me.lemire.integercompression

Class S9

java.lang.Object

me.lemire.integercompression.S9

public final class S9
extends Object

This is a version of Simple9 optimized for NewPFOR, OptPFOR

Adapted by D. Lemire from the Apache Lucene project.

Author:

Daniel Lemire

Constructor Summary

Constructors

Constructor and Description
S9()

Method Summary

Modifier and Type	Method and Description
static int	compress(int[] in, int currentPos, int inlength, int[] out, int tmpoutpos) Compress an integer array using Simple9
static int	estimatecompress(int[] in, int currentPos, int inlength) Estimate size of the compressed output.
static void	uncompress(int[] in, int tmpinpos, int inlength, int[] out, int currentPos, int outlength) Uncompressed data from an input array into an output array

Methods inherited from class java.lang.Object

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

Constructor Detail

S9

public S9()

Method Detail

estimatecompress

public static int estimatecompress(int[] in,
                                   int currentPos,
                                   int inlength)

Estimate size of the compressed output.

Parameters:

in - array to compress

currentPos - where to start reading

inlength - how many integers to read

Returns:

estimated size of the output (in 32-bit integers)

compress

public static int compress(int[] in,
                           int currentPos,
                           int inlength,
                           int[] out,
                           int tmpoutpos)

Compress an integer array using Simple9

Parameters:

in - array to compress

currentPos - where to start reading

inlength - how many integers to read

out - output array

tmpoutpos - location in the output array

Returns:

the number of 32-bit words written (in compressed form)

uncompress

public static void uncompress(int[] in,
                              int tmpinpos,
                              int inlength,
                              int[] out,
                              int currentPos,
                              int outlength)

Uncompressed data from an input array into an output array

Parameters:

in - input array (in compressed form)

tmpinpos - starting location in the compressed input array

inlength - how much data we wish the read (in 32-bit words)

out - output array (in decompressed form)

currentPos - current position in the output array

outlength - available data in the output array