plugeth/light/postprocess.go
Felföldi Zsolt 2cdf6ee7e0 light: CHT and bloom trie indexers working in light mode (#16534)
This PR enables the indexers to work in light client mode by
downloading a part of these tries (the Merkle proofs of the last
values of the last known section) in order to be able to add new
values and recalculate subsequent hashes. It also adds CHT data to
NodeInfo.
2018-08-15 22:25:46 +02:00

402 lines
14 KiB
Go

// Copyright 2017 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 light
import (
"context"
"encoding/binary"
"errors"
"fmt"
"math/big"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/bitutil"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
const (
// CHTFrequencyClient is the block frequency for creating CHTs on the client side.
CHTFrequencyClient = 32768
// CHTFrequencyServer is the block frequency for creating CHTs on the server side.
// Eventually this can be merged back with the client version, but that requires a
// full database upgrade, so that should be left for a suitable moment.
CHTFrequencyServer = 4096
HelperTrieConfirmations = 2048 // number of confirmations before a server is expected to have the given HelperTrie available
HelperTrieProcessConfirmations = 256 // number of confirmations before a HelperTrie is generated
)
// TrustedCheckpoint represents a set of post-processed trie roots (CHT and BloomTrie) associated with
// the appropriate section index and head hash. It is used to start light syncing from this checkpoint
// and avoid downloading the entire header chain while still being able to securely access old headers/logs.
type TrustedCheckpoint struct {
name string
SectionIdx uint64
SectionHead, CHTRoot, BloomRoot common.Hash
}
var (
mainnetCheckpoint = TrustedCheckpoint{
name: "mainnet",
SectionIdx: 179,
SectionHead: common.HexToHash("ae778e455492db1183e566fa0c67f954d256fdd08618f6d5a393b0e24576d0ea"),
CHTRoot: common.HexToHash("646b338f9ca74d936225338916be53710ec84020b89946004a8605f04c817f16"),
BloomRoot: common.HexToHash("d0f978f5dbc86e5bf931d8dd5b2ecbebbda6dc78f8896af6a27b46a3ced0ac25"),
}
ropstenCheckpoint = TrustedCheckpoint{
name: "ropsten",
SectionIdx: 107,
SectionHead: common.HexToHash("e1988f95399debf45b873e065e5cd61b416ef2e2e5deec5a6f87c3127086e1ce"),
CHTRoot: common.HexToHash("15cba18e4de0ab1e95e202625199ba30147aec8b0b70384b66ebea31ba6a18e0"),
BloomRoot: common.HexToHash("e00fa6389b2e597d9df52172cd8e936879eed0fca4fa59db99e2c8ed682562f2"),
}
)
// trustedCheckpoints associates each known checkpoint with the genesis hash of the chain it belongs to
var trustedCheckpoints = map[common.Hash]TrustedCheckpoint{
params.MainnetGenesisHash: mainnetCheckpoint,
params.TestnetGenesisHash: ropstenCheckpoint,
}
var (
ErrNoTrustedCht = errors.New("No trusted canonical hash trie")
ErrNoTrustedBloomTrie = errors.New("No trusted bloom trie")
ErrNoHeader = errors.New("Header not found")
chtPrefix = []byte("chtRoot-") // chtPrefix + chtNum (uint64 big endian) -> trie root hash
ChtTablePrefix = "cht-"
)
// ChtNode structures are stored in the Canonical Hash Trie in an RLP encoded format
type ChtNode struct {
Hash common.Hash
Td *big.Int
}
// GetChtRoot reads the CHT root assoctiated to the given section from the database
// Note that sectionIdx is specified according to LES/1 CHT section size
func GetChtRoot(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) common.Hash {
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
data, _ := db.Get(append(append(chtPrefix, encNumber[:]...), sectionHead.Bytes()...))
