me.lemire.integercompression
Class FastPFOR

java.lang.Object
  me.lemire.integercompression.FastPFOR

All Implemented Interfaces:

IntegerCODEC

public final class FastPFOR
extends Object
implements IntegerCODEC

This is a new PFOR Scheme designed by D. Lemire called FastPFOR.

For details, please see

Daniel Lemire and Leonid Boytsov, Decoding billions of integers per second through vectorization http://arxiv.org/abs/1209.2137

For sufficiently compressible arrays, it is faster and better than other PFOR schemes.

Author:

Daniel Lemire

Constructor Summary

FastPFOR()

FastPFOR(int pagesize)

Method Summary

void	compress(int[] in, IntWrapper inpos, int inlength, int[] out, IntWrapper outpos) Both inpos and outpos are modified to represent how much data was read and written to if 12 ints (inlength = 12) are compressed to 3 ints, then inpos will be incremented by 12 while outpos will be incremented by 3 we use IntWrapper to pass the values by reference.
static void	getBestBFromData(int[] in, int pos, byte[] bestbbestcexceptmaxb)
void	initArrays()
String	toString()
void	uncompress(int[] in, IntWrapper inpos, int inlength, int[] out, IntWrapper outpos)

Methods inherited from class java.lang.Object

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

Constructor Detail

FastPFOR

public FastPFOR(int pagesize)

FastPFOR

public FastPFOR()

Method Detail

initArrays

public void initArrays()

compress

public void compress(int[] in,
                     IntWrapper inpos,
                     int inlength,
                     int[] out,
                     IntWrapper outpos)

Description copied from interface: IntegerCODEC

Both inpos and outpos are modified to represent how much data was read and written to if 12 ints (inlength = 12) are compressed to 3 ints, then inpos will be incremented by 12 while outpos will be incremented by 3 we use IntWrapper to pass the values by reference.

Specified by:

compress in interface IntegerCODEC

getBestBFromData

public static void getBestBFromData(int[] in,
                                    int pos,
                                    byte[] bestbbestcexceptmaxb)

uncompress

public void uncompress(int[] in,
                       IntWrapper inpos,
                       int inlength,
                       int[] out,
                       IntWrapper outpos)

Specified by:

uncompress in interface IntegerCODEC

toString

public String toString()

Overrides:

toString in class Object