me.lemire.integercompression.differential

Class IntegratedBinaryPacking

java.lang.Object

me.lemire.integercompression.differential.IntegratedBinaryPacking

All Implemented Interfaces:

IntegratedIntegerCODEC, SkippableIntegratedIntegerCODEC, IntegerCODEC

public class IntegratedBinaryPacking
extends Object
implements IntegratedIntegerCODEC, SkippableIntegratedIntegerCODEC

Scheme based on a commonly used idea: can be extremely fast. You should only use this scheme on sorted arrays. Use BinaryPacking if you have unsorted arrays. It encodes integers in blocks of 32 integers. For arrays containing an arbitrary number of integers, you should use it in conjunction with another CODEC:

 IntegratedIntegerCODEC is = 
 new IntegratedComposition(new IntegratedBinaryPacking(), 
 new IntegratedVariableByte())
 

For details, please see

Daniel Lemire and Leonid Boytsov, Decoding billions of integers per second through vectorization Software: Practice & Experience http://onlinelibrary.wiley.com/doi/10.1002/spe.2203/abstract http://arxiv.org/abs/1209.2137

Daniel Lemire, Leonid Boytsov, Nathan Kurz, SIMD Compression and the Intersection of Sorted Integers http://arxiv.org/abs/1401.6399

Author:

Daniel Lemire

Constructor Summary

Constructors

Constructor and Description
IntegratedBinaryPacking()

Method Summary

Modifier and Type	Method and Description
void	compress(int[] in, IntWrapper inpos, int inlength, int[] out, IntWrapper outpos) Compress data from an array to another array.
void	headlessCompress(int[] in, IntWrapper inpos, int inlength, int[] out, IntWrapper outpos, IntWrapper initvalue) Compress data from an array to another array.
void	headlessUncompress(int[] in, IntWrapper inpos, int inlength, int[] out, IntWrapper outpos, int num, IntWrapper initvalue) Uncompress data from an array to another array.
String	toString()
void	uncompress(int[] in, IntWrapper inpos, int inlength, int[] out, IntWrapper outpos) Uncompress data from an array to another array.

Methods inherited from class java.lang.Object

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

Constructor Detail

IntegratedBinaryPacking

public IntegratedBinaryPacking()

Method Detail

compress

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

Description copied from interface: IntegerCODEC

Compress data from an array to another array. 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

Parameters:

in - input array

inpos - location in the input array

inlength - how many integers to compress

out - output array

outpos - where to write in the output array

uncompress

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

Description copied from interface: IntegerCODEC

Uncompress data from an array to another array. Both inpos and outpos parameters are modified to indicate new positions after read/write.

Specified by:

uncompress in interface IntegerCODEC

Parameters:

in - array containing data in compressed form

inpos - where to start reading in the array

inlength - length of the compressed data (ignored by some schemes)

out - array where to write the compressed output

outpos - where to write the compressed output in out

toString

public String toString()

Overrides:

toString in class Object

headlessCompress

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

Description copied from interface: SkippableIntegratedIntegerCODEC

Compress data from an array to another array. 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:

headlessCompress in interface SkippableIntegratedIntegerCODEC

Parameters:

in - input array

inpos - location in the input array

inlength - how many integers to compress

out - output array

outpos - where to write in the output array

initvalue - initial value for the purpose of differential coding, the value is automatically updated

headlessUncompress

public void headlessUncompress(int[] in,
                               IntWrapper inpos,
                               int inlength,
                               int[] out,
                               IntWrapper outpos,
                               int num,
                               IntWrapper initvalue)

Description copied from interface: SkippableIntegratedIntegerCODEC

Uncompress data from an array to another array. Both inpos and outpos parameters are modified to indicate new positions after read/write.

Specified by:

headlessUncompress in interface SkippableIntegratedIntegerCODEC

Parameters:

in - array containing data in compressed form

inpos - where to start reading in the array

inlength - length of the compressed data (ignored by some schemes)

out - array where to write the compressed output

outpos - where to write the compressed output in out

num - number of integers we want to decode, the actual number of integers decoded can be less

initvalue - initial value for the purpose of differential coding, the value is automatically updated