org.apache.samza.system.chooser

Class BaseMessageChooser

java.lang.Object

org.apache.samza.system.chooser.BaseMessageChooser

All Implemented Interfaces:

MessageChooser

public abstract class BaseMessageChooser
extends java.lang.Object
implements MessageChooser

An abstract MessageChooser that implements start/stop/register for choosers that don't use them.

Constructor Summary

Constructors

Constructor and Description
BaseMessageChooser()

Method Summary

Methods

Modifier and Type	Method and Description
void	register(SystemStreamPartition systemStreamPartition, java.lang.String offset) Called before start, to let the chooser know that it will be handling envelopes from the given SystemStreamPartition.
void	start() Called after all SystemStreamPartitions have been registered.
void	stop() Called when the chooser is about to be discarded.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.samza.system.chooser.MessageChooser

choose, update

Constructor Detail

BaseMessageChooser

public BaseMessageChooser()

Method Detail

start

public void start()

Description copied from interface: MessageChooser

Called after all SystemStreamPartitions have been registered. Start is used to notify the chooser that it will start receiving update and choose calls.

Specified by:

start in interface MessageChooser

stop

public void stop()

Description copied from interface: MessageChooser

Called when the chooser is about to be discarded. No more messages will be given to the chooser after it is stopped.

Specified by:

stop in interface MessageChooser

register

public void register(SystemStreamPartition systemStreamPartition,
            java.lang.String offset)

Description copied from interface: MessageChooser

Called before start, to let the chooser know that it will be handling envelopes from the given SystemStreamPartition. Register will only be called before start.

Specified by:

register in interface MessageChooser

Parameters:

systemStreamPartition - A SystemStreamPartition that envelopes will be coming from.

offset - The offset of the first message expected for the system/stream/partition that's being registered. If "7" were supplied as the offset, then the MessageChooser can expect the first message it is updated with for the system/stream/partition will have an offset of "7".