mirror of
https://gitlab.com/pulsechaincom/go-pulse.git
synced 2024-12-25 12:57:17 +00:00
ca376ead88
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.
567 lines
17 KiB
Go
567 lines
17 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 implements on-demand retrieval capable state and chain objects
|
|
// for the Ethereum Light Client.
|
|
package les
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/core"
|
|
"github.com/ethereum/go-ethereum/core/types"
|
|
"github.com/ethereum/go-ethereum/crypto"
|
|
"github.com/ethereum/go-ethereum/ethdb"
|
|
"github.com/ethereum/go-ethereum/light"
|
|
"github.com/ethereum/go-ethereum/log"
|
|
"github.com/ethereum/go-ethereum/rlp"
|
|
"github.com/ethereum/go-ethereum/trie"
|
|
)
|
|
|
|
var (
|
|
errInvalidMessageType = errors.New("invalid message type")
|
|
errInvalidEntryCount = errors.New("invalid number of response entries")
|
|
errHeaderUnavailable = errors.New("header unavailable")
|
|
errTxHashMismatch = errors.New("transaction hash mismatch")
|
|
errUncleHashMismatch = errors.New("uncle hash mismatch")
|
|
errReceiptHashMismatch = errors.New("receipt hash mismatch")
|
|
errDataHashMismatch = errors.New("data hash mismatch")
|
|
errCHTHashMismatch = errors.New("cht hash mismatch")
|
|
errCHTNumberMismatch = errors.New("cht number mismatch")
|
|
errUselessNodes = errors.New("useless nodes in merkle proof nodeset")
|
|
)
|
|
|
|
type LesOdrRequest interface {
|
|
GetCost(*peer) uint64
|
|
CanSend(*peer) bool
|
|
Request(uint64, *peer) error
|
|
Validate(ethdb.Database, *Msg) error
|
|
}
|
|
|
|
func LesRequest(req light.OdrRequest) LesOdrRequest {
|
|
switch r := req.(type) {
|
|
case *light.BlockRequest:
|
|
return (*BlockRequest)(r)
|
|
case *light.ReceiptsRequest:
|
|
return (*ReceiptsRequest)(r)
|
|
case *light.TrieRequest:
|
|
return (*TrieRequest)(r)
|
|
case *light.CodeRequest:
|
|
return (*CodeRequest)(r)
|
|
case *light.ChtRequest:
|
|
return (*ChtRequest)(r)
|
|
case *light.BloomRequest:
|
|
return (*BloomRequest)(r)
|
|
default:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// BlockRequest is the ODR request type for block bodies
|
|
type BlockRequest light.BlockRequest
|
|
|
|
// GetCost returns the cost of the given ODR request according to the serving
|
|
// peer's cost table (implementation of LesOdrRequest)
|
|
func (r *BlockRequest) GetCost(peer *peer) uint64 {
|
|
return peer.GetRequestCost(GetBlockBodiesMsg, 1)
|
|
}
|
|
|
|
// CanSend tells if a certain peer is suitable for serving the given request
|
|
func (r *BlockRequest) CanSend(peer *peer) bool {
|
|
return peer.HasBlock(r.Hash, r.Number)
|
|
}
|
|
|
|
// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
|
|
func (r *BlockRequest) Request(reqID uint64, peer *peer) error {
|
|
peer.Log().Debug("Requesting block body", "hash", r.Hash)
|
|
return peer.RequestBodies(reqID, r.GetCost(peer), []common.Hash{r.Hash})
|
|
}
|
|
|
|
// Valid processes an ODR request reply message from the LES network
|
|
// returns true and stores results in memory if the message was a valid reply
|
|
