// Copyright (c) 2002-2009 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:

 // include\mmf\server\mmfdatabuffer.h

 // 

 //

 #ifndef __MMF_SERVER_DATABUFFER_H__

 #define __MMF_SERVER_DATABUFFER_H__

 #include <e32base.h>

 #include <mmf/server/mmfbuffer.h>

 /** 

 @publishedAll

 @released

 Default buffer size if none is specified.

 */

 static const TInt KMMFDataBufferDefaultBufferSize = 32;

 /**

 @publishedAll

 @released

 This class is an abstract class for databuffers that can be presented in the form of a descriptor.

 A constructor is provided which instantiates a CMMFDescriptorBuffer buffer by default.

 @see CMMFDescriptorBuffer

 */

 class CMMFDataBuffer : public CMMFBuffer

 	{

 public:

 	IMPORT_C static CMMFDataBuffer* NewL();

 	IMPORT_C static CMMFDataBuffer* NewL(TInt aMaxBufferSize);

 	/**

 	Destructor.

 	*/

 	virtual ~CMMFDataBuffer() {};

 	/**

 	Returns a reference to the data contained in the buffer (non const version).

 	This is a virtual function that each derived class must implement.

 	@return A reference to the buffer.

 	*/

 	virtual TDes8& Data() = 0;

 	/**

 	Returns a reference to the data contained in the buffer (const version).

 	This is a virtual function that each derived class must implement.

 	@return A reference to the buffer.

 	*/

 	virtual const TDesC8& Data() const = 0;

 	/**

 	Returns the buffer size, in bytes.

 	This is a virtual function that each derived class must implement.

 	@return The buffer size in bytes.

 	*/

 	virtual TUint BufferSize() const = 0;

 	/**

 	Sets the request size. 

 	Used where a component, such as a data source,

 	may not be able to write to the entire maximum length of the buffer

 	(variable bit rate codecs for example).

 	This is a virtual function that each derived class must implement.

 	@param  aSize

 	        The requested size, in bytes.

 	*/

 	virtual void SetRequestSizeL(TInt aSize) = 0;

 protected:

 	/**

 	Protected constructor.

 	*/

 	CMMFDataBuffer(TUid aType): CMMFBuffer(aType) {};

 	};

 /**

 @publishedAll

 @released

 This class is a wrapper class to give a descriptor the same API as a CMMFDataBuffer.

 The purpose of this class is that components such as codecs can use CMMFDataBuffers transparently

 without having to be concerned with whether the buffer is a descriptor buffer

 or a transfer buffer.

 */

 class CMMFDescriptorBuffer : public CMMFDataBuffer

 	{

 public:

 	IMPORT_C static CMMFDescriptorBuffer* NewL();

 	IMPORT_C static CMMFDescriptorBuffer* NewL(TInt aMaxBufferSize);

 	IMPORT_C ~CMMFDescriptorBuffer();

 	IMPORT_C void ReAllocBufferL(TInt aMaxBufferSize);

 	virtual TDes8& Data();

 	virtual const TDesC8& Data() const;

 	virtual void SetStatus(TBufferStatus aStatus);

 	virtual void SetRequestSizeL(TInt aSize);

 	virtual TUint BufferSize() const;

 	virtual void SetPosition (TUint aPosition);

 private:

 	CMMFDescriptorBuffer() : CMMFDataBuffer(KUidMmfDescriptorBuffer), iPtr(0,0,0) {};

 	void ConstructL(TInt aMaxBufferSize);

 private:

 	TUint8* iData;

 	TPtr8 iPtr;

 	};

 /**

 @publishedAll

 @released

 This class is a wrapper class to give a transfer buffer/window the same API as a CMMFDataBuffer.

 The purpose of this class is so that components such as codecs can use CMMFDataBuffers transparently

 without having to be concerned with whether the buffer is a descriptor buffer

 or a transfer buffer.

 The class assumes that a valid RTransferWindow with a RTransferBuffer mapped in already exists.

 Note:

 CMMFTransferBuffers are not supported in EKA2.

 */

 class RTransferWindow

 	{

 	// dummy class

 	};

 class CMMFTransferBuffer : public CMMFDataBuffer

 	{

 public:

 	IMPORT_C static CMMFTransferBuffer* NewL(RTransferWindow& aTransferWindow, TUint aDataLength = 0);

 	IMPORT_C ~CMMFTransferBuffer();

 	virtual TDes8& Data();

 	virtual const TDesC8& Data() const;

 	virtual TUint BufferSize() const;

 	virtual void SetRequestSizeL(TInt aSize);

 	virtual void SetPosition (TUint aPosition);

 	IMPORT_C RTransferWindow& TransferWindow();

 	IMPORT_C void MapOutBuffer();

 	IMPORT_C TInt UpdateTransferWindow(RTransferWindow& aTransferWindow, TUint aDataLength = 0);

 private:

 	/**

 	Private constructor.

 	*/

 	CMMFTransferBuffer() : CMMFDataBuffer(KUidMmfTransferBuffer), iPtr(0,0,0){};

 	void ConstructL(RTransferWindow& aTransferWindow, TUint aDataLength);

 private:

 	RTransferWindow iTransferWindow;

 	TBool iTransferWindowMappedInOK;

 	TPtr8 iPtr;

 	};

 /**

 @publishedAll

 @released

 This class is a wrapper class intended to provide support for shared I/O buffers under EKA2

 This class, unlike other data buffers does not own memory - rather it contains a pointer to already allocated memory

 The purpose of this class is that components such as codecs can use CMMFDataBuffers transparently

 without having to be concerned with whether the buffer is a standard buffer or memory residing in shared I/O

 Users of this class need to be very careful when using buffers of this type.

 It cannot be assumed that a buffer of this type can be written/read by any process other than the current one - example - handing CMMFPtrBuffer to the file server may not work since the file server's process may not have access to write data buffer.

 */

 class CMMFPtrBuffer : public CMMFDataBuffer

 	{

 public:

 	IMPORT_C static CMMFPtrBuffer* NewL();		//unitialised, pointer will be set via SetPtr

 	IMPORT_C static CMMFPtrBuffer* NewL(const TPtr8& aPtr);

 	IMPORT_C ~CMMFPtrBuffer();

 	IMPORT_C void SetPtr(const TPtr8& aPtr);

 	virtual TDes8& Data();

 	virtual const TDesC8& Data() const;

 	virtual void SetStatus(TBufferStatus aStatus);	

 	virtual void SetRequestSizeL(TInt aSize);

 	virtual TUint BufferSize() const;

 	virtual void SetPosition (TUint aPosition);

 private:

 	CMMFPtrBuffer() : CMMFDataBuffer(KUidMmfPtrBuffer), iPtr(0,0,0) {};

 	void ConstructL(const TPtr8& aPtr);

 private:

 	TPtr8 iPtr;

 	};

 #endif