com.ibm.cos.v2.core.internal.http.pipeline.stages.utils

Class RetryableStageHelper

java.lang.Object

com.ibm.cos.v2.core.internal.http.pipeline.stages.utils.RetryableStageHelper

public final class RetryableStageHelper
extends Object

Contains the logic shared by RetryableStage and AsyncRetryableStage when querying and interacting with a RetryStrategy.

Field Summary

Fields

Modifier and Type	Field and Description
static ExecutionAttribute<Duration>	LAST_BACKOFF_DELAY_DURATION
static String	SDK_RETRY_INFO_HEADER

Constructor Summary

Constructors

Constructor and Description
RetryableStageHelper(SdkHttpFullRequest request, RequestExecutionContext context, HttpClientDependencies dependencies)

Method Summary

Modifier and Type	Method and Description
Duration	acquireInitialToken() Invoke when starting the first attempt.
void	adjustClockIfClockSkew(Response<?> response) Adjust the client-side clock skew if the provided response indicates that there is a large skew between the client and service.
int	getAttemptNumber() Retrieve the current attempt number, updated whenever startingAttempt() is invoked.
SdkException	getLastException() Retrieve the last call failure exception encountered by this execution, updated whenever setLastException(java.lang.Throwable) is invoked.
void	logBackingOff(Duration backoffDelay) Log a message to the user at the debug level to indicate how long we will wait before retrying the request.
void	logSendingRequest() Log a message to the user at the debug level to indicate that we are sending the request to the service.
void	recordAttemptSucceeded() Notify the retry strategy that the request attempt succeeded.
SdkHttpFullRequest	requestToSend() Retrieve the request to send to the service, including any detailed retry information headers.
SdkException	retryPolicyDisallowedRetryException() Return the exception that should be thrown, because the retry strategy did not allow the request to be retried.
void	setLastException(Throwable lastException) Update the getLastException() value for this helper.
void	setLastResponse(SdkHttpResponse lastResponse) Set the last HTTP response returned by the service.
void	startingAttempt() Invoke when starting a request attempt, before querying the retry policy.
Optional<Duration>	tryRefreshToken(Duration suggestedDelay) Invoked after a failed attempt and before retrying.

Methods inherited from class java.lang.Object

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

Field Detail

SDK_RETRY_INFO_HEADER

public static final String SDK_RETRY_INFO_HEADER

See Also:

Constant Field Values

LAST_BACKOFF_DELAY_DURATION

public static final ExecutionAttribute<Duration> LAST_BACKOFF_DELAY_DURATION

Constructor Detail

RetryableStageHelper

public RetryableStageHelper(SdkHttpFullRequest request,
                            RequestExecutionContext context,
                            HttpClientDependencies dependencies)

Method Detail

startingAttempt

public void startingAttempt()

Invoke when starting a request attempt, before querying the retry policy.

acquireInitialToken

public Duration acquireInitialToken()

Invoke when starting the first attempt. This method will acquire the initial token and store it as an execution attribute. This method returns a delay that the caller have to wait before attempting the first request. If this method returns Duration.ZERO if the calling code does not have to wait. As of today the only strategy that might return a non-zero value is AdaptiveRetryStrategy.

recordAttemptSucceeded

public void recordAttemptSucceeded()

Notify the retry strategy that the request attempt succeeded.

tryRefreshToken

public Optional<Duration> tryRefreshToken(Duration suggestedDelay)

Invoked after a failed attempt and before retrying. The returned optional will be non-empty if the client can retry or empty if the retry-strategy disallows the retry. The calling code is expected to wait the delay represented in the duration if present before retrying the request.

Parameters:

suggestedDelay - A suggested delay, presumably coming from the server response. The response when present will be at least this amount.

Returns:

An optional time to wait. If the value is not present the retry strategy disallowed the retry and the calling code should not retry.

retryPolicyDisallowedRetryException

public SdkException retryPolicyDisallowedRetryException()

Return the exception that should be thrown, because the retry strategy did not allow the request to be retried.

logBackingOff

public void logBackingOff(Duration backoffDelay)

Log a message to the user at the debug level to indicate how long we will wait before retrying the request.

requestToSend

public SdkHttpFullRequest requestToSend()

Retrieve the request to send to the service, including any detailed retry information headers.

logSendingRequest

public void logSendingRequest()

Log a message to the user at the debug level to indicate that we are sending the request to the service.

adjustClockIfClockSkew

public void adjustClockIfClockSkew(Response<?> response)

Adjust the client-side clock skew if the provided response indicates that there is a large skew between the client and service. This will allow a retried request to be signed with what is likely to be a more accurate time.

getLastException

public SdkException getLastException()

Retrieve the last call failure exception encountered by this execution, updated whenever setLastException(java.lang.Throwable) is invoked.

setLastException

public void setLastException(Throwable lastException)

Update the getLastException() value for this helper. This will be used to determine whether the request should be retried.

setLastResponse

public void setLastResponse(SdkHttpResponse lastResponse)

Set the last HTTP response returned by the service. This will be used to determine whether the request should be retried.

getAttemptNumber

public int getAttemptNumber()

Retrieve the current attempt number, updated whenever startingAttempt() is invoked.