msg_mclass_s Struct Reference

Factory object for protocol messages. More...

#include <msg_mclass.h>

Collaboration diagram for msg_mclass_s:

Data Fields
struct msg_hclass_s	mc_hclass [1]
	Recursive header class.
char const *	mc_name
	Protocol name, e.g., "SIP/2.0".
void *	mc_tag
	Protocol-specific tag.
unsigned	mc_flags
	Default flags.
unsigned	mc_msize
	Size of public message structure.
issize_t(*	mc_extract_body )(msg_t *msg, msg_pub_t *pub, char b[], isize_t bsiz, int eos)
	Function extracting the message contents.
msg_href_t	mc_request [1]
	Request line reference.
msg_href_t	mc_status [1]
	Status line reference.
msg_href_t	mc_separator [1]
	Separator line reference.
msg_href_t	mc_payload [1]
	Message body reference.
msg_href_t	mc_unknown [1]
	Reference for unknown headers.
msg_href_t	mc_error [1]
	Reference for erroneous header.
msg_href_t	mc_multipart [1]
	Multipart body reference.
msg_href_t const *	mc_short
	Short forms (or NULL).
short	mc_hash_size
	Size of parsing table.
short	mc_hash_used
	Number of headers in parsing table.
msg_href_t	mc_hash [MC_HASH_SIZE]
	Hash table for parsing containing reference for each header.
Related Functions
(Note that these are not member functions.)
msg_mclass_t *	msg_mclass_clone (msg_mclass_t const *old, int newsize, int empty)
	Clone a message class.
int	msg_mclass_insert_header (msg_mclass_t *mc, msg_hclass_t *hc, unsigned short offset)
	Add a new header to the message class.
int	msg_mclass_insert_with_mask (msg_mclass_t *mc, msg_hclass_t *hc, unsigned short offset, unsigned short flags)
	Add a new header to the message class.
int	msg_mclass_insert (msg_mclass_t *mc, msg_href_t const *hr)
	Add a header reference to the message class.
msg_href_t const *	msg_find_hclass (msg_mclass_t const *mc, char const *s, isize_t *return_start_of_content)
	Search for a header class.

---

Detailed Description

Factory object for protocol messages.

The message class is a kind of a factory object used to create new message objects for the protocol it represents (see msg_create()).

The message class object contains all the information needed to parse a message. It used when headers are added or removed from the message. When a message is sent, the message class is used to order message components and print (encode) the message in text format.

The message class contains reference objects to headers and other components within the message. Each reference contains a pointer to a header class and a offset to the header objects within public message structure. The parser engine uses these references when it adds a newly parsed header object to the message structure. The function msg_find_hclass() searches for the reference of the named header.

The application can make a copy of existing message class object using the function msg_mclass_clone(). New headers can be added to the message class with the msg_mclass_insert_header() and msg_mclass_insert() functions. The message class of an existing message object can be found out with the function msg_mclass().

See also:

sip_default_mclass(), http_default_mclass(), msg_create(), msg_mclass(), msg_mclass_clone(), msg_mclass_insert_header(), msg_mclass_insert_with_mask(), msg_mclass_insert().

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Friends And Related Function Documentation

msg_href_t const * msg_find_hclass	(	msg_mclass_t const *	mc,
		char const *	s,
		isize_t *	return_start_of_content
	)			[related]

Search for a header class.

The function msg_find_hclass() searches for a header class from a message class based on the contents of the header to be parsed. The buffer s should point to the first character in the header name.

Parameters:

[in]	mc	message class object
[in]	s	header contents
[out]	return_start_of_content	start of header content (may be NULL)

Returns:

The function msg_find_hclass() returns a pointer to a header reference structure. A pointer to a header reference for unknown headers is returned, if the header is not included in the message class.

The return-value parameter return_start_of_content will contain the start of the header contents within s, or 0 upon an error parsing the header name and following colon.

Upon a fatal error, a NULL pointer is returned.

int msg_mclass_insert	(	msg_mclass_t *	mc,
		msg_href_t const *	hr
	)			[related]

Add a header reference to the message class.

Parameters:

[in,out]	mc	pointer to a message class object
[in]	hr	header reference object

Returns:

Number of collisions in hash table, or -1 upon an error.

int msg_mclass_insert_header	(	msg_mclass_t *	mc,
		msg_hclass_t *	hc,
		unsigned short	offset
	)			[related]

Add a new header to the message class.

Insert a header class hc to the message class object mc. If the given offset of the header in public message structure" is zero, the function extends the public message structure in order to store newly inserted header there.

Parameters:

[in,out]	mc	pointer to a message class object
[in]	hc	pointer to a header class object
[in]	offset	offset of the header in public message structure

If the offset is 0, the msg_mclass_insert_header() increases size of the public message structure and places the header at the end of message.

Returns:

Number of collisions in hash table, or -1 upon an error.

Deprecated:

Use msg_mclass_insert_with_mask() instead.

int msg_mclass_insert_with_mask	(	msg_mclass_t *	mc,
		msg_hclass_t *	hc,
		unsigned short	offset,
		unsigned short	flags
	)			[related]

Add a new header to the message class.

Insert a header class hc to the message class mc. If the given offset of the header in public message structure is zero, extend the size of the public message structure in order to store headers at the end of structure.

Parameters:

[in,out]	mc	pointer to a message class
[in]	hc	pointer to a header class
[in]	offset	offset of the header in public message structure
[in]	flags	classification flags for the header

Returns:

Number of collisions in hash table, or -1 upon an error.

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Field Documentation

issize_t(* mc_extract_body)(msg_t *msg, msg_pub_t *pub, char b[], isize_t bsiz, int eos)

Function extracting the message contents.

msg_href_t mc_hash[MC_HASH_SIZE]

Hash table for parsing containing reference for each header.