org.terrier.compression
Class BitUtilities

java.lang.Object
  org.terrier.compression.BitUtilities

public class BitUtilities
extends java.lang.Object

Utility methods for use in the BitFile classes.

Since:

2.0

Author:

Craig Macdonald

Field Summary

static int[]

MSB_BYTES Array of output of mostSignficantBit(byte) for quicker lookups

Constructor Summary

BitUtilities()

Method Summary

static int	mostSignficantBit_Loop(int x) Returns the most significant bit for any positive integer, 0 for -1.
static int	mostSignificantBit(byte x) Returns the most significant bit for any byte value.
static int	mostSignificantBit(int x) Returns the most significant bit for any positive integer.

Methods inherited from class java.lang.Object

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

Field Detail

MSB_BYTES

public static final int[] MSB_BYTES

Array of output of mostSignficantBit(byte) for quicker lookups

Constructor Detail

BitUtilities

public BitUtilities()

Method Detail

mostSignficantBit_Loop

public static int mostSignficantBit_Loop(int x)

Returns the most significant bit for any positive integer, 0 for -1. Computed by iteration

mostSignificantBit

public static int mostSignificantBit(int x)

Returns the most significant bit for any positive integer. 0 for -1. Computed by hard-coded binary search.

mostSignificantBit

public static int mostSignificantBit(byte x)

Returns the most significant bit for any byte value. 0 gives MSB -1.