Java tutorial
/* * 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 com.google.common.collect.Maps; import org.onlab.util.Tools; import org.onosproject.store.primitives.TransactionId; import org.onosproject.store.service.AsyncConsistentTreeMap; import org.onosproject.store.service.MapEvent; import org.onosproject.store.service.MapEventListener; import org.onosproject.store.service.MapTransaction; import org.onosproject.store.service.Versioned; import java.util.Collection; import java.util.Map; import java.util.NavigableMap; import java.util.NavigableSet; import java.util.Set; import java.util.concurrent.CompletableFuture; import java.util.concurrent.Executor; import java.util.function.BiFunction; import java.util.function.Function; import java.util.function.Predicate; import java.util.stream.Collectors; /** * An {@code AsyncConsistentTreeMap} that maps its operations to operations on * a differently typed {@code AsyncConsistentTreeMap} by transcoding operation * inputs and outputs. * * @param <V2> value type of other map * @param <V1> value type of this map */ public class TranscodingAsyncConsistentTreeMap<V1, V2> implements AsyncConsistentTreeMap<V1> { private final AsyncConsistentTreeMap<V2> backingMap; private final Function<V2, V1> valueDecoder; private final Function<V1, V2> valueEncoder; private final Function<Versioned<V2>, Versioned<V1>> versionedValueTransform; private final Map<MapEventListener<String, V1>, TranscodingAsyncConsistentTreeMap.InternalBackingMapEventListener> listeners = Maps .newIdentityHashMap(); public TranscodingAsyncConsistentTreeMap(AsyncConsistentTreeMap<V2> backingMap, Function<V1, V2> valueEncoder, Function<V2, V1> valueDecoder) { this.backingMap = backingMap; this.valueEncoder = v -> v == null ? null : valueEncoder.apply(v); this.valueDecoder = v -> v == null ? null : valueDecoder.apply(v); this.versionedValueTransform = v -> v == null ? null : v.map(valueDecoder); } @Override public CompletableFuture<String> firstKey() { return backingMap.firstKey(); } @Override public CompletableFuture<String> lastKey() { return backingMap.lastKey(); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> ceilingEntry(String key) { return backingMap.ceilingEntry(key).thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> floorEntry(String key) { return backingMap.floorEntry(key).thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> higherEntry(String key) { return backingMap.higherEntry(key).thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> lowerEntry(String key) { return backingMap.lowerEntry(key).thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> firstEntry() { return backingMap.firstEntry().thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> lastEntry() { return backingMap.lastEntry().thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> pollFirstEntry() { return backingMap.pollFirstEntry().thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<Map.Entry<String, Versioned<V1>>> pollLastEntry() { return backingMap.pollLastEntry().thenApply( entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))); } @Override public CompletableFuture<String> lowerKey(String key) { return backingMap.lowerKey(key); } @Override public CompletableFuture<String> floorKey(String key) { return backingMap.floorKey(key); } @Override public CompletableFuture<String> ceilingKey(String key) { return backingMap.ceilingKey(key); } @Override public CompletableFuture<String> higherKey(String key) { return backingMap.higherKey(key); } @Override public CompletableFuture<NavigableSet<String>> navigableKeySet() { return backingMap.navigableKeySet(); } @Override public CompletableFuture<NavigableMap<String, V1>> subMap(String upperKey, String lowerKey, boolean inclusiveUpper, boolean inclusiveLower) { throw new UnsupportedOperationException("This operation is not yet" + "supported."); } @Override public String name() { return backingMap.name(); } @Override public CompletableFuture<Integer> size() { return backingMap.size(); } @Override public CompletableFuture<Boolean> containsKey(String key) { return backingMap.containsKey(key); } @Override public CompletableFuture<Boolean> containsValue(V1 value) { return backingMap.containsValue(valueEncoder.apply(value)); } @Override public CompletableFuture<Versioned<V1>> get(String key) { return backingMap.get(key).thenApply(versionedValueTransform); } @Override public