Module org.elasticsearch.server

Package org.elasticsearch.search.aggregations

Class MultiBucketCollector

java.lang.Object

org.elasticsearch.search.aggregations.BucketCollector

org.elasticsearch.search.aggregations.MultiBucketCollector

public class MultiBucketCollector
extends BucketCollector

A BucketCollector which allows running a bucket collection with several BucketCollectors. It is similar to the MultiCollector except that the wrap(boolean, java.lang.Iterable<? extends org.elasticsearch.search.aggregations.BucketCollector>) method filters out the BucketCollector.NO_OP_BUCKET_COLLECTORs and not the null ones.

Field Summary

Fields inherited from class org.elasticsearch.search.aggregations.BucketCollector

NO_OP_BUCKET_COLLECTOR, NO_OP_COLLECTOR

Method Summary

Modifier and Type	Method	Description
LeafBucketCollector	getLeafCollector(AggregationExecutionContext aggCtx)
void	postCollection()	Post-collection callback.
void	preCollection()	Pre collection callback.
org.apache.lucene.search.ScoreMode	scoreMode()	Indicates what features are required from the scorer.
String	toString()
static BucketCollector	wrap(boolean terminateIfNoop, Iterable<? extends BucketCollector> collectors)	Wraps a list of BucketCollectors with a MultiBucketCollector.

Methods inherited from class org.elasticsearch.search.aggregations.BucketCollector

asCollector

Methods inherited from class java.lang.Object

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

Method Details

wrap

public static BucketCollector wrap(boolean terminateIfNoop,
 Iterable<? extends BucketCollector> collectors)

Wraps a list of BucketCollectors with a MultiBucketCollector. This method works as follows:

• Filters out the BucketCollector.NO_OP_BUCKET_COLLECTORs collectors, so they are not used during search time.
• If the input contains 1 real collector we wrap it in a collector that takes terminateIfNoop into account.
• Otherwise the method returns a MultiBucketCollector which wraps the non-BucketCollector.NO_OP_BUCKET_COLLECTOR collectors.

Parameters:

terminateIfNoop - Pass true if getLeafCollector(org.elasticsearch.search.aggregations.AggregationExecutionContext) should throw CollectionTerminatedException if all leaf collectors are noop. Pass false if terminating would break stuff. The top level collection for aggregations should pass true here because we want to skip collections if all aggregations return NOOP. But when aggregtors themselves call this method they chould *generally* pass false here because they have collection actions to perform even if their sub-aggregators are NOOPs.

scoreMode

public org.apache.lucene.search.ScoreMode scoreMode()

Description copied from class: BucketCollector

Indicates what features are required from the scorer.

Specified by:

scoreMode in class BucketCollector

preCollection

public void preCollection()
                   throws IOException

Description copied from class: BucketCollector

Pre collection callback.

Specified by:

preCollection in class BucketCollector

Throws:

IOException

postCollection

public void postCollection()
                    throws IOException

Description copied from class: BucketCollector

Post-collection callback.

Specified by:

postCollection in class BucketCollector

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

getLeafCollector

public LeafBucketCollector getLeafCollector(AggregationExecutionContext aggCtx)
                                     throws IOException

Specified by:

getLeafCollector in class BucketCollector

Throws:

IOException