| /* |
| * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.util; |
| |
| import java.util.function.Consumer; |
| import java.util.function.IntFunction; |
| import java.util.stream.Stream; |
| import java.util.stream.StreamSupport; |
| import jdk.internal.util.ArraysSupport; |
| |
| /** |
| * Provides a reverse-ordered view of any Deque. Not serializable. |
| */ |
| class ReverseOrderDequeView<E> implements Deque<E> { |
| final Deque<E> base; |
| |
| private ReverseOrderDequeView(Deque<E> deque) { |
| base = deque; |
| } |
| |
| public static <T> Deque<T> of(Deque<T> deque) { |
| if (deque instanceof ReverseOrderDequeView<T> rodv) { |
| return rodv.base; |
| } else { |
| return new ReverseOrderDequeView<>(deque); |
| } |
| } |
| |
| // ========== Iterable ========== |
| |
| public void forEach(Consumer<? super E> action) { |
| for (E e : this) |
| action.accept(e); |
| } |
| |
| public Iterator<E> iterator() { |
| return base.descendingIterator(); |
| } |
| |
| public Spliterator<E> spliterator() { |
| return Spliterators.spliterator(this, Spliterator.ORDERED); |
| } |
| |
| // ========== Collection ========== |
| |
| public boolean add(E e) { |
| base.addFirst(e); |
| return true; |
| } |
| |
| public boolean addAll(Collection<? extends E> c) { |
| boolean modified = false; |
| for (E e : c) { |
| base.addFirst(e); |
| modified = true; |
| } |
| return modified; |
| } |
| |
| public void clear() { |
| base.clear(); |
| } |
| |
| public boolean contains(Object o) { |
| return base.contains(o); |
| } |
| |
| public boolean containsAll(Collection<?> c) { |
| return base.containsAll(c); |
| } |
| |
| public boolean isEmpty() { |
| return base.isEmpty(); |
| } |
| |
| public Stream<E> parallelStream() { |
| return StreamSupport.stream(spliterator(), true); |
| } |
| |
| // copied from AbstractCollection |
| public boolean remove(Object o) { |
| Iterator<E> it = iterator(); |
| if (o==null) { |
| while (it.hasNext()) { |
| if (it.next()==null) { |
| it.remove(); |
| return true; |
| } |
| } |
| } else { |
| while (it.hasNext()) { |
| if (o.equals(it.next())) { |
| it.remove(); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| // copied from AbstractCollection |
| public boolean removeAll(Collection<?> c) { |
| Objects.requireNonNull(c); |
| boolean modified = false; |
| Iterator<?> it = iterator(); |
| while (it.hasNext()) { |
| if (c.contains(it.next())) { |
| it.remove(); |
| modified = true; |
| } |
| } |
| return modified; |
| } |
| |
| // copied from AbstractCollection |
| public boolean retainAll(Collection<?> c) { |
| Objects.requireNonNull(c); |
| boolean modified = false; |
| Iterator<E> it = iterator(); |
| while (it.hasNext()) { |
| if (!c.contains(it.next())) { |
| it.remove(); |
| modified = true; |
| } |
| } |
| return modified; |
| } |
| |
| public int size() { |
| return base.size(); |
| } |
| |
| public Stream<E> stream() { |
| return StreamSupport.stream(spliterator(), false); |
| } |
| |
| public Object[] toArray() { |
| return ArraysSupport.reverse(base.toArray()); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public <T> T[] toArray(T[] a) { |
| return ArraysSupport.toArrayReversed(base, a); |
| } |
| |
| public <T> T[] toArray(IntFunction<T[]> generator) { |
| return ArraysSupport.reverse(base.toArray(generator)); |
| } |
| |
| // copied from AbstractCollection |
| public String toString() { |
| Iterator<E> it = iterator(); |
| if (! it.hasNext()) |
| return "[]"; |
| |
| StringBuilder sb = new StringBuilder(); |
| sb.append('['); |
| for (;;) { |
| E e = it.next(); |
| sb.append(e == this ? "(this Collection)" : e); |
| if (! it.hasNext()) |
| return sb.append(']').toString(); |
| sb.append(',').append(' '); |
| } |
| } |
| |
| // ========== Deque and Queue ========== |
| |
| public void addFirst(E e) { |
| base.addLast(e); |
| } |
| |
| public void addLast(E e) { |
| base.addFirst(e); |
| } |
| |
| public Iterator<E> descendingIterator() { |
| return base.iterator(); |
| } |
| |
| public E element() { |
| return base.getLast(); |
| } |
| |
| public E getFirst() { |
| return base.getLast(); |
| } |
| |
| public E getLast() { |
| return base.getFirst(); |
| } |
| |
| public boolean offer(E e) { |
| return base.offerFirst(e); |
| } |
| |
| public boolean offerFirst(E e) { |
| return base.offerLast(e); |
| } |
| |
| public boolean offerLast(E e) { |
| return base.offerFirst(e); |
| } |
| |
| public E peek() { |
| return base.peekLast(); |
| } |
| |
| public E peekFirst() { |
| return base.peekLast(); |
| } |
| |
| public E peekLast() { |
| return base.peekFirst(); |
| } |
| |
| public E poll() { |
| return base.pollLast(); |
| } |
| |
| public E pollFirst() { |
| return base.pollLast(); |
| } |
| |
| public E pollLast() { |
| return base.pollFirst(); |
| } |
| |
| public E pop() { |
| return base.removeLast(); |
| } |
| |
| public void push(E e) { |
| base.addLast(e); |
| } |
| |
| public E remove() { |
| return base.removeLast(); |
| } |
| |
| public E removeFirst() { |
| return base.removeLast(); |
| } |
| |
| public E removeLast() { |
| return base.removeFirst(); |
| } |
| |
| public boolean removeFirstOccurrence(Object o) { |
| return base.removeLastOccurrence(o); |
| } |
| |
| public boolean removeLastOccurrence(Object o) { |
| return base.removeFirstOccurrence(o); |
| } |
| } |