Package org.elasticsearch.action.support

Class NodeResponseTracker

java.lang.Object

org.elasticsearch.action.support.NodeResponseTracker

public class NodeResponseTracker
extends Object

This class tracks the intermediate responses that will be used to create aggregated cluster response to a request. It also gives the possibility to discard the intermediate results when asked, for example when the initial request is cancelled, in order to release the resources.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	NodeResponseTracker.DiscardedResponsesException	This exception is thrown when the NodeResponseTracker is asked to give information about the responses after they have been discarded.

Constructor Summary

Constructors

Constructor	Description
NodeResponseTracker(int size)
NodeResponseTracker(Collection<Object> array)

Method Summary

Modifier and Type	Method	Description
void	discardIntermediateResponses(Exception cause)	This method discards the results collected so far to free up the resources.
int	getExpectedResponseCount()
Object	getResponse(int nodeIndex)	Returns the tracked response or null if the response hasn't been received yet for a specific index that represents a node of the cluster.
boolean	responsesDiscarded()
boolean	trackResponseAndCheckIfLast(int nodeIndex, Object response)	This method stores a new node response if the intermediate responses haven't been discarded yet.

Methods inherited from class java.lang.Object

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

Constructor Details

NodeResponseTracker

public NodeResponseTracker(int size)

NodeResponseTracker

public NodeResponseTracker(Collection<Object> array)

Method Details

discardIntermediateResponses

public void discardIntermediateResponses(Exception cause)

This method discards the results collected so far to free up the resources.

Parameters:

cause - the discarding, this will be communicated if they try to access the discarded results

responsesDiscarded

public boolean responsesDiscarded()

trackResponseAndCheckIfLast

public boolean trackResponseAndCheckIfLast(int nodeIndex,
 Object response)

This method stores a new node response if the intermediate responses haven't been discarded yet. If the responses are not discarded the method asserts that this is the first response encountered from this node to protect from miscounting the responses in case of a double invocation. If the responses have been discarded we accept this risk for simplicity.

Parameters:

nodeIndex - , the index that represents a single node of the cluster

response - , a response can be either a NodeResponse or an error

Returns:

true if all the nodes' responses have been received, else false

getResponse

public Object getResponse(int nodeIndex)
                   throws NodeResponseTracker.DiscardedResponsesException

Returns the tracked response or null if the response hasn't been received yet for a specific index that represents a node of the cluster.

Throws:

NodeResponseTracker.DiscardedResponsesException - if the responses have been discarded

getExpectedResponseCount

public int getExpectedResponseCount()