| /* |
| * 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.samza.util; |
| |
| import java.util.Iterator; |
| import java.util.LinkedHashSet; |
| import java.util.Set; |
| |
| /** |
| * LinkedinHashSet of bounded size {@code size} with a FIFO eviction policy |
| * |
| * This class is not thread-safe |
| */ |
| public class BoundedLinkedHashSet<T> { |
| |
| private final int cacheSize; |
| private final Set<T> cache; |
| |
| public BoundedLinkedHashSet(int size) { |
| this.cache = new LinkedHashSet<T>(); |
| this.cacheSize = size; |
| } |
| |
| public boolean containsKey(T element) { |
| return cache.contains(element); |
| } |
| |
| public void put(T element) { |
| if (cache.size() > cacheSize) { |
| Iterator iterator = cache.iterator(); |
| if (iterator.hasNext()) { |
| iterator.remove(); |
| } |
| } |
| cache.add(element); |
| } |
| } |