Class UniqueValuesIntEncoder

  extended by org.apache.lucene.util.encoding.IntEncoder
      extended by org.apache.lucene.util.encoding.IntEncoderFilter
          extended by org.apache.lucene.util.encoding.UniqueValuesIntEncoder

public final class UniqueValuesIntEncoder
extends IntEncoderFilter

An IntEncoderFilter which ensures only unique values are encoded. The implementation assumes the values given to encode(int) are sorted. If this is not the case, you can chain this encoder with SortingIntEncoder.

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

Field Summary
Fields inherited from class org.apache.lucene.util.encoding.IntEncoderFilter
Fields inherited from class org.apache.lucene.util.encoding.IntEncoder
Constructor Summary
UniqueValuesIntEncoder(IntEncoder encoder)
          Constructs a new instance with the given encoder.
Method Summary
 IntDecoder createMatchingDecoder()
          Returns an IntDecoder which matches this encoder.
 void encode(int value)
          Encodes an integer to the output stream given in reInit
 void reInit(OutputStream out)
          Reinitializes the encoder with the give OutputStream.
 String toString()
Methods inherited from class org.apache.lucene.util.encoding.IntEncoderFilter
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail


public UniqueValuesIntEncoder(IntEncoder encoder)
Constructs a new instance with the given encoder.

Method Detail


public void encode(int value)
            throws IOException
Description copied from class: IntEncoder
Encodes an integer to the output stream given in reInit

Specified by:
encode in class IntEncoder


public IntDecoder createMatchingDecoder()
Description copied from class: IntEncoder
Returns an IntDecoder which matches this encoder. Every encoder must return an IntDecoder and null is not a valid value. If an encoder is just a filter, it should at least return its wrapped encoder's matching decoder.

NOTE: this method should create a new instance of the matching decoder and leave the instance sharing to the caller. Returning the same instance over and over is risky because encoders and decoders are not thread safe.

Specified by:
createMatchingDecoder in class IntEncoder


public void reInit(OutputStream out)
Description copied from class: IntEncoder
Reinitializes the encoder with the give OutputStream. For re-usability it can be changed without the need to reconstruct a new object.

NOTE: after calling IntEncoder.close(), one must call this method even if the output stream itself hasn't changed. An example case is that the output stream wraps a byte[], and the output stream itself is reset, but its instance hasn't changed. Some implementations of IntEncoder may write some metadata about themselves to the output stream, and therefore it is imperative that one calls this method before encoding any data.

reInit in class IntEncoderFilter


public String toString()
toString in class Object

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