Madan Jampani | dfde6ba | 2016-01-13 21:36:09 -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 | */ |
Madan Jampani | f4c8850 | 2016-01-21 12:35:36 -0800 | [diff] [blame^] | 16 | package org.onosproject.store.primitives.impl; |
Madan Jampani | dfde6ba | 2016-01-13 21:36:09 -0800 | [diff] [blame] | 17 | |
| 18 | import org.onosproject.store.service.AsyncAtomicValue; |
| 19 | import org.onosproject.store.service.AsyncConsistentMap; |
| 20 | import org.onosproject.store.service.AtomicValueEvent; |
| 21 | import org.onosproject.store.service.AtomicValueEventListener; |
| 22 | import org.onosproject.store.service.MapEvent; |
| 23 | import org.onosproject.store.service.MapEventListener; |
| 24 | import org.onosproject.store.service.Versioned; |
| 25 | |
| 26 | import java.util.Set; |
| 27 | import java.util.concurrent.CompletableFuture; |
| 28 | import java.util.concurrent.CopyOnWriteArraySet; |
| 29 | |
| 30 | /** |
| 31 | * Default implementation of {@link AsyncAtomicValue}. |
| 32 | * |
| 33 | * @param <V> value type |
| 34 | */ |
| 35 | public class DefaultAsyncAtomicValue<V> implements AsyncAtomicValue<V> { |
| 36 | |
| 37 | private final Set<AtomicValueEventListener<V>> listeners = new CopyOnWriteArraySet<>(); |
| 38 | private final AsyncConsistentMap<String, V> valueMap; |
| 39 | private final String name; |
| 40 | private final MapEventListener<String, V> mapEventListener = new InternalMapEventListener(); |
| 41 | private final MeteringAgent monitor; |
| 42 | |
| 43 | private static final String COMPONENT_NAME = "atomicValue"; |
| 44 | private static final String GET = "get"; |
| 45 | private static final String GET_AND_SET = "getAndSet"; |
| 46 | private static final String SET = "set"; |
| 47 | private static final String COMPARE_AND_SET = "compareAndSet"; |
| 48 | |
| 49 | public DefaultAsyncAtomicValue(AsyncConsistentMap<String, V> valueMap, |
| 50 | String name, |
| 51 | boolean meteringEnabled) { |
| 52 | this.valueMap = valueMap; |
| 53 | this.name = name; |
| 54 | this.monitor = new MeteringAgent(COMPONENT_NAME, name, meteringEnabled); |
| 55 | } |
| 56 | |
| 57 | @Override |
Madan Jampani | a090a11 | 2016-01-18 16:38:17 -0800 | [diff] [blame] | 58 | public String name() { |
| 59 | return name; |
| 60 | } |
| 61 | |
| 62 | @Override |
Madan Jampani | dfde6ba | 2016-01-13 21:36:09 -0800 | [diff] [blame] | 63 | public CompletableFuture<Boolean> compareAndSet(V expect, V update) { |
| 64 | final MeteringAgent.Context newTimer = monitor.startTimer(COMPARE_AND_SET); |
| 65 | CompletableFuture<Boolean> response; |
| 66 | if (expect == null) { |
| 67 | if (update == null) { |
| 68 | response = CompletableFuture.completedFuture(true); |
| 69 | } |
| 70 | response = valueMap.putIfAbsent(name, update).thenApply(v -> v == null); |
| 71 | } else { |
| 72 | response = update == null |
| 73 | ? valueMap.remove(name, expect) |
| 74 | : valueMap.replace(name, expect, update); |
| 75 | } |
| 76 | return response.whenComplete((r, e) -> newTimer.stop(null)); |
| 77 | } |
| 78 | |
| 79 | @Override |
| 80 | public CompletableFuture<V> get() { |
| 81 | final MeteringAgent.Context newTimer = monitor.startTimer(GET); |
| 82 | return valueMap.get(name) |
| 83 | .thenApply(Versioned::valueOrNull) |
| 84 | .whenComplete((r, e) -> newTimer.stop(null)); |
| 85 | } |
| 86 | |
| 87 | @Override |
| 88 | public CompletableFuture<V> getAndSet(V value) { |
| 89 | final MeteringAgent.Context newTimer = monitor.startTimer(GET_AND_SET); |
| 90 | CompletableFuture<Versioned<V>> previousValue = value == null ? |
| 91 | valueMap.remove(name) : valueMap.put(name, value); |
| 92 | return previousValue.thenApply(Versioned::valueOrNull) |
| 93 | .whenComplete((r, e) -> newTimer.stop(null)); |
| 94 | } |
| 95 | |
| 96 | @Override |
| 97 | public CompletableFuture<Void> set(V value) { |
| 98 | final MeteringAgent.Context newTimer = monitor.startTimer(SET); |
| 99 | CompletableFuture<Void> previousValue = value == null ? |
| 100 | valueMap.remove(name).thenApply(v -> null) : valueMap.put(name, value).thenApply(v -> null); |
| 101 | return previousValue.whenComplete((r, e) -> newTimer.stop(null)); |
| 102 | } |
| 103 | |
| 104 | @Override |
| 105 | public CompletableFuture<Void> addListener(AtomicValueEventListener<V> listener) { |
| 106 | synchronized (listeners) { |
| 107 | if (listeners.add(listener)) { |
| 108 | if (listeners.size() == 1) { |
| 109 | return valueMap.addListener(mapEventListener); |
| 110 | } |
| 111 | } |
| 112 | } |
| 113 | return CompletableFuture.completedFuture(null); |
| 114 | } |
| 115 | |
| 116 | @Override |
| 117 | public CompletableFuture<Void> removeListener(AtomicValueEventListener<V> listener) { |
| 118 | synchronized (listeners) { |
| 119 | if (listeners.remove(listener)) { |
| 120 | if (listeners.size() == 0) { |
| 121 | return valueMap.removeListener(mapEventListener); |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | return CompletableFuture.completedFuture(null); |
| 126 | } |
| 127 | |
| 128 | private class InternalMapEventListener implements MapEventListener<String, V> { |
| 129 | |
| 130 | @Override |
| 131 | public void event(MapEvent<String, V> mapEvent) { |
| 132 | V newValue = mapEvent.type() == MapEvent.Type.REMOVE ? null : mapEvent.value().value(); |
| 133 | AtomicValueEvent<V> atomicValueEvent = new AtomicValueEvent<>(name, AtomicValueEvent.Type.UPDATE, newValue); |
| 134 | listeners.forEach(l -> l.event(atomicValueEvent)); |
| 135 | } |
| 136 | } |
| 137 | } |