org.opendaylight.controller.cluster.access.client

Class BackendInfoResolver<T extends BackendInfo>

java.lang.Object

org.opendaylight.controller.cluster.access.client.BackendInfoResolver<T>

@ThreadSafe
public abstract class BackendInfoResolver<T extends BackendInfo>
extends Object

Caching resolver which resolves a cookie to a leader ActorRef. This class needs to be specialized by the client. It is used by ClientActorBehavior for request dispatch. Results are cached until they are invalidated by either the client actor (when a message timeout is detected) and by the specific frontend (on explicit invalidation or when updated information becomes available).

Author:

Robert Varga

Constructor Summary

Constructors

Constructor and Description
BackendInfoResolver()

Method Summary

Modifier and Type	Method and Description
Optional<T>	getFutureBackendInfo(Long cookie) Return the currently-resolved backend information, if available.
void	invalidateBackend(long cookie, CompletionStage<? extends BackendInfo> info) Invalidate a particular instance of BackendInfo, typically as a response to a request timing out.
protected abstract void	invalidateBackendInfo(CompletionStage<? extends BackendInfo> info) Invalidate previously-resolved shard information.
protected abstract CompletableFuture<T>	resolveBackendInfo(Long cookie) Request new resolution of a particular backend identified by a cookie.

Methods inherited from class java.lang.Object

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

Constructor Detail

BackendInfoResolver

public BackendInfoResolver()

Method Detail

getFutureBackendInfo

public final Optional<T> getFutureBackendInfo(Long cookie)

Return the currently-resolved backend information, if available. This method is guaranteed not to block, but will initiate resolution of the information if there is none.

Parameters:

cookie - Backend cookie

Returns:

Backend information, if available

invalidateBackend

public final void invalidateBackend(long cookie,
                                    @Nonnull
                                    CompletionStage<? extends BackendInfo> info)

Invalidate a particular instance of BackendInfo, typically as a response to a request timing out. If the provided information is not the one currently cached this method does nothing.

Parameters:

cookie - Backend cookie

info - Previous information to be invalidated

resolveBackendInfo

@Nonnull
protected abstract CompletableFuture<T> resolveBackendInfo(@Nonnull
                                                                    Long cookie)

Request new resolution of a particular backend identified by a cookie. This method is invoked when a client requests information which is not currently cached.

Parameters:

cookie - Backend cookie

Returns:

A CompletableFuture resulting in information about the backend

invalidateBackendInfo

protected abstract void invalidateBackendInfo(@Nonnull
                                              CompletionStage<? extends BackendInfo> info)

Invalidate previously-resolved shard information. This method is invoked when a timeout is detected and the information may need to be refreshed.

Parameters:

info - Previous promise of backend information