| /* |
| * Copyright (C) 2018, Konrad Windszus <konrad_w@gmx.de> |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.eclipse.jgit.util; |
| |
| import java.util.LinkedHashMap; |
| |
| /** |
| * Map with only up to n entries. If a new entry is added so that the map |
| * contains more than those n entries the least-recently used entry is removed |
| * from the map. |
| * |
| * @param <K> |
| * the type of keys maintained by this map |
| * @param <V> |
| * the type of mapped values |
| * |
| * @since 5.4 |
| */ |
| public class LRUMap<K, V> extends LinkedHashMap<K, V> { |
| |
| private static final long serialVersionUID = 4329609127403759486L; |
| |
| private final int limit; |
| |
| /** |
| * Constructs an empty map which may contain at most the given amount of |
| * entries. |
| * |
| * @param initialCapacity |
| * the initial capacity |
| * @param limit |
| * the number of entries the map should have at most |
| */ |
| public LRUMap(int initialCapacity, int limit) { |
| super(initialCapacity, 0.75f, true); |
| this.limit = limit; |
| } |
| |
| @Override |
| protected boolean removeEldestEntry(java.util.Map.Entry<K, V> eldest) { |
| return size() > limit; |
| } |
| } |