Package com.lmax.disruptor.util

Class Util

java.lang.Object

com.lmax.disruptor.util.Util

public final class Util
extends Object

Set of common functions used by the Disruptor

Constructor Summary

Constructors

Constructor	Description
Util()

Method Summary

Modifier and Type	Method	Description
static int	ceilingNextPowerOfTwo(int x)	Calculate the next power of 2, greater than or equal to x.
static long	getAddressFromDirectByteBuffer(ByteBuffer buffer)	Gets the address value for the memory that backs a direct byte buffer.
static long	getMinimumSequence(Sequence[] sequences)	Get the minimum sequence from an array of Sequences.
static long	getMinimumSequence(Sequence[] sequences, long minimum)	Get the minimum sequence from an array of Sequences.
static Sequence[]	getSequencesFor(EventProcessor... processors)	Get an array of Sequences for the passed EventProcessors
static sun.misc.Unsafe	getUnsafe()	Get a handle on the Unsafe instance, used for accessing low-level concurrency and memory constructs.
static int	log2(int i)	Calculate the log base 2 of the supplied integer, essentially reports the location of the highest bit.

Methods inherited from class java.lang.Object

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

Constructor Detail

Util

public Util()

Method Detail

ceilingNextPowerOfTwo

public static int ceilingNextPowerOfTwo(int x)

Calculate the next power of 2, greater than or equal to x.

From Hacker's Delight, Chapter 3, Harry S. Warren Jr.

Parameters:

x - Value to round up

Returns:

The next power of 2 from x inclusive

getMinimumSequence

public static long getMinimumSequence(Sequence[] sequences)

Get the minimum sequence from an array of Sequences.

Parameters:

sequences - to compare.

Returns:

the minimum sequence found or Long.MAX_VALUE if the array is empty.

getMinimumSequence

public static long getMinimumSequence(Sequence[] sequences,
                                      long minimum)

Get the minimum sequence from an array of Sequences.

Parameters:

sequences - to compare.

minimum - an initial default minimum. If the array is empty this value will be returned.

Returns:

the smaller of minimum sequence value found in sequences and minimum; minimum if sequences is empty

getSequencesFor

public static Sequence[] getSequencesFor(EventProcessor... processors)

Get an array of Sequences for the passed EventProcessors

Parameters:

processors - for which to get the sequences

Returns:

the array of Sequences

getUnsafe

public static sun.misc.Unsafe getUnsafe()

Get a handle on the Unsafe instance, used for accessing low-level concurrency and memory constructs.

Returns:

The Unsafe

getAddressFromDirectByteBuffer

public static long getAddressFromDirectByteBuffer(ByteBuffer buffer)

Gets the address value for the memory that backs a direct byte buffer.

Parameters:

buffer -

Returns:

The system address for the buffers

log2

public static int log2(int i)

Calculate the log base 2 of the supplied integer, essentially reports the location of the highest bit.

Parameters:

i - Value to calculate log2 for.

Returns:

The log2 value