me.lemire.integercompression
Class XorBinaryPacking

java.lang.Object
  me.lemire.integercompression.XorBinaryPacking

All Implemented Interfaces:

IntegerCODEC, IntegratedIntegerCODEC

public final class XorBinaryPacking
extends Object
implements IntegratedIntegerCODEC

XOR + BinaryPacking.

Author:

MURAOKA Taro http://github.com/koron

Field Summary

static int	BLOCK_LENGTH
static boolean	DEBUG_DISABLE_BITPACKING A flag for debugging.

Constructor Summary

XorBinaryPacking()

Method Summary

void	compress(int[] inBuf, IntWrapper inPos, int inLen, int[] outBuf, IntWrapper outPos) Compress data from an array to another array.
String	toString()
void	uncompress(int[] inBuf, IntWrapper inPos, int inLen, int[] outBuf, IntWrapper outPos) Uncompress data from an array to another array.
static int	xorMaxBits(int[] buf, int offset, int length, int context)
static int	xorPack(int[] inBuf, int inOff, int[] outBuf, int outOff, int validBits, int context, int[] work)
static int	xorUnpack(int[] inBuf, int inOff, int[] outBuf, int outOff, int validBits, int context, int[] work)

Methods inherited from class java.lang.Object

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

Field Detail

DEBUG_DISABLE_BITPACKING

public static final boolean DEBUG_DISABLE_BITPACKING

A flag for debugging.

See Also:

Constant Field Values

BLOCK_LENGTH

public static final int BLOCK_LENGTH

See Also:

Constant Field Values

Constructor Detail

XorBinaryPacking

public XorBinaryPacking()

Method Detail

compress

public void compress(int[] inBuf,
                     IntWrapper inPos,
                     int inLen,
                     int[] outBuf,
                     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:

inBuf - input array

inPos - location in the input array

inLen - how many integers to compress

outBuf - output array

outPos - where to write in the output array

uncompress

public void uncompress(int[] inBuf,
                       IntWrapper inPos,
                       int inLen,
                       int[] outBuf,
                       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:

inBuf - array containing data in compressed form

inPos - where to start reading in the array

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

outBuf - 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

xorMaxBits

public static int xorMaxBits(int[] buf,
                             int offset,
                             int length,
                             int context)

xorPack

public static int xorPack(int[] inBuf,
                          int inOff,
                          int[] outBuf,
                          int outOff,
                          int validBits,
                          int context,
                          int[] work)

xorUnpack

public static int xorUnpack(int[] inBuf,
                            int inOff,
                            int[] outBuf,
                            int outOff,
                            int validBits,
                            int context,
                            int[] work)