go-ethereum/eth/tracers/logger/logger_json.go
Sina M 064f37d6f6
eth/tracers: live chain tracing with hooks (#29189)
Here we add a Go API for running tracing plugins within the main block import process. 

As an advanced user of geth, you can now create a Go file in eth/tracers/live/, and within
that file register your custom tracer implementation. Then recompile geth and select your tracer
on the command line. Hooks defined in the tracer will run whenever a block is processed.

The hook system is defined in package core/tracing. It uses a struct with callbacks, instead of 
requiring an interface, for several reasons:

- We plan to keep this API stable long-term. The core/tracing hook API does not depend on
  on deep geth internals.
- There are a lot of hooks, and tracers will only need some of them. Using a struct allows you
   to implement only the hooks you want to actually use.

All existing tracers in eth/tracers/native have been rewritten to use the new hook system.

This change breaks compatibility with the vm.EVMLogger interface that we used to have.
If you are a user of vm.EVMLogger, please migrate to core/tracing, and sorry for breaking
your stuff. But we just couldn't have both the old and new tracing APIs coexist in the EVM.

---------

Co-authored-by: Matthieu Vachon <matthieu.o.vachon@gmail.com>
Co-authored-by: Delweng <delweng@gmail.com>
Co-authored-by: Martin HS <martin@swende.se>
2024-03-22 18:53:53 +01:00

101 lines
2.9 KiB
Go

// Copyright 2021 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 logger
import (
"encoding/json"
"io"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/core/tracing"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
)
type jsonLogger struct {
encoder *json.Encoder
cfg *Config
env *tracing.VMContext
}
// NewJSONLogger creates a new EVM tracer that prints execution steps as JSON objects
// into the provided stream.
func NewJSONLogger(cfg *Config, writer io.Writer) *tracing.Hooks {
l := &jsonLogger{encoder: json.NewEncoder(writer), cfg: cfg}
if l.cfg == nil {
l.cfg = &Config{}
}
return &tracing.Hooks{
OnTxStart: l.OnTxStart,
OnExit: l.OnExit,
OnOpcode: l.OnOpcode,
OnFault: l.OnFault,
}
}
func (l *jsonLogger) OnFault(pc uint64, op byte, gas uint64, cost uint64, scope tracing.OpContext, depth int, err error) {
// TODO: Add rData to this interface as well
l.OnOpcode(pc, op, gas, cost, scope, nil, depth, err)
}
func (l *jsonLogger) OnOpcode(pc uint64, op byte, gas, cost uint64, scope tracing.OpContext, rData []byte, depth int, err error) {
memory := scope.MemoryData()
stack := scope.StackData()
log := StructLog{
Pc: pc,
Op: vm.OpCode(op),
Gas: gas,
GasCost: cost,
MemorySize: len(memory),
Depth: depth,
RefundCounter: l.env.StateDB.GetRefund(),
Err: err,
}
if l.cfg.EnableMemory {
log.Memory = memory
}
if !l.cfg.DisableStack {
log.Stack = stack
}
if l.cfg.EnableReturnData {
log.ReturnData = rData
}
l.encoder.Encode(log)
}
func (l *jsonLogger) OnExit(depth int, output []byte, gasUsed uint64, err error, reverted bool) {
if depth > 0 {
return
}
type endLog struct {
Output string `json:"output"`
GasUsed math.HexOrDecimal64 `json:"gasUsed"`
Err string `json:"error,omitempty"`
}
var errMsg string
if err != nil {
errMsg = err.Error()
}
l.encoder.Encode(endLog{common.Bytes2Hex(output), math.HexOrDecimal64(gasUsed), errMsg})
}
func (l *jsonLogger) OnTxStart(env *tracing.VMContext, tx *types.Transaction, from common.Address) {
l.env = env
}