开源包mqtt源码_token
github.com/eclipse/paho.mqtt.golang
测试代码
/*
* Copyright (c) 2021 IBM Corp and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v2.0
* and Eclipse Distribution License v1.0 which accompany this distribution.
*
* The Eclipse Public License is available at
* https://www.eclipse.org/legal/epl-2.0/
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Allan Stockdill-Mander
*/
package mqtt
import (
"errors"
"testing"
"time"
)
func TestWaitTimeout(t *testing.T) {
b := baseToken{}
if b.WaitTimeout(time.Second) {
t.Fatal("Should have failed")
}
// Now lets confirm that WaitTimeout returns
// setError() grabs the mutex which previously caused issues
// when there is a result (it returns true in this case)
b = baseToken{complete: make(chan struct{})}
go func(bt *baseToken) {
bt.setError(errors.New("test error"))
}(&b)
if !b.WaitTimeout(5 * time.Second) {
t.Fatal("Should have succeeded")
}
}
token代码
/*
* Copyright (c) 2021 IBM Corp and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v2.0
* and Eclipse Distribution License v1.0 which accompany this distribution.
*
* The Eclipse Public License is available at
* https://www.eclipse.org/legal/epl-2.0/
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Allan Stockdill-Mander
*/
package mqtt
import (
"sync"
"time"
"github.com/eclipse/paho.mqtt.golang/packets"
)
// PacketAndToken is a struct that contains both a ControlPacket and a
// Token. This struct is passed via channels between the client interface
// code and the underlying code responsible for sending and receiving
// MQTT messages.
type PacketAndToken struct {
p packets.ControlPacket
t tokenCompletor
}
// Token defines the interface for the tokens used to indicate when
// actions have completed.
type Token interface {
// Wait will wait indefinitely for the Token to complete, ie the Publish
// to be sent and confirmed receipt from the broker.
Wait() bool
// WaitTimeout takes a time.Duration to wait for the flow associated with the
// Token to complete, returns true if it returned before the timeout or
// returns false if the timeout occurred. In the case of a timeout the Token
// does not have an error set in case the caller wishes to wait again.
WaitTimeout(time.Duration) bool
// Done returns a channel that is closed when the flow associated
// with the Token completes. Clients should call Error after the
// channel is closed to check if the flow completed successfully.
//
// Done is provided for use in select statements. Simple use cases may
// use Wait or WaitTimeout.
Done() <-chan struct{}
Error() error
}
type TokenErrorSetter interface {
setError(error)
}
type tokenCompletor interface {
Token
TokenErrorSetter
flowComplete()
}
type baseToken struct {
m sync.RWMutex
complete chan struct{}
err error
}
// Wait implements the Token Wait method.
func (b *baseToken) Wait() bool {
<-b.complete
return true
}
// WaitTimeout implements the Token WaitTimeout method.
func (b *baseToken) WaitTimeout(d time.Duration) bool {
timer := time.NewTimer(d)
select {
case <-b.complete:
if !timer.Stop() {
<-timer.C
}
return true
case <-timer.C:
}
return false
}
// Done implements the Token Done method.
