org.apache.pulsar.functions.instance.processors

Class AtLeastOnceProcessor

java.lang.Object

org.apache.pulsar.functions.instance.processors.AtLeastOnceProcessor

All Implemented Interfaces:

AutoCloseable, MessageProcessor

public class AtLeastOnceProcessor
extends Object

A message processor that process messages at-most-once.

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.pulsar.client.api.PulsarClient	client
protected org.apache.pulsar.functions.proto.Function.FunctionDetails	functionDetails
protected Source	source

Method Summary

Modifier and Type	Method and Description
void	close()
protected void	initializeOutputProducer(String outputTopic)
void	postReceiveMessage(Record record) Method called when a message is received from input after being put into the process queue.
Record	recieveMessage() Get the next message to process
void	sendOutputMessage(Record srcRecord, org.apache.pulsar.client.api.MessageBuilder outputMsgBuilder) Send the output message to the output topic.
void	setupInput(Class<?> inputType) Setup the source.
void	setupOutput(org.apache.pulsar.functions.api.SerDe outputSerDe) Setup the output with a provided outputSerDe.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.pulsar.functions.instance.processors.MessageProcessor

create, getSource

Field Detail

client

protected final org.apache.pulsar.client.api.PulsarClient client

functionDetails

protected final org.apache.pulsar.functions.proto.Function.FunctionDetails functionDetails

source

protected Source source

Method Detail

initializeOutputProducer

protected void initializeOutputProducer(String outputTopic)
                                 throws Exception

Throws:

Exception

sendOutputMessage

public void sendOutputMessage(Record srcRecord,
                              org.apache.pulsar.client.api.MessageBuilder outputMsgBuilder)

Description copied from interface: MessageProcessor

Send the output message to the output topic. The output message is computed from inputMsg.

If the outputMsgBuilder is null, the implementation doesn't have to send any messages to the output. The implementation can decide to acknowledge the input message based on its process guarantees.

Parameters:

srcRecord - record from source

outputMsgBuilder - output message builder. it can be null.

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface MessageProcessor

setupInput

public void setupInput(Class<?> inputType)
                throws Exception

Description copied from interface: MessageProcessor

Setup the source. Implementation is responsible for initializing the source and for calling open method for source

Specified by:

setupInput in interface MessageProcessor

Parameters:

inputType - the input type of the function

Throws:

Exception

recieveMessage

public Record recieveMessage()
                      throws Exception

Description copied from interface: MessageProcessor

Get the next message to process

Specified by:

recieveMessage in interface MessageProcessor

Returns:

the next input message

Throws:

Exception

postReceiveMessage

public void postReceiveMessage(Record record)

Method called when a message is received from input after being put into the process queue.

The processor implementation can make a decision to process the message based on its processing guarantees. for example, an at-most-once processor can ack the message immediately.

Specified by:

postReceiveMessage in interface MessageProcessor

Parameters:

record - input message.

setupOutput

public void setupOutput(org.apache.pulsar.functions.api.SerDe outputSerDe)
                 throws Exception

Description copied from interface: MessageProcessor

Setup the output with a provided outputSerDe. The implementation of this processor is responsible for setting up the output

Specified by:

setupOutput in interface MessageProcessor

Parameters:

outputSerDe - output serde.

Throws:

Exception