// 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 types
import (
"encoding/json"
"errors"
"fmt"
"io"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"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. These fields are filled in by the node
// but not secured by consensus.
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
// The Removed field is true if this log was reverted due to a chain reorganisation.
// You must pay attention to this field if you receive logs through a filter query.
Removed bool
}
type rlpLog struct {
Address common.Address
Topics []common.Hash
Data []byte
}
type rlpStorageLog struct {
Address common.Address
Topics []common.Hash
Data []byte
BlockNumber uint64
TxHash common.Hash
TxIndex uint
BlockHash common.Hash
Index uint
}
type jsonLog struct {
Address *common.Address `json:"address"`
Topics *[]common.Hash `json:"topics"`
Data *hexutil.Bytes `json:"data"`
BlockNumber *hexutil.Uint64 `json:"blockNumber"`
TxIndex *hexutil.Uint `json:"transactionIndex"`
TxHash *common.Hash `json:"transactionHash"`
BlockHash *common.Hash `json:"blockHash"`
Index *hexutil.Uint `json:"logIndex"`
Removed bool `json:"removed"`
}
// EncodeRLP implements rlp.Encoder.
func (l *Log) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, rlpLog{Address: l.Address, Topics: l.Topics, Data: l.Data})
}
// DecodeRLP implements rlp.Decoder.
func (l *Log) DecodeRLP(s *rlp.Stream) error {
var dec rlpLog
err := s.Decode(&dec)
if err == nil {
l.Address, l.Topics, l.Data = dec.Address, dec.Topics, dec.Data
}
return err
}
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 (l *Log) MarshalJSON() ([]byte, error) {
jslog := &jsonLog{
Address: &l.Address,
Topics: &l.Topics,
Data: (*hexutil.Bytes)(&l.Data),
TxIndex: (*hexutil.Uint)(&l.TxIndex),
TxHash: &l.TxHash,
Index: (*hexutil.Uint)(&l.Index),
Removed: l.Removed,
}
// Set block information for mined logs.
if (l.BlockHash != common.Hash{}) {
jslog.BlockHash = &l.BlockHash
jslog.BlockNumber = (*hexutil.Uint64)(&l.BlockNumber)
}
return json.Marshal(jslog)
}
// UnmarshalJSON implements json.Umarshaler.
func (l *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 == nil ||
dec.TxIndex == nil || dec.TxHash == nil || dec.Index == nil {
return errMissingLogFields
}
declog := Log{
Address: *dec.Address,
Topics: *dec.Topics,
Data: *dec.Data,
TxHash: *dec.TxHash,
TxIndex: uint(*dec.TxIndex),
Index: uint(*dec.Index),
Removed: dec.Removed,
}
// Block information may be missing if the log is received through
// the pending log filter, so it's handled specially here.
if dec.BlockHash != nil && dec.BlockNumber != nil {
declog.BlockHash = *dec.BlockHash
declog.BlockNumber = uint64(*dec.BlockNumber)
}
*l = declog
return nil
}
// LogForStorage is a wrapper around a Log that flattens and parses the entire content of
// a log including non-consensus fields.
type LogForStorage Log
// EncodeRLP implements rlp.Encoder.
func (l *LogForStorage) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, rlpStorageLog{
Address: l.Address,
Topics: l.Topics,
Data: l.Data,
BlockNumber: l.BlockNumber,
TxHash: l.TxHash,
TxIndex: l.TxIndex,
BlockHash: l.BlockHash,
Index: l.Index,
})
}
// DecodeRLP implements rlp.Decoder.
func (l *LogForStorage) DecodeRLP(s *rlp.Stream) error {
var dec rlpStorageLog
err := s.Decode(&dec)
if err == nil {
*l = LogForStorage{
Address: dec.Address,
Topics: dec.Topics,
Data: dec.Data,
BlockNumber: dec.BlockNumber,
TxHash: dec.TxHash,
TxIndex: dec.TxIndex,
BlockHash: dec.BlockHash,
Index: dec.Index,
}
}
return err
}