org.apache.activemq.artemis.utils

Class PowerOf2Util

java.lang.Object

org.apache.activemq.artemis.utils.PowerOf2Util

public final class PowerOf2Util
extends Object

Collection of bit-tricks for power of 2 cases.

Method Summary

Modifier and Type	Method and Description
static int	align(int value, int pow2alignment) Fast alignment operation with power of 2 alignment and value >=0 and value <Integer.MAX_VALUE. In order to be fast is up to the caller to check arguments correctness.
static boolean	isAligned(long value, int pow2alignment) Test if a value is pow2alignment-aligned.
static boolean	isPowOf2(int value) Is a value a positive power of two.

Methods inherited from class java.lang.Object

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

Method Detail

align

public static int align(int value,
                        int pow2alignment)

Fast alignment operation with power of 2 alignment and value >=0 and value <Integer.MAX_VALUE.
In order to be fast is up to the caller to check arguments correctness. Original algorithm is on https://en.wikipedia.org/wiki/Data_structure_alignment.

isPowOf2

public static boolean isPowOf2(int value)

Is a value a positive power of two.

Parameters:

value - to be checked.

Returns:

true if the number is a positive power of two otherwise false.

isAligned

public static boolean isAligned(long value,
                                int pow2alignment)

Test if a value is pow2alignment-aligned.

Parameters:

value - to be tested.

pow2alignment - boundary the address is tested against.

Returns:

true if the address is on the aligned boundary otherwise false.

Throws:

IllegalArgumentException - if the alignment is not a power of 2