-
Notifications
You must be signed in to change notification settings - Fork 2
/
binary.go
106 lines (98 loc) · 2.73 KB
/
binary.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
package parser
import (
"errors"
"io"
"github.com/mitchellh/mapstructure"
"github.com/zishang520/engine.io-go-parser/types"
)
type Placeholder struct {
Placeholder bool `json:"_placeholder" mapstructure:"_placeholder" msgpack:"_placeholder"`
Num int `json:"num" mapstructure:"num" msgpack:"num"`
}
// Replaces every io.Reader | []byte in packet with a numbered placeholder.
func DeconstructPacket(packet *Packet) (pack *Packet, buffers []types.BufferInterface) {
pack = packet
pack.Data = _deconstructPacket(packet.Data, &buffers)
attachments := uint64(len(buffers))
pack.Attachments = &attachments // number of binary 'attachments'
return pack, buffers
}
func _deconstructPacket(data any, buffers *[]types.BufferInterface) any {
if data == nil {
return nil
}
if IsBinary(data) {
_placeholder := &Placeholder{Placeholder: true, Num: len(*buffers)}
rdata := types.NewBytesBuffer(nil)
switch tdata := data.(type) {
case io.Reader:
if c, ok := data.(io.Closer); ok {
defer c.Close()
}
rdata.ReadFrom(tdata)
case []byte:
rdata.Write(tdata)
}
*buffers = append(*buffers, rdata)
return _placeholder
} else {
switch tdata := data.(type) {
case []any:
newData := make([]any, 0, len(tdata))
for _, v := range tdata {
newData = append(newData, _deconstructPacket(v, buffers))
}
return newData
case map[string]any:
newData := map[string]any{}
for k, v := range tdata {
newData[k] = _deconstructPacket(v, buffers)
}
return newData
}
}
return data
}
// Reconstructs a binary packet from its placeholder packet and buffers
func ReconstructPacket(data *Packet, buffers []types.BufferInterface) (_ *Packet, err error) {
data.Data, err = _reconstructPacket(data.Data, &buffers)
data.Attachments = nil // no longer useful
return data, nil
}
func _reconstructPacket(data any, buffers *[]types.BufferInterface) (any, error) {
if data == nil {
return nil, nil
}
switch d := data.(type) {
case []any:
newData := make([]any, 0, len(d))
for _, v := range d {
_data, err := _reconstructPacket(v, buffers)
if err != nil {
return nil, err
}
newData = append(newData, _data)
}
return newData, nil
case map[string]any:
var _placeholder *Placeholder
if mapstructure.Decode(d, &_placeholder) == nil {
if _placeholder.Placeholder {
if _placeholder.Num >= 0 && _placeholder.Num < len(*buffers) {
return (*buffers)[_placeholder.Num], nil // appropriate buffer (should be natural order anyway)
}
return nil, errors.New("illegal attachments")
}
}
newData := map[string]any{}
for k, v := range d {
_data, err := _reconstructPacket(v, buffers)
if err != nil {
return nil, err
}
newData[k] = _data
}
return newData, nil
}
return data, nil
}