root / trunk / Pithos.Core / Agents / CollectionExtensions.cs @ 039a89e5
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// ----------------------------------------------------------------------- |
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// <copyright file="CollectionExtensions.cs" company="GRNET"> |
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// Copyright 2011 GRNET S.A. All rights reserved. |
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// |
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// Redistribution and use in source and binary forms, with or |
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// without modification, are permitted provided that the following |
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// conditions are met: |
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// |
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// 1. Redistributions of source code must retain the above |
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// copyright notice, this list of conditions and the following |
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// disclaimer. |
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// |
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// 2. Redistributions in binary form must reproduce the above |
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// copyright notice, this list of conditions and the following |
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// disclaimer in the documentation and/or other materials |
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// provided with the distribution. |
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// |
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// THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS |
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// OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
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// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR |
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// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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// USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
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// AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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// POSSIBILITY OF SUCH DAMAGE. |
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// |
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// The views and conclusions contained in the software and |
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// documentation are those of the authors and should not be |
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// interpreted as representing official policies, either expressed |
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// or implied, of GRNET S.A. |
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// </copyright> |
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// ----------------------------------------------------------------------- |
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|
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using System.Collections.Concurrent; |
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|
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namespace Pithos.Core.Agents |
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{ |
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using System; |
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using System.Collections.Generic; |
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using System.Linq; |
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using System.Text; |
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|
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/// <summary> |
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/// Extension methods for collections |
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/// </summary> |
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public static class CollectionExtensions |
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{ |
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/// <summary> |
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/// Remove the first message in a queue that matches the predicate |
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/// </summary> |
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/// <param name="predicate">The condition to match</param> |
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/// <remarks>Removes the first message that matches the predicate by dequeing all |
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/// messages and re-enqueing all except the first matching message</remarks> |
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public static void RemoveFirst<TMessage>(this ConcurrentQueue<TMessage> queue, Func<TMessage, bool> predicate) |
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{ |
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//Can this work? Dequeue all items |
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//and then enqueue everything except the filtered items |
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|
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//Possible problems: |
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//* A matching item may be dequeued between one TryDequeue and the next |
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var temp = new Queue<TMessage>(); |
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TMessage message; |
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var alreadyFound = false; |
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while (queue.TryDequeue(out message)) |
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{ |
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if (!predicate(message) || alreadyFound) |
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temp.Enqueue(message); |
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else |
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{ |
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alreadyFound = true; |
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} |
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} |
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|
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queue.AddFromEnumerable(temp); |
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} |
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} |
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} |