org.basex.util
Class Performance

java.lang.Object
  org.basex.util.Performance

public final class Performance
extends Object

This class contains methods for performance measurements.

Author:

Workgroup DBIS, University of Konstanz 2005-10, ISC License, Christian Gruen

Constructor Summary

Performance()
Constructor, initializing the performance timer.

Method Summary

static String	format(long size) Formats a number according to the binary size orders (KB, MB, ...).
static String	format(long size, boolean det) Formats a file size according to the binary size orders (KB, MB, ...).
static void	gc(int n) Performs some garbage collection.
static String	getMem() Returns a formatted representation of the current memory consumption.
long	getTime() Returns the measured execution time in nanoseconds.
String	getTimer() Returns the measured execution time in milliseconds and reinitializes the timer.
String	getTimer(int runs) Returns the measured execution time in milliseconds, divided by the number of runs, and reinitializes the timer.
static String	getTimer(long time, int runs) Returns a string with the measured execution time in milliseconds.
void	initTimer() Initializes the timer.
static void	sleep(long ms) Sleeps the specified number of milliseconds.
static void	stack() Throws and catches an error to display the current stack.
String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Performance

public Performance()

Constructor, initializing the performance timer.

Method Detail

initTimer

public void initTimer()

Initializes the timer.

getTime

public long getTime()

Returns the measured execution time in nanoseconds.

Returns:

execution time

getTimer

public String getTimer()

Returns the measured execution time in milliseconds and reinitializes the timer.

Returns:

execution time

getTimer

public String getTimer(int runs)

Returns the measured execution time in milliseconds, divided by the number of runs, and reinitializes the timer.

Parameters:

runs - number of runs

Returns:

execution time

getTimer

public static String getTimer(long time,
                              int runs)

Returns a string with the measured execution time in milliseconds.

Parameters:

time - measured time in nanoseconds

runs - number of runs

Returns:

execution time

getMem

public static String getMem()

Returns a formatted representation of the current memory consumption.

Returns:

memory consumption

format

public static String format(long size)

Formats a number according to the binary size orders (KB, MB, ...).

Parameters:

size - value to be formatted

Returns:

formatted size value

format

public static String format(long size,
                            boolean det)

Formats a file size according to the binary size orders (KB, MB, ...).

Parameters:

size - file size

det - detailed suffix

Returns:

formatted size value

sleep

public static void sleep(long ms)

Sleeps the specified number of milliseconds.

Parameters:

ms - time in milliseconds to wait

gc

public static void gc(int n)

Performs some garbage collection. GC behavior in Java is a pretty complex task. Still, garbage collection can be forced by calling it several times.

Parameters:

n - number of times to execute garbage collection

stack

public static void stack()

Throws and catches an error to display the current stack.

toString

public String toString()

Overrides:

toString in class Object