Package org.elasticsearch.search.aggregations.bucket.sampler.random

Class RandomSamplerAggregator

java.lang.Object

org.elasticsearch.search.aggregations.BucketCollector

org.elasticsearch.search.aggregations.Aggregator

org.elasticsearch.search.aggregations.AggregatorBase

org.elasticsearch.search.aggregations.bucket.BucketsAggregator

org.elasticsearch.search.aggregations.bucket.sampler.random.RandomSamplerAggregator

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.lucene.search.Collector, org.elasticsearch.core.Releasable, SingleBucketAggregator

public class RandomSamplerAggregator
extends BucketsAggregator
implements SingleBucketAggregator

Nested Class Summary

Nested classes/interfaces inherited from class org.elasticsearch.search.aggregations.bucket.BucketsAggregator

BucketsAggregator.BucketBuilderForFixedCount<B>, BucketsAggregator.BucketBuilderForVariable<B>, BucketsAggregator.ResultBuilderForVariable<B>, BucketsAggregator.SingleBucketResultBuilder

Nested classes/interfaces inherited from class org.elasticsearch.search.aggregations.Aggregator

Aggregator.BucketComparator, Aggregator.Parser, Aggregator.SubAggCollectionMode

Field Summary

Fields inherited from class org.elasticsearch.search.aggregations.bucket.BucketsAggregator

docCountProvider

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

collectableSubAggregators, DEFAULT_WEIGHT, name, parent, subAggregators

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

NO_OP_COLLECTOR

Method Summary

Modifier and Type	Method	Description
InternalAggregation[]	buildAggregations(long[] owningBucketOrds)	Build the results of this aggregation.
InternalAggregation	buildEmptyAggregation()	Build an empty aggregation.
protected LeafBucketCollector	getLeafCollector(org.apache.lucene.index.LeafReaderContext ctx, LeafBucketCollector sub)	This is an optimized leaf collector that iterates the documents provided the RandomSamplingQuery directly.

Methods inherited from class org.elasticsearch.search.aggregations.bucket.BucketsAggregator

bucketComparator, bucketDocCount, buildAggregationsForFixedBucketCount, buildAggregationsForSingleBucket, buildAggregationsForVariableBuckets, buildSubAggsForAllBuckets, buildSubAggsForBuckets, buildSubAggsForBuckets, close, collectBucket, collectExistingBucket, descendsFromGlobalAggregator, getDocCounts, grow, incrementBucketDocCount, maxBucketOrd, preGetSubLeafCollectors, prepareSubAggs, resolveSortPath, rewriteBuckets

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

addRequestCircuitBreakerBytes, bigArrays, buildEmptySubAggregations, doClose, doPostCollection, doPreCollection, getLeafCollector, metadata, name, parent, pointReaderIfAvailable, postCollection, preCollection, scoreMode, searcher, subAggregator, subAggregators, topLevelQuery, toString

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

buildTopLevel, collectDebugInfo, resolveSortPathOnValidAgg

Methods inherited from class java.lang.Object

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

Method Details

buildAggregations

public InternalAggregation[] buildAggregations(long[] owningBucketOrds)
                                        throws IOException

Description copied from class: Aggregator

Build the results of this aggregation.

Specified by:

buildAggregations in class Aggregator

Parameters:

owningBucketOrds - the ordinals of the buckets that we want to collect from this aggregation

Returns:

the results for each ordinal, in the same order as the array of ordinals

Throws:

IOException

buildEmptyAggregation

public InternalAggregation buildEmptyAggregation()

Description copied from class: Aggregator

Build an empty aggregation.

Specified by:

buildEmptyAggregation in class Aggregator

getLeafCollector

protected LeafBucketCollector getLeafCollector(org.apache.lucene.index.LeafReaderContext ctx,
 LeafBucketCollector sub)
                                        throws IOException

This is an optimized leaf collector that iterates the documents provided the RandomSamplingQuery directly. Instead of sampling in the foreground (i.e. iterating the documents as they are matched by the AggregatorBase.topLevelQuery()), iterating the document set returned by RandomSamplingQuery directly allows this aggregation to sample documents in the background. This provides a dramatic speed improvement, especially when a non-trivial AggregatorBase.topLevelQuery() is provided.

Specified by:

getLeafCollector in class AggregatorBase

Parameters:

ctx - reader context

sub - collector

Returns:

this always returns LeafBucketCollector.NO_OP_COLLECTOR

Throws:

IOException - when building the query or extracting docs fails