How to use persistMessages method of mqtt Package
Best Venom code snippet using mqtt.persistMessages
mqtt.go
Source:mqtt.go 
...84 if err != nil {85 result.Err = err.Error()86 }87 case "persistent_queue":88 err = e.persistMessages(ctx)89 if err != nil {90 result.Err = err.Error()91 }92 case "subscriber":93 result.Messages, result.MessagesJSON, result.Topics, err = e.consumeMessages(ctx)94 if err != nil {95 result.Err = err.Error()96 }97 default:98 return nil, fmt.Errorf("clientType %q must be publisher, subscriber or persistent_queue", e.ClientType)99 }100 elapsed := time.Since(start)101 result.TimeSeconds = elapsed.Seconds()102 return result, nil103}104// session prepares a client connection returning a client and a possible error105func (e Executor) session(ctx context.Context, subscriber func(client mq.Client, message mq.Message)) (mq.Client, error) {106 venom.Debug(ctx, "creating session to %v, cleanSession: %v, clientID: %v", e.Addrs, !e.PersistSubscription, e.ClientID)107 opts := mq.NewClientOptions().108 AddBroker(e.Addrs).109 SetConnectTimeout(time.Duration(e.ConnectTimeout) * time.Millisecond).110 SetCleanSession(!e.PersistSubscription).111 SetClientID(e.ClientID).112 SetProtocolVersion(mqttV311).113 SetOnConnectHandler(func(client mq.Client) {114 venom.Debug(ctx, "connection handler called. IsConnected: %v", client.IsConnected())115 })116 client := mq.NewClient(opts)117 // MQTT may send messages prior to a subscription taking place (due to pre-existing persistent session).118 // We cannot subscribe without a connection so we register a route and subscribe later119 if subscriber != nil {120 venom.Debug(ctx, "adding routes: %v", e.Topics)121 for _, topic := range e.Topics {122 client.AddRoute(topic, subscriber)123 }124 }125 token := client.Connect()126 select {127 case <-token.Done():128 if token.Error() != nil {129 venom.Debug(ctx, "connection setup failed")130 return nil, errors.Wrap(token.Error(), "failed to connect to MQTT")131 }132 // else connection complete, all good.133 case <-time.After(time.Duration(e.Timeout) * time.Millisecond):134 venom.Debug(ctx, "connection timeout")135 return nil, errors.Wrap(token.Error(), "failed to connect to MQTT")136 case <-ctx.Done():137 venom.Debug(ctx, "Context requested cancellation in session()")138 return nil, errors.New("Context requested cancellation in session()")139 }140 venom.Debug(ctx, "connection setup completed")141 return client, nil142}143// publishMessages is a step that sends configured messages to client connection144func (e Executor) publishMessages(ctx context.Context) error {145 client, err := e.session(ctx, nil)146 if err != nil {147 venom.Debug(ctx, "Failed to create session (publishMessages)")148 return err149 }150 defer client.Disconnect(disconnectTimeoutMs)151 for i, m := range e.Messages {152 if len(m.Topic) == 0 {153 return errors.Errorf("mandatory field Topic was empty in Messages[%v](%v)", i, m)154 }155 token := client.Publish(m.Topic, m.QOS, m.Retained, m.Payload)156 select {157 case <-token.Done():158 if token.Error() != nil {159 venom.Debug(ctx, "Message publish failed")160 return errors.Wrapf(token.Error(), "Message publish failed: Messages[%v](%v)", i, m)161 }162 // else publish complete, all good.163 case <-time.After(time.Duration(e.Timeout) * time.Millisecond):164 venom.Debug(ctx, "Publish attempt timed out")165 return errors.Errorf("Publish attempt timed out on topic %v", m.Topic)166 case <-ctx.Done():167 venom.Debug(ctx, "Context requested