ca.randolf.math

Class BitTools

Object

ca.randolf.math.BitTools

public class BitTools
extends Object

This class provides static methods that make it easier to work with groups of bits. Since working with individual bits is relatively easy, our emphasis is primarily on groups of bits.

Field Summary

Fields

Modifier and Type	Field and Description
static String	VERSION Version number of this Package (read-only).

Method Summary

Modifier and Type	Method and Description
static long	extract(byte[] value, int pos, int bits) Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.
static long	extract(byte[] value, int elem, int pos, int bits) Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.
static int	extract(int value, int pos, int bits) Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.
static long	extract(long value, int pos, int bits) Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.

Methods inherited from class Object

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

Field Detail

VERSION

public static final String VERSION

Version number of this Package (read-only).

See Also:

Constant Field Values

Method Detail

extract

public static long extract(byte[] value,
                           int pos,
                           int bits)

Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.

Note: The value is treated as an unsigned long.

Parameters:

value - The original number, which is in the form of a byte[] array in the range of 0 to 8 bytes (additional bytes will be ignored), to extract the bits from

pos - Position (0=first/right-most bit representing a value of 1)

bits - Number of bits to extract

Returns:

Extracted bits, shifted all the way to the right

extract

public static long extract(byte[] value,
                           int elem,
                           int pos,
                           int bits)

Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.

Note: The value is treated as an unsigned long.

Parameters:

value - The original number, which is in the form of a byte[] array in the range of 0 to 8 bytes (additional bytes will be ignored), to extract the bits from

elem - Array element to start from (first element is 0)

pos - Position (0=first/right-most bit representing a value of 1)

bits - Number of bits to extract

Returns:

Extracted bits, shifted all the way to the right

extract

public static int extract(int value,
                          int pos,
                          int bits)

Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.

Note: The value is treated as an unsigned integer.

Parameters:

value - The original number to extract the bits from

pos - Position (0=first/right-most bit representing a value of 1)

bits - Number of bits to extract

Returns:

Extracted bits, shifted all the way to the right

extract

public static long extract(long value,
                           int pos,
                           int bits)

Retrieves the specified number of bits starting from position pos, then shifts them to all the way to the right where the right-most bit represents the value of 1.

Note: The value is treated as an unsigned long.

Parameters:

value - The original number to extract the bits from

pos - Position (0=first/right-most bit representing a value of 1)

bits - Number of bits to extract

Returns:

Extracted bits, shifted all the way to the right