Package com.pervasivecode.utils.stats

Class SimpleDurationEstimator

  • All Implemented Interfaces:
    DurationEstimator
    public class SimpleDurationEstimator
extends Object
implements DurationEstimator
    This is a trivial DurationEstimator that just uses the total amount processed divided by the total time elapsed to estimate the rate (that is, it's blind to any short-term fluctuations in rate that may occur, and only examines the entire process).

    Example: If an instance was created 4 seconds ago according to the TimeSource passed to the constructor, and recordAmountSoFar has been called once per second with values {0, 0, 0, 1000}, the estimated rate returned after each recordAmountSoFar call would be {0.0f, 0.0f, 0.0f, 250.0f}.

    Time values are internally limited to milliseconds precision.

    • Constructor Detail

      • SimpleDurationEstimator

        public SimpleDurationEstimator​(com.pervasivecode.utils.time.api.TimeSource timeSource)
        Create and start a SimpleDurationEstimator, with an initial progress value of zero.
        Parameters:
        timeSource - The source of time to be used to determine how much time has elapsed.

      • SimpleDurationEstimator

        public SimpleDurationEstimator​(com.pervasivecode.utils.time.api.TimeSource timeSource,
                               long initialProgressValue)
        Create and start a SimpleDurationEstimator, with an initial progress value specified by the caller.
        Parameters:
        timeSource - The source of time to be used to determine how much time has elapsed.
        initialProgressValue - The initial value to be used when estimating progress.

    • Method Detail

      • recordAmountSoFar

        public void recordAmountSoFar​(long newAmount)
        Replace the existing progress amount value with a new one.
        Specified by:
        recordAmountSoFar in interface DurationEstimator
        Parameters:
        newAmount - The new progress amount.

      • estimatedRateAsAmountPerSecond

        public float estimatedRateAsAmountPerSecond()
        Get an estimate of the rate of change of the progress amount per second.
        Specified by:
        estimatedRateAsAmountPerSecond in interface DurationEstimator
        Returns:
        The estimated rate.

      • estimateTimeToProcessAmount

        public Optional<Duration> estimateTimeToProcessAmount​(long amountLeft)
        Using the current estimatedRateAsAmountPerSecond, predict how much time would be needed to process a specified amount starting now.
        Specified by:
        estimateTimeToProcessAmount in interface DurationEstimator
        Parameters:
        amountLeft - The amount whose processing time is to be estimated.
        Returns:
        The amount of time that would be required to process the specified amount, given the current estimated rate.