go-ethereum/light/postprocess.go
Felföldi Zsolt ca376ead88 les, light: LES/2 protocol version (#14970)
This PR implements the new LES protocol version extensions:

* new and more efficient Merkle proofs reply format (when replying to
  a multiple Merkle proofs request, we just send a single set of trie
  nodes containing all necessary nodes)
* BBT (BloomBitsTrie) works similarly to the existing CHT and contains
  the bloombits search data to speed up log searches
* GetTxStatusMsg returns the inclusion position or the
  pending/queued/unknown state of a transaction referenced by hash
* an optional signature of new block data (number/hash/td) can be
  included in AnnounceMsg to provide an option for "very light
  clients" (mobile/embedded devices) to skip expensive Ethash check
  and accept multiple signatures of somewhat trusted servers (still a
  lot better than trusting a single server completely and retrieving
  everything through RPC). The new client mode is not implemented in
  this PR, just the protocol extension.
2017-10-24 15:19:09 +02:00

296 lines
11 KiB
Go

// 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 light
import (
"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/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 (
ChtFrequency = 32768
ChtV1Frequency = 4096 // as long as we want to retain LES/1 compatibility, servers generate CHTs with the old, higher frequency
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, bloomTrieRoot common.Hash
}
var (
mainnetCheckpoint = trustedCheckpoint{
name: "ETH mainnet",
sectionIdx: 129,
sectionHead: common.HexToHash("64100587c8ec9a76870056d07cb0f58622552d16de6253a59cac4b580c899501"),
chtRoot: common.HexToHash("bb4fb4076cbe6923c8a8ce8f158452bbe19564959313466989fda095a60884ca"),
bloomTrieRoot: common.HexToHash("0db524b2c4a2a9520a42fd842b02d2e8fb58ff37c75cf57bd0eb82daeace6716"),
}
ropstenCheckpoint = trustedCheckpoint{
name: "Ropsten testnet",
sectionIdx: 50,
sectionHead: common.HexToHash("00bd65923a1aa67f85e6b4ae67835784dd54be165c37f056691723c55bf016bd"),
chtRoot: common.HexToHash("6f56dc61936752cc1f8c84b4addabdbe6a1c19693de3f21cb818362df2117f03"),
bloomTrieRoot: common.HexToHash("aca7d7c504d22737242effc3fdc604a762a0af9ced898036b5986c3a15220208"),
}
)
// 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)*(ChtFrequency/ChtV1Frequency)-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 {
db, cdb ethdb.Database
section, sectionSize uint64
lastHash common.Hash
trie *trie.Trie
}
// NewBloomTrieIndexer creates a BloomTrie chain indexer
func NewChtIndexer(db ethdb.Database, clientMode bool) *core.ChainIndexer {
cdb := ethdb.NewTable(db, ChtTablePrefix)
idb := ethdb.NewTable(db, "chtIndex-")
var sectionSize, confirmReq uint64
if clientMode {
sectionSize = ChtFrequency
confirmReq = HelperTrieConfirmations
} else {
sectionSize = ChtV1Frequency
confirmReq = HelperTrieProcessConfirmations
}
return core.NewChainIndexer(db, idb, &ChtIndexerBackend{db: db, cdb: cdb, sectionSize: sectionSize}, sectionSize, confirmReq, time.Millisecond*100, "cht")
}
// Reset implements core.ChainIndexerBackend
func (c *ChtIndexerBackend) Reset(section uint64, lastSectionHead common.Hash) error {
var root common.Hash
if section > 0 {
root = GetChtRoot(c.db, section-1, lastSectionHead)
}
var err error
c.trie, err = trie.New(root, c.cdb)
c.section = section
return err
}
// Process implements core.ChainIndexerBackend
func (c *ChtIndexerBackend) Process(header *types.Header) {
hash, num := header.Hash(), header.Number.Uint64()
c.lastHash = hash
td := core.GetTd(c.db, 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)
}
// Commit implements core.ChainIndexerBackend
func (c *ChtIndexerBackend) Commit() error {
batch := c.cdb.NewBatch()
root, err := c.trie.CommitTo(batch)
if err != nil {
return err
} else {
batch.Write()
if ((c.section+1)*c.sectionSize)%ChtFrequency == 0 {
log.Info("Storing CHT", "idx", c.section*c.sectionSize/ChtFrequency, "sectionHead", fmt.Sprintf("%064x", c.lastHash), "root", fmt.Sprintf("%064x", root))
}
StoreChtRoot(c.db, c.section, c.lastHash, root)
}
return nil
}
const (
BloomTrieFrequency = 32768
ethBloomBitsSection = 4096
ethBloomBitsConfirmations = 256
)
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 {
db, cdb ethdb.Database
section, parentSectionSize, bloomTrieRatio uint64
trie *trie.Trie
sectionHeads []common.Hash
}
// NewBloomTrieIndexer creates a BloomTrie chain indexer
func NewBloomTrieIndexer(db ethdb.Database, clientMode bool) *core.ChainIndexer {
cdb := ethdb.NewTable(db, BloomTrieTablePrefix)
idb := ethdb.NewTable(db, "bltIndex-")
backend := &BloomTrieIndexerBackend{db: db, cdb: cdb}
var confirmReq uint64
if clientMode {
backend.parentSectionSize = BloomTrieFrequency
confirmReq = HelperTrieConfirmations
} else {
backend.parentSectionSize = ethBloomBitsSection
confirmReq = HelperTrieProcessConfirmations
}
backend.bloomTrieRatio = BloomTrieFrequency / backend.parentSectionSize
backend.sectionHeads = make([]common.Hash, backend.bloomTrieRatio)
return core.NewChainIndexer(db, idb, backend, BloomTrieFrequency, confirmReq-ethBloomBitsConfirmations, time.Millisecond*100, "bloomtrie")
}
// Reset implements core.ChainIndexerBackend
func (b *BloomTrieIndexerBackend) Reset(section uint64, lastSectionHead common.Hash) error {
var root common.Hash
if section > 0 {
root = GetBloomTrieRoot(b.db, section-1, lastSectionHead)
}
var err error
b.trie, err = trie.New(root, b.cdb)
b.section = section
return err
}
// Process implements core.ChainIndexerBackend
func (b *BloomTrieIndexerBackend) Process(header *types.Header) {
num := header.Number.Uint64() - b.section*BloomTrieFrequency
if (num+1)%b.parentSectionSize == 0 {
b.sectionHeads[num/b.parentSectionSize] = header.Hash()
}
}
// 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 := core.GetBloomBits(b.db, 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[:])
}
}
batch := b.cdb.NewBatch()
root, err := b.trie.CommitTo(batch)
if err != nil {
return err
} else {
batch.Write()
sectionHead := b.sectionHeads[b.bloomTrieRatio-1]
log.Info("Storing BloomTrie", "section", b.section, "sectionHead", fmt.Sprintf("%064x", sectionHead), "root", fmt.Sprintf("%064x", root), "compression ratio", float64(compSize)/float64(decompSize))
StoreBloomTrieRoot(b.db, b.section, sectionHead, root)
}
return nil
}