/*

* Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

/**

 @file

 @internalComponent

 @released

*/

#ifndef CCNTEVENTQUEUE_H

#define CCNTEVENTQUEUE_H

#include <e32base.h>

#include <cntdb.h>

#include <cntdbobs.h> // for tcontactdbobserverevent.

#define  KMaxNumberOfEventsInEventQueue 1000

#if defined(_DEBUG)	// For OOM testing set granularity to 1

	const TInt KCntEventGranularity = 1;

#else

	const TInt KCntEventGranularity = 10;

#endif

/**

The CEventQueue class is used to queue database events on the Server for later

consumption by Client-side objects which make IPC calls to read events from the

queue.  An instance of this class is owned by each CCntSession object.

When a Contacts database is openend, created or replaced in the method

CCntSession::FileOpenCreateReplaceL() then the CCntSession object is registered

as a database event observer of the associated CCntDbManager.

Then when a database event occurs the database event callback interface

implemented by CCntSession (i.e. the MContactDbObserver::HandleDatabaseEventL()

method) is called and the event placed in this queue.

*/

class CEventQueue : public CBase

	{

public:

	CEventQueue();

	~CEventQueue();

	void QueueEvent(const TContactDbObserverEvent &aEvent);

	void RequestEvent(const RMessage2& aMessage);

	void CancelEventRequest();

private:

	enum TFlag

		{

		EQueueError=0x0001,

		EValidEventMsg=0x0002

		};

private:

	void Flush();

	void SendEvent(const TContactDbObserverEvent &aEvent);

	void SetFlag(TFlag aFlag);

	void ClearFlag(TFlag aFlag);

	TBool Flag(TFlag aFlag);

private:

	RArray<TContactDbObserverEvent> iEvents;

	RMessage2 iEventMsg;

	TInt iFlags;

	TInt iEventsInQueue;

	};

#endif