Madan Jampani | d352010 | 2015-08-14 11:06:03 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2015 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 | 3d6a2f6 | 2015-08-12 07:19:07 -0700 | [diff] [blame] | 16 | package org.onosproject.store.consistent.impl; |
| 17 | |
| 18 | import java.util.concurrent.CompletableFuture; |
| 19 | |
| 20 | import org.onosproject.core.ApplicationId; |
| 21 | import org.onosproject.store.service.Serializer; |
| 22 | import org.onosproject.store.service.Versioned; |
| 23 | |
| 24 | import com.google.common.cache.CacheBuilder; |
| 25 | import com.google.common.cache.CacheLoader; |
| 26 | import com.google.common.cache.LoadingCache; |
| 27 | |
| 28 | /** |
| 29 | * Extension of DefaultAsyncConsistentMap that provides a weaker read consistency |
| 30 | * guarantee in return for better read performance. |
| 31 | * |
| 32 | * @param <K> key type |
| 33 | * @param <V> value type |
| 34 | */ |
| 35 | public class AsyncCachingConsistentMap<K, V> extends DefaultAsyncConsistentMap<K, V> { |
| 36 | |
| 37 | private final LoadingCache<K, CompletableFuture<Versioned<V>>> cache = |
| 38 | CacheBuilder.newBuilder() |
| 39 | .maximumSize(10000) // TODO: make configurable |
| 40 | .build(new CacheLoader<K, CompletableFuture<Versioned<V>>>() { |
| 41 | @Override |
| 42 | public CompletableFuture<Versioned<V>> load(K key) |
| 43 | throws Exception { |
| 44 | return AsyncCachingConsistentMap.super.get(key); |
| 45 | } |
| 46 | }); |
| 47 | |
| 48 | public AsyncCachingConsistentMap(String name, |
| 49 | ApplicationId applicationId, |
| 50 | Database database, |
| 51 | Serializer serializer, |
| 52 | boolean readOnly, |
| 53 | boolean purgeOnUninstall, |
| 54 | boolean meteringEnabled) { |
| 55 | super(name, applicationId, database, serializer, readOnly, purgeOnUninstall, meteringEnabled); |
| 56 | addListener(event -> cache.invalidate(event.key())); |
| 57 | } |
| 58 | |
| 59 | @Override |
| 60 | public CompletableFuture<Versioned<V>> get(K key) { |
| 61 | CompletableFuture<Versioned<V>> cachedValue = cache.getIfPresent(key); |
| 62 | if (cachedValue != null) { |
| 63 | if (cachedValue.isCompletedExceptionally()) { |
| 64 | cache.invalidate(key); |
| 65 | } else { |
| 66 | return cachedValue; |
| 67 | } |
| 68 | } |
| 69 | return cache.getUnchecked(key); |
| 70 | } |
| 71 | } |