Base packet class. More...

#include <ArBasePacket.h>

Inherited by ArAMPTUPacket, ArDPPTUPacket, ArLMS1XXPacket, ArLMS2xxPacket, ArRobotPacket, ArRVisionPacket, ArS3SeriesPacket, ArSonyPacket, ArSZSeriesPacket, and ArVCC4Packet.

Public Member Functions
	ArBasePacket (ArTypes::UByte2 bufferSize=0, ArTypes::UByte2 headerLength=0, char *buf=NULL, ArTypes::UByte2 footerLength=0)
	Constructor. More...

	ArBasePacket (const ArBasePacket &other)
	Copy constructor.

virtual ArTypes::Byte	bufToByte (void)
	Gets a ArTypes::Byte from the buffer.

virtual ArTypes::Byte2	bufToByte2 (void)
	Gets a ArTypes::Byte2 from the buffer.

virtual ArTypes::Byte4	bufToByte4 (void)
	Gets a ArTypes::Byte4 from the buffer.

virtual void	bufToData (char *data, int length)
	Gets length bytes from buffer and puts them into data. More...

virtual void	bufToData (unsigned char *data, int length)
	Gets length bytes from buffer and puts them into data. More...

virtual void	bufToStr (char *buf, int len)
	Gets a string from the buffer. More...

virtual ArTypes::UByte	bufToUByte (void)
	Gets a ArTypes::UByte from the buffer.

virtual ArTypes::UByte2	bufToUByte2 (void)
	Gets a ArTypes::UByte2 from the buffer.

virtual ArTypes::UByte4	bufToUByte4 (void)
	Gets a ArTypes::UByte4 from the buffer.

virtual void	byte2ToBuf (ArTypes::Byte2 val)
	Puts ArTypes::Byte2 into packets buffer.

virtual void	byte4ToBuf (ArTypes::Byte4 val)
	Puts ArTypes::Byte4 into packets buffer.

virtual void	byteToBuf (ArTypes::Byte val)
	Puts ArTypes::Byte into packets buffer.

virtual void	dataToBuf (const char *data, int length)
	Copies length bytes from data into packet buffer. More...

virtual void	dataToBuf (const unsigned char *data, int length)
	Copies length bytes from data into packet buffer. More...

virtual void	duplicatePacket (ArBasePacket *packet)
	Makes this packet a duplicate of another packet. More...

virtual void	empty (void)
	resets the length for more data to be added More...

virtual void	finalizePacket (void)
	MakeFinals the packet in preparation for sending, must be done.

virtual const char *	getBuf (void) const
	Gets a const pointer to the buffer the packet uses.

virtual char *	getBuf (void)
	Gets a pointer to the buffer the packet uses.

virtual ArTypes::UByte2	getDataLength (void) const
	Gets the length of the data in the packet.

virtual ArTypes::UByte2	getDataReadLength (void) const
	Gets how far into the data of the packet that has been read.

virtual ArTypes::UByte2	getFooterLength (void) const
	Gets the length of the header.

virtual ArTypes::UByte2	getHeaderLength (void) const
	Gets the length of the header.

virtual ArTypes::UByte2	getLength (void) const
	Gets the total length of the packet.

virtual ArTypes::UByte2	getMaxLength (void) const
	Gets the maximum length packet.

virtual ArTypes::UByte2	getReadLength (void) const
	Gets how far into the packet that has been read.

virtual bool	isValid (void)
	Returns whether the packet is valid, i.e. no error has occurred when reading/writing. More...

virtual void	log (void)
	ArLogs the hex and decimal values of each byte of the packet, and possibly extra metadata as well.