// to the request (implementation of LesOdrRequest)
|
|
func (r *BlockRequest) Validate(db ethdb.Database, msg *Msg) error {
|
|
log.Debug("Validating block body", "hash", r.Hash)
|
|
|
|
// Ensure we have a correct message with a single block body
|
|
if msg.MsgType != MsgBlockBodies {
|
|
return errInvalidMessageType
|
|
}
|
|
bodies := msg.Obj.([]*types.Body)
|
|
if len(bodies) != 1 {
|
|
return errInvalidEntryCount
|
|
}
|
|
body := bodies[0]
|
|
|
|
// Retrieve our stored header and validate block content against it
|
|
header := core.GetHeader(db, r.Hash, r.Number)
|
|
if header == nil {
|
|
return errHeaderUnavailable
|
|
}
|
|
if header.TxHash != types.DeriveSha(types.Transactions(body.Transactions)) {
|
|
return errTxHashMismatch
|
|
}
|
|
if header.UncleHash != types.CalcUncleHash(body.Uncles) {
|
|
return errUncleHashMismatch
|
|
}
|
|
// Validations passed, encode and store RLP
|
|
data, err := rlp.EncodeToBytes(body)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
r.Rlp = data
|
|
return nil
|
|
}
|
|
|
|
// ReceiptsRequest is the ODR request type for block receipts by block hash
|
|
type ReceiptsRequest light.ReceiptsRequest
|
|
|
|
// GetCost returns the cost of the given ODR request according to the serving
|
|
// peer's cost table (implementation of LesOdrRequest)
|
|
func (r *ReceiptsRequest) GetCost(peer *peer) uint64 {
|
|
return peer.GetRequestCost(GetReceiptsMsg, 1)
|
|
}
|
|
|
|
// CanSend tells if a certain peer is suitable for serving the given request
|
|
func (r *ReceiptsRequest) CanSend(peer *peer) bool {
|
|
return peer.HasBlock(r.Hash, r.Number)
|
|
}
|
|
|
|
// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
|
|
func (r *ReceiptsRequest) Request(reqID uint64, peer *peer) error {
|
|
peer.Log().Debug("Requesting block receipts", "hash", r.Hash)
|
|
return peer.RequestReceipts(reqID, r.GetCost(peer), []common.Hash{r.Hash})
|
|
}
|
|
|
|
// Valid processes an ODR request reply message from the LES network
|
|
// returns true and stores results in memory if the message was a valid reply
|
|
// to the request (implementation of LesOdrRequest)
|
|
func (r *ReceiptsRequest) Validate(db ethdb.Database, msg *Msg) error {
|
|
log.Debug("Validating block receipts", "hash", r.Hash)
|
|
|
|
// Ensure we have a correct message with a single block receipt
|
|
if msg.MsgType != MsgReceipts {
|
|
return errInvalidMessageType
|
|
}
|
|
receipts := msg.Obj.([]types.Receipts)
|
|
if len(receipts) != 1 {
|
|
return errInvalidEntryCount
|
|
}
|
|
receipt := receipts[0]
|
|
|
|
// Retrieve our stored header and validate receipt content against it
|
|
header := core.GetHeader(db, r.Hash, r.Number)
|
|
if header == nil {
|
|
return errHeaderUnavailable
|
|
}
|
|
if header.ReceiptHash != types.DeriveSha(receipt) {
|
|
return errReceiptHashMismatch
|
|
}
|
|
// Validations passed, store and return
|
|
r.Receipts = receipt
|
|
return nil
|
|
}
|
|
|
|
type ProofReq struct {
|
|
BHash common.Hash
|
|
AccKey, Key []byte
|
|
FromLevel uint
|
|
}
|
|
|
|
// ODR request type for state/storage trie entries, see LesOdrRequest interface
|
|
