Package org.jclouds.rest.suppliers

Class MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier<T>

java.lang.Object

com.google.common.collect.ForwardingObject

org.jclouds.rest.suppliers.MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier<T>

All Implemented Interfaces:

com.google.common.base.Supplier<T>, Supplier<T>

public class MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier<T>
extends com.google.common.collect.ForwardingObject
implements com.google.common.base.Supplier<T>

This will retry the supplier if it encounters a timeout exception, but not if it encounters an AuthorizationException.

A shared exception reference is used so that anyone who encounters an authorizationexception will be short-circuited. This prevents accounts from being locked out.

details

http://code.google.com/p/google-guice/issues/detail?id=483 guice doesn't remember when singleton providers throw exceptions. in this case, if the supplier fails with an authorization exception, it is called again for each provider method that depends on it. To short-circuit this, we remember the last exception trusting that guice is single-threaded. Note this implementation is folded into the same class, vs being decorated as stacktraces are exceptionally long and difficult to grok otherwise. We use LoadingCache to deal with concurrency issues related to the supplier.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier.ValueLoadedEvent<V>

Method Summary

Modifier and Type	Method	Description
static <T> MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier<T>	create(AtomicReference<AuthorizationException> authException, com.google.common.base.Supplier<T> delegate, long duration, TimeUnit unit)
static <T> MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier<T>	create(AtomicReference<AuthorizationException> authException, com.google.common.base.Supplier<T> delegate, long duration, TimeUnit unit, ValueLoadedCallback<T> valueLoadedCallback)	Creates a memoized supplier that calls the given callback each time values are loaded.
protected com.google.common.base.Supplier<T>	delegate()
T	get()
String	toString()

Methods inherited from class java.lang.Object

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

Method Details

create

public static <T>
MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier<T> create(AtomicReference<AuthorizationException> authException,
 com.google.common.base.Supplier<T> delegate,
 long duration,
 TimeUnit unit)

create

public static <T>
MemoizedRetryOnTimeOutButNotOnAuthorizationExceptionSupplier<T> create(AtomicReference<AuthorizationException> authException,
 com.google.common.base.Supplier<T> delegate,
 long duration,
 TimeUnit unit,
 ValueLoadedCallback<T> valueLoadedCallback)

Creates a memoized supplier that calls the given callback each time values are loaded.

delegate

protected com.google.common.base.Supplier<T> delegate()

Specified by:

delegate in class com.google.common.collect.ForwardingObject

get

public T get()

Specified by:

get in interface com.google.common.base.Supplier<T>

Specified by:

get in interface Supplier<T>

toString

public String toString()

Overrides:

toString in class com.google.common.collect.ForwardingObject