go-ethereum/internal/ethapi/logtracer.go

152 lines
4.0 KiB
Go

// Copyright 2023 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 ethapi
import (
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/tracing"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
)
var (
// keccak256("Transfer(address,address,uint256)")
transferTopic = common.HexToHash("ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef")
// ERC-7528
transferAddress = common.HexToAddress("0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE")
)
// tracer is a simple tracer that records all logs and
// ether transfers. Transfers are recorded as if they
// were logs. Transfer events include:
// - tx value
// - call value
// - self destructs
//
// The log format for a transfer is:
// - address: 0x0000000000000000000000000000000000000000
// - data: Value
// - topics:
// - Transfer(address,address,uint256)
// - Sender address
// - Recipient address
type tracer struct {
// logs keeps logs for all open call frames.
// This lets us clear logs for failed calls.
logs [][]*types.Log
count int
traceTransfers bool
blockNumber uint64
blockHash common.Hash
txHash common.Hash
txIdx uint
}
func newTracer(traceTransfers bool, blockNumber uint64, blockHash, txHash common.Hash, txIndex uint) *tracer {
return &tracer{
traceTransfers: traceTransfers,
blockNumber: blockNumber,
blockHash: blockHash,
txHash: txHash,
txIdx: txIndex,
}
}
func (t *tracer) Hooks() *tracing.Hooks {
return &tracing.Hooks{
OnEnter: t.onEnter,
OnExit: t.onExit,
OnLog: t.onLog,
}
}
func (t *tracer) onEnter(depth int, typ byte, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int) {
t.logs = append(t.logs, make([]*types.Log, 0))
if vm.OpCode(typ) != vm.DELEGATECALL && value != nil && value.Cmp(common.Big0) > 0 {
t.captureTransfer(from, to, value)
}
}
func (t *tracer) onExit(depth int, output []byte, gasUsed uint64, err error, reverted bool) {
if depth == 0 {
t.onEnd(reverted)
return
}
size := len(t.logs)
if size <= 1 {
return
}
// pop call
call := t.logs[size-1]
t.logs = t.logs[:size-1]
size--
// Clear logs if call failed.
if !reverted {
t.logs[size-1] = append(t.logs[size-1], call...)
}
}
func (t *tracer) onEnd(reverted bool) {
if reverted {
t.logs[0] = nil
}
}
func (t *tracer) onLog(log *types.Log) {
t.captureLog(log.Address, log.Topics, log.Data)
}
func (t *tracer) captureLog(address common.Address, topics []common.Hash, data []byte) {
t.logs[len(t.logs)-1] = append(t.logs[len(t.logs)-1], &types.Log{
Address: address,
Topics: topics,
Data: data,
BlockNumber: t.blockNumber,
BlockHash: t.blockHash,
TxHash: t.txHash,
TxIndex: t.txIdx,
Index: uint(t.count),
})
t.count++
}
func (t *tracer) captureTransfer(from, to common.Address, value *big.Int) {
if !t.traceTransfers {
return
}
topics := []common.Hash{
transferTopic,
common.BytesToHash(from.Bytes()),
common.BytesToHash(to.Bytes()),
}
t.captureLog(transferAddress, topics, common.BigToHash(value).Bytes())
}
// reset prepares the tracer for the next transaction.
func (t *tracer) reset(txHash common.Hash, txIdx uint) {
t.logs = nil
t.txHash = txHash
t.txIdx = txIdx
}
func (t *tracer) Logs() []*types.Log {
return t.logs[0]
}