cancellation in publishMessages()")168 return errors.New("Context requested cancellation in publishMessages()")169 }170 venom.Debug(ctx, "Message[%v] %q sent (topic: %q)", i, m.Payload, m.Topic)171 }172 return nil173}174// consumeMessages is a step to consume messages from mqtt broker using client connection175func (e Executor) consumeMessages(ctx context.Context) (messages []interface{}, messagesJSON []interface{}, topics []string, err error) {176 ch := make(chan mq.Message, 1)177 defer close(ch)178 subscriber := newSubscriber(ctx, ch)179 client, err := e.session(ctx, subscriber)180 if err != nil {181 venom.Debug(ctx, "Failed to create session (consumeMessages)")182 return nil, nil, nil, err183 }184 defer client.Disconnect(disconnectTimeoutMs)185 start := time.Now()186 for _, topic := range e.Topics {187 token := client.Subscribe(topic, e.QOS, subscriber)188 select {189 case <-token.Done():190 if token.Error() != nil {191 venom.Debug(ctx, "Failed to subscribe")192 return nil, nil, nil, errors.Wrapf(token.Error(), "failed to subscribe to topic %v", topic)193 }194 // else subscription complete, all good.195 case <-time.After(time.Duration(e.Timeout) * time.Millisecond):196 venom.Debug(ctx, "Subscription attempt timed out")197 return nil, nil, nil, errors.Errorf("Subscription attempt timed out on topic %v", topic)198 case <-ctx.Done():199 venom.Debug(ctx, "Context requested cancellation")200 return nil, nil, nil, errors.New("Context requested cancellation")201 }202 }203 messages = []interface{}{}204 messagesJSON = []interface{}{}205 topics = []string{}206 venom.Debug(ctx, "message limit %d", e.MessageLimit)207 ctx2, cancel := context.WithTimeout(ctx, time.Duration(e.Timeout)*time.Millisecond)208 defer cancel()209 for i := 0; i < e.MessageLimit; i++ {210 venom.Debug(ctx, "Reading message n° %d", i)211 var t string212 var m []byte213 select {214 case msg := <-ch:215 m = msg.Payload()216 t = msg.Topic()217 case <-ctx2.Done():218 break219 }220 messages = append(messages, m)221 topics = append(topics, t)222 s := string(m)223 venom.Debug(ctx, "message received. topic: %s len(%d), %s", t, len(m), s)224 var bodyJSONArray []interface{}225 if err := venom.JSONUnmarshal(m, &bodyJSONArray); err != nil {226 bodyJSONMap := map[string]interface{}{}227 err := venom.JSONUnmarshal(m, &bodyJSONMap)228 if err != nil {229 venom.Debug(ctx, "unable to decode message as json")230 }231 messagesJSON = append(messagesJSON, bodyJSONMap)232 } else {233 messagesJSON = append(messagesJSON, bodyJSONArray)234 }235 }236 d := time.Since(start)237 venom.Debug(ctx, "read(s) took %v msec", d.Milliseconds())238 return messages, messagesJSON, topics, nil239}240// persistMessages is a step that registers or un-registers persistent topic subscriptions against a given client id241func (e Executor) persistMessages(ctx context.Context) error {242 client, err := e.session(ctx, nil)243 if err != nil {244 venom.Debug(ctx, "Failed to create session (persistMessages)")245 return err246 }247 defer client.Disconnect(disconnectTimeoutMs)248 for _, topic := range e.Topics {249 token := client.Subscribe(topic, e.QOS, func(client mq.Client, message mq.Message) {250 venom.Debug(ctx, "msg received in persist request: %v", string(message.Payload()))251 })252 select {253 case <-token.Done():254 if token.Error() != nil {255 venom.Debug(ctx, "Failed to subscribe")256 return errors.Wrapf(token.Error(), "failed to subscribe to topic %v", topic)257 }258 // else subscription complete, all good....
