Package org.elasticsearch.search.aggregations

Class LeafBucketCollector

java.lang.Object
org.elasticsearch.search.aggregations.LeafBucketCollector
All Implemented Interfaces:
org.apache.lucene.search.LeafCollector
Direct Known Subclasses:
LeafBucketCollectorBase, ProfilingLeafBucketCollector
public abstract class LeafBucketCollector
extends java.lang.Object
implements org.apache.lucene.search.LeafCollector
Per-leaf bucket collector.

  • Field Summary

    Fields
    Modifier and Type Field Description
    static LeafBucketCollector NO_OP_COLLECTOR  

  • Constructor Summary

    Constructors
    Constructor Description
    LeafBucketCollector()  

  • Method Summary

    Modifier and Type Method Description
    void collect​(int doc)  
    abstract void collect​(int doc, long owningBucketOrd)
    Collect the given doc in the bucket owned by owningBucketOrd.
    void setScorer​(org.apache.lucene.search.Scorable scorer)  
    static LeafBucketCollector wrap​(java.lang.Iterable<LeafBucketCollector> collectors)  

    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

  • Field Details

  • Constructor Details

    • LeafBucketCollector

      public LeafBucketCollector()

  • Method Details

    • wrap

      public static LeafBucketCollector wrap​(java.lang.Iterable<LeafBucketCollector> collectors)

    • collect

      public abstract void collect​(int doc, long owningBucketOrd) throws java.io.IOException
      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.
      Throws:
      java.io.IOException

    • collect

      public final void collect​(int doc) throws java.io.IOException
      Specified by:
      collect in interface org.apache.lucene.search.LeafCollector
      Throws:
      java.io.IOException

    • setScorer

      public void setScorer​(org.apache.lucene.search.Scorable scorer) throws java.io.IOException
      Specified by:
      setScorer in interface org.apache.lucene.search.LeafCollector
      Throws:
      java.io.IOException