Class StopWatch

java.lang.Object
org.elasticsearch.common.StopWatch

public class StopWatch
extends java.lang.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 Description
    static class  StopWatch.TaskInfo
    Inner class to hold data about one task executed within the stop watch.
  • Constructor Summary

    Constructors 
    Constructor Description
    StopWatch()
    Construct a new stop watch.
    StopWatch​(java.lang.String id)
    Construct a new stop watch with the given id.
  • Method Summary

    Modifier and Type Method Description
    boolean isRunning()
    Return whether the stop watch is currently running.
    TimeValue lastTaskTime()
    Return the time taken by the last task.
    java.lang.String prettyPrint()
    Return a string with a table describing all tasks performed.
    java.lang.String shortSummary()
    Return a short description of the total running time.
    StopWatch start()
    Start an unnamed task.
    StopWatch start​(java.lang.String taskName)
    Start a named task.
    StopWatch stop()
    Stop the current task.
    StopWatch.TaskInfo[] taskInfo()
    Return an array of the data for tasks performed.
    Releasable timing​(java.lang.String taskName)  
    java.lang.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 Details

    • StopWatch

      public StopWatch()
      Construct a new stop watch. Does not start any task.
    • StopWatch

      public StopWatch​(java.lang.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 Details

    • start

      public StopWatch start() throws java.lang.IllegalStateException
      Start an unnamed task. The results are undefined if stop() or timing methods are called without invoking this method.
      Throws:
      java.lang.IllegalStateException
      See Also:
      stop()
    • start

      public StopWatch start​(java.lang.String taskName) throws java.lang.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:
      java.lang.IllegalStateException
      See Also:
      stop()
    • stop

      public StopWatch stop() throws java.lang.IllegalStateException
      Stop the current task. The results are undefined if timing methods are called without invoking at least one pair start() / #stop() methods.
      Throws:
      java.lang.IllegalStateException
      See Also:
      start()
    • timing

      public Releasable timing​(java.lang.String taskName)
    • isRunning

      public boolean isRunning()
      Return whether the stop watch is currently running.
    • lastTaskTime

      public TimeValue lastTaskTime() throws java.lang.IllegalStateException
      Return the time taken by the last task.
      Throws:
      java.lang.IllegalStateException
    • totalTime

      public TimeValue totalTime()
      Return the total time for all tasks.
    • taskInfo

      public StopWatch.TaskInfo[] taskInfo()
      Return an array of the data for tasks performed.
    • shortSummary

      public java.lang.String shortSummary()
      Return a short description of the total running time.
    • prettyPrint

      public java.lang.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 java.lang.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 java.lang.Object