go-ethereum/core/vm/logger.go
2017-06-05 09:04:05 +02:00

288 lines
9 KiB
Go

// Copyright 2015 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 vm
import (
"encoding/hex"
"encoding/json"
"fmt"
"io"
"math/big"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/core/types"
)
type Storage map[common.Hash]common.Hash
func (self Storage) Copy() Storage {
cpy := make(Storage)
for key, value := range self {
cpy[key] = value
}
return cpy
}
// LogConfig are the configuration options for structured logger the EVM
type LogConfig struct {
DisableMemory bool // disable memory capture
DisableStack bool // disable stack capture
DisableStorage bool // disable storage capture
FullStorage bool // show full storage (slow)
Limit int // maximum length of output, but zero means unlimited
}
// StructLog is emitted to the EVM each cycle and lists information about the current internal state
// prior to the execution of the statement.
type StructLog struct {
Pc uint64
Op OpCode
Gas uint64
GasCost uint64
Memory []byte
Stack []*big.Int
Storage map[common.Hash]common.Hash
Depth int
Err error
}
type StructLogJsonOut struct {
Pc uint64 `json:"pc"`
Op OpCode `json:"op"`
OpName string `json:"opName"`
Gas math.HexOrDecimal64 `json:"gas"`
GasCost math.HexOrDecimal64 `json:"gasCost"`
Memory string `json:"memory"`
Stack hexArray `json:"stack"`
//Storage map[common.Hash]common.Hash `json:"storage"`
Depth int `json:"depth"`
//Err error
}
type hexArray []*big.Int
// MarshalJSON encodes the memory as 32-byte hex strings instead of bigints
func (a hexArray) MarshalJSON() ([]byte, error) {
if items := ([]*big.Int)(a); len(items) > 0 {
hexitems := make([]*math.HexOrDecimal256, len(items))
for i, item := range items {
x := math.HexOrDecimal256(*item)
hexitems[i] = &x
}
return json.Marshal(hexitems)
}
return []byte("[]"), nil
}
// MarshalJSON encodes StructLog for json output
func (s StructLog) MarshalJSON() ([]byte, error) {
var enc StructLogJsonOut
enc.Pc = s.Pc
enc.Op = s.Op
enc.OpName = s.Op.String()
enc.Gas = math.HexOrDecimal64(s.Gas)
enc.GasCost = math.HexOrDecimal64(s.GasCost)
//enc.Memory = fmt.Sprintf("0x%v", len(common.Bytes2Hex(s.Memory))/2)
enc.Memory = fmt.Sprintf("%v bytes", len(s.Memory))
enc.Stack = s.Stack
//enc.Storage = s.Storage
enc.Depth = s.Depth
return json.Marshal(&enc)
}
// Tracer is used to collect execution traces from an EVM transaction
// execution. CaptureState is called for each step of the VM with the
// current VM state.
// Note that reference types are actual VM data structures; make copies
// if you need to retain them beyond the current call.
type Tracer interface {
CaptureState(env *EVM, pc uint64, op OpCode, gas, cost uint64, memory *Memory, stack *Stack, contract *Contract, depth int, err error) error
CaptureEnd(output []byte, gasUsed uint64, t time.Duration) error
}
// StructLogger is an EVM state logger and implements Tracer.
//
// StructLogger can capture state based on the given Log configuration and also keeps
// a track record of modified storage which is used in reporting snapshots of the
// contract their storage.
type StructLogger struct {
cfg LogConfig
logs []StructLog
changedValues map[common.Address]Storage
}
// JSONLogger merely contains a writer, and immediately outputs to that channel,
// instead of collecting logs
type JSONLogger struct {
encoder *json.Encoder
}
// NewStructLogger returns a new logger
func NewStructLogger(cfg *LogConfig) *StructLogger {
logger := &StructLogger{
changedValues: make(map[common.Address]Storage),
}
if cfg != nil {
logger.cfg = *cfg
}
return logger
}
// NewJSONLogger returns a new JSON logger
func NewJSONLogger(writer io.Writer) *JSONLogger {
logger := &JSONLogger{
encoder: json.NewEncoder(writer),
}
return logger
}
// CaptureState outputs state information on the logger
func (l *JSONLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost uint64, memory *Memory, stack *Stack, contract *Contract, depth int, err error) error {
log := StructLog{pc, op, gas + cost, cost, memory.Data(), stack.Data(), nil, env.depth, err}
return l.encoder.Encode(log)
}
func (l *JSONLogger) CaptureEnd(output []byte, gasUsed uint64, t time.Duration) error {
type endLog struct {
Output string `json:"output"`
GasUsed math.HexOrDecimal64 `json:"gasUsed"`
Time time.Duration `json:"time"`
}
log := endLog{common.Bytes2Hex(output), math.HexOrDecimal64(gasUsed), t}
return l.encoder.Encode(log)
}
// CaptureState logs a new structured log message and pushes it out to the environment
//
// CaptureState also tracks SSTORE ops to track dirty values.
