Package me.lemire.integercompression

Class Composition

java.lang.Object

me.lemire.integercompression.Composition

All Implemented Interfaces:

IntegerCODEC

public class Composition
extends Object
implements IntegerCODEC

Helper class to compose schemes.

Author:

Daniel Lemire

Constructor Summary

Constructors

Constructor	Description
Composition(IntegerCODEC f1, IntegerCODEC f2)	Compose a scheme from a first one (f1) and a second one (f2).

Method Summary

Modifier and Type	Method	Description
void	compress(int[] in, IntWrapper inpos, int inlength, int[] out, IntWrapper outpos)	Compress 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 Details

Composition

public Composition(IntegerCODEC f1,
 IntegerCODEC f2)

Compose a scheme from a first one (f1) and a second one (f2). The first one is called first and then the second one tries to compress whatever remains from the first run. By convention, the first scheme should be such that if, during decoding, a 32-bit zero is first encountered, then there is no output.

Parameters:

f1 - first codec

f2 - second codec

Method Details

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 - where to start reading in the 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 start writing the uncompressed output in out

toString

public String toString()

Overrides:

toString in class Object