type TrieRequest light.TrieRequest
|
|
|
|
// GetCost returns the cost of the given ODR request according to the serving
|
|
// peer's cost table (implementation of LesOdrRequest)
|
|
func (r *TrieRequest) GetCost(peer *peer) uint64 {
|
|
switch peer.version {
|
|
case lpv1:
|
|
return peer.GetRequestCost(GetProofsV1Msg, 1)
|
|
case lpv2:
|
|
return peer.GetRequestCost(GetProofsV2Msg, 1)
|
|
default:
|
|
panic(nil)
|
|
}
|
|
}
|
|
|
|
// CanSend tells if a certain peer is suitable for serving the given request
|
|
func (r *TrieRequest) CanSend(peer *peer) bool {
|
|
return peer.HasBlock(r.Id.BlockHash, r.Id.BlockNumber)
|
|
}
|
|
|
|
// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
|
|
func (r *TrieRequest) Request(reqID uint64, peer *peer) error {
|
|
peer.Log().Debug("Requesting trie proof", "root", r.Id.Root, "key", r.Key)
|
|
req := ProofReq{
|
|
BHash: r.Id.BlockHash,
|
|
AccKey: r.Id.AccKey,
|
|
Key: r.Key,
|
|
}
|
|
return peer.RequestProofs(reqID, r.GetCost(peer), []ProofReq{req})
|
|
}
|
|
|
|
// Valid processes an ODR request reply message from the LES network
|
|
// returns true and stores results in memory if the message was a valid reply
|
|
// to the request (implementation of LesOdrRequest)
|
|
func (r *TrieRequest) Validate(db ethdb.Database, msg *Msg) error {
|
|
log.Debug("Validating trie proof", "root", r.Id.Root, "key", r.Key)
|
|
|
|
switch msg.MsgType {
|
|
case MsgProofsV1:
|
|
proofs := msg.Obj.([]light.NodeList)
|
|
if len(proofs) != 1 {
|
|
return errInvalidEntryCount
|
|
}
|
|
nodeSet := proofs[0].NodeSet()
|
|
// Verify the proof and store if checks out
|
|
if _, err, _ := trie.VerifyProof(r.Id.Root, r.Key, nodeSet); err != nil {
|
|
return fmt.Errorf("merkle proof verification failed: %v", err)
|
|
}
|
|
r.Proof = nodeSet
|
|
return nil
|
|
|
|
case MsgProofsV2:
|
|
proofs := msg.Obj.(light.NodeList)
|
|
// Verify the proof and store if checks out
|
|
nodeSet := proofs.NodeSet()
|
|
reads := &readTraceDB{db: nodeSet}
|
|
if _, err, _ := trie.VerifyProof(r.Id.Root, r.Key, reads); err != nil {
|
|
return fmt.Errorf("merkle proof verification failed: %v", err)
|
|
}
|
|
// check if all nodes have been read by VerifyProof
|
|
if len(reads.reads) != nodeSet.KeyCount() {
|
|
return errUselessNodes
|
|
}
|
|
r.Proof = nodeSet
|
|
return nil
|
|
|
|
default:
|
|
return errInvalidMessageType
|
|
}
|
|
}
|
|
|
|
type CodeReq struct {
|
|
BHash common.Hash
|
|
AccKey []byte
|
|
}
|
|
|
|
// ODR request type for node data (used for retrieving contract code), see LesOdrRequest interface
|
|
type CodeRequest light.CodeRequest
|
|
|
|
// GetCost returns the cost of the given ODR request according to the serving
|
|
// peer's cost table (implementation of LesOdrRequest)
|
|
func (r *CodeRequest) GetCost(peer *peer) uint64 {
|
|
return peer.GetRequestCost(GetCodeMsg, 1)
|
|
}
|
|
|
|
// CanSend tells if a certain peer is suitable for serving the given request
|
|
func (r *CodeRequest) CanSend(peer *peer) bool {
|
|
return peer.HasBlock(r.Id.BlockHash, r.Id.BlockNumber)
|
|
}
|
|
|
|
// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
