wolfstudy commented on a change in pull request #3854: [issue #3767] support go function for pulsar URL: https://github.com/apache/pulsar/pull/3854#discussion_r272039217
########## File path: pulsar-function-go/pf/instance.go ########## @@ -0,0 +1,289 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package pf + +import ( + "context" + "errors" + "time" + + "github.com/apache/pulsar/pulsar-client-go/pulsar" + "github.com/apache/pulsar/pulsar-function-go/log" + "github.com/apache/pulsar/pulsar-function-go/pb" +) + +const PulsarServiceURL = "pulsar://localhost:6650" + +type GoInstance struct { + function Function + context *FunctionContext + producer pulsar.Producer + consumers []pulsar.Consumer + client pulsar.Client + msg []pulsar.Message +} + +func NewGoInstance() *GoInstance { + goInstance := &GoInstance{ + context: NewFuncContext(), + } + return goInstance +} + +type Handler struct { + handler Function +} + +func (gi *GoInstance) handlerMsg() (output []byte, err error) { + ctx, cancel := context.WithCancel(context.Background()) + defer cancel() + fc := NewFuncContext() + ctx = NewContext(ctx, fc) + + if gi.msg == nil { + return nil, errors.New("no messages to be processed") + } + for _, msg := range gi.msg { + ctx = context.WithValue(ctx, "current-msg", msg) + ctx = context.WithValue(ctx, "current-topic", msg.Topic()) + msgInput := msg.Payload() + output, err = gi.function.Process(ctx, msgInput) + if err != nil { + log.Errorf("process function err:%v", err) + return nil, err + } + } + return output, nil +} + +func (gi *GoInstance) setupClient() { + client, err := pulsar.NewClient(pulsar.ClientOptions{ + URL: PulsarServiceURL, + }) + if err != nil { + log.Errorf("create client error:%v", err) + return + } + gi.client = client +} + +func (gi *GoInstance) StartFunction(function Function) { + // Setup consumers and input deserializers + consumerType := pulsar.Shared + gi.context = NewFuncContext() + gi.setupClient() + if int32(gi.context.InstanceConf.FuncDetails.Source.SubscriptionType) == pb.SubscriptionType_value["FAILOVER"] { + consumerType = pulsar.Failover + } + + funcDetails := gi.context.InstanceConf.FuncDetails + subscriptionName := funcDetails.Tenant + "/" + funcDetails.Namespace + "/" + funcDetails.Name + + properties := getProperties(getDefaultSubscriptionName( + funcDetails.Tenant, + funcDetails.Namespace, + funcDetails.Name), gi.context.InstanceConf.InstanceID) + + channel := make(chan pulsar.ConsumerMessage) + + for topic, consumerConf := range funcDetails.Source.InputSpecs { + log.Debugf("Setting up consumer for topic: %s with subscription name: %s", topic, subscriptionName) + if consumerConf.ReceiverQueueSize != nil { + if consumerConf.IsRegexPattern { + consumer, err := gi.client.Subscribe(pulsar.ConsumerOptions{ + TopicsPattern: topic, + ReceiverQueueSize: int(consumerConf.ReceiverQueueSize.Value), + SubscriptionName: subscriptionName, + Properties: properties, + Type: consumerType, + MessageChannel: channel, + }) + if err != nil { + log.Errorf("create consumer error:%s", err.Error()) + } + gi.consumers = append(gi.consumers, consumer) + } else { + consumer, err := gi.client.Subscribe(pulsar.ConsumerOptions{ + Topic: topic, + SubscriptionName: subscriptionName, + Properties: properties, + Type: consumerType, + ReceiverQueueSize: int(consumerConf.ReceiverQueueSize.Value), + MessageChannel: channel, + }) + if err != nil { + log.Errorf("create consumer error:%s", err.Error()) + } + + gi.consumers = append(gi.consumers, consumer) + } + } else { + if consumerConf.IsRegexPattern { + consumer, err := gi.client.Subscribe(pulsar.ConsumerOptions{ + TopicsPattern: topic, + SubscriptionName: subscriptionName, + Properties: properties, + Type: consumerType, + MessageChannel: channel, + }) + if err != nil { + log.Errorf("create consumer error:%s", err.Error()) + } + gi.consumers = append(gi.consumers, consumer) + } else { + consumer, err := gi.client.Subscribe(pulsar.ConsumerOptions{ + Topic: topic, + SubscriptionName: subscriptionName, + Properties: properties, + Type: consumerType, + MessageChannel: channel, + }) + if err != nil { + log.Errorf("create consumer error:%s", err.Error()) + } + gi.consumers = append(gi.consumers, consumer) + } + } + gi.context.InputTopics = append(gi.context.InputTopics, topic) + + CLOSE: + for { + select { + case cm := <-channel: + gi.msg = append(gi.msg, cm.Message) + case <-time.After(time.Millisecond * 500): + close(channel) + break CLOSE + } + } + } + + gi.actualExecution(function) + gi.close() +} + +func (gi *GoInstance) actualExecution(function Function) { + gi.function = function + output, err := gi.handlerMsg() + err = gi.processResult(output) + if err != nil { + log.Errorf("process output result err:%v", err) + return + } +} + +func (gi *GoInstance) processResult(output []byte) error { + gi.context = NewFuncContext() + atLeastOnce := gi.context.InstanceConf.FuncDetails.ProcessingGuarantees == pb.ProcessingGuarantees_ATLEAST_ONCE + + if output != nil && gi.context.InstanceConf.FuncDetails.Sink.Topic != "" && + len(gi.context.InstanceConf.FuncDetails.Sink.Topic) > 0 { + if gi.producer == nil { + err := gi.setUpProducer() + if err != nil { + log.Errorf("set up producer error:%s", err.Error()) + return err + } + } + + asyncMsg := pulsar.ProducerMessage{ + Payload: output, + } + // Attempt to send the message asynchronously and handle the response + gi.producer.SendAsync(context.Background(), asyncMsg, func(message pulsar.ProducerMessage, e error) { + if e != nil { + log.Fatal(e) Review comment: @srkukarni thanks. ``` if (output != nil){ if autoAck { if e != nil { if atLeastOnce { gi.nackInputMessage(msgInput) } else if effectivelyOnce { panic("in effectively-once case, this is error.") } } else if !atMostOnce { gi.ackInputMessage(msgInput) } } } else { if autoAck { gi.ackInputMessage(msgInput) } } ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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