com.google.api.gax.retrying

Class ExponentialRetryAlgorithm

java.lang.Object

com.google.api.gax.retrying.ExponentialRetryAlgorithm

All Implemented Interfaces:

TimedRetryAlgorithm

@BetaApi
public class ExponentialRetryAlgorithm
extends Object
implements TimedRetryAlgorithm

The timed retry algorithm which uses randomized exponential backoff factor for calculating the next attempt execution time.

This class is thread-safe.

Constructor Summary

Constructors

Constructor and Description
ExponentialRetryAlgorithm(RetrySettings globalSettings, com.google.api.core.ApiClock clock) Creates a new exponential retry algorithm instance.

Method Summary

Modifier and Type	Method and Description
boolean	accept(TimedAttemptSettings nextAttemptSettings) Returns true if another attempt should be made, or false otherwise.
TimedAttemptSettings	createFirstAttempt() Creates a first attempt TimedAttemptSettings.
TimedAttemptSettings	createNextAttempt(TimedAttemptSettings prevSettings) Creates a next attempt TimedAttemptSettings.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExponentialRetryAlgorithm

public ExponentialRetryAlgorithm(RetrySettings globalSettings,
                                 com.google.api.core.ApiClock clock)

Creates a new exponential retry algorithm instance.

Parameters:

globalSettings - global retry settings (attempt independent)

clock - clock to use for time-specific calculations

Throws:

NullPointerException - if either globalSettings or clock is null

Method Detail

createFirstAttempt

public TimedAttemptSettings createFirstAttempt()

Creates a first attempt TimedAttemptSettings. The first attempt is configured to be executed immediately.

Specified by:

createFirstAttempt in interface TimedRetryAlgorithm

Returns:

first attempt settings

createNextAttempt

public TimedAttemptSettings createNextAttempt(TimedAttemptSettings prevSettings)

Creates a next attempt TimedAttemptSettings. The implementation increments the current attempt count and uses randomized exponential backoff factor for calculating next attempt execution time.

Specified by:

createNextAttempt in interface TimedRetryAlgorithm

Parameters:

prevSettings - previous attempt settings

Returns:

next attempt settings

accept

public boolean accept(TimedAttemptSettings nextAttemptSettings)

Returns true if another attempt should be made, or false otherwise.

Specified by:

accept in interface TimedRetryAlgorithm

Parameters:

nextAttemptSettings - attempt settings, which will be used for the next attempt, if accepted

Returns:

true if nextAttemptSettings does not exceed either maxAttempts limit or totalTimeout limit, or false otherwise