org.sindice.siren.index.codecs.block

Class BlockDecompressor

java.lang.Object

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

Direct Known Subclasses:

AForBlockDecompressor, VIntBlockDecompressor

public abstract class BlockDecompressor
extends Object

Abstraction over the block decompression algorithm.

Constructor Summary

Constructors

Constructor and Description
BlockDecompressor()

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	decompress(org.apache.lucene.util.BytesRef input, org.apache.lucene.util.IntsRef output) Decompress the specified byte array into a list of integers.
abstract 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

Constructor Detail

BlockDecompressor

public BlockDecompressor()

Method Detail

getWindowSize

public abstract int getWindowSize()

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.

decompress

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

Decompress the specified byte array into a list of integers.