+++ /dev/null
-/*
- * Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0 which accompanies this distribution,
- * and is available at http://www.eclipse.org/legal/epl-v10.html
- */
-package org.opendaylight.controller.cluster.access.client;
-
-import com.google.common.annotations.Beta;
-import java.util.AbstractQueue;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.Queue;
-import org.opendaylight.yangtools.concepts.Immutable;
-
-/**
- * A specialized always-empty implementation of {@link java.util.Queue}. This implementation will always refuse new
- * elements in its {@link #offer(Object)} method.
- * @author Robert Varga
- *
- * @param <E> the type of elements held in this collection
- */
-// TODO: move this class into yangtools.util
-@Beta
-public final class EmptyQueue<E> extends AbstractQueue<E> implements Immutable {
- private static final EmptyQueue<?> INSTANCE = new EmptyQueue<>();
-
- private EmptyQueue() {
- // No instances
- }
-
- @SuppressWarnings("unchecked")
- public static <T> Queue<T> getInstance() {
- return (Queue<T>) INSTANCE;
- }
-
- @Override
- public boolean offer(final E entry) {
- return false;
- }
-
- @Override
- public E poll() {
- return null;
- }
-
- @Override
- public E peek() {
- return null;
- }
-
- @Override
- public Iterator<E> iterator() {
- return Collections.emptyIterator();
- }
-
- @Override
- public int size() {
- return 0;
- }
-}