go-ethereum/core/vm/log.go
Felix Lange 704fde01e8 core/types, core/vm: improve docs, add JSON marshaling methods
In this commit, core/types's types learn how to encode and decode
themselves as JSON. The encoding is very similar to what the RPC API
uses. The RPC API is missing some output fields (e.g. transaction
signature values) which will be added to the API in a later commit. Some
fields that the API generates are ignored by the decoder methods here.
2016-08-04 03:55:33 +02:00

135 lines
4.5 KiB
Go

// Copyright 2014 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/json"
"errors"
"fmt"
"io"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/rlp"
)
var errMissingLogFields = errors.New("missing required JSON log fields")
// Log represents a contract log event. These events are generated by the LOG
// opcode and stored/indexed by the node.
type Log struct {
// Consensus fields.
Address common.Address // address of the contract that generated the event
Topics []common.Hash // list of topics provided by the contract.
Data []byte // supplied by the contract, usually ABI-encoded
// Derived fields (don't reorder!).
BlockNumber uint64 // block in which the transaction was included
TxHash common.Hash // hash of the transaction
TxIndex uint // index of the transaction in the block
BlockHash common.Hash // hash of the block in which the transaction was included
Index uint // index of the log in the receipt
}
type jsonLog struct {
Address *common.Address `json:"address"`
Topics *[]common.Hash `json:"topics"`
Data string `json:"data"`
BlockNumber string `json:"blockNumber"`
TxIndex string `json:"transactionIndex"`
TxHash *common.Hash `json:"transactionHash"`
BlockHash *common.Hash `json:"blockHash"`
Index string `json:"logIndex"`
}
func NewLog(address common.Address, topics []common.Hash, data []byte, number uint64) *Log {
return &Log{Address: address, Topics: topics, Data: data, BlockNumber: number}
}
func (l *Log) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, []interface{}{l.Address, l.Topics, l.Data})
}
func (l *Log) DecodeRLP(s *rlp.Stream) error {
var log struct {
Address common.Address
Topics []common.Hash
Data []byte
}
if err := s.Decode(&log); err != nil {
return err
}
l.Address, l.Topics, l.Data = log.Address, log.Topics, log.Data
return nil
}
func (l *Log) String() string {
return fmt.Sprintf(`log: %x %x %x %x %d %x %d`, l.Address, l.Topics, l.Data, l.TxHash, l.TxIndex, l.BlockHash, l.Index)
}
// MarshalJSON implements json.Marshaler.
func (r *Log) MarshalJSON() ([]byte, error) {
return json.Marshal(&jsonLog{
Address: &r.Address,
Topics: &r.Topics,
Data: fmt.Sprintf("0x%x", r.Data),
BlockNumber: fmt.Sprintf("0x%x", r.BlockNumber),
TxIndex: fmt.Sprintf("0x%x", r.TxIndex),
TxHash: &r.TxHash,
BlockHash: &r.BlockHash,
Index: fmt.Sprintf("0x%x", r.Index),
})
}
// UnmarshalJSON implements json.Umarshaler.
func (r *Log) UnmarshalJSON(input []byte) error {
var dec jsonLog
if err := json.Unmarshal(input, &dec); err != nil {
return err
}
if dec.Address == nil || dec.Topics == nil || dec.Data == "" || dec.BlockNumber == "" ||
dec.TxIndex == "" || dec.TxHash == nil || dec.BlockHash == nil || dec.Index == "" {
return errMissingLogFields
}
declog := Log{
Address: *dec.Address,
Topics: *dec.Topics,
TxHash: *dec.TxHash,
BlockHash: *dec.BlockHash,
}
if _, err := fmt.Sscanf(dec.Data, "0x%x", &declog.Data); err != nil {
return fmt.Errorf("invalid hex log data")
}
if _, err := fmt.Sscanf(dec.BlockNumber, "0x%x", &declog.BlockNumber); err != nil {
return fmt.Errorf("invalid hex log block number")
}
if _, err := fmt.Sscanf(dec.TxIndex, "0x%x", &declog.TxIndex); err != nil {
return fmt.Errorf("invalid hex log tx index")
}
if _, err := fmt.Sscanf(dec.Index, "0x%x", &declog.Index); err != nil {
return fmt.Errorf("invalid hex log index")
}
*r = declog
return nil
}
type Logs []*Log
// LogForStorage is a wrapper around a Log that flattens and parses the entire
// content of a log, as opposed to only the consensus fields originally (by hiding
// the rlp interface methods).
type LogForStorage Log