org.b3log.latke.util

Class Stopwatchs

java.lang.Object

org.b3log.latke.util.Stopwatchs

public final class Stopwatchs
extends Object

Stop watch utilities for timing of a thread of tasks.

Invokes method start(java.lang.String) for timing a task, invokes method end() for stop timing the corresponding task, the start and end must match exactly.

Note: Remember to release a stopwatch if finished statistics finally to avoid memory leak.

See the following example snippet codes:

     Stopwatchs.start("task 1");
     // task 1 includes three sub-tasks: task 1.1, task 1.2 and task 1.3
     // .... task 1 processing ....

     Stopwatchs.start("task 1.1");
     // .... task 1.1 processing ....
     Stopwatchs.end(); // Ends 1.1

     Stopwatchs.start("task 1.2");
     // task 1.2 includes two sub-tasks: task 1.2.1 and task 1.2.2
     // .... task 1.2 processing ....

     Stopwatchs.start("task 1.2.1");
     // .... task 1.2.1 processing ....
     Stopwatchs.end(); // Ends 1.2.1

     Stopwatchs.start("task 1.2.2");
     // .... task 1.2.2 processing ....
     Stopwatchs.end(); // Ends 1.2.2

     Stopwatchs.end(); // Ends 1.2

     Stopwatchs.start("task 1.3");
     // .... task 1.3 processing ....
     Stopwatchs.end(); // Ends 1.3

     Stopwatchs.end(); // Ends 1

     // Shows the timing statistics
     System.out.println(Stopwatchs.getTimingStat());

     Stopwatchs.release();
 

Outputs:

 [100.0]%, [80]ms [task 1]
   [62.5]%, [50]ms [task 1.1]
   [25.0]%, [20]ms [task 1.2]
     [0.0]%, [0]ms [task 1.2.1]
     [25.0]%, [20]ms [task 1.2.2]
   [12.5]%, [10]ms [task 1.3]
 

Version:

1.0.0.3, May 30, 2012

Author:

Liang Ding

See Also:

Stopwatchs.Stopwatch, getTimingStat()

Method Summary

Modifier and Type	Method and Description
static void	end() Ends the timing of the recent task started by start(java.lang.String).
static long	getElapsed(String taskTitle) Gets elapsed time from the specified parent stopwatch with the specified task title.
static String	getTimingStat() Gets the current timing statistics.
static void	release() Releases the thread-local stopwatch.
static void	start(String taskTitle) Starts a task timing with the specified task title.

Methods inherited from class java.lang.Object

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

Method Detail

start

public static void start(String taskTitle)

Starts a task timing with the specified task title.

Parameters:

taskTitle - the specified task title

end

public static void end()

Ends the timing of the recent task started by start(java.lang.String).

release

public static void release()

Releases the thread-local stopwatch.

Sets the thread-local stopwatch with null.

getTimingStat

public static String getTimingStat()

Gets the current timing statistics.

If a task is not ended, the outputs will be minus for percentage and elapsed, the absolute value of the elapsed filed is the start time.

Returns:

the current timing statistics, returns "No stopwatch" if not stopwatch

getElapsed

public static long getElapsed(String taskTitle)

Gets elapsed time from the specified parent stopwatch with the specified task title.

Parameters:

taskTitle - the specified task title

Returns:

• elapsed time of the found task if it is ended
• the current time subtracts the start time of the found task if it is running
• -1 if not found any stopwatch corresponding to the specified task title