return common.BytesToHash(data)
}
// GetChtV2Root reads the CHT root assoctiated to the given section from the database
// Note that sectionIdx is specified according to LES/2 CHT section size
func GetChtV2Root(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) common.Hash {
return GetChtRoot(db, (sectionIdx+1)*(CHTFrequencyClient/CHTFrequencyServer)-1, sectionHead)
}
// StoreChtRoot writes the CHT root assoctiated to the given section into the database
// Note that sectionIdx is specified according to LES/1 CHT section size
func StoreChtRoot(db ethdb.Database, sectionIdx uint64, sectionHead, root common.Hash) {
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
db.Put(append(append(chtPrefix, encNumber[:]...), sectionHead.Bytes()...), root.Bytes())
}
// ChtIndexerBackend implements core.ChainIndexerBackend
type ChtIndexerBackend struct {
diskdb, trieTable ethdb.Database
odr OdrBackend
triedb *trie.Database
section, sectionSize uint64
lastHash common.Hash
trie *trie.Trie
}
// NewBloomTrieIndexer creates a BloomTrie chain indexer
func NewChtIndexer(db ethdb.Database, clientMode bool, odr OdrBackend) *core.ChainIndexer {
var sectionSize, confirmReq uint64
if clientMode {
sectionSize = CHTFrequencyClient
confirmReq = HelperTrieConfirmations
} else {
sectionSize = CHTFrequencyServer
confirmReq = HelperTrieProcessConfirmations
}
idb := ethdb.NewTable(db, "chtIndex-")
trieTable := ethdb.NewTable(db, ChtTablePrefix)
backend := &ChtIndexerBackend{
diskdb: db,
odr: odr,
trieTable: trieTable,
triedb: trie.NewDatabase(trieTable),
sectionSize: sectionSize,
}
return core.NewChainIndexer(db, idb, backend, sectionSize, confirmReq, time.Millisecond*100, "cht")
}
// fetchMissingNodes tries to retrieve the last entry of the latest trusted CHT from the
// ODR backend in order to be able to add new entries and calculate subsequent root hashes
func (c *ChtIndexerBackend) fetchMissingNodes(ctx context.Context, section uint64, root common.Hash) error {
batch := c.trieTable.NewBatch()
r := &ChtRequest{ChtRoot: root, ChtNum: section - 1, BlockNum: section*c.sectionSize - 1}
for {
err := c.odr.Retrieve(ctx, r)
switch err {
case nil:
r.Proof.Store(batch)
return batch.Write()
case ErrNoPeers:
// if there are no peers to serve, retry later
select {
case <-ctx.Done():
return ctx.Err()
case <-time.After(time.Second * 10):
// stay in the loop and try again
}
default:
return err
}
}
}
// Reset implements core.ChainIndexerBackend
func (c *ChtIndexerBackend) Reset(ctx context.Context, section uint64, lastSectionHead common.Hash) error {
var root common.Hash
if section > 0 {
root = GetChtRoot(c.diskdb, section-1, lastSectionHead)
}
var err error
c.trie, err = trie.New(root, c.triedb)
if err != nil && c.odr != nil {
err = c.fetchMissingNodes(ctx, section, root)
if err == nil {
c.trie, err = trie.New(root, c.triedb)
}
}
c.section = section
return err
}
// Process implements core.ChainIndexerBackend
func (c *ChtIndexerBackend) Process(ctx context.Context, header *types.Header) error {
hash, num := header.Hash(), header.Number.Uint64()
c.lastHash = hash
td := rawdb.ReadTd(c.diskdb, hash, num)
if td == nil {
panic(nil)
}
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], num)
data, _ := rlp.EncodeToBytes(ChtNode{hash, td})
c.trie.Update(encNumber[:], data)
return nil
}
// Commit implements core.ChainIndexerBackend
func (c *ChtIndexerBackend) Commit() error {
root, err := c.trie.Commit(nil)
if err != nil {
return err
}
c.triedb.Commit(root, false)
if ((c.section+1)*c.sectionSize)%CHTFrequencyClient == 0 {
log.Info("Storing CHT", "section", c.section*c.sectionSize/CHTFrequencyClient, "head", fmt.Sprintf("%064x", c.lastHash), "root", fmt.Sprintf("%064x", root))
}
StoreChtRoot(c.diskdb, c.section, c.lastHash, root)
return nil
}
const (
BloomTrieFrequency = 32768
ethBloomBitsSection = 4096
)
var (
bloomTriePrefix = []byte("bltRoot-") // bloomTriePrefix + bloomTrieNum (uint64 big endian) -> trie root hash
BloomTrieTablePrefix = "blt-"
)
// GetBloomTrieRoot reads the BloomTrie root assoctiated to the given section from the database
func GetBloomTrieRoot(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) common.Hash {
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
data, _ := db.Get(append(append(bloomTriePrefix, encNumber[:]...), sectionHead.Bytes()...))
