com.google.api.gax.retrying

Class ExponentialRetryAlgorithm

java.lang.Object

com.google.api.gax.retrying.ExponentialRetryAlgorithm

All Implemented Interfaces:

TimedRetryAlgorithm

Direct Known Subclasses:

ExponentialPollAlgorithm, OperationTimedPollAlgorithm

public class ExponentialRetryAlgorithm
extends Object
implements TimedRetryAlgorithm

The timed retry algorithm which uses jittered 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
TimedAttemptSettings	createFirstAttempt() Creates a first attempt TimedAttemptSettings.
TimedAttemptSettings	createNextAttempt(TimedAttemptSettings prevSettings) Creates a next attempt TimedAttemptSettings.
protected long	nextRandomLong(long bound)
boolean	shouldRetry(TimedAttemptSettings nextAttemptSettings) Returns true if another attempt should be made, or false otherwise.

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

shouldRetry

public boolean shouldRetry(TimedAttemptSettings nextAttemptSettings)

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

Specified by:

shouldRetry 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

nextRandomLong

protected long nextRandomLong(long bound)