A protocol for transmitting large blocks of data over a network. More...

#include <visiontransfer/datablockprotocol.h>

Public Types
enum	ProtocolType { PROTOCOL_TCP, PROTOCOL_UDP }

Public Member Functions
	DataBlockProtocol (ProtocolType protType, int maxUdpPacketSize)
	Creates a new instance. More...

int	getProtocolOverhead () const
	Returns the size of the overhead data that is required for transferring a single network message. More...

int	getMaxReceptionSize () const
	Returns the maximum paload size that can be recedived. More...

void	startTransfer ()
	Starts the transfer of a new data block. More...

void	resetTransfer ()
	Stops the current transfer. More...

void	setTransferData (unsigned char *data, int size, int validBytes=0x7FFFFFFF)
	Sets a new chunk of data that should be transferred. More...

void	setTransferValidBytes (int validBytes)
	Updates the number of valid bytes in a partial transmission. More...

const unsigned char *	getTransferMessage (int &length)
	Gets the next network message for the current transfer. More...

bool	transferComplete ()
	Returns true if the current transfer has been completed. More...

void	setReceiveDataSize (int size)
	Sets the total size of the data that shall be received. More...

unsigned char *	getNextReceiveBuffer (int maxLength)
	Gets a buffer for receiving the next network message. More...

void	resetReception ()
	Resets the message reception. More...

bool	processReceivedMessage (int length)
	Handles a received network message. More...

unsigned char *	getReceivedData (int &length)
	Returns the data that has been received for the current data block. More...

void	finishReception ()
	Finishes reception of the current data block. More...

Static Public Attributes
static const int	MAX_TCP_BYTES_TRANSFER = 0xFFFF

static const int	MAX_UDP_RECEPTION = 0x4000

static const int	MAX_OUTSTANDING_BYTES = 2*MAX_TCP_BYTES_TRANSFER

Detailed Description

A protocol for transmitting large blocks of data over a network.

The protocol slices the large data block into several smaller chunks that can be transmitted over a network. In UDP mode, each chunk contains a sequence number.

This class is intended to be used by ImageProtocol and should normally not be used directly.

Definition at line 34 of file datablockprotocol.h.

Constructor & Destructor Documentation

DataBlockProtocol::DataBlockProtocol	(	ProtocolType	protType,
		int	maxUdpPacketSize
	)

Creates a new instance.

Parameters

protType	The target network protocol.
maxUdpPacketSize	Maximum allowed size of a UDP packet when sending data.

Definition at line 30 of file datablockprotocol.cpp.

Member Function Documentation

void DataBlockProtocol::finishReception ( )

Finishes reception of the current data block.

The first network message that is added after calling this method will start the reception of a new data block.

Definition at line 221 of file datablockprotocol.cpp.

int DataBlockProtocol::getMaxReceptionSize ( ) const

Returns the maximum paload size that can be recedived.

Definition at line 132 of file datablockprotocol.cpp.

unsigned char * DataBlockProtocol::getNextReceiveBuffer ( int maxLength )

Gets a buffer for receiving the next network message.

The returned buffer is a subsection of the internal receive buffer

Definition at line 140 of file datablockprotocol.cpp.

int DataBlockProtocol::getProtocolOverhead ( ) const

inline

Returns the size of the overhead data that is required for transferring a single network message.

Definition at line 59 of file datablockprotocol.h.

unsigned char * DataBlockProtocol::getReceivedData ( int & length )

Returns the data that has been received for the current data block.

Parameters

length Will be set to the number of bytes that have been received.

Returns: Pointer to the buffer containing the received data.

The received data is valid until receiving the first byte of a new data block.

Definition at line 230 of file datablockprotocol.cpp.

const unsigned char * DataBlockProtocol::getTransferMessage ( int & length )

Gets the next network message for the current transfer.

Parameters

length The length of the network message.

Returns: Pointer to the network message data.

If the transfer has already been completed or if there are currently no more valid bytes to be transmitted, a null pointer is returned.

Definition at line 77 of file datablockprotocol.cpp.

bool DataBlockProtocol::processReceivedMessage ( int length )

Handles a received network message.

Please see ImageProtocol::processReceivedMessage() for further details.

Definition at line 155 of file datablockprotocol.cpp.

void DataBlockProtocol::resetReception ( )

Resets the message reception.

Definition at line 225 of file datablockprotocol.cpp.

void DataBlockProtocol::resetTransfer ( )

Stops the current transfer.

Definition at line 52 of file datablockprotocol.cpp.

void DataBlockProtocol::setReceiveDataSize ( int size )

Sets the total size of the data that shall be received.

Parameters

size	New data size.

This method has to be called before receiving the first data item. It can be called within an active transfer. This is typically done to set the expected data size after the header has been received.

Definition at line 117 of file datablockprotocol.cpp.

void DataBlockProtocol::setTransferData	(	unsigned char *	data,
		int	size,
		int	validBytes = `0x7FFFFFFF`
	)

Sets a new chunk of data that should be transferred.

Parameters

data	Pointer to the data that should be transferred.
size	Total size of the data transfer.
validBytes	The number of bytes that are currently valid in `data`.

Part of data will be overwritten. There must be at least 2 additional bytes before the start of data.

If validBytes is set to a value smaller than the total transfer size, only a partial transfer is performed. Subsequent calls to setTransferValidBytes() are then necessary.

Definition at line 57 of file datablockprotocol.cpp.

void DataBlockProtocol::setTransferValidBytes ( int validBytes )

Updates the number of valid bytes in a partial transmission.

Parameters

validBytes The number of already valid bytes in the previously set data pointer.

This method has to be called whenever new data is available in a partial transfer.

See also: setTransferData()

Definition at line 65 of file datablockprotocol.cpp.

void DataBlockProtocol::startTransfer ( )

Starts the transfer of a new data block.

Call this method before setTransferData().

Definition at line 46 of file datablockprotocol.cpp.

bool DataBlockProtocol::transferComplete ( )

Returns true if the current transfer has been completed.

Definition at line 113 of file datablockprotocol.cpp.

The documentation for this class was generated from the following files:

visiontransfer/datablockprotocol.h
visiontransfer/datablockprotocol.cpp

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation