/source/library/Interlace/ReactorCore/TimerQueue.cs

#region Using Directives and Copyright Notice



// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd

// All rights reserved.

// 

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are met:

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above copyright

//       notice, this list of conditions and the following disclaimer in the

//       documentation and/or other materials provided with the distribution.

//     * Neither the name of the Computer Consultancy Pty Ltd nor the

//       names of its contributors may be used to endorse or promote products

//       derived from this software without specific prior written permission.

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 

// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 

// ARE DISCLAIMED. IN NO EVENT SHALL COMPUTER CONSULTANCY PTY LTD BE LIABLE 

// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 

// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 

// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 

// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 

// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 

// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

// DAMAGE.



using System;

using System.Collections.Generic;

using System.Text;



using Interlace.Collections;



#endregion



namespace Interlace.ReactorCore

{

    public class TimerQueue

    {

        PriorityQueue<TimerQueueEntry> _queue = new PriorityQueue<TimerQueueEntry>();



        public TimerQueue()

        {

        }



        public TimerHandle Add(DateTime fireAt, TimerCallback callback, object state)

        {

            TimerQueueEntry entry = new TimerQueueEntry(fireAt, callback, state);



            _queue.Enqueue(entry);



            return new TimerHandle(entry);

        }



        public bool IsEmpty

        {

            get { return _queue.Count == 0; }

        }



        readonly TimeSpan _zeroTimeSpan = new TimeSpan(0);



        public TimeSpan GetTimeUntilNextFireable(DateTime now)

        {

            if (IsEmpty) throw new InvalidOperationException("The time until the next timer " +

                "is not available on an empty queue.");



            TimerQueueEntry entry = _queue.Peek();



            TimeSpan time = entry.GetTimeUntilFireable(now);



            if (time < _zeroTimeSpan) return _zeroTimeSpan;



            return time;

        }



        public void FireAllFireable(DateTime now)

        {

            while (_queue.Count > 0)

            {

                TimerQueueEntry entry = _queue.Peek();



                if (!entry.IsFireable(now)) break;



                _queue.Dequeue();



                entry.Fire();

            }

        }



        public void CancelAll()

        {

            while (_queue.Count > 0)

            {

                TimerQueueEntry entry = _queue.Dequeue();

                entry.Cancel();

            }

        }

    }

}