org.jivesoftware.openfire.archive

Class Archiver<E>

java.lang.Object

org.jivesoftware.openfire.archive.Archiver<E>

All Implemented Interfaces:

Runnable

public abstract class Archiver<E>
extends Object
implements Runnable

An abstract runnable that adds to-be-archived data to the database. This implementation is designed to reduce the work load on the database, by batching work where possible, without severely delaying database writes. This implementation acts as a consumer (in context of the producer-consumer design pattern), where the queue that is used to relay work from both processes is passed as an argument to the constructor of this class.

Author:

Guus der Kinderen, guus.der.kinderen@gmail.com

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Archiver(String id, int maxWorkQueueSize, Duration maxPurgeInterval, Duration gracePeriod) Instantiates a new archiver.

Method Summary

Modifier and Type	Method and Description
void	archive(E data)
Duration	availabilityETA(Instant instant) Returns an estimation on how long it takes for all data that arrived before a certain instant will have become available in the data store.
Duration	availabilityETAOnLocalNode(Instant instant) Returns an estimation on how long it takes for all data that arrived before a certain instant will have become available in the data store.
Duration	getGracePeriod()
String	getId()
Duration	getMaxPurgeInterval()
int	getMaxWorkQueueSize()
void	run()
void	setGracePeriod(Duration gracePeriod)
void	setMaxPurgeInterval(Duration maxPurgeInterval)
void	setMaxWorkQueueSize(int maxWorkQueueSize)
void	stop()
protected abstract void	store(List<E> batch)

Methods inherited from class java.lang.Object

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

Constructor Detail

Archiver

protected Archiver(String id,
                   int maxWorkQueueSize,
                   Duration maxPurgeInterval,
                   Duration gracePeriod)

Instantiates a new archiver.

Parameters:

id - A unique identifier for this archiver.

maxWorkQueueSize - Do not add more than this amount of queries in a batch.

maxPurgeInterval - Do not delay longer than this amount before storing data in the database.

gracePeriod - Maximum amount of milliseconds to wait for 'more' work to arrive, before committing the batch.

Method Detail

archive

public void archive(E data)

getId

public String getId()

run

public void run()

Specified by:

run in interface Runnable

stop

public void stop()

availabilityETA

public Duration availabilityETA(Instant instant)

Returns an estimation on how long it takes for all data that arrived before a certain instant will have become available in the data store. When data is immediately available, 'zero', is returned; Beware: implementations are free to apply a low-effort mechanism to determine a non-zero estimate. Notably, an implementation can choose to not obtain ETAs from individual cluster nodes, when the local cluster node is reporting a non-zero ETA. However, a return value of 'zero' must be true for the entire cluster (and is, in effect, not an 'estimate', but a matter of fact. This method is intended to be used to determine if it's safe to construct an answer (based on database content) to a request for archived data. Such response should only be generated after all data that was queued before the request arrived has been written to the database. This method performs a cluster-wide check, unlike availabilityETAOnLocalNode(Instant).

Parameters:

instant - The timestamp of the data that should be available (cannot be null).

Returns:

A period of time, zero when the requested data is already available.

availabilityETAOnLocalNode

public Duration availabilityETAOnLocalNode(Instant instant)

Returns an estimation on how long it takes for all data that arrived before a certain instant will have become available in the data store. When data is immediately available, 'zero', is returned; This method is intended to be used to determine if it's safe to construct an answer (based on database content) to a request for archived data. Such response should only be generated after all data that was queued before the request arrived has been written to the database. This method performs a check on the local cluster-node only, unlike availabilityETA(Instant).

Parameters:

instant - The timestamp of the data that should be available (cannot be null).

Returns:

A period of time, zero when the requested data is already available.

getMaxWorkQueueSize

public int getMaxWorkQueueSize()

setMaxWorkQueueSize

public void setMaxWorkQueueSize(int maxWorkQueueSize)

getMaxPurgeInterval

public Duration getMaxPurgeInterval()

setMaxPurgeInterval

public void setMaxPurgeInterval(Duration maxPurgeInterval)

getGracePeriod

public Duration getGracePeriod()

setGracePeriod

public void setGracePeriod(Duration gracePeriod)

store

protected abstract void store(List<E> batch)