persistMessages
Using AI Code Generation
1import (2func main() {3 opts.SetClientID("go-simple")4 opts.SetUsername("test")5 opts.SetPassword("test")6 opts.SetCleanSession(false)7 client := mqtt.NewClient(opts)8 if token := client.Connect(); token.Wait() && token.Error() != nil {9 panic(token.Error())10 }11 client.Subscribe("test", 1, func(client mqtt.Client, msg mqtt.Message) {12 fmt.Printf("TOPIC: %s\n", msg.Topic())13 fmt.Printf("MSG: %s\n", msg.Payload())14 })15 token := client.Publish("test", 1, false, "Hello World")16 token.Wait()17 time.Sleep(3 * time.Second)18 client.Disconnect(250)19}20import (21func main() {22 opts.SetClientID("go-simple")23 opts.SetUsername("test")24 opts.SetPassword("test")25 opts.SetCleanSession(false)26 client := mqtt.NewClient(opts)27 if token := client.Connect(); token.Wait() && token.Error() != nil {28 panic(token.Error())29 }30 client.Subscribe("test", 1, func(client mqtt.Client, msg mqtt.Message) {31 fmt.Printf("TOPIC: %s\n", msg.Topic())32 fmt.Printf("MSG: %s\n", msg.Payload())33 })34 token := client.Publish("test", 1, false, "Hello World")35 token.Wait()36 time.Sleep(3 * time.Second)37 client.Disconnect(250)38}39import (40func main() {41 opts.SetClientID("go-simple")42 opts.SetUsername("test")43 opts.SetPassword("test")44 opts.SetCleanSession(false)45 client := mqtt.NewClient(opts)
persistMessages
Using AI Code Generation
1import (2func main() {3 opts.SetClientID("go-simple")4 opts.SetUsername("admin")5 opts.SetPassword("public")6 c := mqtt.NewClient(opts)7 if token := c.Connect(); token.Wait() && token.Error() != nil {8 panic(token.Error())9 }10 if token := c.Subscribe("go-mqtt/sample", 0, nil); token.Wait() && token.Error() != nil {11 fmt.Println(token.Error())12 os.Exit(1)13 }14 time.Sleep(3 * time.Second)15 if token := c.Publish("go-mqtt/sample", 0, false, "test"); token.Wait() && token.Error() != nil {16 fmt.Println(token.Error())17 os.Exit(1)18 }19 time.Sleep(3 * time.Second)20 c.Disconnect(250)21}22import (23func main() {24 opts.SetClientID("go-simple")25 opts.SetUsername("admin")26 opts.SetPassword("public")27 c := mqtt.NewClient(opts)28 if token := c.Connect(); token.Wait() && token.Error() != nil {29 panic(token.Error())30 }31 if token := c.Subscribe("go-mqtt/sample", 0, nil); token.Wait() && token.Error() != nil {32 fmt.Println(token.Error())33 os.Exit(1)34 }35 time.Sleep(3 * time.Second)36 if token := c.Publish("go-mqtt/sample", 0, false, "test"); token.Wait() && token.Error() != nil {37 fmt.Println(token.Error())38 os.Exit(1)39 }40 time.Sleep(3 * time.Second)41 c.Disconnect(250)42}
persistMessages
Using AI Code Generation
1import (2func main() {3 qMgr, err = ibmmq.Connx("QM1", nil)4 if err != nil {5 fmt.Println(err)6 }7 defer qMgr.Disc()8 mqod = ibmmq.NewMQOD()9 qObject, err = qMgr.Open(mqod, openOptions)10 if err != nil {11 fmt.Println(err)12 }13 defer qObject.Close(0)14 putmqmd = ibmmq.NewMQMD()15 putmqgmo = ibmmq.NewMQGMO()16 msgHandle, err = qObject.Put1(putmqmd, putmqgmo, []byte(msg))17 if err != nil {18 fmt.Println(err)19 }20 msg, err = qObject.Get1(putmqmd, putmqgmo, msgHandle)21 if err != nil {22 fmt.Println(err)23 }24 fmt.Println("Message received: ", msg)
persistMessages
Using AI Code Generation
