co.cask.cdap.messaging

Class StoreRequest

java.lang.Object

com.google.common.collect.UnmodifiableIterator<T>

com.google.common.collect.AbstractIterator<byte[]>

co.cask.cdap.messaging.StoreRequest

All Implemented Interfaces:

Iterator<byte[]>

public abstract class StoreRequest
extends com.google.common.collect.AbstractIterator<byte[]>

This class represents messages to be store to the messaging system. The message payloads are provide through the Iterator.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	StoreRequest(co.cask.cdap.proto.id.TopicId topicId, boolean transactional, long transactionWritePointer)

Method Summary

Modifier and Type	Method and Description
protected byte[]	computeNext()
protected abstract byte[]	doComputeNext() Returns the next message payloads or return null to signal the end of payload messages.
co.cask.cdap.proto.id.TopicId	getTopicId()
long	getTransactionWritePointer() Returns the transaction write pointer if the message is going to be published transactionally, that is when isTransactional() returns true.
boolean	isTransactional() Returns true if the message should be published transactionally.

Methods inherited from class com.google.common.collect.AbstractIterator

endOfData, hasNext, next, peek

Methods inherited from class com.google.common.collect.UnmodifiableIterator

remove

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

StoreRequest

protected StoreRequest(co.cask.cdap.proto.id.TopicId topicId,
                       boolean transactional,
                       long transactionWritePointer)

Method Detail

getTopicId

public co.cask.cdap.proto.id.TopicId getTopicId()

isTransactional

public boolean isTransactional()

Returns true if the message should be published transactionally.

getTransactionWritePointer

public long getTransactionWritePointer()

Returns the transaction write pointer if the message is going to be published transactionally, that is when isTransactional() returns true.

computeNext

protected final byte[] computeNext()

Specified by:

computeNext in class com.google.common.collect.AbstractIterator<byte[]>

doComputeNext

@Nullable
protected abstract byte[] doComputeNext()

Returns the next message payloads or return null to signal the end of payload messages. If this method returns null on the first time being called, it means this StoreRequest represents a message table entry that reference to payload table. It requires isTransactional() returns true and getTransactionWritePointer() should return the transaction write pointer for messages stored in the Payload Table prior to this call.