|
|
func (r *CodeRequest) Request(reqID uint64, peer *peer) error {
|
|
peer.Log().Debug("Requesting code data", "hash", r.Hash)
|
|
req := CodeReq{
|
|
BHash: r.Id.BlockHash,
|
|
AccKey: r.Id.AccKey,
|
|
}
|
|
return peer.RequestCode(reqID, r.GetCost(peer), []CodeReq{req})
|
|
}
|
|
|
|
// Valid processes an ODR request reply message from the LES network
|
|
// returns true and stores results in memory if the message was a valid reply
|
|
// to the request (implementation of LesOdrRequest)
|
|
func (r *CodeRequest) Validate(db ethdb.Database, msg *Msg) error {
|
|
log.Debug("Validating code data", "hash", r.Hash)
|
|
|
|
// Ensure we have a correct message with a single code element
|
|
if msg.MsgType != MsgCode {
|
|
return errInvalidMessageType
|
|
}
|
|
reply := msg.Obj.([][]byte)
|
|
if len(reply) != 1 {
|
|
return errInvalidEntryCount
|
|
}
|
|
data := reply[0]
|
|
|
|
// Verify the data and store if checks out
|
|
if hash := crypto.Keccak256Hash(data); r.Hash != hash {
|
|
return errDataHashMismatch
|
|
}
|
|
r.Data = data
|
|
return nil
|
|
}
|
|
|
|
const (
|
|
// helper trie type constants
|
|
htCanonical = iota // Canonical hash trie
|
|
htBloomBits // BloomBits trie
|
|
|
|
// applicable for all helper trie requests
|
|
auxRoot = 1
|
|
// applicable for htCanonical
|
|
auxHeader = 2
|
|
)
|
|
|
|
type HelperTrieReq struct {
|
|
HelperTrieType uint
|
|
TrieIdx uint64
|
|
Key []byte
|
|
FromLevel, AuxReq uint
|
|
}
|
|
|
|
type HelperTrieResps struct { // describes all responses, not just a single one
|
|
Proofs light.NodeList
|
|
AuxData [][]byte
|
|
}
|
|
|
|
// legacy LES/1
|
|
type ChtReq struct {
|
|
ChtNum, BlockNum uint64
|
|
FromLevel uint
|
|
}
|
|
|
|
// legacy LES/1
|
|
type ChtResp struct {
|
|
Header *types.Header
|
|
Proof []rlp.RawValue
|
|
}
|
|
|
|
// ODR request type for requesting headers by Canonical Hash Trie, see LesOdrRequest interface
|
|
type ChtRequest light.ChtRequest
|
|
|
|
// GetCost returns the cost of the given ODR request according to the serving
|
|
// peer's cost table (implementation of LesOdrRequest)
|
|
func (r *ChtRequest) GetCost(peer *peer) uint64 {
|
|
switch peer.version {
|
|
case lpv1:
|
|
return peer.GetRequestCost(GetHeaderProofsMsg, 1)
|
|
case lpv2:
|
|
return peer.GetRequestCost(GetHelperTrieProofsMsg, 1)
|
|
default:
|
|
panic(nil)
|
|
}
|
|
}
|
|
|
|
// CanSend tells if a certain peer is suitable for serving the given request
|
|
func (r *ChtRequest) CanSend(peer *peer) bool {
|
|
peer.lock.RLock()
|
|
defer peer.lock.RUnlock()
|
|
|
|
return peer.headInfo.Number >= light.HelperTrieConfirmations && r.ChtNum <= (peer.headInfo.Number-light.HelperTrieConfirmations)/light.ChtFrequency
|
|
}
|
|
|
|
// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
|
|
func (r *ChtRequest) Request(reqID uint64, peer *peer) error {
|
|
peer.Log().Debug("Requesting CHT", "cht", r.ChtNum, "block", r.BlockNum)
|
|
var encNum [8]byte
|
|
binary.BigEndian.PutUint64(encNum[:], r.BlockNum)
|
|
req := HelperTrieReq{
|
|
HelperTrieType: htCanonical,
|
|
TrieIdx: r.ChtNum,
|
|
