Package org.elasticsearch.action

Class ResultDeduplicator<T,R>

java.lang.Object

org.elasticsearch.action.ResultDeduplicator<T,R>

Type Parameters:

T - Request type

public final class ResultDeduplicator<T,R>
extends Object

Deduplicator for arbitrary keys and results that can be used to ensure a given action is only executed once at a time for a given request.

Constructor Summary

Constructors

Constructor	Description
ResultDeduplicator()

Method Summary

Modifier and Type	Method	Description
void	clear()	Remove all tracked requests from this instance so that the first time executeOnce(T, org.elasticsearch.action.ActionListener<R>, java.util.function.BiConsumer<T, org.elasticsearch.action.ActionListener<R>>) is invoked with any request it triggers an actual request execution.
void	executeOnce(T request, ActionListener<R> listener, BiConsumer<T,ActionListener<R>> callback)	Ensures a given request not executed multiple times when another equal request is already in-flight.
int	size()

Methods inherited from class java.lang.Object

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

Constructor Details

ResultDeduplicator

public ResultDeduplicator()

Method Details

executeOnce

public void executeOnce(T request,
 ActionListener<R> listener,
 BiConsumer<T,ActionListener<R>> callback)

Ensures a given request not executed multiple times when another equal request is already in-flight. If the request is not yet known to the deduplicator it will invoke the passed callback with an ActionListener that must be completed by the caller when the request completes. Once that listener is completed the request will be removed from the deduplicator's internal state. If the request is already known to the deduplicator it will keep track of the given listener and invoke it when the listener passed to the callback on first invocation is completed.

Parameters:

request - Request to deduplicate

listener - Listener to invoke on request completion

callback - Callback to be invoked with request and completion listener the first time the request is added to the deduplicator

clear

public void clear()

Remove all tracked requests from this instance so that the first time executeOnce(T, org.elasticsearch.action.ActionListener<R>, java.util.function.BiConsumer<T, org.elasticsearch.action.ActionListener<R>>) is invoked with any request it triggers an actual request execution. Use this e.g. for requests to master that need to be sent again on master failover.

size

public int size()