--- /dev/null
+/*
+ * Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.access.client;
+
+import akka.actor.ActorRef;
+import com.google.common.base.Preconditions;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import java.util.ArrayDeque;
+import java.util.Iterator;
+import java.util.Optional;
+import java.util.Queue;
+import javax.annotation.concurrent.GuardedBy;
+import org.opendaylight.controller.cluster.access.ABIVersion;
+import org.opendaylight.controller.cluster.access.concepts.Request;
+import org.opendaylight.controller.cluster.access.concepts.RequestException;
+import org.opendaylight.controller.cluster.access.concepts.Response;
+import org.opendaylight.controller.cluster.access.concepts.ResponseEnvelope;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import scala.concurrent.duration.FiniteDuration;
+
+/**
+ * Implementation-internal intermediate subclass between {@link AbstractClientConnection} and two-out of three of its
+ * sublcasses. It allows us to share some code.
+ *
+ * @author Robert Varga
+ *
+ * @param <T> Concrete {@link BackendInfo} type
+ */
+abstract class AbstractReceivingClientConnection<T extends BackendInfo> extends AbstractClientConnection<T> {
+ private static final Logger LOG = LoggerFactory.getLogger(AbstractReceivingClientConnection.class);
+
+ private final Queue<TransmittedConnectionEntry> inflight = new ArrayDeque<>();
+ private final T backend;
+
+ private long lastProgress;
+
+ AbstractReceivingClientConnection(final ClientActorContext context, final Long cookie, final T backend) {
+ super(context, cookie);
+ this.backend = Preconditions.checkNotNull(backend);
+ this.lastProgress = readTime();
+ }
+
+ AbstractReceivingClientConnection(final AbstractReceivingClientConnection<T> oldConnection) {
+ super(oldConnection);
+ this.backend = oldConnection.backend;
+ this.lastProgress = oldConnection.lastProgress;
+ }
+
+ @Override
+ public final Optional<T> getBackendInfo() {
+ return Optional.of(backend);
+ }
+
+ final ActorRef remoteActor() {
+ return backend.getActor();
+ }
+
+ final int remoteMaxMessages() {
+ return backend.getMaxMessages();
+ }
+
+ final ABIVersion remoteVersion() {
+ return backend.getVersion();
+ }
+
+ final long sessionId() {
+ return backend.getSessionId();
+ }
+
+ final int inflightSize() {
+ return inflight.size();
+ }
+
+ final void appendToInflight(final TransmittedConnectionEntry entry) {
+ // This should never fail
+ inflight.add(entry);
+ }
+
+ @GuardedBy("this")
+ @Override
+ void spliceToSuccessor(final ReconnectForwarder successor) {
+ ConnectionEntry entry = inflight.poll();
+ while (entry != null) {
+ successor.forwardEntry(entry);
+ entry = inflight.poll();
+ }
+
+ super.spliceToSuccessor(successor);
+ }
+
+ @Override
+ void receiveResponse(final ResponseEnvelope<?> envelope) {
+ Optional<TransmittedConnectionEntry> maybeEntry = findMatchingEntry(inflight, envelope);
+ if (maybeEntry == null) {
+ LOG.debug("Request for {} not found in inflight queue, checking pending queue", envelope);
+ maybeEntry = findMatchingEntry(pending(), envelope);
+ }
+
+ if (maybeEntry == null || !maybeEntry.isPresent()) {
+ LOG.warn("No request matching {} found, ignoring response", envelope);
+ return;
+ }
+
+ lastProgress = readTime();
+ maybeEntry.get().complete(envelope.getMessage());
+
+ // We have freed up a slot, try to transmit something
+ final int toSend = remoteMaxMessages() - inflight.size();
+ if (toSend > 0) {
+ sendMessages(toSend);
+ }
+ }
+
+ @Override
+ boolean isEmpty() {
+ return inflight.isEmpty() && super.isEmpty();
+ }
+
+ @Override
+ void poison(final RequestException cause) {
+ super.poison(cause);
+ poisonQueue(inflight, cause);
+ }
+
+ /**
+ * Transmit a given number of messages.
+ *
+ * @param count Number of messages to transmit, guaranteed to be positive.
+ */
+ abstract void sendMessages(int count);
+
+ /*
+ * We are using tri-state return here to indicate one of three conditions:
+ * - if a matching entry is found, return an Optional containing it
+ * - if a matching entry is not found, but it makes sense to keep looking at other queues, return null
+ * - if a conflicting entry is encountered, indicating we should ignore this request, return an empty Optional
+ */
+ @SuppressFBWarnings(value = "NP_OPTIONAL_RETURN_NULL",
+ justification = "Returning null Optional is documented in the API contract.")
+ private static Optional<TransmittedConnectionEntry> findMatchingEntry(final Queue<? extends ConnectionEntry> queue,
+ final ResponseEnvelope<?> envelope) {
+ // Try to find the request in a queue. Responses may legally come back in a different order, hence we need
+ // to use an iterator
+ final Iterator<? extends ConnectionEntry> it = queue.iterator();
+ while (it.hasNext()) {
+ final ConnectionEntry e = it.next();
+ final Request<?, ?> request = e.getRequest();
+ final Response<?, ?> response = envelope.getMessage();
+
+ // First check for matching target, or move to next entry
+ if (!request.getTarget().equals(response.getTarget())) {
+ continue;
+ }
+
+ // Sanity-check logical sequence, ignore any out-of-order messages
+ if (request.getSequence() != response.getSequence()) {
+ LOG.debug("Expecting sequence {}, ignoring response {}", request.getSequence(), envelope);
+ return Optional.empty();
+ }
+
+ // Check if the entry has (ever) been transmitted
+ if (!(e instanceof TransmittedConnectionEntry)) {
+ return Optional.empty();
+ }
+
+ final TransmittedConnectionEntry te = (TransmittedConnectionEntry) e;
+
+ // Now check session match
+ if (envelope.getSessionId() != te.getSessionId()) {
+ LOG.debug("Expecting session {}, ignoring response {}", te.getSessionId(), envelope);
+ return Optional.empty();
+ }
+ if (envelope.getTxSequence() != te.getTxSequence()) {
+ LOG.warn("Expecting txSequence {}, ignoring response {}", te.getTxSequence(), envelope);
+ return Optional.empty();
+ }
+
+ LOG.debug("Completing request {} with {}", request, envelope);
+ it.remove();
+ return Optional.of(te);
+ }
+
+ return null;
+ }
+
+ @SuppressFBWarnings(value = "NP_OPTIONAL_RETURN_NULL",
+ justification = "Returning null Optional is documented in the API contract.")
+ @Override
+ final Optional<FiniteDuration> checkTimeout(final long now) {
+ final Optional<FiniteDuration> xmit = checkTimeout(inflight.peek(), now);
+ if (xmit == null) {
+ return null;
+ }
+ final Optional<FiniteDuration> pend = super.checkTimeout(now);
+ if (pend == null) {
+ return null;
+ }
+ if (!xmit.isPresent()) {
+ return pend;
+ }
+ if (!pend.isPresent()) {
+ return xmit;
+ }
+
+ return Optional.of(xmit.get().min(pend.get()));
+ }
+}
Code Review / controller.git / blobdiff