1import (2func main() {3 fmt.Println("Hello World")4 mqttClient = mqtt.NewClient(mqtt.NewClientOptions())5 mqttClient.Connect()6 mqttClient.Publish("topic", 1, false, "message")7 mqttClient.Disconnect(250)8}9import (10func main() {11 fmt.Println("Hello World")12 mqttClient = mqtt.NewClient(mqtt.NewClientOptions())13 mqttClient.Connect()14 mqttClient.Publish("topic", 1, false, "message")15 mqttClient.Disconnect(250)16}17import (18func main() {19 fmt.Println("Hello World")20 mqttClient = mqtt.NewClient(mqtt.NewClientOptions())21 mqttClient.Connect()22 mqttClient.Publish("topic", 1, false, "message")23 mqttClient.Disconnect(250)24}25import (26func main() {27 fmt.Println("Hello World")28 mqttClient = mqtt.NewClient(mqtt.NewClientOptions())29 mqttClient.Connect()30 mqttClient.Publish("topic", 1, false, "message")31 mqttClient.Disconnect(250)32}33import (34func main() {35 fmt.Println("Hello World")36 mqttClient = mqtt.NewClient(mqtt.NewClientOptions())37 mqttClient.Connect()38 mqttClient.Publish("topic", 1, false, "message")39 mqttClient.Disconnect(250)40}
persistMessages
Using AI Code Generation
1import (2func main() {3 mqtt := Mqtt{}4 mqtt.Init("localhost", 1883, "test", "test", "test")5 mqtt.Connect()6 mqtt.Subscribe("topic1")7 mqtt.PersistMessages("topic1", "topic2", "test.json")8 time.Sleep(10 * time.Second)9}10import (11func main() {12 mqtt := Mqtt{}13 mqtt.Init("localhost", 1883, "test", "test", "test")14 mqtt.Connect()15 mqtt.Subscribe("topic2")16 mqtt.ReadPersistedMessages("topic2", "test.json")17 time.Sleep(10 * time.Second)18}
persistMessages
Using AI Code Generation
1import (2func main() {3 mqtt := mqtt.New()4 mqtt.SetClientId("go-client")5 mqtt.SetUsername("username")6 mqtt.SetPassword("password")7 mqtt.SetCleanSession(true)8 mqtt.SetKeepAlive(60)9 mqtt.SetWillTopic("willtopic")10 mqtt.SetWillMessage("willmessage")11 mqtt.SetWillQos(1)12 mqtt.SetWillRetained(true)13 mqtt.SetAutoReconnect(true)14 mqtt.SetReconnectInterval(5)15 mqtt.SetPersistMessages(true)16 mqtt.SetPersistDir("/home/username/")17 mqtt.SetPersistQos(1)18 mqtt.SetPersistRetained(true)19 mqtt.SetPersistMaxSize(100)20 mqtt.SetPersistMaxMessages(100)21 mqtt.SetDebug(true)22 mqtt.SetErrorChannel(make(chan error))23 mqtt.SetMessageChannel(make(chan mqtt.Message))24 mqtt.SetConnectHandler(func() {25 fmt.Println("Connected")26 })27 mqtt.SetDisconnectHandler(func() {28 fmt.Println("Disconnected")29 })30 mqtt.SetReconnectHandler(func() {31 fmt.Println("Reconnected")32 })33 mqtt.SetPublishHandler(func(msg mqtt.Message) {34 fmt.Println("Published")35 })36 mqtt.SetSubscribeHandler(func(topic string) {37 fmt.Println("Subscribed")38 })39 mqtt.SetUnsubscribeHandler(func(topic string) {40 fmt.Println("Unsubscribed")41 })42 mqtt.SetMessageHandler(func(msg mqtt.Message) {43 fmt.Println("Message received")44 })45 mqtt.Connect()46 mqtt.Publish("topic", "message", 1, true)47 mqtt.Subscribe("topic", 1)48 mqtt.Unsubscribe("topic")49 mqtt.Disconnect()50}51import (52func main() {53 mqtt := mqtt.New()54 mqtt.SetClientId("go-client")55 mqtt.SetUsername("username")56 mqtt.SetPassword("password")57 mqtt.SetCleanSession(true)58 mqtt.SetKeepAlive(60)59 mqtt.SetWillTopic("willtopic")60 mqtt.SetWillMessage("willmessage")
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