Key: encNum[:],
|
|
AuxReq: auxHeader,
|
|
}
|
|
return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), []HelperTrieReq{req})
|
|
}
|
|
|
|
// Valid processes an ODR request reply message from the LES network
|
|
// returns true and stores results in memory if the message was a valid reply
|
|
// to the request (implementation of LesOdrRequest)
|
|
func (r *ChtRequest) Validate(db ethdb.Database, msg *Msg) error {
|
|
log.Debug("Validating CHT", "cht", r.ChtNum, "block", r.BlockNum)
|
|
|
|
switch msg.MsgType {
|
|
case MsgHeaderProofs: // LES/1 backwards compatibility
|
|
proofs := msg.Obj.([]ChtResp)
|
|
if len(proofs) != 1 {
|
|
return errInvalidEntryCount
|
|
}
|
|
proof := proofs[0]
|
|
|
|
// Verify the CHT
|
|
var encNumber [8]byte
|
|
binary.BigEndian.PutUint64(encNumber[:], r.BlockNum)
|
|
|
|
value, err, _ := trie.VerifyProof(r.ChtRoot, encNumber[:], light.NodeList(proof.Proof).NodeSet())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
var node light.ChtNode
|
|
if err := rlp.DecodeBytes(value, &node); err != nil {
|
|
return err
|
|
}
|
|
if node.Hash != proof.Header.Hash() {
|
|
return errCHTHashMismatch
|
|
}
|
|
// Verifications passed, store and return
|
|
r.Header = proof.Header
|
|
r.Proof = light.NodeList(proof.Proof).NodeSet()
|
|
r.Td = node.Td
|
|
case MsgHelperTrieProofs:
|
|
resp := msg.Obj.(HelperTrieResps)
|
|
if len(resp.AuxData) != 1 {
|
|
return errInvalidEntryCount
|
|
}
|
|
nodeSet := resp.Proofs.NodeSet()
|
|
headerEnc := resp.AuxData[0]
|
|
if len(headerEnc) == 0 {
|
|
return errHeaderUnavailable
|
|
}
|
|
header := new(types.Header)
|
|
if err := rlp.DecodeBytes(headerEnc, header); err != nil {
|
|
return errHeaderUnavailable
|
|
}
|
|
|
|
// Verify the CHT
|
|
var encNumber [8]byte
|
|
binary.BigEndian.PutUint64(encNumber[:], r.BlockNum)
|
|
|
|
reads := &readTraceDB{db: nodeSet}
|
|
value, err, _ := trie.VerifyProof(r.ChtRoot, encNumber[:], reads)
|
|
if err != nil {
|
|
return fmt.Errorf("merkle proof verification failed: %v", err)
|
|
}
|
|
if len(reads.reads) != nodeSet.KeyCount() {
|
|
return errUselessNodes
|
|
}
|
|
|
|
var node light.ChtNode
|
|
if err := rlp.DecodeBytes(value, &node); err != nil {
|
|
return err
|
|
}
|
|
if node.Hash != header.Hash() {
|
|
return errCHTHashMismatch
|
|
}
|
|
if r.BlockNum != header.Number.Uint64() {
|
|
return errCHTNumberMismatch
|
|
}
|
|
// Verifications passed, store and return
|
|
r.Header = header
|
|
r.Proof = nodeSet
|
|
r.Td = node.Td
|
|
default:
|
|
return errInvalidMessageType
|
|
}
|
|
return nil
|
|
}
|
|
|
|
type BloomReq struct {
|
|
BloomTrieNum, BitIdx, SectionIdx, FromLevel uint64
|
|
}
|
|
|
|
// ODR request type for requesting headers by Canonical Hash Trie, see LesOdrRequest interface
|
|
type BloomRequest light.BloomRequest
|
|
|
|
// GetCost returns the cost of the given ODR request according to the serving
|
|
// peer's cost table (implementation of LesOdrRequest)
|
|
func (r *BloomRequest) GetCost(peer *peer) uint64 {
|
|
return peer.GetRequestCost(GetHelperTrieProofsMsg, len(r.SectionIdxList))
|
|
}
|
|
|
|
