plugeth/light/odr_util.go

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// Copyright 2016 The go-ethereum Authors
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// 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/>.
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package light
import (
"bytes"
"context"
"errors"
"math/big"
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"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/txpool"
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"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/rlp"
)
// errNonCanonicalHash is returned if the requested chain data doesn't belong
// to the canonical chain. ODR can only retrieve the canonical chain data covered
// by the CHT or Bloom trie for verification.
var errNonCanonicalHash = errors.New("hash is not currently canonical")
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// GetHeaderByNumber retrieves the canonical block header corresponding to the
// given number. The returned header is proven by local CHT.
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func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*types.Header, error) {
// Try to find it in the local database first.
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db := odr.Database()
hash := rawdb.ReadCanonicalHash(db, number)
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// If there is a canonical hash, there should have a header too.
// But if it's pruned, re-fetch from network again.
if (hash != common.Hash{}) {
if header := rawdb.ReadHeader(db, hash, number); header != nil {
return header, nil
}
}
// Retrieve the header via ODR, ensure the requested header is covered
// by local trusted CHT.
chts, _, chtHead := odr.ChtIndexer().Sections()
if number >= chts*odr.IndexerConfig().ChtSize {
return nil, errNoTrustedCht
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}
r := &ChtRequest{
ChtRoot: GetChtRoot(db, chts-1, chtHead),
ChtNum: chts - 1,
BlockNum: number,
Config: odr.IndexerConfig(),
}
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if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
}
return r.Header, nil
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}
// GetCanonicalHash retrieves the canonical block hash corresponding to the number.
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func GetCanonicalHash(ctx context.Context, odr OdrBackend, number uint64) (common.Hash, error) {
hash := rawdb.ReadCanonicalHash(odr.Database(), number)
if hash != (common.Hash{}) {
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return hash, nil
}
header, err := GetHeaderByNumber(ctx, odr, number)
if err != nil {
return common.Hash{}, err
}
// number -> canonical mapping already be stored in db, get it.
return header.Hash(), nil
}
// GetTd retrieves the total difficulty corresponding to the number and hash.
func GetTd(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (*big.Int, error) {
td := rawdb.ReadTd(odr.Database(), hash, number)
if td != nil {
return td, nil
}
header, err := GetHeaderByNumber(ctx, odr, number)
if err != nil {
return nil, err
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}
if header.Hash() != hash {
return nil, errNonCanonicalHash
}
// <hash, number> -> td mapping already be stored in db, get it.
return rawdb.ReadTd(odr.Database(), hash, number), nil
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}
// GetBodyRLP retrieves the block body (transactions and uncles) in RLP encoding.
func GetBodyRLP(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (rlp.RawValue, error) {
if data := rawdb.ReadBodyRLP(odr.Database(), hash, number); data != nil {
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return data, nil
}
// Retrieve the block header first and pass it for verification.
header, err := GetHeaderByNumber(ctx, odr, number)
if err != nil {
return nil, errNoHeader
}
if header.Hash() != hash {
return nil, errNonCanonicalHash
}
r := &BlockRequest{Hash: hash, Number: number, Header: header}
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if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
}
return r.Rlp, nil
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}
// GetBody retrieves the block body (transactions, uncles) corresponding to the
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// hash.
func GetBody(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (*types.Body, error) {
data, err := GetBodyRLP(ctx, odr, hash, number)
if err != nil {
return nil, err
}
body := new(types.Body)
if err := rlp.Decode(bytes.NewReader(data), body); err != nil {
return nil, err
}
return body, nil
}
// GetBlock retrieves an entire block corresponding to the hash, assembling it
// back from the stored header and body.
func GetBlock(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (*types.Block, error) {
// Retrieve the block header and body contents
header, err := GetHeaderByNumber(ctx, odr, number)
if err != nil {
return nil, errNoHeader
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}
body, err := GetBody(ctx, odr, hash, number)
if err != nil {
return nil, err
}
// Reassemble the block and return
return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles), nil
}
// GetBlockReceipts retrieves the receipts generated by the transactions included
// in a block given by its hash. Receipts will be filled in with context data.
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func GetBlockReceipts(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (types.Receipts, error) {
// Assume receipts are already stored locally and attempt to retrieve.
receipts := rawdb.ReadRawReceipts(odr.Database(), hash, number)
if receipts == nil {
header, err := GetHeaderByNumber(ctx, odr, number)
if err != nil {
return nil, errNoHeader
}
if header.Hash() != hash {
return nil, errNonCanonicalHash
}
r := &ReceiptsRequest{Hash: hash, Number: number, Header: header}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
}
receipts = r.Receipts
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}
// If the receipts are incomplete, fill the derived fields
if len(receipts) > 0 && receipts[0].TxHash == (common.Hash{}) {
block, err := GetBlock(ctx, odr, hash, number)
if err != nil {
return nil, err
}
genesis := rawdb.ReadCanonicalHash(odr.Database(), 0)
config := rawdb.ReadChainConfig(odr.Database(), genesis)
if err := receipts.DeriveFields(config, block.Hash(), block.NumberU64(), block.Transactions()); err != nil {
return nil, err
}
rawdb.WriteReceipts(odr.Database(), hash, number, receipts)
}
return receipts, nil
}
// GetBlockLogs retrieves the logs generated by the transactions included in a
// block given by its hash. Logs will be filled in with context data.
