org.elasticsearch.search.aggregations.bucket.sampler

Class SamplerAggregator

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.SingleBucketAggregator

org.elasticsearch.search.aggregations.bucket.sampler.SamplerAggregator

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, org.apache.lucene.search.Collector, Releasable

Direct Known Subclasses:

DiversifiedBytesHashSamplerAggregator, DiversifiedMapSamplerAggregator, DiversifiedNumericSamplerAggregator, DiversifiedOrdinalsSamplerAggregator

public class SamplerAggregator
extends SingleBucketAggregator

Aggregate on only the top-scoring docs on a shard. TODO currently the diversity feature of this agg offers only 'script' and 'field' as a means of generating a de-dup value. In future it would be nice if users could use any of the "bucket" aggs syntax (geo, date histogram...) as the basis for generating de-dup values. Their syntax for creating bucket values would be preferable to users having to recreate this logic in a 'script' e.g. to turn a datetime in milliseconds into a month key value.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SamplerAggregator.ExecutionMode

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

Aggregator.Parser, Aggregator.SubAggCollectionMode

Field Summary

Fields

Modifier and Type	Field and Description
protected BestDocsDeferringCollector	bdd
static ParseField	EXECUTION_HINT_FIELD
static ParseField	MAX_DOCS_PER_VALUE_FIELD
static ParseField	SHARD_SIZE_FIELD
protected int	shardSize

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

collectableSubAggregators, context, DEFAULT_WEIGHT, name, parent, subAggregators

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

NO_OP_COLLECTOR

Constructor Summary

Constructors

Constructor and Description
SamplerAggregator(java.lang.String name, int shardSize, AggregatorFactories factories, SearchContext context, Aggregator parent, java.util.List<PipelineAggregator> pipelineAggregators, java.util.Map<java.lang.String,java.lang.Object> metaData)

Method Summary

Modifier and Type	Method and Description
InternalAggregation	buildAggregation(long owningBucketOrdinal) Build an aggregation for data that has been collected into bucket.
InternalAggregation	buildEmptyAggregation() Build an empty aggregation.
protected void	doClose() Release instance-specific data.
DeferringBucketCollector	getDeferringCollector()
protected LeafBucketCollector	getLeafCollector(org.apache.lucene.index.LeafReaderContext ctx, LeafBucketCollector sub) Get a LeafBucketCollector for the given ctx, which should delegate to the given collector.
boolean	needsScores() Most aggregators don't need scores, make sure to extend this method if your aggregator needs them.
protected boolean	shouldDefer(Aggregator aggregator) This method should be overidden by subclasses that want to defer calculation of a child aggregation until a first pass is complete and a set of buckets has been pruned.

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

bucketAggregations, bucketDocCount, bucketEmptyAggregations, close, collectBucket, collectExistingBucket, getDocCounts, grow, incrementBucketDocCount, maxBucketOrd

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

buildEmptySubAggregations, context, doPostCollection, doPreCollection, getLeafCollector, metaData, name, parent, pipelineAggregators, postCollection, preCollection, runDeferredCollections, subAggregator, subAggregators, toString

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

descendsFromBucketAggregator

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

wrap

Methods inherited from class java.lang.Object

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

Field Detail

SHARD_SIZE_FIELD

public static final ParseField SHARD_SIZE_FIELD

MAX_DOCS_PER_VALUE_FIELD

public static final ParseField MAX_DOCS_PER_VALUE_FIELD

EXECUTION_HINT_FIELD

public static final ParseField EXECUTION_HINT_FIELD

shardSize

protected final int shardSize

bdd

protected BestDocsDeferringCollector bdd

Constructor Detail

SamplerAggregator

public SamplerAggregator(java.lang.String name,
                         int shardSize,
                         AggregatorFactories factories,
                         SearchContext context,
                         Aggregator parent,
                         java.util.List<PipelineAggregator> pipelineAggregators,
                         java.util.Map<java.lang.String,java.lang.Object> metaData)
                  throws java.io.IOException

Throws:

java.io.IOException

Method Detail

needsScores

public boolean needsScores()

Description copied from class: AggregatorBase

Most aggregators don't need scores, make sure to extend this method if your aggregator needs them.

Specified by:

needsScores in interface org.apache.lucene.search.Collector

Overrides:

needsScores in class AggregatorBase

getDeferringCollector

public DeferringBucketCollector getDeferringCollector()

Overrides:

getDeferringCollector in class AggregatorBase

shouldDefer

protected boolean shouldDefer(Aggregator aggregator)

Description copied from class: AggregatorBase

This method should be overidden by subclasses that want to defer calculation of a child aggregation until a first pass is complete and a set of buckets has been pruned. Deferring collection will require the recording of all doc/bucketIds from the first pass and then the sub class should call AggregatorBase.runDeferredCollections(long...) for the selected set of buckets that survive the pruning.

Overrides:

shouldDefer in class AggregatorBase

Parameters:

aggregator - the child aggregator

Returns:

true if the aggregator should be deferred until a first pass at collection has completed

buildAggregation

public InternalAggregation buildAggregation(long owningBucketOrdinal)
                                     throws java.io.IOException

Description copied from class: Aggregator

Build an aggregation for data that has been collected into bucket.

Specified by:

buildAggregation in class Aggregator

Throws:

java.io.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 java.io.IOException

Description copied from class: AggregatorBase

Get a LeafBucketCollector for the given ctx, which should delegate to the given collector.

Specified by:

getLeafCollector in class AggregatorBase

Throws:

java.io.IOException

doClose

protected void doClose()

Description copied from class: AggregatorBase

Release instance-specific data.

Overrides:

doClose in class AggregatorBase