-
Notifications
You must be signed in to change notification settings - Fork 0
/
messages.go
148 lines (125 loc) · 2.85 KB
/
messages.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
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
/*
* Copyright (c) 2022, Gideon Williams <gideon@gideonw.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
package proto
import (
"bytes"
"encoding/binary"
"encoding/gob"
"io"
)
type MessageType uint8
const (
MessageTypeHello MessageType = iota
MessageTypeIdentify
MessageTypeAssign
MessageTypeAlive
MessageTypeStatus
MessageTypeAccept
)
// The Message type wraps all messages sent between workers and servers
type Message struct {
Type MessageType
Data []byte
}
// Read a Message from an io.Reader
func (m *Message) Read(reader io.Reader) error {
lengthPrefix := make([]byte, 4)
err := binary.Read(reader, binary.LittleEndian, &lengthPrefix)
if err != nil {
return err
}
messageLength := binary.LittleEndian.Uint32(lengthPrefix)
messageBuffer := make([]byte, messageLength)
_, err = io.ReadFull(reader, messageBuffer)
if err != nil {
return err
}
m.Type = MessageType(messageBuffer[0])
m.Data = messageBuffer[1:]
return nil
}
// Write a Message to an io.Writer.
func (m *Message) Write(writer io.Writer) error {
// 1 byte for MessageType, and 4 bytes for message length
b := make([]byte, len(m.Data)+1+4)
binary.LittleEndian.PutUint32(b, uint32(len(m.Data)+1))
b[4] = byte(m.Type)
copy(b[5:], m.Data)
_, err := writer.Write(b)
if err != nil {
return err
}
return nil
}
type ProtocolObject interface {
Encode() (Message, error)
Decode(Message) error
}
type (
Identify struct {
ID string
Capacity uint
}
Assign struct {
Jobs []Job `json:"jobs"`
}
Status struct {
// JobQueue of accepted jobs
JobQueue []Job
// ActiveJobs are the jobs currently being worked
ActiveJobs []Job
// [JobID]: [StatusCode]count
Results map[string]map[int]int
}
)
func encode(obj interface{}) ([]byte, error) {
var encoded bytes.Buffer
enc := gob.NewEncoder(&encoded)
err := enc.Encode(obj)
if err != nil {
return nil, err
}
return encoded.Bytes(), nil
}
func (id *Identify) Encode() (Message, error) {
data, err := encode(id)
if err != nil {
return Message{}, err
}
return Message{Type: MessageTypeIdentify, Data: data}, nil
}
func (id *Identify) Decode(m Message) error {
buf := bytes.NewBuffer(m.Data)
dec := gob.NewDecoder(buf)
err := dec.Decode(id)
return err
}
func (assign *Assign) Encode() (Message, error) {
data, err := encode(assign)
if err != nil {
return Message{}, err
}
return Message{Type: MessageTypeAssign, Data: data}, nil
}
func (assign *Assign) Decode(m Message) error {
buf := bytes.NewBuffer(m.Data)
dec := gob.NewDecoder(buf)
err := dec.Decode(assign)
return err
}
func (status *Status) Encode() (Message, error) {
data, err := encode(status)
if err != nil {
return Message{}, err
}
return Message{Type: MessageTypeAssign, Data: data}, nil
}
func (status *Status) Decode(m Message) error {
buf := bytes.NewBuffer(m.Data)
dec := gob.NewDecoder(buf)
err := dec.Decode(status)
return err
}