aboutsummaryrefslogtreecommitdiffstats
path: root/core/types/log.go
blob: 006f62bbf6f6814e1d7620f25a9c533ed122e980 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
// 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 (
    "io"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/common/hexutil"
    "github.com/ethereum/go-ethereum/rlp"
)

//go:generate gencodec -type Log -field-override logMarshaling -out gen_log_json.go

// 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 of the contract that generated the event
    Address common.Address `json:"address" gencodec:"required"`
    // list of topics provided by the contract.
    Topics []common.Hash `json:"topics" gencodec:"required"`
    // supplied by the contract, usually ABI-encoded
    Data []byte `json:"data" gencodec:"required"`

    // Derived fields. These fields are filled in by the node
    // but not secured by consensus.
    // block in which the transaction was included
    BlockNumber uint64 `json:"blockNumber"`
    // hash of the transaction
    TxHash common.Hash `json:"transactionHash" gencodec:"required"`
    // index of the transaction in the block
    TxIndex uint `json:"transactionIndex" gencodec:"required"`
    // hash of the block in which the transaction was included
    BlockHash common.Hash `json:"blockHash"`
    // index of the log in the block
    Index uint `json:"logIndex" gencodec:"required"`

    // 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 `json:"removed"`
}

type logMarshaling struct {
    Data        hexutil.Bytes
    BlockNumber hexutil.Uint64
    TxIndex     hexutil.Uint
    Index       hexutil.Uint
}

type rlpLog struct {
    Address common.Address
    Topics  []common.Hash
    Data    []byte
}

// rlpStorageLog is the storage encoding of a log.
type rlpStorageLog rlpLog

// legacyRlpStorageLog is the previous storage encoding of a log including some redundant fields.
type legacyRlpStorageLog struct {
    Address     common.Address
    Topics      []common.Hash
    Data        []byte
    BlockNumber uint64
    TxHash      common.Hash
    TxIndex     uint
    BlockHash   common.Hash
    Index       uint
}

// 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
}

// 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,
    })
}

// DecodeRLP implements rlp.Decoder.
//
// Note some redundant fields(e.g. block number, tx hash etc) will be assembled later.
func (l *LogForStorage) DecodeRLP(s *rlp.Stream) error {
    blob, err := s.Raw()
    if err != nil {
        return err
    }
    var dec rlpStorageLog
    err = rlp.DecodeBytes(blob, &dec)
    if err == nil {
        *l = LogForStorage{
            Address: dec.Address,
            Topics:  dec.Topics,
            Data:    dec.Data,
        }
    } else {
        // Try to decode log with previous definition.
        var dec legacyRlpStorageLog
        err = rlp.DecodeBytes(blob, &dec)
        if err == nil {
            *l = LogForStorage{
                Address: dec.Address,
                Topics:  dec.Topics,
                Data:    dec.Data,
            }
        }
    }
    return err
}