org.elasticsearch.common

Class StopWatch

java.lang.Object

org.elasticsearch.common.StopWatch

public class StopWatch
extends Object

Simple stop watch, allowing for timing of a number of tasks, exposing total running time and running time for each named task.

Conceals use of System.nanoTime(), improving the readability of application code and reducing the likelihood of calculation errors.

Note that this object is not designed to be thread-safe and does not use synchronization.

This class is normally used to verify performance during proof-of-concepts and in development, rather than as part of production applications.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	StopWatch.TaskInfo Inner class to hold data about one task executed within the stop watch.

Constructor Summary

Constructors

Constructor and Description
StopWatch() Construct a new stop watch.
StopWatch(String id) Construct a new stop watch with the given id.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	isRunning() Return whether the stop watch is currently running.
StopWatch	keepTaskList(boolean keepTaskList) Determine whether the TaskInfo array is built over time.
String	lastTaskName() Return the name of the last task.
TimeValue	lastTaskTime() Return the time taken by the last task.
String	prettyPrint() Return a string with a table describing all tasks performed.
String	shortSummary() Return a short description of the total running time.
StopWatch	start() Start an unnamed task.
StopWatch	start(String taskName) Start a named task.
StopWatch	stop() Stop the current task.
int	taskCount() Return the number of tasks timed.
StopWatch.TaskInfo[]	taskInfo() Return an array of the data for tasks performed.
String	toString() Return an informative string describing all tasks performed For custom reporting, call getTaskInfo() and use the task info directly.
TimeValue	totalTime() Return the total time for all tasks.

Methods inherited from class java.lang.Object

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

Constructor Detail

StopWatch

public StopWatch()

Construct a new stop watch. Does not start any task.

StopWatch

public StopWatch(String id)

Construct a new stop watch with the given id. Does not start any task.

Parameters:

id - identifier for this stop watch. Handy when we have output from multiple stop watches and need to distinguish between them.

Method Detail

keepTaskList

public StopWatch keepTaskList(boolean keepTaskList)

Determine whether the TaskInfo array is built over time. Set this to "false" when using a StopWatch for millions of intervals, or the task info structure will consume excessive memory. Default is "true".

start

public StopWatch start()
                throws IllegalStateException

Start an unnamed task. The results are undefined if stop() or timing methods are called without invoking this method.

Throws:

IllegalStateException

See Also:

stop()

start

public StopWatch start(String taskName)
                throws IllegalStateException

Start a named task. The results are undefined if stop() or timing methods are called without invoking this method.

Parameters:

taskName - the name of the task to start

Throws:

IllegalStateException

See Also:

stop()

stop

public StopWatch stop()
               throws IllegalStateException

Stop the current task. The results are undefined if timing methods are called without invoking at least one pair start() / stop() methods.

Throws:

IllegalStateException

See Also:

start()

isRunning

public boolean isRunning()

Return whether the stop watch is currently running.

lastTaskTime

public TimeValue lastTaskTime()
                       throws IllegalStateException

Return the time taken by the last task.

Throws:

IllegalStateException

lastTaskName

public String lastTaskName()
                    throws IllegalStateException

Return the name of the last task.

Throws:

IllegalStateException

totalTime

public TimeValue totalTime()

Return the total time for all tasks.

taskCount

public int taskCount()

Return the number of tasks timed.

taskInfo

public StopWatch.TaskInfo[] taskInfo()

Return an array of the data for tasks performed.

shortSummary

public String shortSummary()

Return a short description of the total running time.

prettyPrint

public String prettyPrint()

Return a string with a table describing all tasks performed. For custom reporting, call getTaskInfo() and use the task info directly.

toString

public String toString()

Return an informative string describing all tasks performed For custom reporting, call getTaskInfo() and use the task info directly.

Overrides:

toString in class Object