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 Summary

Modifier and Type	Method and Description
long	getCurrentRetryDelayInMs() Returns the current delay before each retry to wait in milliseconds.
long	getExpRetryDelayExtensionInMs() Returns the exponential retry delay extension time in milliseconds.
long	getInitialRetryDelayInMs() Returns the initial delay before each retry to wait in milliseconds.
long	getNextRetryDelayInMs() Calculates the next retry delay in milliseconds.
int	getRetryCount() The current state regarding the retires.
int	getRetryNumber() Returns the number of retires this instance allows altogether.
boolean	nextRetry() Tests whether a next retry is possible.

Methods inherited from interface org.refcodes.controlflow.Retryable

hasNextRetry

Methods inherited from interface org.refcodes.mixin.Restartable

restart

Methods inherited from interface org.refcodes.mixin.Abortable

abort

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