stats.Log("Generating state snapshot", dl.root, accIt.Key)
logged = time.Now()
}
// Some account processed, unmark the marker
accMarker = nil
}
// Snapshot fully generated, set the marker to nil
if batch.ValueSize() > 0 {
batch.Write()
}
log.Info("Generated state snapshot", "accounts", stats.accounts, "slots", stats.slots,
"storage", stats.storage, "elapsed", common.PrettyDuration(time.Since(stats.start)))
dl.lock.Lock()
dl.genMarker = nil
close(dl.genPending)
dl.lock.Unlock()
// Someone will be looking for us, wait it out
abort := <-dl.genAbort
abort <- nil
}