return common.BytesToHash(data)
}
// StoreBloomTrieRoot writes the BloomTrie root assoctiated to the given section into the database
func StoreBloomTrieRoot(db ethdb.Database, sectionIdx uint64, sectionHead, root common.Hash) {
var encNumber [8]byte
binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
db.Put(append(append(bloomTriePrefix, encNumber[:]...), sectionHead.Bytes()...), root.Bytes())
}
// BloomTrieIndexerBackend implements core.ChainIndexerBackend
type BloomTrieIndexerBackend struct {
diskdb, trieTable ethdb.Database
odr OdrBackend
triedb *trie.Database
section, parentSectionSize, bloomTrieRatio uint64
trie *trie.Trie
sectionHeads []common.Hash
}
// NewBloomTrieIndexer creates a BloomTrie chain indexer
func NewBloomTrieIndexer(db ethdb.Database, clientMode bool, odr OdrBackend) *core.ChainIndexer {
trieTable := ethdb.NewTable(db, BloomTrieTablePrefix)
backend := &BloomTrieIndexerBackend{
diskdb: db,
odr: odr,
trieTable: trieTable,
triedb: trie.NewDatabase(trieTable),
}
idb := ethdb.NewTable(db, "bltIndex-")
if clientMode {
backend.parentSectionSize = BloomTrieFrequency
} else {
backend.parentSectionSize = ethBloomBitsSection
}
backend.bloomTrieRatio = BloomTrieFrequency / backend.parentSectionSize
backend.sectionHeads = make([]common.Hash, backend.bloomTrieRatio)
return core.NewChainIndexer(db, idb, backend, BloomTrieFrequency, 0, time.Millisecond*100, "bloomtrie")
}
// fetchMissingNodes tries to retrieve the last entries of the latest trusted bloom trie from the
// ODR backend in order to be able to add new entries and calculate subsequent root hashes
func (b *BloomTrieIndexerBackend) fetchMissingNodes(ctx context.Context, section uint64, root common.Hash) error {
indexCh := make(chan uint, types.BloomBitLength)
type res struct {
nodes *NodeSet
err error
}
resCh := make(chan res, types.BloomBitLength)
for i := 0; i < 20; i++ {
go func() {
for bitIndex := range indexCh {
r := &BloomRequest{BloomTrieRoot: root, BloomTrieNum: section - 1, BitIdx: bitIndex, SectionIdxList: []uint64{section - 1}}
for {
if err := b.odr.Retrieve(ctx, r); err == ErrNoPeers {
// if there are no peers to serve, retry later
select {
case <-ctx.Done():
resCh <- res{nil, ctx.Err()}
return
case <-time.After(time.Second * 10):
// stay in the loop and try again
}
} else {
resCh <- res{r.Proofs, err}
break
}
}
}
}()
}
for i := uint(0); i < types.BloomBitLength; i++ {
indexCh <- i
}
close(indexCh)
batch := b.trieTable.NewBatch()
for i := uint(0); i < types.BloomBitLength; i++ {
res := <-resCh
if res.err != nil {
return res.err
}
res.nodes.Store(batch)
}
return batch.Write()
}
// Reset implements core.ChainIndexerBackend
func (b *BloomTrieIndexerBackend) Reset(ctx context.Context, section uint64, lastSectionHead common.Hash) error {
var root common.Hash
if section > 0 {
root = GetBloomTrieRoot(b.diskdb, section-1, lastSectionHead)
}
var err error
b.trie, err = trie.New(root, b.triedb)
if err != nil && b.odr != nil {
err = b.fetchMissingNodes(ctx, section, root)
if err == nil {
b.trie, err = trie.New(root, b.triedb)
}
}
b.section = section
return err
}
// Process implements core.ChainIndexerBackend
func (b *BloomTrieIndexerBackend) Process(ctx context.Context, header *types.Header) error {
num := header.Number.Uint64() - b.section*BloomTrieFrequency
if (num+1)%b.parentSectionSize == 0 {
b.sectionHeads[num/b.parentSectionSize] = header.Hash()
}
return nil
}
// Commit implements core.ChainIndexerBackend
func (b *BloomTrieIndexerBackend) Commit() error {
var compSize, decompSize uint64
for i := uint(0); i < types.BloomBitLength; i++ {
var encKey [10]byte
binary.BigEndian.PutUint16(encKey[0:2], uint16(i))
binary.BigEndian.PutUint64(encKey[2:10], b.section)
var decomp []byte
for j := uint64(0); j < b.bloomTrieRatio; j++ {
data, err := rawdb.ReadBloomBits(b.diskdb, i, b.section*b.bloomTrieRatio+j, b.sectionHeads[j])
if err != nil {
return err
}
decompData, err2 := bitutil.DecompressBytes(data, int(b.parentSectionSize/8))
if err2 != nil {
return err2
}
decomp = append(decomp, decompData...)
}
comp := bitutil.CompressBytes(decomp)
decompSize += uint64(len(decomp))
compSize += uint64(len(comp))
if len(comp) > 0 {
b.trie.Update(encKey[:], comp)
} else {
b.trie.Delete(encKey[:])
}
}
root, err := b.trie.Commit(nil)
if err != nil {
return err
}
b.triedb.Commit(root, false)
sectionHead := b.sectionHeads[b.bloomTrieRatio-1]
log.Info("Storing bloom trie", "section", b.section, "head", fmt.Sprintf("%064x", sectionHead), "root", fmt.Sprintf("%064x", root), "compression", float64(compSize)/float64(decompSize))
StoreBloomTrieRoot(b.diskdb, b.section, sectionHead, root)
return nil
}