org.apache.bookkeeper.common.util

Class MathUtils

java.lang.Object

org.apache.bookkeeper.common.util.MathUtils

Direct Known Subclasses:

MathUtils

public class MathUtils
extends java.lang.Object

Provides misc math functions that don't come standard.

Constructor Summary

Constructors

Constructor and Description
MathUtils()

Method Summary

Modifier and Type	Method and Description
static long	elapsedMicroSec(long startNanoTime) Microseconds elapsed since the time specified, the input is nanoTime the only conversion happens when computing the elapsed time.
static long	elapsedMSec(long startNanoTime) Milliseconds elapsed since the time specified, the input is nanoTime the only conversion happens when computing the elapsed time.
static long	elapsedNanos(long startNanoTime) Nanoseconds elapsed since the time specified, the input is nanoTime the only conversion happens when computing the elapsed time.
static int	findNextPositivePowerOfTwo(int value)
static long	nowInNano() Current time from some arbitrary time base in the past, counting in nanoseconds, and not affected by settimeofday or similar system clock changes.
static int	signSafeMod(long dividend, int divisor)

Methods inherited from class java.lang.Object

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

Constructor Detail

MathUtils

public MathUtils()

Method Detail

signSafeMod

public static int signSafeMod(long dividend,
                              int divisor)

findNextPositivePowerOfTwo

public static int findNextPositivePowerOfTwo(int value)

nowInNano

public static long nowInNano()

Current time from some arbitrary time base in the past, counting in nanoseconds, and not affected by settimeofday or similar system clock changes. This is appropriate to use when computing how much longer to wait for an interval to expire.

NOTE: only use it for measuring. http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/System.html#nanoTime%28%29

Returns:

current time in nanoseconds.

elapsedMSec

public static long elapsedMSec(long startNanoTime)

Milliseconds elapsed since the time specified, the input is nanoTime the only conversion happens when computing the elapsed time.

Parameters:

startNanoTime - the start of the interval that we are measuring

Returns:

elapsed time in milliseconds.

elapsedMicroSec

public static long elapsedMicroSec(long startNanoTime)

Microseconds elapsed since the time specified, the input is nanoTime the only conversion happens when computing the elapsed time.

Parameters:

startNanoTime - the start of the interval that we are measuring

Returns:

elapsed time in microseconds.

elapsedNanos

public static long elapsedNanos(long startNanoTime)

Nanoseconds elapsed since the time specified, the input is nanoTime the only conversion happens when computing the elapsed time.

Parameters:

startNanoTime - the start of the interval that we are measuring

Returns:

elapsed time in nanoseconds.