60 lines
1.7 KiB
Java
60 lines
1.7 KiB
Java
/*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.apache.el.util;
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import java.util.Map;
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import java.util.WeakHashMap;
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import java.util.concurrent.ConcurrentHashMap;
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public final class ConcurrentCache<K,V> {
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private final int size;
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private final Map<K,V> eden;
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private final Map<K,V> longterm;
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public ConcurrentCache(int size) {
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this.size = size;
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this.eden = new ConcurrentHashMap<>(size);
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this.longterm = new WeakHashMap<>(size);
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}
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public V get(K k) {
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V v = this.eden.get(k);
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if (v == null) {
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synchronized (longterm) {
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v = this.longterm.get(k);
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}
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if (v != null) {
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this.eden.put(k, v);
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}
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}
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return v;
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}
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public void put(K k, V v) {
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if (this.eden.size() >= size) {
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synchronized (longterm) {
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this.longterm.putAll(this.eden);
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}
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this.eden.clear();
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}
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this.eden.put(k, v);
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}
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}
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