Module org.elasticsearch.server

Package org.elasticsearch.search.aggregations.metrics

Class NonCollectingSingleMetricAggregator

java.lang.Object

org.elasticsearch.search.aggregations.BucketCollector

org.elasticsearch.search.aggregations.Aggregator

org.elasticsearch.search.aggregations.AggregatorBase

org.elasticsearch.search.aggregations.metrics.MetricsAggregator

org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator

org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator.SingleValue

org.elasticsearch.search.aggregations.metrics.NonCollectingSingleMetricAggregator

All Implemented Interfaces:

Closeable, AutoCloseable, Releasable

public final class NonCollectingSingleMetricAggregator
extends NumericMetricsAggregator.SingleValue

An NumericMetricsAggregator.SingleValue that is not collected, this can typically be used when running an aggregation over a field that doesn't have a mapping. see NonCollectingAggregator

Nested Class Summary

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

NumericMetricsAggregator.MultiValue, NumericMetricsAggregator.SingleValue

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

Aggregator.BucketComparator, Aggregator.Parser, Aggregator.SubAggCollectionMode

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

BucketCollector.BucketCollectorWrapper

Field Summary

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_BUCKET_COLLECTOR, NO_OP_COLLECTOR

Constructor Summary

Constructors

Constructor	Description
NonCollectingSingleMetricAggregator(String name, AggregationContext context, Aggregator parent, InternalNumericMetricsAggregation.SingleValue emptyAggregation, Map<String,Object> metadata)	Build a NonCollectingSingleMetricAggregator for NumericMetricsAggregator.SingleValue aggregators.

Method Summary

Modifier and Type	Method	Description
InternalAggregation	buildAggregation(long owningBucketOrd)	Build an aggregation for data that has been collected into owningBucketOrd.
InternalAggregation	buildEmptyAggregation()	Build an empty aggregation.
LeafBucketCollector	getLeafCollector(AggregationExecutionContext aggCtx, LeafBucketCollector sub)	Collect results for this leaf.
double	metric(long owningBucketOrd)

Methods inherited from class org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator.SingleValue

bucketComparator

Methods inherited from class org.elasticsearch.search.aggregations.metrics.MetricsAggregator

buildAggregations

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

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

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

buildTopLevel, collectDebugInfo, resolveSortPath, resolveSortPathOnValidAgg

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

Constructor Details

NonCollectingSingleMetricAggregator

public NonCollectingSingleMetricAggregator(String name,
 AggregationContext context,
 Aggregator parent,
 InternalNumericMetricsAggregation.SingleValue emptyAggregation,
 Map<String,Object> metadata)
                                    throws IOException

Build a NonCollectingSingleMetricAggregator for NumericMetricsAggregator.SingleValue aggregators.

Throws:

IOException

Method Details

getLeafCollector

public LeafBucketCollector getLeafCollector(AggregationExecutionContext aggCtx,
 LeafBucketCollector sub)

Description copied from class: AggregatorBase

Collect results for this leaf.

Most Aggregators will return a custom LeafBucketCollector that collects document information for every hit. Callers of this method will make sure to call collect for every hit. So any Aggregator that returns a customer LeafBucketCollector from this method runs at best O(hits) time. See the sum Aggregator for a fairly strait forward example of this.

Some Aggregators are able to correctly collect results on their own, without being iterated by the top level query or the rest of the aggregations framework. These aggregations collect what they need by calling methods on LeafReaderContext and then they return LeafBucketCollector.NO_OP_COLLECTOR to signal that they've done their own collection. These aggregations can do better than O(hits). See the min Aggregator for an example of an aggregation that does this. It happens to run in constant time in some cases.

In other cases MinAggregator can't get correct results by taking the constant time path so instead it returns a custom LeafBucketCollector. This is fairly common for aggregations that have these fast paths because most of these fast paths are only possible when the aggregation is at the root of the tree.

Its also useful to look at the filters Aggregator chooses whether or not it can use the fast path before building the Aggregator rather than on each leaf. Either is fine.

Specified by:

getLeafCollector in class AggregatorBase

buildAggregation

public InternalAggregation buildAggregation(long owningBucketOrd)
                                     throws IOException

Description copied from class: MetricsAggregator

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

Specified by:

buildAggregation in class MetricsAggregator

Throws:

IOException

buildEmptyAggregation

public InternalAggregation buildEmptyAggregation()

Description copied from class: Aggregator

Build an empty aggregation.

Specified by:

buildEmptyAggregation in class Aggregator

metric

public double metric(long owningBucketOrd)

Specified by:

metric in class NumericMetricsAggregator.SingleValue