| /* |
| * 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.ignite.internal.util; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.concurrent.ConcurrentMap; |
| import org.apache.ignite.internal.util.typedef.internal.S; |
| import org.jetbrains.annotations.Nullable; |
| import org.jsr166.ConcurrentLinkedHashMap; |
| |
| /** |
| * Concurrent linked set implementation. |
| */ |
| public class GridConcurrentLinkedHashSet<E> extends GridSetWrapper<E> { |
| /** */ |
| private static final long serialVersionUID = 0L; |
| |
| /** |
| * Creates a new, empty set with a default initial capacity, |
| * load factor, and concurrencyLevel. |
| */ |
| public GridConcurrentLinkedHashSet() { |
| super(new ConcurrentLinkedHashMap<E, E>()); |
| } |
| |
| /** |
| * Creates a new, empty set with the specified initial |
| * capacity, and with default load factor and concurrencyLevel. |
| * |
| * @param initCap The initial capacity. The implementation |
| * performs internal sizing to accommodate this many elements. |
| * @throws IllegalArgumentException if the initial capacity of |
| * elements is negative. |
| */ |
| public GridConcurrentLinkedHashSet(int initCap) { |
| super(new ConcurrentLinkedHashMap<E, E>(initCap)); |
| } |
| |
| /** |
| * Creates a new, empty set with the specified initial |
| * capacity, load factor, and concurrency level. |
| * |
| * @param initCap The initial capacity. The implementation |
| * performs internal sizing to accommodate this many elements. |
| * @param loadFactor The load factor threshold, used to control resizing. |
| * Resizing may be performed when the average number of elements per |
| * bin exceeds this threshold. |
| * @param conLevel The estimated number of concurrently |
| * updating threads. The implementation performs internal sizing |
| * to try to accommodate this many threads. |
| * @throws IllegalArgumentException if the initial capacity is |
| * negative or the load factor or concurrency level are |
| * non-positive. |
| */ |
| public GridConcurrentLinkedHashSet(int initCap, float loadFactor, int conLevel) { |
| super(new ConcurrentLinkedHashMap<E, E>(initCap, loadFactor, conLevel)); |
| } |
| |
| /** |
| * Creates a new set with the same elements as the given collection. The |
| * collection is created with a capacity of twice the number of mappings in |
| * the given map or 11 (whichever is greater), and a default load factor |
| * and concurrencyLevel. |
| * |
| * @param c Collection to add. |
| */ |
| public GridConcurrentLinkedHashSet(Collection<E> c) { |
| super(new ConcurrentLinkedHashMap<E, E>(c.size())); |
| |
| addAll(c); |
| } |
| |
| /** |
| * Note that unlike regular add operation on a set, this method will only |
| * add the passed in element if it's not already present in set. |
| * |
| * @param e Element to add. |
| * @return {@code True} if element was added. |
| */ |
| @Override public boolean add(E e) { |
| ConcurrentMap<E, Object> m = (ConcurrentMap<E, Object>)map; |
| |
| return m.putIfAbsent(e, e) == null; |
| } |
| |
| /** |
| * Note that unlike regular add operation on a set, this method will only |
| * add the passed in element if it's not already present in set. |
| * |
| * @param e Element to add. |
| * @return Value previously present in set or {@code null} if set didn't have this value. |
| */ |
| @Nullable public E addx(E e) { |
| ConcurrentMap<E, E> m = (ConcurrentMap<E, E>)map; |
| |
| return m.putIfAbsent(e, e); |
| } |
| |
| /** |
| * @return Descending iterator. |
| */ |
| public Iterator<E> descendingIterator() { |
| return ((ConcurrentLinkedHashMap<E, E>)map).descendingKeySet().iterator(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public String toString() { |
| return S.toString(GridConcurrentLinkedHashSet.class, this, "elements", map().keySet()); |
| } |
| } |