/
msgcfilter.go
124 lines (106 loc) · 3.88 KB
/
msgcfilter.go
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
// Copyright (c) 2017 The btcsuite developers
// Copyright (c) 2017 The Lightning Network Developers
// Copyright (c) 2018 The Decred developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package wire
import (
"fmt"
"io"
"github.com/bitum-project/bitumd/chaincfg/chainhash"
)
const (
// MaxCFilterDataSize is the maximum byte size of a committed filter.
// The maximum size is currently defined as 256KiB.
MaxCFilterDataSize = 256 * 1024
)
// MsgCFilter implements the Message interface and represents a cfilter message.
// It is used to deliver a committed filter in response to a getcfilter
// (MsgGetCFilter) message.
type MsgCFilter struct {
BlockHash chainhash.Hash
FilterType FilterType
Data []byte
}
// BtcDecode decodes r using the wire protocol encoding into the receiver.
// This is part of the Message interface implementation.
func (msg *MsgCFilter) BtcDecode(r io.Reader, pver uint32) error {
if pver < NodeCFVersion {
str := fmt.Sprintf("cfilter message invalid for protocol "+
"version %d", pver)
return messageError("MsgCFilter.BtcDecode", str)
}
// Read the hash of the filter's block
err := readElement(r, &msg.BlockHash)
if err != nil {
return err
}
// Read filter type
err = readElement(r, (*uint8)(&msg.FilterType))
if err != nil {
return err
}
// Read filter data
msg.Data, err = ReadVarBytes(r, pver, MaxCFilterDataSize,
"cfilter data")
return err
}
// BtcEncode encodes the receiver to w using the wire protocol encoding. This is
// part of the Message interface implementation.
func (msg *MsgCFilter) BtcEncode(w io.Writer, pver uint32) error {
if pver < NodeCFVersion {
str := fmt.Sprintf("cfilter message invalid for protocol "+
"version %d", pver)
return messageError("MsgCFHeaders.BtcEncode", str)
}
size := len(msg.Data)
if size > MaxCFilterDataSize {
str := fmt.Sprintf("cfilter size too large for message "+
"[size %v, max %v]", size, MaxCFilterDataSize)
return messageError("MsgCFilter.BtcEncode", str)
}
err := writeElement(w, &msg.BlockHash)
if err != nil {
return err
}
err = binarySerializer.PutUint8(w, uint8(msg.FilterType))
if err != nil {
return err
}
return WriteVarBytes(w, pver, msg.Data)
}
// Deserialize decodes a filter from r into the receiver using a format that is
// suitable for long-term storage such as a database. This function differs from
// BtcDecode in that BtcDecode decodes from the wire protocol as it was sent
// across the network. The wire encoding can technically differ depending on
// the protocol version and doesn't even really need to match the format of a
// stored filter at all. As of the time this comment was written, the encoded
// filter is the same in both instances, but there is a distinct difference and
// separating the two allows the API to be flexible enough to deal with changes.
func (msg *MsgCFilter) Deserialize(r io.Reader) error {
// At the current time, there is no difference between the wire encoding
// and the stable long-term storage format. As a result, make use of
// BtcDecode.
return msg.BtcDecode(r, 0)
}
// Command returns the protocol command string for the message. This is part
// of the Message interface implementation.
func (msg *MsgCFilter) Command() string {
return CmdCFilter
}
// MaxPayloadLength returns the maximum length the payload can be for the
// receiver. This is part of the Message interface implementation.
func (msg *MsgCFilter) MaxPayloadLength(pver uint32) uint32 {
return uint32(VarIntSerializeSize(MaxCFilterDataSize)) +
MaxCFilterDataSize + chainhash.HashSize + 1
}
// NewMsgCFilter returns a new cfilter message that conforms to the Message
// interface. See MsgCFilter for details.
func NewMsgCFilter(blockHash *chainhash.Hash, filterType FilterType,
data []byte) *MsgCFilter {
return &MsgCFilter{
BlockHash: *blockHash,
FilterType: filterType,
Data: data,
}
}