import akka.actor.ActorRef;
import akka.actor.Status;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionStage;
+import com.google.common.base.Throwables;
+import com.google.common.base.Verify;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.Consumer;
+import org.opendaylight.controller.cluster.access.client.ClientActorBehavior;
+import org.opendaylight.controller.cluster.access.client.ClientActorContext;
+import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
-import org.opendaylight.controller.cluster.datastore.actors.client.ClientActorBehavior;
-import org.opendaylight.controller.cluster.datastore.actors.client.ClientActorContext;
+import org.opendaylight.controller.cluster.access.concepts.Response;
+import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
* {@link ClientActorBehavior} acting as an intermediary between the backend actors and the DistributedDataStore
* frontend.
*
+ * <p>
* This class is not visible outside of this package because it breaks the actor containment. Services provided to
* Java world outside of actor containment are captured in {@link DistributedDataStoreClient}.
*
+ * <p>
* IMPORTANT: this class breaks actor containment via methods implementing {@link DistributedDataStoreClient} contract.
* When touching internal state, be mindful of the execution context from which execution context, Actor
* or POJO, is the state being accessed or modified.
*
+ * <p>
* THREAD SAFETY: this class must always be kept thread-safe, so that both the Actor System thread and the application
* threads can run concurrently. All state transitions must be made in a thread-safe manner. When in
* doubt, feel free to synchronize on this object.
*
+ * <p>
* PERFORMANCE: this class lies in a performance-critical fast path. All code needs to be concise and efficient, but
* performance must not come at the price of correctness. Any optimizations need to be carefully analyzed
* for correctness and performance impact.
*
+ * <p>
* TRADE-OFFS: part of the functionality runs in application threads without switching contexts, which makes it ideal
* for performing work and charging applications for it. That has two positive effects:
* - CPU usage is distributed across applications, minimizing work done in the actor thread
*/
final class DistributedDataStoreClientBehavior extends ClientActorBehavior implements DistributedDataStoreClient {
private static final Logger LOG = LoggerFactory.getLogger(DistributedDataStoreClientBehavior.class);
- private static final Object SHUTDOWN = new Object() {
- @Override
- public String toString() {
- return "SHUTDOWN";
- }
- };
- private long nextHistoryId;
+ private final Map<LocalHistoryIdentifier, ClientLocalHistory> histories = new ConcurrentHashMap<>();
+ private final AtomicLong nextHistoryId = new AtomicLong(1);
+ private final ModuleShardBackendResolver resolver;
+ private final SingleClientHistory singleHistory;
+
+ private volatile Throwable aborted;
- DistributedDataStoreClientBehavior(final ClientActorContext context) {
+ DistributedDataStoreClientBehavior(final ClientActorContext context, final ActorContext actorContext) {
super(context);
+ resolver = new ModuleShardBackendResolver(context.getIdentifier(), actorContext);
+ singleHistory = new SingleClientHistory(this, new LocalHistoryIdentifier(getIdentifier(), 0));
}
//
@Override
protected void haltClient(final Throwable cause) {
- // FIXME: Add state flushing here once we have state
+ // If we have encountered a previous problem there is not cleanup necessary, as we have already cleaned up
+ // Thread safely is not an issue, as both this method and any failures are executed from the same (client actor)
+ // thread.
+ if (aborted != null) {
+ abortOperations(cause);
+ }
}
- private void createLocalHistory(final CreateLocalHistoryCommand command) {
- final CompletableFuture<ClientLocalHistory> future = command.future();
- final LocalHistoryIdentifier historyId = new LocalHistoryIdentifier(getIdentifier(), nextHistoryId++);
- LOG.debug("{}: creating a new local history {} for {}", persistenceId(), historyId, future);
+ private void abortOperations(final Throwable cause) {
+ // This acts as a barrier, application threads check this after they have added an entry in the maps,
+ // and if they observe aborted being non-null, they will perform their cleanup and not return the handle.
+ aborted = cause;
+
+ for (ClientLocalHistory h : histories.values()) {
+ h.localAbort(cause);
+ }
+ histories.clear();
+ }
- // FIXME: initiate backend instantiation
- future.completeExceptionally(new UnsupportedOperationException("Not implemented yet"));
+ private DistributedDataStoreClientBehavior shutdown(final ClientActorBehavior currentBehavior) {
+ abortOperations(new IllegalStateException("Client " + getIdentifier() + " has been shut down"));
+ return null;
}
@Override
- protected ClientActorBehavior onCommand(final Object command) {
- if (command instanceof CreateLocalHistoryCommand) {
- createLocalHistory((CreateLocalHistoryCommand) command);
- } else if (command instanceof GetClientRequest) {
+ protected DistributedDataStoreClientBehavior onCommand(final Object command) {
+ if (command instanceof GetClientRequest) {
((GetClientRequest) command).getReplyTo().tell(new Status.Success(this), ActorRef.noSender());
- } else if (SHUTDOWN.equals(command)) {
- // FIXME: Add shutdown procedures here
- return null;
} else {
LOG.warn("{}: ignoring unhandled command {}", persistenceId(), command);
}
//
//
+ @SuppressWarnings("checkstyle:IllegalCatch")
+ private static <K, V extends LocalAbortable> V returnIfOperational(final Map<K , V> map, final K key, final V value,
+ final Throwable aborted) {
+ Verify.verify(map.put(key, value) == null);
+
+ if (aborted != null) {
+ try {
+ value.localAbort(aborted);
+ } catch (Exception e) {
+ LOG.debug("Close of {} failed", value, e);
+ }
+ map.remove(key, value);
+ throw Throwables.propagate(aborted);
+ }
+
+ return value;
+ }
+
@Override
- public CompletionStage<ClientLocalHistory> createLocalHistory() {
- final CreateLocalHistoryCommand command = new CreateLocalHistoryCommand();
- self().tell(command, ActorRef.noSender());
- return command.future();
+ public ClientLocalHistory createLocalHistory() {
+ final LocalHistoryIdentifier historyId = new LocalHistoryIdentifier(getIdentifier(),
+ nextHistoryId.getAndIncrement());
+ final ClientLocalHistory history = new ClientLocalHistory(this, historyId);
+ LOG.debug("{}: creating a new local history {}", persistenceId(), history);
+
+ return returnIfOperational(histories, historyId, history, aborted);
+ }
+
+ @Override
+ public ClientTransaction createTransaction() {
+ return singleHistory.createTransaction();
}
@Override
public void close() {
- self().tell(SHUTDOWN, ActorRef.noSender());
+ context().executeInActor(this::shutdown);
+ }
+
+ @Override
+ protected ModuleShardBackendResolver resolver() {
+ return resolver;
}
+
+ void sendRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> completer) {
+ sendRequest(request, response -> {
+ completer.accept(response);
+ return this;
+ });
+ }
+
}