erigon-pulse/core/vm/logger.go
Jeffrey Wilcke 3fc7c97827 core, core/vm: implemented a generic environment (#3348)
Environment is now a struct (not an interface). This
reduces a lot of tech-debt throughout the codebase where a virtual
machine environment had to be implemented in order to test or run it.

The new environment is suitable to be used en the json tests, core
consensus and light client.
2016-12-06 02:16:03 +01:00

211 lines
6.6 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 (
"fmt"
"math/big"
"os"
"unicode"
"github.com/ethereum/go-ethereum/common"
)
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 Environment 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 *big.Int
GasCost *big.Int
Memory []byte
Stack []*big.Int
Storage map[common.Hash]common.Hash
Depth int
Err error
}
// 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 *Environment, pc uint64, op OpCode, gas, cost *big.Int, memory *Memory, stack *Stack, contract *Contract, depth int, err error) 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
}
// NewLogger 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
}
// 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 *Environment, pc uint64, op OpCode, gas, cost *big.Int, 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 TraceLimitReachedError
}
// 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.GetAccount(contract.Address()).ForEachStorage(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, new(big.Int).Set(gas), cost, mem, stck, storage, env.Depth, err}
l.logs = append(l.logs, log)
return nil
}
// StructLogs returns a list of captured log entries
func (l *StructLogger) StructLogs() []StructLog {
return l.logs
}
// StdErrFormat formats a slice of StructLogs to human readable format
func StdErrFormat(logs []StructLog) {
fmt.Fprintf(os.Stderr, "VM STAT %d OPs\n", len(logs))
for _, log := range logs {
fmt.Fprintf(os.Stderr, "PC %08d: %s GAS: %v COST: %v", log.Pc, log.Op, log.Gas, log.GasCost)
if log.Err != nil {
fmt.Fprintf(os.Stderr, " ERROR: %v", log.Err)
}
fmt.Fprintf(os.Stderr, "\n")
fmt.Fprintln(os.Stderr, "STACK =", len(log.Stack))
for i := len(log.Stack) - 1; i >= 0; i-- {
fmt.Fprintf(os.Stderr, "%04d: %x\n", len(log.Stack)-i-1, common.LeftPadBytes(log.Stack[i].Bytes(), 32))
}
const maxMem = 10
addr := 0
fmt.Fprintln(os.Stderr, "MEM =", len(log.Memory))
for i := 0; i+16 <= len(log.Memory) && addr < maxMem; i += 16 {
data := log.Memory[i : i+16]
str := fmt.Sprintf("%04d: % x ", addr*16, data)
for _, r := range data {
if r == 0 {
str += "."
} else if unicode.IsPrint(rune(r)) {
str += fmt.Sprintf("%s", string(r))
} else {
str += "?"
}
}
addr++
fmt.Fprintln(os.Stderr, str)
}
fmt.Fprintln(os.Stderr, "STORAGE =", len(log.Storage))
for h, item := range log.Storage {
fmt.Fprintf(os.Stderr, "%x: %x\n", h, item)
}
fmt.Fprintln(os.Stderr)
}
}