com.gemstone.gemfire.internal.cache.RegionQueue Maven / Gradle / Ivy
/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* 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. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.internal.cache;
import com.gemstone.gemfire.cache.*;
import com.gemstone.gemfire.internal.offheap.Releasable;
import com.gemstone.gemfire.internal.size.SingleObjectSizer;
import java.util.List;
/**
* Interface RegionQueue is an interface for queue
* implementations backed by regions.
*
* @author Barry Oglesby
*
* @since 4.2
*/
public interface RegionQueue extends Releasable
{
/**
* A token used to signify this is a WAN queue. It is set in the callback
* argument.
*/
public static final String WAN_QUEUE_TOKEN = "WAN_QUEUE_TOKEN";
/**
* Puts an object onto the tail of the queue
*
* @param object
* The object to put onto the queue
*
* @throws InterruptedException
* @throws CacheException
*/
public void put(Object object) throws InterruptedException, CacheException;
/**
* Returns the underlying region that backs this queue.
*/
public Region getRegion();
/**
* Takes the first object from the head of the queue. This method returns null
* if there are no objects on the queue.
*
* @return The object taken
*
* @throws CacheException
* @throws InterruptedException
*/
public Object take() throws CacheException, InterruptedException;
/**
* Takes up to batchSize number of objects from the head of the queue. As soon
* as it gets a null response from a take, it stops taking.
*
* @param batchSize
* The number of objects to take from the queue
*
* @return the List of objects taken from the queue
*
* @throws CacheException
* @throws InterruptedException
*/
public List take(int batchSize) throws CacheException, InterruptedException;
/**
* Removes a single object from the head of the queue without returning it.
* This method assumes that the queue contains at least one object.
*
* @throws InterruptedException
* @throws CacheException
*/
public void remove() throws InterruptedException, CacheException;
/**
* Peeks the first object from the head of the queue without removing it. This
* method returns null if there are no objects on the queue.
*
* @return The object peeked
* @throws InterruptedException
* @throws CacheException
*/
public Object peek() throws InterruptedException, CacheException;
/**
* Peeks up to batchSize number of objects from the head of the queue without
* removing them. As soon as it gets a null response from a peek, it stops
* peeking.
*
* @param batchSize
* The number of objects to peek from the queue
*
* @return The list of objects peeked
* @throws InterruptedException
* @throws CacheException
*/
public List peek(int batchSize) throws InterruptedException, CacheException;
/**
* Peeks either a batchSize number of elements from the queue or until
* timeToWait milliseconds have elapsed (whichever comes first). If it has
* peeked batchSize number of elements from the queue before timeToWait
* milliseconds have elapsed, it stops peeking. If timeToWait milliseconds
* elapse before batchSize number of elements has been peeked, it stops.
*
* @param batchSize
* The number of objects to peek from the queue
* @param timeToWait
* The number of milliseconds to attempt to peek
*
* @return The list of objects peeked
* @throws InterruptedException
* @throws CacheException
*
*/
public List peek(int batchSize, int timeToWait) throws InterruptedException, CacheException;
/**
* Returns the size of the queue
*
* @return the size of the queue
*/
public int size();
/**
* Add a CacheListener to the queue
*
* @param listener
* The CacheListener to add
*/
public void addCacheListener(CacheListener listener);
/**
* Remove the CacheListener from the queue
*/
public void removeCacheListener();
//TODO:Asif: Remove this method. Added this justto make it compilable
public void remove(int top) throws CacheException;
public void close();
/**
* Estimate constant memory usage of the queue excluding the queue entries.
*
* @param sizer
* @return estimated constant memory overhead.
*/
public long estimateMemoryFootprint(SingleObjectSizer sizer);
}