// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "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

*/

#ifndef ZEROCOPYTRANSFERSTRATEGY_H

#define ZEROCOPYTRANSFERSTRATEGY_H

#include "usbtransferstrategy.h"

NONSHARABLE_CLASS(RUsbZeroCopyTransferStrategy) : public RUsbTransferStrategy

	{

public:

	RUsbZeroCopyTransferStrategy();

	virtual TInt RegisterTransferDescriptor(RUsbTransferDescriptor& aTransferDesc, TInt aRequiredSize, TUint aStartAlignment, TInt aRequiredMaxPackets);

	virtual void ResetTransferDescriptors();

	virtual TInt InitialiseTransferDescriptors(RUsbInterface& aInterface);

	virtual void Close();

public: // Interrupt transfer descriptor methods

	virtual TPtr8	IntrWritableBuffer(TInt aHandle);

	virtual void	IntrSaveData(TInt aHandle, TInt aLength);

	virtual void	IntrSetZlpStatus(TInt aHandle, RUsbTransferDescriptor::TZlpStatus aZlpStatus);

	virtual TPtrC8	IntrBuffer(TInt aHandle) const;

public: // Bulk transfer descriptor methods

	virtual TPtr8	BulkWritableBuffer(TInt aHandle);

	virtual void	BulkSaveData(TInt aHandle, TInt aLength);

	virtual void	BulkSetZlpStatus(TInt aHandle, RUsbTransferDescriptor::TZlpStatus aZlpStatus);

	virtual TPtrC8	BulkBuffer(TInt aHandle) const;

public: // Isochronous transfer descriptor methods

	virtual void	IsocReset(TInt aHandle);

	virtual TPacketLengths IsocLengths(TInt aHandle);

	virtual TPacketResults IsocResults(TInt aHandle);

	virtual TInt	IsocMaxPacketSize(TInt aHandle);

	virtual TPtr8	IsocWritablePackets(TInt aHandle, TInt aWriteHandle, TInt aNumPacketsRequested, TInt& aMaxNumPacketsAbleToWrite);

	virtual TInt	IsocSaveMultiple(TInt aHandle, TInt aWriteHandle, TInt aNumOfPackets);

	virtual TPtrC8	IsocPackets(TInt aHandle, TInt aFirstPacketIndex, TInt aNumPacketsRequested, TInt& aNumPacketsReturned) const;

	virtual void	IsocReceivePackets(TInt aHandle, TInt aNumOfPackets);

private: // Standard (Bulk, Ctrl and Intr) Buffer methods

	TPtr8	WritableBuffer(TInt aHandle);

	void	SaveData(TInt aHandle, TInt aLength);

	void	SetZlpStatus(TInt aHandle, RUsbTransferDescriptor::TZlpStatus aZlpStatus);

	TPtrC8	Buffer(TInt aHandle) const;

private: // Isoc Buffer methods

	void	Reset(TInt aHandle);

	TPacketLengths Lengths(TInt aHandle);

	TPacketResults Results(TInt aHandle);

	TInt	MaxPacketSize(TInt aHandle);

	TPtr8	WritablePackets(TInt aHandle, TInt aWriteHandle, TInt aNumPacketsRequested, TInt& aMaxNumPacketsAbleToWrite);

	TInt	SaveMultiple(TInt aHandle, TInt aWriteHandle, TInt aNumOfPackets);

	TPtrC8	Packets(TInt aHandle, TInt aFirstPacketIndex, TInt aNumPacketsRequested, TInt& aNumPacketsReturned) const;

	void	ReceivePackets(TInt aHandle, TInt aNumOfPackets);

private:

	NONSHARABLE_STRUCT(TUsbTransferDescriptorDetails)

		{

        TUsbTransferDescriptorDetails(RUsbTransferDescriptor&, TInt, TUint, TInt);

		RUsbTransferDescriptor& iTransferDesc;

		const TInt iRequiredSize;

		TUint iRequiredAlignment;

		const TInt iRequiredMaxPackets;

		// Members to aid internal logic

		TInt iAssignedOffset;

		TInt iLengthsOffset; // Only applicable to isoc

		TInt iReqLenOffset; // Only applicable to isoc

		TInt iResultsOffset; // Only applicable to isoc

		TInt iNumElements; // Only applicable to isoc

		};

private:

	TInt CalculateDataLayout(TInt& aCurrentOffset, TInt& aNumStandardTransfers, TInt& aNumIsocTransfers, TInt& aNumIsocElements);

	void CalculateMetaDataLayout(TInt& aCurrentOffset, TInt& aMetaDataStart, TInt aNumStandardTransfers, TInt aNumIsocTransfers, TInt aNumIsocElements);

	void InitialiseMetaData(TInt aMetaDataOffset, TInt aNumStandardTransfers, TInt aNumIsocTransfers, TInt aNumIsocElements);

	TInt UsedPackets(TInt aHeaderOffset);

	TBool IsPowerOfTwo(TUint aNumber);

	TInt IncNeededToAlign(TInt aOffset, TUint aAlignment);

	static TBool CompareTransferDescriptor(const RUsbTransferDescriptor* aTransferDesc, const TUsbTransferDescriptorDetails& aDetails);

private: //Calculate additional alignment related methods

	TInt GetMaximumMaxPacketSize(TInt& aMaxMaxBulk, TInt& aMaxMaxInterrupt);

	TInt CaculateAdditionalAlignment(TInt aCurrentOffset, TInt aMaxMaxBulk, TInt aMaxMaxInterrupt, TUsbTransferDescriptorDetails& aTransferDetails);

private:

	RArray<TUsbTransferDescriptorDetails> iRegisteredTransfers;

private:

	RUsbInterface* iInterfaceHandle;

	RChunk iChunk;

	TInt iBaseOffset;

	TInt iPageSize;

	};

#endif // ZEROCOPYTRANSFERSTRATEGY_H