Module io.helidon.common.reactive
Package io.helidon.common.reactive

Interface RetrySchema

  • Functional Interface:
    This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
    @FunctionalInterface
public interface RetrySchema
    Defines delay for next read/poll operation in a polling publisher.

    Schema defines a delay before next poll if the last one did not get new data.

    It is possible to use included static factory methods for some standard schemas.

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      static RetrySchema constant​(long delay)
      Creates the retry schema with a constant result.
      static RetrySchema geometric​(long firstDelay, double ratio, long maxDelay)
      Creates the retry schema as a bounded geometric series.
      static RetrySchema linear​(long firstDelay, long delayIncrement, long maxDelay)
      Creates the retry schema with a linear delay increment.
      long nextDelay​(int retryCount, long lastDelay)
      Returns a delay before next read if the last one poll did not get new data.

    • Method Detail

      • nextDelay

        long nextDelay​(int retryCount,
               long lastDelay)
        Returns a delay before next read if the last one poll did not get new data.
        Parameters:
        retryCount - a count of already poll retries. It is 0 when called first time and resets every time when poll returns some data.
        lastDelay - a last returned value. 0 in first call. Resets when some data are get.
        Returns:
        a delay in milliseconds before next poll attempt. If less then zero then Publisher completes with onError message.

      • linear

        static RetrySchema linear​(long firstDelay,
                          long delayIncrement,
                          long maxDelay)
        Creates the retry schema with a linear delay increment. It returns firstDelay for the first call and then it increments it's value for every call by delayIncrement until reach a limit defined by maxDelay.
        Parameters:
        firstDelay - a delay to returns for the first call
        delayIncrement - an increment of the returned value.
        maxDelay - the maximal value to return
        Returns:
        computed retry delay with a linear increment

      • constant

        static RetrySchema constant​(long delay)
        Creates the retry schema with a constant result.
        Parameters:
        delay - a constant delay to return
        Returns:
        a delay value

      • geometric

        static RetrySchema geometric​(long firstDelay,
                             double ratio,
                             long maxDelay)
        Creates the retry schema as a bounded geometric series.
        Parameters:
        firstDelay - a delay to returns for the first call
        ratio - a geometric series ratio
        maxDelay - the maximal value to return
        Returns:
        computed retry delay