version 3.0

event/callback_queue.h

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+/*
+ * Copyright (c) 2010-2011 Juli Mallett. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR 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 AUTHOR OR CONTRIBUTORS 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.
+ */
+
+#ifndef	EVENT_CALLBACK_QUEUE_H
+#define	EVENT_CALLBACK_QUEUE_H
+
+#include <deque>
+#include <event/callback.h>
+#include <event/action.h>
+
+////////////////////////////////////////////////////////////////////////////////
+//                                                                            //
+// File:           callback_queue.h                                           //
+// Description:    collection classes for event callback management           //
+// Project:        WANProxy XTech                                             //
+// Adapted by:     Andreu Vidal Bramfeld-Software                             //
+// Last modified:  2015-04-01                                                 //
+//                                                                            //
+////////////////////////////////////////////////////////////////////////////////
+
+class CallbackQueue 
+{
+	class QueuedAction : public Action 
+	{
+		CallbackQueue& queue_;
+		uint64_t generation_;
+		Callback* callback_;
+		
+	public:
+		QueuedAction (CallbackQueue& q, uint64_t g, Callback* cb)
+		: queue_(q),
+		  generation_(g),
+		  callback_(cb)
+		{ 
+		}
+		
+		~QueuedAction ()
+		{
+			delete callback_;
+		}
+		
+		virtual void cancel ()
+		{
+			cancelled_ = true;
+			queue_.cancel (this);
+		}
+		
+   	friend class CallbackQueue;
+	};
+
+	std::deque<QueuedAction*> queue_;
+	uint64_t generation_;
+	
+public:
+	CallbackQueue ()
+	: queue_(),
+	  generation_(0)
+	{ }
+
+	~CallbackQueue ()
+	{
+		std::deque<QueuedAction*>::iterator it;
+		for (it = queue_.begin (); it != queue_.end (); ++it) 
+		{
+			delete *it;
+			*it = 0;
+		}
+	}
+
+	Action* schedule (Callback* cb)
+	{
+		QueuedAction* a = new QueuedAction (*this, generation_, cb);
+		queue_.push_back (a);
+		return (a);
+	}
+
+	/*
+	 * Runs all callbacks that have already been queued, but none that
+	 * are added by callbacks that are called as part of the drain
+	 * operation.  Returns true if there are queued callbacks that were
+	 * added during drain.
+	 */
+	bool drain (void)
+	{
+		generation_++;
+		while (! queue_.empty ()) 
+		{
+			QueuedAction* a = queue_.front ();
+			if (a->generation_ >= generation_)
+				return (true);
+			queue_.pop_front ();
+			if (a->callback_)
+				a->callback_->execute ();
+		}
+		return (false);
+	}
+
+	bool empty () const
+	{
+		return (queue_.empty ());
+	}
+
+	void perform ()
+	{
+		if (! queue_.empty ())
+		{
+			QueuedAction* a = queue_.front ();
+			if (a->callback_)
+				a->callback_->execute ();
+		}
+	}
+
+	void cancel (QueuedAction* a)
+	{
+		std::deque<QueuedAction*>::iterator it;
+		for (it = queue_.begin (); it != queue_.end (); ++it) 
+		{
+			if (*it == a)
+			{
+				queue_.erase (it);
+				break;
+			}
+		}
+		delete a;
+	}
+};
+
+#endif /* !EVENT_CALLBACK_QUEUE_H */