content: /*
   * Copyright (c) 2015. Rick Hightower, Geoff Chandler
   *
   * 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.
   *
   * QBit - The Microservice lib for Java : JSON, WebSocket, REST. Be The Web!
   */
  
  package io.advantageous.qbit.queue;
  
  import io.advantageous.qbit.QBit;
  import io.advantageous.qbit.concurrent.PeriodicScheduler;
  import io.advantageous.qbit.queue.impl.AutoFlushingSendQueue;
  import io.advantageous.qbit.service.Stoppable;
  
  import java.util.concurrent.TimeUnit;
  
  /**
   * Represents a queue manager.
   * Queues are split up into receivers views and sender views to facilitate batching.
   * created by Richard on 8/4/14.
   *
   * @author rhightower
   */
  public interface Queue<T> extends Stoppable {
  
      /**
       * This returns a thread safe receive queue. Pulling an item off of the queue makes it unavailable to other thread.
       *
       * @return receive queue
       */
      ReceiveQueue<T> receiveQueue();
  
      /**
       * This returns a NON-thread safe SendQueue queue.
       * It is not thread safe so that you can batch sends to minimize thread hand-off
       * and to maximize IO throughput. Each call to this method returns a forwardEvent queue
       * that can only be access from one thread.
       * You get MT behavior by having a SendQueue per thread.
       *
       * @return forwardEvent queue
       */
      SendQueue<T> sendQueue();
  
  
      default SendQueue<T> sendQueueWithAutoFlush(final int interval, final TimeUnit timeUnit) {
  
          PeriodicScheduler periodicScheduler = QBit.factory().periodicScheduler();
  
          return sendQueueWithAutoFlush(periodicScheduler, interval, timeUnit);
      }
  
      default SendQueue<T> sendQueueWithAutoFlush(final PeriodicScheduler periodicScheduler,
                                                  final int interval, final TimeUnit timeUnit) {
  
          SendQueue<T> sendQueue = sendQueue();
          return new AutoFlushingSendQueue<>(sendQueue, periodicScheduler, interval, timeUnit);
      }
  
      /**
       * This starts up a listener which will listen to items on the
       * receive queue. It will notify when the queue is empty, when the queue is idle, when the queue is shutdown, etc.
       * <p>
       * An idle queue is an indication that it is a good time to do periodic cleanup, etc.
       *
       * @param listener listener
       */
      void startListener(ReceiveQueueListener<T> listener);
  
      int size();
  
      default boolean started() {
          return true;
      }
  
  
      default String name() {
          return "NO OP";
      }
  }
  