org.sindice.siren.index.codecs.block

Class AForBlockDecompressor

java.lang.Object

org.sindice.siren.index.codecs.block.BlockDecompressor

org.sindice.siren.index.codecs.block.AForBlockDecompressor

public class AForBlockDecompressor
extends BlockDecompressor

Implementation of BlockDecompressor based on the Adaptive Frame Of Reference algorithm.

See Also:

AForBlockCompressor

Field Summary

Fields

Modifier and Type	Field and Description
protected org.sindice.siren.index.codecs.block.AForFrameDecompressor.FrameDecompressor[]	decompressors

Constructor Summary

Constructors

Constructor and Description
AForBlockDecompressor()

Method Summary

Methods

Modifier and Type	Method and Description
void	decompress(org.apache.lucene.util.BytesRef input, org.apache.lucene.util.IntsRef output) Decompress the specified byte array into a list of integers.
int	getWindowSize() Return the window size over the IntsRef output buffer used during decompression.

Methods inherited from class java.lang.Object

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

Field Detail

decompressors

protected final org.sindice.siren.index.codecs.block.AForFrameDecompressor.FrameDecompressor[] decompressors

Constructor Detail

AForBlockDecompressor

public AForBlockDecompressor()

Method Detail

decompress

public void decompress(org.apache.lucene.util.BytesRef input,
              org.apache.lucene.util.IntsRef output)

Description copied from class: BlockDecompressor

Decompress the specified byte array into a list of integers.

Specified by:

decompress in class BlockDecompressor

getWindowSize

public int getWindowSize()

Description copied from class: BlockDecompressor

Return the window size over the IntsRef output buffer used during decompression.

This is to avoid ArrayIndexOutOfBoundsException if the decompressor is working on a buffer which size does not match a multiple of the window size.

For example, AForBlockDecompressor is performing decompression using a window of 32 integers. In the case of short postings list with 5 integers, the instantiated output buffer must be a multiple of window size, i.e., 32 in this case. If the postings list would contain 33 integers instead, then the instantiated output buffer should be 64.

Specified by:

getWindowSize in class BlockDecompressor