Messages

DGTL messages API. More...

Files
file	dgtl_msg.h
	Declarations for DGTL Messages API.

Functions
dgtl_msg_t *	dgtl_msg_alloc (uint8_t pkt_type, size_t length)
	Allocate a DGTL message. More...
void	dgtl_msg_free (dgtl_msg_t *msg)
	Free DGTL message. More...
void *	dgtl_msg_get_param_ptr (dgtl_msg_t *msg, size_t *length)
	Get pointer to message contents parameters. More...
void *	dgtl_msg_to_raw_ptr (dgtl_msg_t *msg)
	Get pointer for raw buffer of DGTL message. More...
dgtl_msg_t *	dgtl_msg_from_raw_ptr (void *ptr, uint8_t pkt_type)
	Get DGTL message pointer from raw buffer. More...

Variables
typedef	__PACKED_UNION
	DGTL message. More...

Detailed Description

DGTL messages API.

Function Documentation

dgtl_msg_alloc()

dgtl_msg_t* dgtl_msg_alloc	(	uint8_t	pkt_type,
		size_t	length
	)

Allocate a DGTL message.

This function allocates an empty DGTL message.

The allocated message contents has following structure:

,– packet type indicator | ,– packet header (length depends on packet type indicator) | | ,– packet parameters | | | v v v ,—.-------—.------------—. | 1 | 2 .. X | X+1 .. length | '—'-------—'------------—' ^ ^ | | | | | -- message parameters pointer – message pointer

The message contents parameters pointer can be obtained using dgtl_msg_get_param_ptr() helper.

The allocated message has to be freed using dgtl_msg_free() after use.

Warning

The application shall not change packet type indicator for already allocated message, this may result in an undefined behavior.

Parameters

[in]	pkt_type	packet type indicator
[in]	length	packet length

Returns

DGTL message

dgtl_msg_free()

void dgtl_msg_free

(

dgtl_msg_t *

msg

)

Free DGTL message.

This function should be used to free a DGTL message previously allocated using other DGTL APIs.

Parameters

[in]

msg

DGTL message

dgtl_msg_from_raw_ptr()

dgtl_msg_t* dgtl_msg_from_raw_ptr	(	void *	ptr,
		uint8_t	pkt_type
	)

Get DGTL message pointer from raw buffer.

Warning

This function is intended for internal usage only and shall not be used by regular applications.

Parameters

[in]	ptr	buffer pointer
[in]	pkt_type	packet type, as stored in buffer

Returns

DGTL message

dgtl_msg_get_param_ptr()

void* dgtl_msg_get_param_ptr	(	dgtl_msg_t *	msg,
		size_t *	length
	)

Get pointer to message contents parameters.

This function returns a pointer to message contents parameters. length parameter is optional and, if supplied, will be filled with message contents parameters length.

Warning

This function should only be called on an already initialized message which has proper packet header set. Calling it on a message which is not properly initialized may result in undefined behavior.

Parameters

[in]	msg	DGTL message
[out]	length	message contents parameters length

Returns

message contents pointer

dgtl_msg_to_raw_ptr()

void* dgtl_msg_to_raw_ptr

(

dgtl_msg_t *

msg

)

Get pointer for raw buffer of DGTL message.

Warning

This function is intended for internal usage only and shall not be used by regular applications.

Parameters

[in]

msg

DGTL message

Returns

buffer pointer

Variable Documentation

__PACKED_UNION

typedef __PACKED_UNION

Initial value:

{
        const uint8_t pkt_type

DGTL message.