Metadata API.

Classes
struct	jack_property_t
struct	jack_description_t
Typedefs
typedef void(*	JackPropertyChangeCallback )(jack_uuid_t subject, const char *key, jack_property_change_t change, void *arg)
Enumerations
enum	jack_property_change_t {   PropertyCreated, PropertyChanged, PropertyDeleted, PropertyCreated,   PropertyChanged, PropertyDeleted }
Functions
int	jack_set_property (jack_client_t *, jack_uuid_t subject, const char *key, const char *value, const char *type)
int	jack_get_property (jack_uuid_t subject, const char *key, char **value, char **type)
void	jack_free_description (jack_description_t *desc, int free_description_itself)
int	jack_get_properties (jack_uuid_t subject, jack_description_t *desc)
int	jack_get_all_properties (jack_description_t **descs)
int	jack_remove_property (jack_client_t *client, jack_uuid_t subject, const char *key)
int	jack_remove_properties (jack_client_t *client, jack_uuid_t subject)
int	jack_remove_all_properties (jack_client_t *client)
int	jack_set_property_change_callback (jack_client_t *client, JackPropertyChangeCallback callback, void *arg)

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Function Documentation

int jack_set_property	(	jack_client_t *	,
		jack_uuid_t	subject,
		const char *	key,
		const char *	value,
		const char *	type
	)

Set a property on subject.

See the above documentation for rules about subject and key.

Parameters:

	subject	The subject to set the property on.
	key	The key of the property.
	value	The value of the property.
	type	The type of the property. See the discussion of types in the definition of jack_property_t above.

Returns:

0 on success.

int jack_get_property	(	jack_uuid_t	subject,
		const char *	key,
		char **	value,
		char **	type
	)

Get a property on subject.

Parameters:

	subject	The subject to get the property from.
	key	The key of the property.
	value	Set to the value of the property if found, or NULL otherwise. The caller must free this value with jack_free().
	type	The type of the property if set, or NULL. See the discussion of types in the definition of jack_property_t above. If non-null, the caller must free this value with jack_free().

Returns:

0 on success, -1 if the subject has no key property.

void jack_free_description	(	jack_description_t *	desc,
		int	free_description_itself
	)

Free a description.

Parameters:

	desc	a jack_description_t whose associated memory will all be released
	free_description_itself	if non-zero, then
	desc	will also be passed to free()

int jack_get_properties	(	jack_uuid_t	subject,
		jack_description_t *	desc
	)

Get a description of subject.

Parameters:

	subject	The subject to get all properties of.
	desc	Set to the description of subject if found, or NULL otherwise. The caller must free this value with jack_free_description().

Returns:

0 on success, -1 if no subject with any properties exists.

int jack_get_all_properties

(

jack_description_t **

descs

)

Get descriptions for all subjects with metadata.

Parameters:

descs

Set to a NULL-terminated array of descriptions. The caller must free each of these with jack_free_description(), and the array itself with jack_free().

Returns:

0 on success.

int jack_remove_property	(	jack_client_t *	client,
		jack_uuid_t	subject,
		const char *	key
	)

Remove a single property on a subject.

Parameters:

	client	The JACK client making the request to remove the property.
	subject	The subject to remove the property from.
	key	The key of the property to be removed.

Returns:

0 on success, -1 otherwise

int jack_remove_properties	(	jack_client_t *	client,
		jack_uuid_t	subject
	)

Remove all properties on a subject.

Parameters:

	client	The JACK client making the request to remove some properties.
	subject	The subject to remove all properties from.

Returns:

a count of the number of properties removed, or -1 on error.

int jack_remove_all_properties

(

jack_client_t *

client

)

Remove all properties.

WARNING!! This deletes all metadata managed by a running JACK server. Data lost cannot be recovered (though it can be recreated by new calls to jack_set_property()).

Parameters:

client

The JACK client making the request to remove all properties

Returns:

0 on success, -1 otherwise

int jack_set_property_change_callback	(	jack_client_t *	client,
		JackPropertyChangeCallback	callback,
		void *	arg
	)

Arrange for client to call callback whenever a property is created, changed or deleted.

Parameters:

	client	the JACK client making the request
	callback	the function to be invoked when a property change occurs
	arg	the argument to be passed to
	callback	when it is invoked

Returns:

0 success, -1 otherwise.