Module org.elasticsearch.server

Package org.elasticsearch.search.aggregations

Class LeafBucketCollectorBase

java.lang.Object

org.elasticsearch.search.aggregations.LeafBucketCollector

org.elasticsearch.search.aggregations.LeafBucketCollectorBase

All Implemented Interfaces:

org.apache.lucene.search.LeafCollector

public class LeafBucketCollectorBase
extends LeafBucketCollector

A LeafBucketCollector that delegates all calls to the sub leaf aggregator and sets the scorer on its source of values if it implements ScorerAware.

Field Summary

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

NO_OP_COLLECTOR

Constructor Summary

Constructors

Constructor	Description
LeafBucketCollectorBase(LeafBucketCollector sub, Object values)

Method Summary

Modifier and Type	Method	Description
void	collect(int doc, long bucket)	Collect the given doc in the bucket owned by owningBucketOrd.
void	setScorer(org.apache.lucene.search.Scorable s)

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

collect, isNoop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.search.LeafCollector

competitiveIterator

Constructor Details

LeafBucketCollectorBase

public LeafBucketCollectorBase(LeafBucketCollector sub,
 Object values)

Parameters:

sub - The leaf collector for sub aggregations.

values - The values. ScorerAware.setScorer(org.apache.lucene.search.Scorable) will be called automatically on them if they implement ScorerAware.

Method Details

setScorer

public void setScorer(org.apache.lucene.search.Scorable s)
               throws IOException

Specified by:

setScorer in interface org.apache.lucene.search.LeafCollector

Overrides:

setScorer in class LeafBucketCollector

Throws:

IOException

collect

public void collect(int doc,
 long bucket)
             throws IOException

Description copied from class: LeafBucketCollector

Collect the given doc in the bucket owned by owningBucketOrd.

The implementation of this method metric aggregations is generally something along the lines of

 array[owningBucketOrd] += loadValueFromDoc(doc)
 

Bucket aggregations have more trouble because their job is to make new ordinals. So their implementation generally looks kind of like

 long myBucketOrd = mapOwningBucketAndValueToMyOrd(owningBucketOrd, loadValueFromDoc(doc));
 collectBucket(doc, myBucketOrd);
 

Some bucket aggregations "know" how many ordinals each owning ordinal needs so they can map "densely". The range aggregation, for example, can perform this mapping with something like:

 return rangeCount * owningBucketOrd + matchingRange(value);
 

Other aggregations don't know how many buckets will fall into any particular owning bucket. The terms aggregation, for example, uses LongKeyedBucketOrds which amounts to a hash lookup.

Specified by:

collect in class LeafBucketCollector

Throws:

IOException