/*
 * Copyright (C) 2003-2017 Sebastiano Vigna
 *
 * Licensed 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 PACKAGE;

/** A class providing static methods and objects that do useful things with type-specific priority queues.
 *
 * @see it.unimi.dsi.fastutil.PriorityQueue
 */

public final class PRIORITY_QUEUES {

	private PRIORITY_QUEUES() {}

	/** A synchronized wrapper class for priority queues. */

	public static class SynchronizedPriorityQueue KEY_GENERIC implements PRIORITY_QUEUE KEY_GENERIC {
		protected final PRIORITY_QUEUE KEY_GENERIC q;
		protected final Object sync;

		protected SynchronizedPriorityQueue(final PRIORITY_QUEUE KEY_GENERIC q, final Object sync) {
			this.q = q;
			this.sync = sync;
		}

		protected SynchronizedPriorityQueue(final PRIORITY_QUEUE KEY_GENERIC q) {
			this.q = q;
			this.sync = this;
		}

		@Override
		public void enqueue(KEY_GENERIC_TYPE x) { synchronized(sync) { q.enqueue(x); } }

		@Override
		public KEY_GENERIC_TYPE DEQUEUE() { synchronized(sync) { return q.DEQUEUE(); } }

		@Override
		public KEY_GENERIC_TYPE FIRST() { synchronized(sync) { return q.FIRST(); } }

		@Override
		public KEY_GENERIC_TYPE LAST() { synchronized(sync) { return q.LAST(); } }

		@Override
		public boolean isEmpty() { synchronized(sync) { return q.isEmpty(); } }

		@Override
		public int size() { synchronized(sync) { return q.size(); } }

		@Override
		public void clear() { synchronized(sync) { q.clear(); } }

		@Override
		public void changed() { synchronized(sync) { q.changed(); } }

		@Override
		public KEY_COMPARATOR KEY_SUPER_GENERIC comparator() { synchronized(sync) { return q.comparator(); } }

#if KEYS_PRIMITIVE

		@Deprecated
		@Override
		public void enqueue(KEY_CLASS x) { synchronized(sync) { q.enqueue(x); } }

		@Deprecated
		@Override
		public KEY_CLASS dequeue() { synchronized(sync) { return q.dequeue(); } }

		@Deprecated
		@Override
		public KEY_CLASS first() { synchronized(sync) { return q.first(); } }

		@Deprecated
		@Override
		public KEY_CLASS last() { synchronized(sync) { return q.last(); } }

#endif
		@Override
		public int hashCode() { synchronized(sync) { return q.hashCode(); } }

		@Override
		public boolean equals(final Object o) { if (o == this) return true; synchronized(sync) { return q.equals(o); } }

		private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
			synchronized(sync) { s.defaultWriteObject(); }
		}
	}


	/** Returns a synchronized type-specific priority queue backed by the specified type-specific priority queue.
	 *
	 * @param q the priority queue to be wrapped in a synchronized priority queue.
	 * @return a synchronized view of the specified priority queue.
	 */
	public static KEY_GENERIC PRIORITY_QUEUE KEY_GENERIC synchronize(final PRIORITY_QUEUE KEY_GENERIC q) {	return new SynchronizedPriorityQueue(q); }

	/** Returns a synchronized type-specific priority queue backed by the specified type-specific priority queue, using an assigned object to synchronize.
	 *
	 * @param q the priority queue to be wrapped in a synchronized priority queue.
	 * @param sync an object that will be used to synchronize the access to the priority queue.
	 * @return a synchronized view of the specified priority queue.
	 */

	public static KEY_GENERIC PRIORITY_QUEUE KEY_GENERIC synchronize(final PRIORITY_QUEUE KEY_GENERIC q, final Object sync) { return new SynchronizedPriorityQueue(q, sync); }


}