func (l *StructLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost uint64, memory *Memory, stack *Stack, contract *Contract, depth int, err error) error {
// check if already accumulated the specified number of logs
if l.cfg.Limit != 0 && l.cfg.Limit <= len(l.logs) {
return ErrTraceLimitReached
}
// initialise new changed values storage container for this contract
// if not present.
if l.changedValues[contract.Address()] == nil {
l.changedValues[contract.Address()] = make(Storage)
}
// capture SSTORE opcodes and determine the changed value and store
// it in the local storage container. NOTE: we do not need to do any
// range checks here because that's already handler prior to calling
// this function.
switch op {
case SSTORE:
var (
value = common.BigToHash(stack.data[stack.len()-2])
address = common.BigToHash(stack.data[stack.len()-1])
)
l.changedValues[contract.Address()][address] = value
}
// copy a snapstot of the current memory state to a new buffer
var mem []byte
if !l.cfg.DisableMemory {
mem = make([]byte, len(memory.Data()))
copy(mem, memory.Data())
}
// copy a snapshot of the current stack state to a new buffer
var stck []*big.Int
if !l.cfg.DisableStack {
stck = make([]*big.Int, len(stack.Data()))
for i, item := range stack.Data() {
stck[i] = new(big.Int).Set(item)
}
}
// Copy the storage based on the settings specified in the log config. If full storage
// is disabled (default) we can use the simple Storage.Copy method, otherwise we use
// the state object to query for all values (slow process).
var storage Storage
if !l.cfg.DisableStorage {
if l.cfg.FullStorage {
storage = make(Storage)
// Get the contract account and loop over each storage entry. This may involve looping over
// the trie and is a very expensive process.
env.StateDB.ForEachStorage(contract.Address(), func(key, value common.Hash) bool {
storage[key] = value
// Return true, indicating we'd like to continue.
return true
})
} else {
// copy a snapshot of the current storage to a new container.
storage = l.changedValues[contract.Address()].Copy()
}
}
// create a new snaptshot of the EVM.
log := StructLog{pc, op, gas, cost, mem, stck, storage, env.depth, err}
l.logs = append(l.logs, log)
return nil
}
func (l *StructLogger) CaptureEnd(output []byte, gasUsed uint64, t time.Duration) error {
fmt.Printf("0x%x", output)
return nil
}
// StructLogs returns a list of captured log entries
func (l *StructLogger) StructLogs() []StructLog {
return l.logs
}
// WriteTrace writes a formatted trace to the given writer
func WriteTrace(writer io.Writer, logs []StructLog) {
for _, log := range logs {
fmt.Fprintf(writer, "%-10spc=%08d gas=%v cost=%v", log.Op, log.Pc, log.Gas, log.GasCost)
if log.Err != nil {
fmt.Fprintf(writer, " ERROR: %v", log.Err)
}
fmt.Fprintf(writer, "\n")
for i := len(log.Stack) - 1; i >= 0; i-- {
fmt.Fprintf(writer, "%08d %x\n", len(log.Stack)-i-1, math.PaddedBigBytes(log.Stack[i], 32))
}
fmt.Fprint(writer, hex.Dump(log.Memory))
for h, item := range log.Storage {
fmt.Fprintf(writer, "%x: %x\n", h, item)
}
fmt.Fprintln(writer)
}
}
// WriteLogs writes vm logs in a readable format to the given writer
func WriteLogs(writer io.Writer, logs []*types.Log) {
for _, log := range logs {
fmt.Fprintf(writer, "LOG%d: %x bn=%d txi=%x\n", len(log.Topics), log.Address, log.BlockNumber, log.TxIndex)
for i, topic := range log.Topics {
fmt.Fprintf(writer, "%08d %x\n", i, topic)
}
fmt.Fprint(writer, hex.Dump(log.Data))
fmt.Fprintln(writer)
}
}