CompletableFuture<Versioned<V1>> computeIf(String key, Predicate<? super V1> condition, BiFunction<? super String, ? super V1, ? extends V1> remappingFunction) { try { return backingMap .computeIf(key, v -> condition.test(valueDecoder.apply(v)), (k, v) -> valueEncoder.apply(remappingFunction.apply(key, valueDecoder.apply(v)))) .thenApply(versionedValueTransform); } catch (Exception e) { return Tools.exceptionalFuture(e); } } @Override public CompletableFuture<Versioned<V1>> put(String key, V1 value) { return backingMap.put(key, valueEncoder.apply(value)).thenApply(versionedValueTransform); } @Override public CompletableFuture<Versioned<V1>> putAndGet(String key, V1 value) { return backingMap.putAndGet(key, valueEncoder.apply(value)).thenApply(versionedValueTransform); } @Override public CompletableFuture<Versioned<V1>> remove(String key) { return backingMap.remove(key).thenApply(versionedValueTransform); } @Override public CompletableFuture<Void> clear() { return backingMap.clear(); } @Override public CompletableFuture<Set<String>> keySet() { return backingMap.keySet(); } @Override public CompletableFuture<Collection<Versioned<V1>>> values() { return backingMap.values() .thenApply(valueSet -> valueSet.stream().map(versionedValueTransform).collect(Collectors.toSet())); } @Override public CompletableFuture<Set<Map.Entry<String, Versioned<V1>>>> entrySet() { return backingMap.entrySet().thenApply(entries -> entries.stream() .map(entry -> Maps.immutableEntry(entry.getKey(), versionedValueTransform.apply(entry.getValue()))) .collect(Collectors.toSet())); } @Override public CompletableFuture<Versioned<V1>> putIfAbsent(String key, V1 value) { return backingMap.putIfAbsent(key, valueEncoder.apply(value)).thenApply(versionedValueTransform); } @Override public CompletableFuture<Boolean> remove(String key, V1 value) { return backingMap.remove(key, valueEncoder.apply(value)); } @Override public CompletableFuture<Boolean> remove(String key, long version) { return backingMap.remove(key, version); } @Override public CompletableFuture<Versioned<V1>> replace(String key, V1 value) { return backingMap.replace(key, valueEncoder.apply(value)).thenApply(versionedValueTransform); } @Override public CompletableFuture<Boolean> replace(String key, V1 oldValue, V1 newValue) { return backingMap.replace(key, valueEncoder.apply(oldValue), valueEncoder.apply(newValue)); } @Override public CompletableFuture<Boolean> replace(String key, long oldVersion, V1 newValue) { return backingMap.replace(key, oldVersion, valueEncoder.apply(newValue)); } @Override public CompletableFuture<Void> addListener(MapEventListener<String, V1> listener, Executor executor) { InternalBackingMapEventListener backingMapEventListener = listeners.computeIfAbsent(listener, k -> new InternalBackingMapEventListener(listener)); return backingMap.addListener(backingMapEventListener, executor); } @Override public CompletableFuture<Void> removeListener(MapEventListener<String, V1> listener) { InternalBackingMapEventListener backingMapEventListener = listeners.remove(listener); if (backingMapEventListener == null) { return CompletableFuture.completedFuture(null); } else { return backingMap.removeListener(backingMapEventListener); } } @Override public CompletableFuture<Boolean> prepare(MapTransaction<String, V1> transaction) { throw new UnsupportedOperationException("This operation is not yet " + "supported."); } @Override public CompletableFuture<Void> commit(TransactionId transactionId) { throw new UnsupportedOperationException("This operation is not yet " + "supported."); } @Override public CompletableFuture<Void> rollback(TransactionId transactionId) { throw new UnsupportedOperationException("This operation is not yet " + "supported."); } @Override public CompletableFuture<Boolean> prepareAndCommit(MapTransaction<String, V1> transaction) { throw new UnsupportedOperationException("This operation is not yet " + "supported."); } private class InternalBackingMapEventListener implements MapEventListener<String, V2> { private final MapEventListener<String, V1> listener; InternalBackingMapEventListener(MapEventListener<String, V1> listener) { this.listener = listener; } @Override public void event(MapEvent<String, V2> event) { listener.event(new MapEvent<String, V1>(event.name(), event.key(), event.newValue() != null ? event.newValue().map(valueDecoder) : null, event.oldValue() != null ? event.oldValue().map(valueDecoder) : null)); } } }