Package org.refcodes.controlflow

Interface RetryCounter

  • All Superinterfaces:
    org.refcodes.mixin.Abortable, org.refcodes.mixin.Restartable, Retryable
    All Known Implementing Classes:
    RetryCounterImpl

    public interface RetryCounter
extends Retryable
    The RetryCounter can be used in loops to test whether a retry should take place and in case a retry is to take place, then a given period of time (delay) is waited and the internal retry counter is decremented. In case no more retries are "available" the business logic may act accordingly such as throwing an exception.

    In case a delay greater than 0 is set, then each retry is being delayed by the according amount of milliseconds, in case no retries are left, then delaying is skipped. A delay of 0 or smaller skips delaying altogether.

    The first call to nextRetry() does not delay as the first call is not considered to be a retry. In case an exponential retry delay extension time has been provided, then the retry delay upon calling nextRetry() is extended by that exponential delay (being increased for each retry).

    ATTENTION: The first call the nextRetry() increments the retry counter getRetryCount() to be 1 and not 0, so the retry counter is actually a "try" counter, having the first "try" upon invoking nextRetry().

    • Method Detail

      • getNextRetryDelayInMs

        long getNextRetryDelayInMs​()
        Calculates the next retry delay in milliseconds. This is the time the nextRetry() method will wait in case its rules match for doing a sleep.
        Returns:
        The next retry delay in milliseconds.

      • getInitialRetryDelayInMs

        long getInitialRetryDelayInMs​()
        Returns the initial delay before each retry to wait in milliseconds. The getCurrentRetryDelayInMs() is calculated from the initial delay and the exponential retry delay added for each retry (not added for the first call to nextRetry()).
        Returns:
        The delay to being set in milliseconds.

      • getCurrentRetryDelayInMs

        long getCurrentRetryDelayInMs​()
        Returns the current delay before each retry to wait in milliseconds. When less than or equal to 0, then the delay is skipped. The current delay is calculated by extending the getInitialRetryDelayInMs() with the getExpRetryDelayExtensionInMs() per retry. ------------------------------------------------------------------------- The current retry delay gets incremented for each retry by an exponential retry delay extension time calculated from in case it is greater than 0. -------------------------------------------------------------------------
        Returns:
        The delay to being set in milliseconds.

      • getExpRetryDelayExtensionInMs

        long getExpRetryDelayExtensionInMs​()
        Returns the exponential retry delay extension time in milliseconds. In case an exponential retry delay extension time has been provided, then the retry delay upon calling nextRetry() is extended by that exponential delay (being increased for each retry): ------------------------------------------------------------------------- "(getRetryDelayInMs() + (Math.pow( 4, getRetryCount() - 1 ) * getExpRetryDelayExtensionInMs())" -------------------------------------------------------------------------
        Returns:
        The exponential retry delay extension time in milliseconds.

      • getRetryNumber

        int getRetryNumber​()
        Returns the number of retires this instance allows altogether.
        Returns:
        The number of altogether retries.

      • nextRetry

        boolean nextRetry​()
        Tests whether a next retry is possible. In case this is true, then the retry count is incremented by one. In case this is not the first call to the retry counter, then the thread is delayed by the configured delay time. In case ------------------------------------------------------------------------- The first call does not delay as the first call is not considered to be a retry. In case an exponential retry delay extension time has been provided, then the retry delay is extended by that exponential delay being increased for each retry. ------------------------------------------------------------------------- ATTENTION: The first call the nextRetry() increments the retry counter getRetryCount() to be 1 and not 0, so the retry counter is actually a "try" counter, having the first "try" upon invoking nextRetry(). -------------------------------------------------------------------------
        Specified by:
        nextRetry in interface Retryable
        Returns:
        True in case there is a next retry as of Retryable.hasNextRetry().

      • getRetryCount

        int getRetryCount​()
        The current state regarding the retires. It specifies at which retry we currently are. ------------------------------------------------------------------------- ATTENTION: The first call the nextRetry() increments the retry counter getRetryCount() to be 1 and not 0, so the retry counter is actually a "try" counter, having the first "try" upon invoking nextRetry(). -------------------------------------------------------------------------
        Specified by:
        getRetryCount in interface Retryable
        Returns:
        The number of retries used up so far