| /* |
| * Copyright 2015 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.consistent.impl; |
| |
| import java.util.concurrent.CompletableFuture; |
| |
| import org.onosproject.core.ApplicationId; |
| import org.onosproject.store.service.Serializer; |
| import org.onosproject.store.service.Versioned; |
| |
| import com.google.common.cache.CacheBuilder; |
| import com.google.common.cache.CacheLoader; |
| import com.google.common.cache.LoadingCache; |
| |
| /** |
| * Extension of {@link DefaultAsyncConsistentMap} that provides a weaker read consistency |
| * guarantee in return for better read performance. |
| * <p> |
| * For read/write operations that are local to a node this map implementation provides |
| * guarantees similar to a ConsistentMap. However for read/write operations executed |
| * across multiple nodes this implementation only provides eventual consistency. |
| * |
| * @param <K> key type |
| * @param <V> value type |
| */ |
| public class AsyncCachingConsistentMap<K, V> extends DefaultAsyncConsistentMap<K, V> { |
| |
| private final LoadingCache<K, CompletableFuture<Versioned<V>>> cache = |
| CacheBuilder.newBuilder() |
| .maximumSize(10000) // TODO: make configurable |
| .build(new CacheLoader<K, CompletableFuture<Versioned<V>>>() { |
| @Override |
| public CompletableFuture<Versioned<V>> load(K key) |
| throws Exception { |
| return AsyncCachingConsistentMap.super.get(key); |
| } |
| }); |
| |
| public AsyncCachingConsistentMap(String name, |
| ApplicationId applicationId, |
| Database database, |
| Serializer serializer, |
| boolean readOnly, |
| boolean purgeOnUninstall, |
| boolean meteringEnabled) { |
| super(name, applicationId, database, serializer, readOnly, purgeOnUninstall, meteringEnabled); |
| addListener(event -> cache.invalidate(event.key())); |
| } |
| |
| @Override |
| public CompletableFuture<Versioned<V>> get(K key) { |
| CompletableFuture<Versioned<V>> cachedValue = cache.getIfPresent(key); |
| if (cachedValue != null) { |
| if (cachedValue.isCompletedExceptionally()) { |
| cache.invalidate(key); |
| } else { |
| return cachedValue; |
| } |
| } |
| return cache.getUnchecked(key); |
| } |
| |
| @Override |
| protected void beforeUpdate(K key) { |
| super.beforeUpdate(key); |
| cache.invalidate(key); |
| } |
| } |