| // Copyright (C) 2018 The Android Open Source Project |
| // |
| // 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 com.googlesource.gerrit.modules.cache.pg; |
| |
| import com.google.common.cache.CacheLoader; |
| import com.google.gerrit.common.TimeUtil; |
| import java.util.concurrent.Executor; |
| |
| public class PgCacheLoader<K, V> extends CacheLoader<K, ValueHolder<V>> { |
| private final Executor executor; |
| private final PgSqlStore<K, V> store; |
| private final CacheLoader<K, V> loader; |
| |
| PgCacheLoader(Executor executor, PgSqlStore<K, V> store, CacheLoader<K, V> loader) { |
| this.executor = executor; |
| this.store = store; |
| this.loader = loader; |
| } |
| |
| @Override |
| public ValueHolder<V> load(K key) throws Exception { |
| if (store.mightContain(key)) { |
| ValueHolder<V> h = store.getIfPresent(key); |
| if (h != null) { |
| return h; |
| } |
| } |
| |
| final ValueHolder<V> h = new ValueHolder<>(loader.load(key)); |
| h.created = TimeUtil.nowMs(); |
| executor.execute(() -> store.put(key, h)); |
| return h; |
| } |
| } |