// CanSend tells if a certain peer is suitable for serving the given request
|
|
func (r *BloomRequest) CanSend(peer *peer) bool {
|
|
peer.lock.RLock()
|
|
defer peer.lock.RUnlock()
|
|
|
|
if peer.version < lpv2 {
|
|
return false
|
|
}
|
|
return peer.headInfo.Number >= light.HelperTrieConfirmations && r.BloomTrieNum <= (peer.headInfo.Number-light.HelperTrieConfirmations)/light.BloomTrieFrequency
|
|
}
|
|
|
|
// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
|
|
func (r *BloomRequest) Request(reqID uint64, peer *peer) error {
|
|
peer.Log().Debug("Requesting BloomBits", "bloomTrie", r.BloomTrieNum, "bitIdx", r.BitIdx, "sections", r.SectionIdxList)
|
|
reqs := make([]HelperTrieReq, len(r.SectionIdxList))
|
|
|
|
var encNumber [10]byte
|
|
binary.BigEndian.PutUint16(encNumber[0:2], uint16(r.BitIdx))
|
|
|
|
for i, sectionIdx := range r.SectionIdxList {
|
|
binary.BigEndian.PutUint64(encNumber[2:10], sectionIdx)
|
|
reqs[i] = HelperTrieReq{
|
|
HelperTrieType: htBloomBits,
|
|
TrieIdx: r.BloomTrieNum,
|
|
Key: common.CopyBytes(encNumber[:]),
|
|
}
|
|
}
|
|
return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), reqs)
|
|
}
|
|
|
|
// Valid processes an ODR request reply message from the LES network
|
|
// returns true and stores results in memory if the message was a valid reply
|
|
// to the request (implementation of LesOdrRequest)
|
|
func (r *BloomRequest) Validate(db ethdb.Database, msg *Msg) error {
|
|
log.Debug("Validating BloomBits", "bloomTrie", r.BloomTrieNum, "bitIdx", r.BitIdx, "sections", r.SectionIdxList)
|
|
|
|
// Ensure we have a correct message with a single proof element
|
|
if msg.MsgType != MsgHelperTrieProofs {
|
|
return errInvalidMessageType
|
|
}
|
|
resps := msg.Obj.(HelperTrieResps)
|
|
proofs := resps.Proofs
|
|
nodeSet := proofs.NodeSet()
|
|
reads := &readTraceDB{db: nodeSet}
|
|
|
|
r.BloomBits = make([][]byte, len(r.SectionIdxList))
|
|
|
|
// Verify the proofs
|
|
var encNumber [10]byte
|
|
binary.BigEndian.PutUint16(encNumber[0:2], uint16(r.BitIdx))
|
|
|
|
for i, idx := range r.SectionIdxList {
|
|
binary.BigEndian.PutUint64(encNumber[2:10], idx)
|
|
value, err, _ := trie.VerifyProof(r.BloomTrieRoot, encNumber[:], reads)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
r.BloomBits[i] = value
|
|
}
|
|
|
|
if len(reads.reads) != nodeSet.KeyCount() {
|
|
return errUselessNodes
|
|
}
|
|
r.Proofs = nodeSet
|
|
return nil
|
|
}
|
|
|
|
// readTraceDB stores the keys of database reads. We use this to check that received node
|
|
// sets contain only the trie nodes necessary to make proofs pass.
|
|
type readTraceDB struct {
|
|
db trie.DatabaseReader
|
|
reads map[string]struct{}
|
|
}
|
|
|
|
// Get returns a stored node
|
|
func (db *readTraceDB) Get(k []byte) ([]byte, error) {
|
|
if db.reads == nil {
|
|
db.reads = make(map[string]struct{})
|
|
}
|
|
db.reads[string(k)] = struct{}{}
|
|
return db.db.Get(k)
|
|
}
|
|
|
|
// Has returns true if the node set contains the given key
|
|
func (db *readTraceDB) Has(key []byte) (bool, error) {
|
|
_, err := db.Get(key)
|
|
return err == nil, nil
|
|
}
|