func GetBlockLogs(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) ([][]*types.Log, error) {
receipts, err := GetBlockReceipts(ctx, odr, hash, number)
if err != nil {
return nil, err
}
logs := make([][]*types.Log, len(receipts))
for i, receipt := range receipts {
logs[i] = receipt.Logs
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}
return logs, nil
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}
// GetUntrustedBlockLogs retrieves the logs generated by the transactions included in a
// block. The retrieved logs are regarded as untrusted and will not be stored in the
// database. This function should only be used in light client checkpoint syncing.
func GetUntrustedBlockLogs(ctx context.Context, odr OdrBackend, header *types.Header) ([][]*types.Log, error) {
// Retrieve the potentially incomplete receipts from disk or network
hash, number := header.Hash(), header.Number.Uint64()
receipts := rawdb.ReadRawReceipts(odr.Database(), hash, number)
if receipts == nil {
r := &ReceiptsRequest{Hash: hash, Number: number, Header: header, Untrusted: true}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
}
receipts = r.Receipts
// Untrusted receipts won't be stored in the database. Therefore
// derived fields computation is unnecessary.
}
// Return the logs without deriving any computed fields on the receipts
logs := make([][]*types.Log, len(receipts))
for i, receipt := range receipts {
logs[i] = receipt.Logs
}
return logs, nil
}
// GetBloomBits retrieves a batch of compressed bloomBits vectors belonging to
// the given bit index and section indexes.
func GetBloomBits(ctx context.Context, odr OdrBackend, bit uint, sections []uint64) ([][]byte, error) {
var (
reqIndex []int
reqSections []uint64
db = odr.Database()
result = make([][]byte, len(sections))
)
blooms, _, sectionHead := odr.BloomTrieIndexer().Sections()
for i, section := range sections {
sectionHead := rawdb.ReadCanonicalHash(db, (section+1)*odr.IndexerConfig().BloomSize-1)
// If we don't have the canonical hash stored for this section head number,
// we'll still look for an entry with a zero sectionHead (we store it with
// zero section head too if we don't know it at the time of the retrieval)
if bloomBits, _ := rawdb.ReadBloomBits(db, bit, section, sectionHead); len(bloomBits) != 0 {
result[i] = bloomBits
continue
}
// TODO(rjl493456442) Convert sectionIndex to BloomTrie relative index
if section >= blooms {
return nil, errNoTrustedBloomTrie
}
reqSections = append(reqSections, section)
reqIndex = append(reqIndex, i)
}
// Find all bloombits in database, nothing to query via odr, return.
if reqSections == nil {
return result, nil
}
// Send odr request to retrieve missing bloombits.
r := &BloomRequest{
BloomTrieRoot: GetBloomTrieRoot(db, blooms-1, sectionHead),
BloomTrieNum: blooms - 1,
BitIdx: bit,
SectionIndexList: reqSections,
Config: odr.IndexerConfig(),
}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
}
for i, idx := range reqIndex {
result[idx] = r.BloomBits[i]
}
return result, nil
}
// GetTransaction retrieves a canonical transaction by hash and also returns
// its position in the chain. There is no guarantee in the LES protocol that
// the mined transaction will be retrieved back for sure because of different
// reasons(the transaction is unindexed, the malicious server doesn't reply it
// deliberately, etc). Therefore, unretrieved transactions will receive a certain
// number of retries, thus giving a weak guarantee.
func GetTransaction(ctx context.Context, odr OdrBackend, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error) {
r := &TxStatusRequest{Hashes: []common.Hash{txHash}}
if err := odr.RetrieveTxStatus(ctx, r); err != nil || r.Status[0].Status != txpool.TxStatusIncluded {
return nil, common.Hash{}, 0, 0, err
}
pos := r.Status[0].Lookup
// first ensure that we have the header, otherwise block body retrieval will fail
// also verify if this is a canonical block by getting the header by number and checking its hash
if header, err := GetHeaderByNumber(ctx, odr, pos.BlockIndex); err != nil || header.Hash() != pos.BlockHash {
return nil, common.Hash{}, 0, 0, err
}
body, err := GetBody(ctx, odr, pos.BlockHash, pos.BlockIndex)
if err != nil || uint64(len(body.Transactions)) <= pos.Index || body.Transactions[pos.Index].Hash() != txHash {
return nil, common.Hash{}, 0, 0, err
}
return body.Transactions[pos.Index], pos.BlockHash, pos.BlockIndex, pos.Index, nil
}