Package ca.uhn.fhir.util

Class StopWatch

  • public class StopWatch
extends Object
    A multipurpose stopwatch which can be used to time tasks and produce human readable output about task duration, throughput, estimated task completion, etc.

    Thread Safety Note: StopWatch is not intended to be thread safe.

    Since:
    HAPI FHIR 3.3.0

    • Constructor Detail

      • StopWatch

        public StopWatch​(Date theStart)
        Constructor
        Parameters:
        theStart - The time to record as the start for this timer

      • StopWatch

        public StopWatch​(long theStart)
        Constructor
        Parameters:
        theStart - The time that the stopwatch was started

    • Method Detail

      • endCurrentTask

        public void endCurrentTask()
        Finish the counter on the current task (which was started by calling startTask(String). This method has no effect if no task is currently started so it's ok to call it more than once.

      • formatMillisPerOperation

        public String formatMillisPerOperation​(long theNumOperations)
        Returns a nice human-readable display of the time taken per operation. Note that this may not actually output the number of milliseconds if the time taken per operation was very long (over 10 seconds)
        See Also:
        formatMillis(long)

      • formatThroughput

        public String formatThroughput​(long theNumOperations,
                               TimeUnit theUnit)
        Determine the current throughput per unit of time (specified in theUnit) assuming that theNumOperations operations have happened.

        For example, if this stopwatch has 2 seconds elapsed, and this method is called for theNumOperations=30 and TimeUnit=SECONDS, this method will return 15

        See Also:
        getThroughput(long, TimeUnit)

      • getEstimatedTimeRemaining

        public String getEstimatedTimeRemaining​(double theCompleteToDate,
                                        double theTotal)
        Given an amount of something completed so far, and a total amount, calculates how long it will take for something to complete
        Parameters:
        theCompleteToDate - The amount so far
        theTotal - The total (must be higher than theCompleteToDate
        Returns:
        A formatted amount of time

      • getMillisPerOperation

        public long getMillisPerOperation​(long theNumOperations)
        Parameters:
        theNumOperations - Ok for this to be 0, it will be treated as 1

      • getThroughput

        public double getThroughput​(long theNumOperations,
                            TimeUnit theUnit)
        Determine the current throughput per unit of time (specified in theUnit) assuming that theNumOperations operations have happened.

        For example, if this stopwatch has 2 seconds elapsed, and this method is called for theNumOperations=30 and TimeUnit=SECONDS, this method will return 15

        See Also:
        formatThroughput(long, TimeUnit)

      • startTask

        public void startTask​(String theTaskName)
        Starts a counter for a sub-task

        Thread Safety Note: This method is not threadsafe! Do not use subtasks in a multithreaded environment.

        Parameters:
        theTaskName - Note that if theTaskName is blank or empty, no task is started

      • formatMillis

        public static String formatMillis​(long theMillis)
        Formats a number of milliseconds for display (e.g. in a log file), tailoring the output to how big the value actually is.

        Example outputs:

        • 133ms
        • 00:00:10.223
        • 1.7 days
        • 64 days

      • formatMillis

        public static String formatMillis​(double theMillis)
        Formats a number of milliseconds for display (e.g. in a log file), tailoring the output to how big the value actually is.

        Example outputs:

        • 133ms
        • 00:00:10.223
        • 1.7 days
        • 64 days