*/
package org.opendaylight.controller.cluster.databroker.actors.dds;
-import akka.actor.ActorRef;
-import akka.actor.Status;
-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 java.util.function.Function;
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.access.concepts.Response;
-import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
/**
- * {@link ClientActorBehavior} acting as an intermediary between the backend actors and the DistributedDataStore
- * frontend.
- *
- * 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}.
- *
- * 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.
- *
- * 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.
- *
- * 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.
- *
- * 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
- * - CPU usage provides back-pressure towards the application.
+ * {@link AbstractDataStoreClientBehavior} which performs module-based sharding.
*
* @author Robert Varga
*/
-final class DistributedDataStoreClientBehavior extends ClientActorBehavior implements DistributedDataStoreClient {
- private static final Logger LOG = LoggerFactory.getLogger(DistributedDataStoreClientBehavior.class);
-
- private final Map<TransactionIdentifier, ClientTransaction> transactions = new ConcurrentHashMap<>();
- private final Map<LocalHistoryIdentifier, ClientLocalHistory> histories = new ConcurrentHashMap<>();
- private final AtomicLong nextHistoryId = new AtomicLong(1);
- private final AtomicLong nextTransactionId = new AtomicLong();
- private final ModuleShardBackendResolver resolver;
- private final SingleClientHistory singleHistory;
-
- private volatile Throwable aborted;
-
- DistributedDataStoreClientBehavior(final ClientActorContext context, final ActorContext actorContext) {
- super(context);
- resolver = new ModuleShardBackendResolver(context.getIdentifier(), actorContext);
- singleHistory = new SingleClientHistory(this, new LocalHistoryIdentifier(getIdentifier(), 0));
- }
-
- //
- //
- // Methods below are invoked from the client actor thread
- //
- //
-
- @Override
- protected void haltClient(final Throwable cause) {
- // 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 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();
-
- for (ClientTransaction t : transactions.values()) {
- t.localAbort(cause);
- }
- transactions.clear();
- }
-
- private DistributedDataStoreClientBehavior shutdown(final ClientActorBehavior currentBehavior) {
- abortOperations(new IllegalStateException("Client " + getIdentifier() + " has been shut down"));
- return null;
- }
-
- @Override
- protected DistributedDataStoreClientBehavior onCommand(final Object command) {
- if (command instanceof GetClientRequest) {
- ((GetClientRequest) command).getReplyTo().tell(new Status.Success(this), ActorRef.noSender());
- } else {
- LOG.warn("{}: ignoring unhandled command {}", persistenceId(), command);
- }
-
- return this;
- }
-
- //
- //
- // Methods below are invoked from application threads
- //
- //
-
- 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);
- }
+final class DistributedDataStoreClientBehavior extends AbstractDataStoreClientBehavior {
+ private final Function<YangInstanceIdentifier, Long> pathToShard;
- return value;
+ private DistributedDataStoreClientBehavior(final ClientActorContext context,
+ final ModuleShardBackendResolver resolver) {
+ super(context, resolver);
+ pathToShard = resolver::resolveShardForPath;
}
- @Override
- 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() {
- final TransactionIdentifier txId = new TransactionIdentifier(singleHistory.getIdentifier(),
- nextTransactionId.getAndIncrement());
- final ClientTransaction tx = new ClientTransaction(singleHistory, txId);
- LOG.debug("{}: creating a new transaction {}", persistenceId(), tx);
-
- return returnIfOperational(transactions, txId, tx, aborted);
- }
-
- @Override
- public void close() {
- context().executeInActor(this::shutdown);
+ DistributedDataStoreClientBehavior(final ClientActorContext context, final ActorContext actorContext) {
+ this(context, new ModuleShardBackendResolver(context.getIdentifier(), actorContext));
}
@Override
- protected ModuleShardBackendResolver resolver() {
- return resolver;
+ Long resolveShardForPath(final YangInstanceIdentifier path) {
+ return pathToShard.apply(path);
}
-
- void transactionComplete(final ClientTransaction transaction) {
- transactions.remove(transaction.getIdentifier());
- }
-
- void sendRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> completer) {
- sendRequest(request, response -> {
- completer.accept(response);
- return this;
- });
- }
-
}