| /* |
| * Copyright 2016-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.store.primitives.impl; |
| |
| import java.util.Map; |
| import java.util.concurrent.CompletableFuture; |
| import java.util.concurrent.Executor; |
| import java.util.function.Consumer; |
| |
| import org.onosproject.store.service.AsyncAtomicValue; |
| import org.onosproject.store.service.AtomicValueEventListener; |
| import org.onosproject.store.service.DistributedPrimitive; |
| import org.onosproject.store.service.Topic; |
| |
| import com.google.common.collect.Maps; |
| |
| /** |
| * Default implementation of {@link Topic}. |
| * |
| * @param <T> topic message type. |
| */ |
| public class DefaultDistributedTopic<T> implements Topic<T> { |
| |
| private final AsyncAtomicValue<T> atomicValue; |
| private final Map<Consumer<T>, AtomicValueEventListener<T>> callbacks = Maps.newIdentityHashMap(); |
| |
| DefaultDistributedTopic(AsyncAtomicValue<T> atomicValue) { |
| this.atomicValue = atomicValue; |
| } |
| |
| @Override |
| public String name() { |
| return atomicValue.name(); |
| } |
| |
| @Override |
| public Type primitiveType() { |
| return DistributedPrimitive.Type.TOPIC; |
| } |
| |
| @Override |
| public CompletableFuture<Void> destroy() { |
| return atomicValue.destroy(); |
| } |
| |
| @Override |
| public CompletableFuture<Void> publish(T message) { |
| return atomicValue.set(message); |
| } |
| |
| @Override |
| public CompletableFuture<Void> subscribe(Consumer<T> callback, Executor executor) { |
| AtomicValueEventListener<T> valueListener = |
| event -> executor.execute(() -> callback.accept(event.newValue())); |
| if (callbacks.putIfAbsent(callback, valueListener) == null) { |
| return atomicValue.addListener(valueListener); |
| } |
| return CompletableFuture.completedFuture(null); |
| } |
| |
| @Override |
| public CompletableFuture<Void> unsubscribe(Consumer<T> callback) { |
| AtomicValueEventListener<T> valueListener = callbacks.remove(callback); |
| if (valueListener != null) { |
| return atomicValue.removeListener(valueListener); |
| } |
| return CompletableFuture.completedFuture(null); |
| } |
| } |