I²C over TCP. More...

Detailed Description

This library includes protocol (de)serialization functions for sending and receiving I²C messages over TCP. These functions are used by the main controller and the puzzle box client (pbc). This library does not include any puzzle bus specific code.

mpack is used for the actual (de)serialization, and the functions in this library act as helpers for parsing from chunked data streams.

To use these functions, include the following statement in your CMakeLists.txt:

# include pbdrv
add_subdirectory(lib/i2ctcp)
 
# link with executable
target_link_libraries(main i2ctcp)

Classes
struct	i2ctcp_msg_t
	I²C over TCP message (v1) More...

Functions
int	i2ctcp_read (i2ctcp_msg_t target, const char buf, size_t buf_sz)
	Read chunk of input stream, and store resulting message in `target`.

void	i2ctcp_read_reset (i2ctcp_msg_t *target)
	Reset the remaining message data counter.

bool	i2ctcp_write (const i2ctcp_msg_t target, char buf, size_t buf_sz)
	Allocate and write a msgpack-formatted message to `buf`.

Function Documentation

◆ i2ctcp_read()

int i2ctcp_read	(	i2ctcp_msg_t *	target,
		const char *	buf,
		size_t	buf_sz )

This function is called for each chunk of data from an input stream, and will parse the next puzzle bus message into target. The input stream is assumed to only contain messages encoded by i2ctcp_write()

Parameters

target	Pointer to struct that will contain the finished message data
buf	Pointer to input stream data chunk
buf_sz	Size of `buf`

Returns: Integer representing amount of bytes required to finish message, or -1 if the message header could not be read. If this function returns 0, the message in target is complete.

Note: target->data will automatically be allocated by this function, even if the message is not fully parsed. This variable must be free'd by the caller after each complete message to prevent memory leaks.

◆ i2ctcp_read_reset()

void i2ctcp_read_reset ( i2ctcp_msg_t * target )

Calling this function has the effect of forcing i2ctcp_read() to parse the next buffer chunk as the start of a new message. This function may be called before reading a TCP frame's data to mitigate any synchronization issues arising from earlier corrupt or otherwise malformed messages.

◆ i2ctcp_write()

bool i2ctcp_write	(	const i2ctcp_msg_t *	target,
		char **	buf,
		size_t *	buf_sz )

This function allocates a buffer large enough to fit the message specified in target, and encodes the data in target in a format that can be decoded later using i2ctcp_read().