org.basex.util
Class Performance

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

public final class Performance
extends java.lang.Object

This class contains methods for performance measurements.

Author:
BaseX Team 2005-12, BSD License, Christian Gruen

Constructor Summary
Performance()
           
 
Method Summary
static java.lang.String format(long size)
          Formats a number according to the binary size orders (KB, MB, ...).
static java.lang.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 java.lang.String getMemory()
          Returns a formatted representation of the current memory consumption.
 java.lang.String getTime()
          Returns the measured execution time in milliseconds and reinitializes the timer.
 java.lang.String getTime(int runs)
          Returns the measured execution time in milliseconds, divided by the number of runs, and reinitializes the timer.
static java.lang.String getTime(long time, int runs)
          Returns a string with the measured execution time in milliseconds.
static long memory()
          Returns the current memory consumption in bytes.
static void sleep(long ms)
          Sleeps the specified number of milliseconds.
 long time()
          Returns the measured execution time in nanoseconds.
 java.lang.String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

Performance

public Performance()
Method Detail

time

public long time()
Returns the measured execution time in nanoseconds.

Returns:
execution time

getTime

public java.lang.String getTime()
Returns the measured execution time in milliseconds and reinitializes the timer.

Returns:
execution time

getTime

public java.lang.String getTime(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

getTime

public static java.lang.String getTime(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

getMemory

public static java.lang.String getMemory()
Returns a formatted representation of the current memory consumption.

Returns:
memory consumption

format

public static java.lang.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 java.lang.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

memory

public static long memory()
Returns the current memory consumption in bytes.

Returns:
memory consumption

toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object