/*

 * Copyright (c) 2000-2009 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: 

 *

 */

 #ifndef UNIQUEINSTANCEBASE_H_

 #define UNIQUEINSTANCEBASE_H_

 #include <e32base.h>

 // The namespace UniqueInstance contains definitions that are not useful to the

 // user, but are useful to the implementation. There is no need to use any symbols

 // within it directly.

 namespace UniqueInstance

 {

 /**

 @internalComponent

 */

 typedef TInt TCompareFn(void*,void*);

 /**

 destroy free aObject.

 @internalComponent

 */

 typedef void TDeleteFn(void* aObjectToBeDeleted);

 /** 

 Copy aObjectToCopy into a newly allocated buffer, return the new object.

 aObjectSize is the size of the object that the repository has been specialised

 to work with. If this is not a true size of the object (for example in the case

 of HBufC) this value should be ignored.

 @internalComponent

 */

 typedef void* TCopyFnL(void* aObjectToCopy, TInt aObjectSize);

 struct SElement;

 class CRepositoryImpl;

 class RInstanceImpl;

 /**

  * Type-unsafe repository with shared equivalent objects.

  *

  * @internalComponent

  * @since App-frameworks6.1

  */

 NONSHARABLE_CLASS(CUniqueInstanceRepositoryBase) : public CBase

 	{

 public:

 	static void* DumbCopyL(void* aObjectTocopy, TInt aNumberOfBytes);

 	static void DumbDelete(void* aDeleteThis);

 	void ConstructL(TCompareFn*, TDeleteFn*, TCopyFnL*,

 		TInt aMaxLinks, TInt aObjectSize);

 	~CUniqueInstanceRepositoryBase();

 	void Test() const;

 private:

 	friend class RInstanceImpl;

 	CRepositoryImpl* iImpl;

 	};

 /**

  * Type-unsafe repository client.

  *

  * @internalComponent

  * @since App-frameworks6.1

  */

 class RInstanceImpl

 	{

 public:

 	explicit RInstanceImpl(CUniqueInstanceRepositoryBase& aRepository);

 	~RInstanceImpl();		// asserts that no object is owned

 	void TakeL(void* aObject);

 	void TakeCopyL(void* aObject);

 	void* Peek() const;

 	void CopyTo(RInstanceImpl& aOther) const;

 	void MoveTo(RInstanceImpl& aOther);

 	void* DropL();

 	void Close();

 private:

 	RInstanceImpl(RInstanceImpl&);					// unimplemented

 	RInstanceImpl &operator=(const RInstanceImpl&);	// unimplemented

 	SElement* iPtr;

 	CRepositoryImpl* iRepository;

 	};

 }

 #endif	// UNIQUEINSTANCEBASE_H_