ArBasePacket &	operator= (const ArBasePacket &other)
	Assignment operator.

virtual void	printHex (void)
	ArLogs the hex value of each byte in the packet.

virtual void	resetRead (void)
	Restart the reading process. More...

virtual void	resetValid ()
	Resets the valid state of the packet. More...

virtual void	setBuf (char *buf, ArTypes::UByte2 bufferSize)
	Sets the buffer the packet is using.

virtual bool	setHeaderLength (ArTypes::UByte2 length)
	Sets the length of the header.

virtual bool	setLength (ArTypes::UByte2 length)
	Sets the length of the packet.

virtual void	setMaxLength (ArTypes::UByte2 bufferSize)
	Sets the maximum buffer size (if new size is <= current does nothing)

virtual void	setReadLength (ArTypes::UByte2 readLength)
	Sets the read length.

virtual void	strNToBuf (const char *str, int length)
	Copies the given number of bytes from str into packet buffer. More...

virtual void	strToBuf (const char *str)
	Puts a NULL-terminated string into packet buffer. More...

virtual void	strToBufPadded (const char *str, int length)
	Copies length bytes from str, if str ends before length, pads data with 0s. More...

virtual void	uByte2ToBuf (ArTypes::UByte2 val)
	Puts ArTypes::UByte2 into packet buffer.

virtual void	uByte4ToBuf (ArTypes::UByte4 val)
	Puts ArTypes::UByte 4 into packet buffer.

virtual void	uByteToBuf (ArTypes::UByte val)
	Puts ArTypes::UByte into packets buffer.

virtual	~ArBasePacket ()
	Destructor.

Protected Member Functions
bool	hasWriteCapacity (int bytes)
	Returns true if there is enough room in the packet to add the specified number of bytes.

bool	isNextGood (int bytes)

Protected Attributes
char *	myBuf

ArTypes::UByte2	myFooterLength

ArTypes::UByte2	myHeaderLength

bool	myIsValid

ArTypes::UByte2	myLength

ArTypes::UByte2	myMaxLength

bool	myOwnMyBuf

ArTypes::UByte2	myReadLength

Detailed Description

Base packet class.

This class is a base class for specific packet types implemented by base classes. In most cases, you would not instantiate this class directly, but instead use a subclass. However, ArBasePacket contains many of the functions used to access the packet's data.

A packet is a sequence of values stored in a buffer. The contents of a packet's data buffer is read from a device or other program or written to the device (for example, a serial port or TCP port using an ArDeviceConnection or using ArNetworking), optionally preceded by a header with some identifying data and a length, and optionally followed by a footer with a checksum of the data. (If the header length of a particular packet type is 0, no header is written or expected on read, and likewise with footer.)

Values are added to the buffer or removed from the buffer in sequence. The "bufTo" methods are used to remove values from the buffer, and the "ToBuf" methods are used to add values to the buffer. There are different methods for different sized values.

ArBasePacket keeps a current position index in the buffer, which is the position at which new values are added or values are removed.

A buffer may be statically allocated externally and supplied to the constructor (also give a buffer size to determine the maximum amount of data that can be placed in that bufer), or automatically and dynamically allocated by ArBasePacket as needed (the default behavior).

When it is time to write out a packet, call finalizePacket() to set up the footer if neccesary. To reuse a packet, use empty() to reset the buffer; new data will then be added to the beginning of the buffer again.

Constructor & Destructor Documentation

◆ ArBasePacket()

ArBasePacket::ArBasePacket	(	ArTypes::UByte2	bufferSize = `0`,
		ArTypes::UByte2	headerLength = `0`,
		char *	buf = `NULL`,
		ArTypes::UByte2	footerLength = `0`
	)

Constructor.

Parameters

bufferSize	size of the buffer
headerLength	length of the header
buf	buffer packet uses, if NULL, instance will allocate memory
footerLength	length of the footer following the data

Member Function Documentation

◆ bufToData() [1/2]

void ArBasePacket::bufToData	(	char *	data,
		int	length
	)

virtual

Gets length bytes from buffer and puts them into data.

copies length bytes from the buffer into data, length is passed in, not read from packet

Parameters

data	character array to copy the data into
length	number of bytes to copy into data

◆ bufToData() [2/2]

void ArBasePacket::bufToData	(	unsigned char *	data,
		int	length
	)

virtual

Gets length bytes from buffer and puts them into data.

