path: root/core/vm/evm/logger_json.go

// Copyright 2017 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.

package evm

import (
    "encoding/json"
    "io"
    "math/big"
    "time"

    "github.com/dexon-foundation/dexon/common"
    "github.com/dexon-foundation/dexon/common/math"
    "github.com/dexon-foundation/dexon/core/vm"
)

type JSONLogger struct {
    encoder *json.Encoder
    cfg     *LogConfig
}

// NewJSONLogger creates a new EVM tracer that prints execution steps as JSON objects
// into the provided stream.
func NewJSONLogger(cfg *LogConfig, writer io.Writer) *JSONLogger {
    l := &JSONLogger{json.NewEncoder(writer), cfg}
    if l.cfg == nil {
        l.cfg = &LogConfig{}
    }
    return l
}

func (l *JSONLogger) CaptureStart(from common.Address, to common.Address, create bool, input []byte, gas uint64, value *big.Int) error {
    return nil
}

// CaptureState outputs state information on the logger.
func (l *JSONLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost uint64, memory *vm.Memory, stack *vm.Stack, contract *Contract, depth int, err error) error {
    log := StructLog{
        Pc:            pc,
        Op:            op,
        Gas:           gas,
        GasCost:       cost,
        MemorySize:    memory.Len(),
        Storage:       nil,
        Depth:         depth,
        RefundCounter: env.StateDB.GetRefund(),
        Err:           err,
    }
    if !l.cfg.DisableMemory {
        log.Memory = memory.Data()
    }
    if !l.cfg.DisableStack {
        log.Stack = stack.Data
    }
    return l.encoder.Encode(log)
}

// CaptureFault outputs state information on the logger.
func (l *JSONLogger) CaptureFault(env *EVM, pc uint64, op OpCode, gas, cost uint64, memory *vm.Memory, stack *vm.Stack, contract *Contract, depth int, err error) error {
    return nil
}

// CaptureEnd is triggered at end of execution.
func (l *JSONLogger) CaptureEnd(output []byte, gasUsed uint64, t time.Duration, err error) error {
    type endLog struct {
        Output  string              `json:"output"`
        GasUsed math.HexOrDecimal64 `json:"gasUsed"`
        Time    time.Duration       `json:"time"`
        Err     string              `json:"error,omitempty"`
    }
    if err != nil {
        return l.encoder.Encode(endLog{common.Bytes2Hex(output), math.HexOrDecimal64(gasUsed), t, err.Error()})
    }
    return l.encoder.Encode(endLog{common.Bytes2Hex(output), math.HexOrDecimal64(gasUsed), t, ""})
}