CMMFTransferBuffer Class Reference

#include <mmf/server/mmfdatabuffer.h>

Link against: mmfserverbaseclasses.lib

class CMMFTransferBuffer : public CMMFDataBuffer

Inherits from

CMMFTransferBuffer
- CMMFDataBuffer
  - CMMFBuffer
    - CBase

Public Member Functions
	~CMMFTransferBuffer()
virtual TUint	BufferSize()
virtual TDes8 &	Data()
virtual const TDesC8 &	Data()
IMPORT_C void	MapOutBuffer()
IMPORT_C CMMFTransferBuffer *	NewL(RTransferWindow &, TUint)
virtual void	SetPosition(TUint)
virtual void	SetRequestSizeL(TInt)
IMPORT_C RTransferWindow &	TransferWindow()
IMPORT_C TInt	UpdateTransferWindow(RTransferWindow &, TUint)

Inherited Attributes
	CMMFBuffer::iFrameNumber
	CMMFBuffer::iLastBuffer
	CMMFBuffer::iPosition
	CMMFBuffer::iRequestSize
	CMMFBuffer::iStatus
	CMMFBuffer::iTimeToPlay
	CMMFBuffer::iType

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()
	CMMFBuffer::CMMFBuffer(TUid)
	CMMFBuffer::FrameNumber()const
	CMMFBuffer::IsFileServerSafe(TUid)
	CMMFBuffer::IsSupportedDataBuffer(TUid)
	CMMFBuffer::LastBuffer()const
	CMMFBuffer::NextFrame()
	CMMFBuffer::Position()const
	CMMFBuffer::RequestSize()const
	CMMFBuffer::SetFrameNumber(TUint)
	CMMFBuffer::SetLastBuffer(TBool)
	CMMFBuffer::SetStatus(TBufferStatus)
	CMMFBuffer::SetTimeToPlay(TTimeIntervalMicroSeconds)
	CMMFBuffer::Status()
	CMMFBuffer::TimeToPlay()const
	CMMFBuffer::Type()const
	CMMFBuffer::~CMMFBuffer()
	CMMFDataBuffer::CMMFDataBuffer(TUid)
	CMMFDataBuffer::NewL()
	CMMFDataBuffer::NewL(TInt)
	CMMFDataBuffer::~CMMFDataBuffer()

Constructor & Destructor Documentation

~CMMFTransferBuffer ( )

IMPORT_C

~CMMFTransferBuffer

(

)

CMMFTransferBuffer destructor

Destructor maps out RTransferBuffer and closes RTransferWindow.

Member Function Documentation

BufferSize ( )

TUint

BufferSize

(

)

const [virtual]

Reimplemented from CMMFDataBuffer::BufferSize()const

Returns the actual data size (ie. not the max length) of the data contained in the CMMFTransferBuffer.

Return Value: The size in bytes of the data contained in the CMMFTransferBuffer.

Data ( )

TDes8 &

Data

(

)

[virtual]

Reimplemented from CMMFDataBuffer::Data()

Returns a descriptor to the data contained in the CMMFTransferBuffer.

Return Value: A reference to a TPtr containing the CMMFTransferBuffer data.

Data ( )

const TDesC8 &

Data

(

)

const [virtual]

Reimplemented from CMMFDataBuffer::Data()const

Returns a descriptor to the data contained in the CMMFTransferBuffer.

Return Value: A const reference to a TPtr containing the CMMFTransferBuffer data.

MapOutBuffer ( )

IMPORT_C void

MapOutBuffer

(

)

Maps the buffer out of the transfer window.

This method should be called in preference to calling MapOutBuffer directly on the RtransferWindow so that the CMMFTransferBuffer knows that it is no longer available.

NewL ( RTransferWindow &, TUint )

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

This function is not supported under EKA2.

Method to instantiate a CMMFTransferBuffer. This NewL creates a CMMFTransferBuffer.

Parameters
aTransferWindow	This is a valid RTransferWindow that has an RTransferBuffer mapped in.
aDataLength	This parameter sets the length of the actual data present in the transferbuffer. This is because the length of actual data may be less than the length of the mapped in transfer buffer.

Return Value: A pointer to a new CMMFTransferBuffer.

SetPosition ( TUint )

void

SetPosition

(

TUint

aPosition

)

[virtual]

Reimplemented from CMMFBuffer::SetPosition(TUint)

Sets the position.

This method is used by components (eg codecs) which read data from a buffer and wish to store a read position marker for further reads.

Note: The position cannot exceed the size of the actual data not the max length.

Parameters
aPosition	The position.

SetRequestSizeL ( TInt )

void

SetRequestSizeL

(

TInt

aSize

)

[virtual]

Reimplemented from CMMFDataBuffer::SetRequestSizeL(TInt)

Sets the request size.

This function is used in cases where a component (eg. a data source) may not be able or be desirable to write to the entire max length of the buffer (eg. variable bit rate codecs). In this case, the SetRequestSizeL can be set which can be read by the RequestSize() function in the component so that it knows to only write data upto the request size and not fill the buffer up to its max length.

Parameters
aSize	The request size.

TransferWindow ( )

IMPORT_C RTransferWindow &

TransferWindow

(

)

This function is not supported under EKA2.

Returns a reference to the transfer window currently used by the CMMFtransferBuffer.

Return Value: A reference to the current RTransferWindow.

UpdateTransferWindow ( RTransferWindow &, TUint )

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

This method is not supported under EKA2.

Modifies the CMMFTransferBuffer by updating the RTransferWindow.

This method is used if the same CMMFTransferBuffer is used throughout eg. if a single CMMFTransferBuffer is created upfront but a different transfer window (or the same transfer window with a different buffer mapped in is used). That is the same CMMFTransferBuffer but the actrual buffer may be different.

Note: If the updated RTransferWindow is new, then the old buffer must be mapped out first by a call to CMMFTransferBuffer::MapOutBuffer() and the RtransferWindow handle closed outside the CMMFTransferBuffer.

Parameters
aTransferWindow	The RTransferWindow to update - can be a new RTransferWindow or the same RTransferWindow with a new RTransferBuffer mapped in.
aDataLength	The length of the data.

Return Value: An error code indicating if the function call was successful. KErrNone on success, otherwise another of the system-wide error codes.