This was added to get around having to cast data you put in, since the data shouldn't really matter if its signed or unsigned.

copies length bytes from the buffer into data, length is passed in, not read from packet

Parameters

data	character array to copy the data into
length	number of bytes to copy into data

◆ bufToStr()

void ArBasePacket::bufToStr	(	char *	buf,
		int	len
	)

virtual

Gets a string from the buffer.

Copy a string from the packet buffer into the given buffer, stopping when the end of the packet buffer is reached, the given length is reached, or a NUL character ('\0') is reached.

If the given length is not large enough, then the remainder of the string is flushed from the packet. A NUL character ('\0') is appended to buf if there is sufficient room after copying the sting from the packet, otherwise no NUL is added (i.e. if len bytes are copied).

Parameters

buf	Destination buffer
len	Maximum number of characters to copy into the destination buffer

◆ dataToBuf() [1/2]

void ArBasePacket::dataToBuf	(	const char *	data,
		int	length
	)

virtual

Copies length bytes from data into packet buffer.

Parameters

data	chacter array to copy into buffer
length	how many bytes to copy from data into packet

◆ dataToBuf() [2/2]

void ArBasePacket::dataToBuf	(	const unsigned char *	data,
		int	length
	)

virtual

Copies length bytes from data into packet buffer.

This was added to get around having to cast data you put in, since the data shouldn't really matter if its signed or unsigned.

Parameters

data	chacter array to copy into buffer
length	how many bytes to copy from data into packet

◆ duplicatePacket()

void ArBasePacket::duplicatePacket ( ArBasePacket * packet )

virtual

Makes this packet a duplicate of another packet.

Copies the given packets buffer into the buffer of this packet, also sets this length and readlength to what the given packet has.

Parameters

packet the packet to duplicate

◆ empty()

void ArBasePacket::empty ( void )

virtual

resets the length for more data to be added

Sets the packet length back to be the packets header length again.

◆ isValid()

bool ArBasePacket::isValid ( void )

virtual

Returns whether the packet is valid, i.e. no error has occurred when reading/writing.

A packet is considered "invalid" if an attempt is made to write too much data into the packet, or to read too much data from the packet.

Calls to empty() and resetRead() will restore the valid state.

◆ resetRead()

void ArBasePacket::resetRead ( void )

virtual

Restart the reading process.

Sets the length read back to the header length so the packet can be reread using the other methods.

◆ resetValid()

void ArBasePacket::resetValid ( )

virtual

Resets the valid state of the packet.

Resets the packet to the "valid" state.

This method should generally only be called externally when the application has taken some recovery action. For example, if an attempt to write a long string to the packet fails (and isValid() returns false), then a smaller string may be written instead.

◆ strNToBuf()

void ArBasePacket::strNToBuf	(	const char *	str,
		int	length
	)

virtual

Copies the given number of bytes from str into packet buffer.

This method performs no bounds checking on the given length and the contents of the string.

Deprecated:: use strToBufPadded(), strToBuf(), or dataToBuf() instead

For string operations, strNToBufPadded() is preferred. For raw data operations, dataToBuf() is preferred.

Parameters

str	character array to copy into the packet buffer
length	how many characters to copy from str into the packet buffer

◆ strToBuf()

void ArBasePacket::strToBuf ( const char * str )

virtual

Puts a NULL-terminated string into packet buffer.

Parameters

str	string to copy into buffer

◆ strToBufPadded()

void ArBasePacket::strToBufPadded	(	const char *	str,
		int	length
	)

virtual

Copies length bytes from str, if str ends before length, pads data with 0s.

If string ends before length it pads the string with NUL ('\0') characters.

Parameters

str	character array to copy into buffer
length	how many bytes to copy from the str into packet

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

ArBasePacket.h
ArBasePacket.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ArBasePacket()

Member Function Documentation

◆ bufToData() [1/2]

◆ bufToData() [2/2]

◆ bufToStr()

◆ dataToBuf() [1/2]

◆ dataToBuf() [2/2]

◆ duplicatePacket()

◆ empty()

◆ isValid()

◆ resetRead()

◆ resetValid()

◆ strNToBuf()

◆ strToBuf()

◆ strToBufPadded()