Jordan Halterman | 400bbe5 | 2018-04-05 23:07:47 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2018-present Open Networking Foundation |
| 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.impl; |
| 17 | |
| 18 | import java.util.Collection; |
| 19 | import java.util.Map; |
| 20 | import java.util.concurrent.CompletableFuture; |
| 21 | import java.util.function.Consumer; |
| 22 | import java.util.function.Function; |
| 23 | |
| 24 | import com.google.common.collect.Maps; |
| 25 | import org.onosproject.store.service.AsyncAtomicValue; |
| 26 | import org.onosproject.store.service.AtomicValueEvent; |
| 27 | import org.onosproject.store.service.AtomicValueEventListener; |
| 28 | |
| 29 | /** |
| 30 | * An {@code AsyncAtomicValue} that transcodes values. |
| 31 | */ |
| 32 | public class TranscodingAsyncAtomicValue<V1, V2> implements AsyncAtomicValue<V1> { |
| 33 | private final AsyncAtomicValue<V2> backingValue; |
| 34 | private final Function<V1, V2> valueEncoder; |
| 35 | private final Function<V2, V1> valueDecoder; |
| 36 | private final Map<AtomicValueEventListener<V1>, InternalValueEventListener> listeners = Maps.newIdentityHashMap(); |
| 37 | |
| 38 | public TranscodingAsyncAtomicValue( |
| 39 | AsyncAtomicValue<V2> backingValue, Function<V1, V2> valueEncoder, Function<V2, V1> valueDecoder) { |
| 40 | this.backingValue = backingValue; |
| 41 | this.valueEncoder = k -> k == null ? null : valueEncoder.apply(k); |
| 42 | this.valueDecoder = k -> k == null ? null : valueDecoder.apply(k); |
| 43 | } |
| 44 | |
| 45 | @Override |
| 46 | public String name() { |
| 47 | return backingValue.name(); |
| 48 | } |
| 49 | |
| 50 | @Override |
| 51 | public CompletableFuture<Boolean> compareAndSet(V1 expect, V1 update) { |
| 52 | return backingValue.compareAndSet(valueEncoder.apply(expect), valueEncoder.apply(update)); |
| 53 | } |
| 54 | |
| 55 | @Override |
| 56 | public CompletableFuture<V1> get() { |
| 57 | return backingValue.get().thenApply(valueDecoder); |
| 58 | } |
| 59 | |
| 60 | @Override |
| 61 | public CompletableFuture<V1> getAndSet(V1 value) { |
| 62 | return backingValue.getAndSet(valueEncoder.apply(value)).thenApply(valueDecoder); |
| 63 | } |
| 64 | |
| 65 | @Override |
| 66 | public CompletableFuture<Void> set(V1 value) { |
| 67 | return backingValue.set(valueEncoder.apply(value)); |
| 68 | } |
| 69 | |
| 70 | @Override |
| 71 | public CompletableFuture<Void> addListener(AtomicValueEventListener<V1> listener) { |
| 72 | synchronized (listeners) { |
| 73 | InternalValueEventListener backingMapListener = |
| 74 | listeners.computeIfAbsent(listener, k -> new InternalValueEventListener(listener)); |
| 75 | return backingValue.addListener(backingMapListener); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | @Override |
| 80 | public CompletableFuture<Void> removeListener(AtomicValueEventListener<V1> listener) { |
| 81 | synchronized (listeners) { |
| 82 | InternalValueEventListener backingMapListener = listeners.remove(listener); |
| 83 | if (backingMapListener != null) { |
| 84 | return backingValue.removeListener(backingMapListener); |
| 85 | } else { |
| 86 | return CompletableFuture.completedFuture(null); |
| 87 | } |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | @Override |
| 92 | public void addStatusChangeListener(Consumer<Status> listener) { |
| 93 | backingValue.addStatusChangeListener(listener); |
| 94 | } |
| 95 | |
| 96 | @Override |
| 97 | public void removeStatusChangeListener(Consumer<Status> listener) { |
| 98 | backingValue.removeStatusChangeListener(listener); |
| 99 | } |
| 100 | |
| 101 | @Override |
| 102 | public Collection<Consumer<Status>> statusChangeListeners() { |
| 103 | return backingValue.statusChangeListeners(); |
| 104 | } |
| 105 | |
| 106 | private class InternalValueEventListener implements AtomicValueEventListener<V2> { |
| 107 | private final AtomicValueEventListener<V1> listener; |
| 108 | |
| 109 | InternalValueEventListener(AtomicValueEventListener<V1> listener) { |
| 110 | this.listener = listener; |
| 111 | } |
| 112 | |
| 113 | @Override |
| 114 | public void event(AtomicValueEvent<V2> event) { |
| 115 | listener.event(new AtomicValueEvent<>( |
| 116 | event.name(), |
| 117 | event.newValue() != null ? valueDecoder.apply(event.newValue()) : null, |
| 118 | event.oldValue() != null ? valueDecoder.apply(event.oldValue()) : null)); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | } |