org.apache.lucene.facet.encoding
Class DGapIntEncoder

java.lang.Object
  extended by org.apache.lucene.facet.encoding.IntEncoder
      extended by org.apache.lucene.facet.encoding.IntEncoderFilter
          extended by org.apache.lucene.facet.encoding.DGapIntEncoder

public final class DGapIntEncoder
extends IntEncoderFilter

An IntEncoderFilter which encodes the gap between the given values, rather than the values themselves. This encoder usually yields better encoding performance space-wise (i.e., the final encoded values consume less space) if the values are 'close' to each other.

NOTE: this encoder assumes the values are given to encode(IntsRef, BytesRef) in an ascending sorted manner, which ensures only positive values are encoded and thus yields better performance. If you are not sure whether the values are sorted or not, it is possible to chain this encoder with SortingIntEncoder to ensure the values will be sorted before encoding.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary
 
Fields inherited from class org.apache.lucene.facet.encoding.IntEncoderFilter
encoder
 
Constructor Summary
DGapIntEncoder(IntEncoder encoder)
          Initializes with the given encoder.
 
Method Summary
 IntDecoder createMatchingDecoder()
          Returns an IntDecoder which can decode the values that were encoded with this encoder.
 void encode(IntsRef values, BytesRef buf)
          Encodes the values to the given buffer.
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

DGapIntEncoder

public DGapIntEncoder(IntEncoder encoder)
Initializes with the given encoder.

Method Detail

encode

public void encode(IntsRef values,
                   BytesRef buf)
Description copied from class: IntEncoder
Encodes the values to the given buffer. Note that the buffer's offset and length are set to 0.

Specified by:
encode in class IntEncoder

createMatchingDecoder

public IntDecoder createMatchingDecoder()
Description copied from class: IntEncoder
Returns an IntDecoder which can decode the values that were encoded with this encoder.

Specified by:
createMatchingDecoder in class IntEncoder

toString

public String toString()
Overrides:
toString in class Object


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