Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2016 Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onosproject.store.primitives.resources.impl; |
| 17 | |
| 18 | import io.atomix.catalyst.util.Listener; |
| 19 | import io.atomix.copycat.client.CopycatClient; |
| 20 | import io.atomix.resource.Consistency; |
| 21 | import io.atomix.resource.Resource; |
| 22 | import io.atomix.resource.ResourceTypeInfo; |
| 23 | |
| 24 | import java.util.Map; |
| 25 | import java.util.Set; |
| 26 | import java.util.concurrent.CompletableFuture; |
| 27 | import java.util.function.Consumer; |
| 28 | |
| 29 | import org.onosproject.cluster.Leadership; |
| 30 | import org.onosproject.cluster.NodeId; |
| 31 | import org.onosproject.event.Change; |
| 32 | import org.onosproject.store.service.AsyncLeaderElector; |
| 33 | |
| 34 | import com.google.common.collect.Sets; |
| 35 | |
| 36 | /** |
| 37 | * Distributed resource providing the {@link AsyncLeaderElector} primitive. |
| 38 | */ |
| 39 | @ResourceTypeInfo(id = -152, stateMachine = AtomixLeaderElectorState.class) |
| 40 | public class AtomixLeaderElector |
| 41 | extends Resource<AtomixLeaderElector, Resource.Options> implements AsyncLeaderElector { |
| 42 | private final Set<Consumer<Change<Leadership>>> leadershipChangeListeners = |
| 43 | Sets.newConcurrentHashSet(); |
| 44 | |
| 45 | private Listener<Change<Leadership>> listener; |
| 46 | |
| 47 | public AtomixLeaderElector(CopycatClient client, Resource.Options options) { |
| 48 | super(client, options); |
| 49 | } |
| 50 | |
| 51 | @Override |
| 52 | public String name() { |
| 53 | return null; |
| 54 | } |
| 55 | |
| 56 | @Override |
| 57 | public CompletableFuture<AtomixLeaderElector> open() { |
| 58 | return super.open().thenApply(result -> { |
| 59 | client.session().onEvent("change", this::handleEvent); |
| 60 | return result; |
| 61 | }); |
| 62 | } |
| 63 | |
| 64 | private void handleEvent(Change<Leadership> change) { |
| 65 | leadershipChangeListeners.forEach(l -> l.accept(change)); |
| 66 | } |
| 67 | |
| 68 | @Override |
| 69 | public AtomixLeaderElector with(Consistency consistency) { |
| 70 | super.with(consistency); |
| 71 | return this; |
| 72 | } |
| 73 | |
| 74 | @Override |
| 75 | public CompletableFuture<Leadership> run(String topic, NodeId nodeId) { |
| 76 | return submit(new AtomixLeaderElectorCommands.Run(topic, nodeId)); |
| 77 | } |
| 78 | |
| 79 | @Override |
| 80 | public CompletableFuture<Void> withdraw(String topic) { |
| 81 | return submit(new AtomixLeaderElectorCommands.Withdraw(topic)); |
| 82 | } |
| 83 | |
| 84 | @Override |
| 85 | public CompletableFuture<Boolean> anoint(String topic, NodeId nodeId) { |
| 86 | return submit(new AtomixLeaderElectorCommands.Anoint(topic, nodeId)); |
| 87 | } |
| 88 | |
| 89 | @Override |
| 90 | public CompletableFuture<Leadership> getLeadership(String topic) { |
| 91 | return submit(new AtomixLeaderElectorCommands.GetLeadership(topic)); |
| 92 | } |
| 93 | |
| 94 | @Override |
| 95 | public CompletableFuture<Map<String, Leadership>> getLeaderships() { |
| 96 | return submit(new AtomixLeaderElectorCommands.GetAllLeaderships()); |
| 97 | } |
| 98 | |
| 99 | public CompletableFuture<Set<String>> getElectedTopics(NodeId nodeId) { |
| 100 | return submit(new AtomixLeaderElectorCommands.GetElectedTopics(nodeId)); |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Leadership change listener context. |
| 105 | */ |
| 106 | private final class LeadershipChangeListener implements Listener<Change<Leadership>> { |
| 107 | private final Consumer<Change<Leadership>> listener; |
| 108 | |
| 109 | private LeadershipChangeListener(Consumer<Change<Leadership>> listener) { |
| 110 | this.listener = listener; |
| 111 | } |
| 112 | |
| 113 | @Override |
| 114 | public void accept(Change<Leadership> change) { |
| 115 | listener.accept(change); |
| 116 | } |
| 117 | |
| 118 | @Override |
| 119 | public void close() { |
| 120 | synchronized (AtomixLeaderElector.this) { |
| 121 | submit(new AtomixLeaderElectorCommands.Unlisten()); |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | @Override |
| 127 | public CompletableFuture<Void> addChangeListener(Consumer<Change<Leadership>> consumer) { |
| 128 | leadershipChangeListeners.add(consumer); |
| 129 | return setupListener(); |
| 130 | } |
| 131 | |
| 132 | @Override |
| 133 | public CompletableFuture<Void> removeChangeListener(Consumer<Change<Leadership>> consumer) { |
| 134 | leadershipChangeListeners.remove(consumer); |
| 135 | return teardownListener(); |
| 136 | } |
| 137 | |
| 138 | private CompletableFuture<Void> setupListener() { |
| 139 | if (listener == null && !leadershipChangeListeners.isEmpty()) { |
| 140 | Consumer<Change<Leadership>> changeConsumer = change -> { |
| 141 | leadershipChangeListeners.forEach(consumer -> consumer.accept(change)); |
| 142 | }; |
| 143 | return submit(new AtomixLeaderElectorCommands.Listen()) |
| 144 | .thenAccept(v -> listener = new LeadershipChangeListener(changeConsumer)); |
| 145 | } |
| 146 | return CompletableFuture.completedFuture(null); |
| 147 | } |
| 148 | |
| 149 | private CompletableFuture<Void> teardownListener() { |
| 150 | if (listener != null && leadershipChangeListeners.isEmpty()) { |
| 151 | listener.close(); |
| 152 | listener = null; |
| 153 | return submit(new AtomixLeaderElectorCommands.Unlisten()); |
| 154 | } |
| 155 | return CompletableFuture.completedFuture(null); |
| 156 | } |
| 157 | } |