Java tutorial
/* * Copyright 2015-present Open Networking Laboratory * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.onosproject.incubator.rpc.grpc; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.base.Preconditions.checkNotNull; import static com.google.common.cache.RemovalListeners.asynchronous; import static org.onosproject.net.DeviceId.deviceId; import static org.onosproject.net.LinkKey.linkKey; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import org.apache.commons.lang3.tuple.Pair; import org.onosproject.grpc.net.Link.ConnectPoint.ElementIdCase; import org.onosproject.grpc.net.Link.LinkType; import org.onosproject.grpc.net.link.LinkProviderServiceRpcGrpc.LinkProviderServiceRpcImplBase; import org.onosproject.grpc.net.link.LinkService.LinkDetectedMsg; import org.onosproject.grpc.net.link.LinkService.LinkVanishedMsg; import org.onosproject.grpc.net.link.LinkService.Void; import org.onosproject.incubator.protobuf.net.ProtobufUtils; import org.onosproject.net.ConnectPoint; import org.onosproject.net.DeviceId; import org.onosproject.net.Link; import org.onosproject.net.LinkKey; import org.onosproject.net.PortNumber; import org.onosproject.net.SparseAnnotations; import org.onosproject.net.link.DefaultLinkDescription; import org.onosproject.net.link.LinkDescription; import org.onosproject.net.link.LinkProviderService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.cache.Cache; import com.google.common.cache.CacheBuilder; import com.google.common.cache.RemovalNotification; import com.google.common.annotations.Beta; import io.grpc.stub.StreamObserver; // Only single instance will be created and bound to gRPC LinkProviderService /** * Server-side implementation of gRPC version of LinkProviderService. */ @Beta final class LinkProviderServiceServerProxy extends LinkProviderServiceRpcImplBase { /** * Silence time in seconds, until link gets treated as vanished. */ private static final int EVICT_LIMIT = 3 * 3; private final Logger log = LoggerFactory.getLogger(getClass()); private final GrpcRemoteServiceServer server; // TODO implement aging mechanism to automatically remove // stale links reported by dead client, etc. /** * Evicting Cache to track last seen time. */ private final Cache<Pair<String, LinkKey>, LinkDescription> lastSeen; LinkProviderServiceServerProxy(GrpcRemoteServiceServer server) { this.server = checkNotNull(server); ScheduledExecutorService executor = server.getSharedExecutor(); lastSeen = CacheBuilder.newBuilder().expireAfterWrite(EVICT_LIMIT, TimeUnit.SECONDS) .removalListener(asynchronous(this::onRemove, executor)).build(); executor.scheduleWithFixedDelay(lastSeen::cleanUp, EVICT_LIMIT, EVICT_LIMIT, TimeUnit.SECONDS); } private void onRemove(RemovalNotification<Pair<String, LinkKey>, LinkDescription> n) { if (n.wasEvicted()) { getLinkProviderServiceFor(n.getKey().getLeft()).linkVanished(n.getValue()); } } /** * Gets or creates {@link LinkProviderService} registered for given ProviderId scheme. * * @param scheme ProviderId scheme. * @return {@link LinkProviderService} */ private LinkProviderService getLinkProviderServiceFor(String scheme) { return server.getLinkProviderServiceFor(scheme); } @Override public void linkDetected(LinkDetectedMsg request, StreamObserver<Void> responseObserver) { try { onLinkDetected(request, responseObserver); // If onNext call was not mandatory, it can be removed. responseObserver.onNext(Void.getDefaultInstance()); responseObserver.onCompleted(); } catch (Exception e) { log.error("Exception caught", e); responseObserver.onError(e); } } private void onLinkDetected(LinkDetectedMsg request, StreamObserver<Void> responseObserver) { String scheme = request.getProviderId(); LinkProviderService linkProviderService = getLinkProviderServiceFor(scheme); LinkDescription linkDescription = translate(request.getLinkDescription()); linkProviderService.linkDetected(linkDescription); lastSeen.put(Pair.of(scheme, linkKey(linkDescription)), linkDescription); } @Override public void linkVanished(LinkVanishedMsg request, StreamObserver<Void> responseObserver) { try { onLinksVanished(request, responseObserver); // If onNext call was not mandatory, it can be removed. responseObserver.onNext(Void.getDefaultInstance()); responseObserver.onCompleted(); } catch (Exception e) { log.error("Exception caught", e); responseObserver.onError(e); } } private void onLinksVanished(LinkVanishedMsg request, StreamObserver<Void> responseObserver) { String scheme = request.getProviderId(); switch (request.getSubjectCase()) { case CONNECT_POINT: ConnectPoint cp = translate(request.getConnectPoint()); getLinkProviderServiceFor(scheme).linksVanished(cp); break; case DEVICE_ID: DeviceId did = deviceId(request.getDeviceId()); getLinkProviderServiceFor(scheme).linksVanished(did); break; case LINK_DESCRIPTION: LinkDescription desc = translate(request.getLinkDescription()); getLinkProviderServiceFor(scheme).linkVanished(desc); lastSeen.invalidate(Pair.of(scheme, linkKey(desc))); break; case SUBJECT_NOT_SET: default: // do nothing break; } } /** * Translates gRPC message to corresponding ONOS object. * * @param connectPoint gRPC message. * @return {@link ConnectPoint} */ private ConnectPoint translate(org.onosproject.grpc.net.Link.ConnectPoint connectPoint) { checkArgument(connectPoint.getElementIdCase() == ElementIdCase.DEVICE_ID, "Only DeviceId supported."); return new ConnectPoint(deviceId(connectPoint.getDeviceId()), PortNumber.fromString(connectPoint.getPortNumber())); } /** * Translates gRPC message to corresponding ONOS object. * * @param linkDescription gRPC message * @return {@link LinkDescription} */ private LinkDescription translate(org.onosproject.grpc.net.Link.LinkDescription linkDescription) { ConnectPoint src = translate(linkDescription.getSrc()); ConnectPoint dst = translate(linkDescription.getDst()); Link.Type type = translate(linkDescription.getType()); SparseAnnotations annotations = ProtobufUtils.asAnnotations(linkDescription.getAnnotations()); return new DefaultLinkDescription(src, dst, type, annotations); } /** * Translates gRPC message to corresponding ONOS object. * * @param type gRPC message enum * @return {@link org.onosproject.net.Link.Type Link.Type} */ private Link.Type translate(LinkType type) { switch (type) { case DIRECT: return Link.Type.DIRECT; case EDGE: return Link.Type.EDGE; case INDIRECT: return Link.Type.INDIRECT; case OPTICAL: return Link.Type.INDIRECT; case TUNNEL: return Link.Type.TUNNEL; case VIRTUAL: return Link.Type.VIRTUAL; case UNRECOGNIZED: default: return Link.Type.DIRECT; } } }