Package org.elasticsearch.search.aggregations.metrics

Class AbstractLinearCounting

java.lang.Object
org.elasticsearch.search.aggregations.metrics.AbstractLinearCounting
public abstract class AbstractLinearCounting
extends java.lang.Object
Linear counter, implemented based on pseudo code from http://static.googleusercontent.com/media/research.google.com/fr//pubs/archive/40671.pdf and its appendix https://docs.google.com/document/d/1gyjfMHy43U9OWBXxfaeG-3MjGzejW1dlpyMwEYAAWEI/view?fullscreen Trying to understand what this class does without having read the paper is considered adventurous. The algorithm just keep a record of all distinct values provided encoded as an integer.

  • Nested Class Summary

    Nested Classes 
    Modifier and Type Class Description
    static interface  AbstractLinearCounting.HashesIterator
    Iterator over the hash values

  • Field Summary

    Fields 
    Modifier and Type Field Description
    static int MAX_PRECISION  
    static int MIN_PRECISION  
    protected int p  

  • Constructor Summary

    Constructors 
    Constructor Description
    AbstractLinearCounting​(int precision)  

  • Method Summary

    Modifier and Type Method Description
    protected abstract int addEncoded​(long bucketOrd, int encoded)
    Add encoded value to the linear counting.
    long cardinality​(long bucketOrd)
    Returns the current computed cardinality
    int collect​(long bucketOrd, long hash)  
    int precision()
    Precision of the algorithm
    protected abstract int size​(long bucketOrd)
    number of values in the counter.
    protected abstract AbstractLinearCounting.HashesIterator values​(long bucketOrd)
    return the current values in the counter.

    Methods inherited from class java.lang.Object

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

  • Field Details

  • Constructor Details

  • Method Details

    • addEncoded

      protected abstract int addEncoded​(long bucketOrd, int encoded)
      Add encoded value to the linear counting. Implementor should only accept the value if it has not been seen before.

    • size

      protected abstract int size​(long bucketOrd)
      number of values in the counter.

    • values

      protected abstract AbstractLinearCounting.HashesIterator values​(long bucketOrd)
      return the current values in the counter.

    • collect

      public int collect​(long bucketOrd, long hash)

    • cardinality

      public long cardinality​(long bucketOrd)
      Returns the current computed cardinality

    • precision

      public int precision()
      Precision of the algorithm