func (b *baseToken) Done() <-chan struct{} {
return b.complete
}
func (b *baseToken) flowComplete() {
select {
case <-b.complete:
default:
close(b.complete)
}
}
func (b *baseToken) Error() error {
b.m.RLock()
defer b.m.RUnlock()
return b.err
}
func (b *baseToken) setError(e error) {
b.m.Lock()
b.err = e
b.flowComplete()
b.m.Unlock()
}
func newToken(tType byte) tokenCompletor {
switch tType {
case packets.Connect:
return &ConnectToken{baseToken: baseToken{complete: make(chan struct{})}}
case packets.Subscribe:
return &SubscribeToken{baseToken: baseToken{complete: make(chan struct{})}, subResult: make(map[string]byte)}
case packets.Publish:
return &PublishToken{baseToken: baseToken{complete: make(chan struct{})}}
case packets.Unsubscribe:
return &UnsubscribeToken{baseToken: baseToken{complete: make(chan struct{})}}
case packets.Disconnect:
return &DisconnectToken{baseToken: baseToken{complete: make(chan struct{})}}
}
return nil
}
// ConnectToken is an extension of Token containing the extra fields
// required to provide information about calls to Connect()
type ConnectToken struct {
baseToken
returnCode byte
sessionPresent bool
}
// ReturnCode returns the acknowledgement code in the connack sent
// in response to a Connect()
func (c *ConnectToken) ReturnCode() byte {
c.m.RLock()
defer c.m.RUnlock()
return c.returnCode
}
// SessionPresent returns a bool representing the value of the
// session present field in the connack sent in response to a Connect()
func (c *ConnectToken) SessionPresent() bool {
c.m.RLock()
defer c.m.RUnlock()
return c.sessionPresent
}
// PublishToken is an extension of Token containing the extra fields
// required to provide information about calls to Publish()
type PublishToken struct {
baseToken
messageID uint16
}
// MessageID returns the MQTT message ID that was assigned to the
// Publish packet when it was sent to the broker
func (p *PublishToken) MessageID() uint16 {
return p.messageID
}
// SubscribeToken is an extension of Token containing the extra fields
// required to provide information about calls to Subscribe()
type SubscribeToken struct {
baseToken
subs []string
subResult map[string]byte
messageID uint16
}
// Result returns a map of topics that were subscribed to along with
// the matching return code from the broker. This is either the Qos
// value of the subscription or an error code.
func (s *SubscribeToken) Result() map[string]byte {
s.m.RLock()
defer s.m.RUnlock()
return s.subResult
}
// UnsubscribeToken is an extension of Token containing the extra fields
// required to provide information about calls to Unsubscribe()
type UnsubscribeToken struct {
baseToken
messageID uint16
}
// DisconnectToken is an extension of Token containing the extra fields
// required to provide information about calls to Disconnect()
type DisconnectToken struct {
baseToken
}
分析
去除业务，这个token包主要是为了表示动作完成的操作
附加
可以综合mqtt文档看一下mqtt包控制报文类型
// mqtt 控制包类型
// Below are the constants assigned to each of the MQTT packet type
// 下面来自mqtt 中文文档
//Table 2.1 - Control packet types
//
//|Name |Value |Direction of flow |Description
//|Reserved |0 |Forbidden |Reserved
//|CONNECT |1 |Client to Server |
//|CONNACK |2 |Server to Client |Connect acknowledgment
//|PUBLISH |3 |Client to Server or Server to Client |Publish message
//|PUBACK |4 |Client to Server or Server to Client |Publish acknowledgment
//|PUBREC |5 |Client to Server or Server to Client |Publish received (assured delivery part 1)
//|PUBREL |6 |Client to Server or Server to Client |Publish release (assured delivery part 2)
//|PUBCOMP |7 |Client to Server or Server to Client |Publish complete (assured delivery part 3)
//|SUBSCRIBE |8 |Client to Server |Client subscribe request
//|SUBACK |9 |Server to Client |Subscribe acknowledgment
//|UNSUBSCRIBE |10 |Client to Server |Unsubscribe request
//|UNSUBACK |11 |Server to Client |Unsubscribe acknowledgment
//|PINGREQ |12 |Client to Server |PING request
//|PINGRESP |13 |Server to Client |PING response
//|DISCONNECT |14 |Client to Server |Client is disconnecting
//|Reserved |15 |Forbidden |Reserved
const (
Connect = 1
Connack = 2
Publish = 3
Puback = 4
Pubrec = 5
Pubrel = 6
Pubcomp = 7
Subscribe = 8
Suback = 9
Unsubscribe = 10
Unsuback = 11
Pingreq = 12
Pingresp = 13
Disconnect = 14
)