| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.el.util; |
| |
| import java.util.Map; |
| import java.util.WeakHashMap; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| public final class ConcurrentCache<K,V> { |
| |
| private final int size; |
| |
| private final Map<K,V> eden; |
| |
| private final Map<K,V> longterm; |
| |
| public ConcurrentCache(int size) { |
| this.size = size; |
| this.eden = new ConcurrentHashMap<>(size); |
| this.longterm = new WeakHashMap<>(size); |
| } |
| |
| public V get(K k) { |
| V v = this.eden.get(k); |
| if (v == null) { |
| synchronized (longterm) { |
| v = this.longterm.get(k); |
| } |
| if (v != null) { |
| this.eden.put(k, v); |
| } |
| } |
| return v; |
| } |
| |
| public void put(K k, V v) { |
| if (this.eden.size() >= size) { |
| synchronized (longterm) { |
| this.longterm.putAll(this.eden); |
| } |
| this.eden.clear(); |
| } |
| this.eden.put(k, v); |
| } |
| } |