# &develguide;

## Available Functions

### `ul_register_domain(name)`

The function registers a new domain. Domain is just another name for table used in registrar. The function is called from fixups in registrar. It gets name of the domain as a parameter and returns pointer to a new domain structure. The fixup than 'fixes' the parameter in registrar so that it will pass the pointer instead of the name every time save() or lookup() is called. Some usrloc functions get the pointer as parameter when called. For more details see implementation of save function in registrar.

Meaning of the parameters is as follows:

- const char* name - Name of the domain (also called table) to be registered.

### `ul_insert_urecord(domain, aor, rec)`

The function creates a new record structure and inserts it in the specified domain. The record is structure that contains all the contacts for belonging to the specified username.

Meaning of the parameters is as follows:

- udomain_t* domain - Pointer to domain returned by ul_register_udomain.

- str* aor - Address of Record (aka username) of the new record (at this time the record will contain no contacts yet).

- urecord_t** rec - The newly created record structure.

### `ul_delete_urecord(domain, aor)`

The function deletes all the contacts bound with the given Address Of Record.

Meaning of the parameters is as follows:

- udomain_t* domain - Pointer to domain returned by ul_register_udomain.

- str* aor - Address of record (aka username) of the record, that should be deleted.

### `ul_delete_urecord_by_ruid(domain, ruid)`

The function deletes from given domain a contact with given ruid.

Meaning of the parameters is as follows:

- udomain_t* domain - Pointer to domain returned by ul_register_udomain.

- str* ruid - ruid of contact that should be deleted.

### `ul_get_urecord(domain, aor)`

The function returns pointer to record with given Address of Record.

Meaning of the parameters is as follows:

- udomain_t* domain - Pointer to domain returned by ul_register_udomain.

- str* aor - Address of Record of request record.

### `ul_lock_udomain(domain)`

The function lock the specified domain, it means, that no other processes will be able to access during the time. This prevents race conditions. Scope of the lock is the specified domain, that means, that multiple domain can be accessed simultaneously, they don't block each other.

Meaning of the parameters is as follows:

- udomain_t* domain - Domain to be locked.

### `ul_unlock_udomain(domain)`

Unlock the specified domain previously locked by ul_lock_udomain.

Meaning of the parameters is as follows:

- udomain_t* domain - Domain to be unlocked.

### `ul_release_urecord(record)`

Do some sanity checks - if all contacts have been removed, delete the entire record structure.

Meaning of the parameters is as follows:

- urecord_t* record - Record to be released.

### `ul_insert_ucontact(record, contact, expires, q, callid, cseq, flags, cont, ua, sock)`

The function inserts a new contact in the given record with specified parameters.

Meaning of the parameters is as follows:

- urecord_t* record - Record in which the contact should be inserted.

- str* contact - Contact &uri;.

- time_t expires - Expires of the contact in absolute value.

- float q - q value of the contact.

- str* callid - Call-ID of the REGISTER message that contained the contact.

- int cseq - CSeq of the REGISTER message that contained the contact.

- unsigned int flags - Flags to be set.

- ucontact_t* cont - Pointer to newly created structure.

- str* ua - User-Agent of the REGISTER message that contained the contact.

- struct socket_info *sock - socket on which the REGISTER message was received on.

### `ul_delete_ucontact (record, contact)`

The function deletes given contact from record.

Meaning of the parameters is as follows:

- urecord_t* record - Record from which the contact should be removed.

- ucontact_t* contact - Contact to be deleted.

### `ul_get_ucontact(record, contact)`

The function tries to find contact with given Contact &uri; and returns pointer to structure representing the contact.

Meaning of the parameters is as follows:

- urecord_t* record - Record to be searched for the contact.

- str_t* contact - &uri; of the request contact.

### `ul_get_all_ucontacts (buf, len, flags)`

The function retrieves all contacts of all registered users and returns them in the caller-supplied buffer. If the buffer is too small, the function returns positive value indicating how much additional space would be necessary to accommodate all of them. Please note that the positive return value should be used only as a hint, as there is no guarantee that during the time between two subsequent calls number of registered contacts will remain the same.

If flag parameter is set to non-zero value then only contacts that have the specified flags set will be returned. It is, for example, possible to list only contacts that are behind NAT.

Meaning of the parameters is as follows:

- void* buf - Buffer for returning contacts.

- int len - Length of the buffer.

- unsigned int flags - Flags that must be set.

### `ul_update_ucontact(contact, expires, q, callid, cseq, set, res, ua, sock)`

The function updates contact with new values.

Meaning of the parameters is as follows:

- ucontact_t* contact - Contact &uri;.

- time_t expires - Expires of the contact in absolute value.

- float q - q value of the contact.

- str* callid - Call-ID of the REGISTER message that contained the contact.

- int cseq - CSeq of the REGISTER message that contained the contact.

- unsigned int set - OR value of flags to be set.

- unsigned int res - OR value of flags to be reset.

- str* ua - User-Agent of the REGISTER message that contained the contact.

- struct socket_info *sock - socket on which the REGISTER message was received on.

### `ul_bind_ursloc(api)`

The function imports all functions that are exported by the USRLOC module. Overs for other modules which want to user the internal USRLOC API an easy way to load and access the functions.

Meaning of the parameters is as follows:

- usrloc_api_t* api - USRLOC API

### `ul_register_ulcb(type, callback, param)`

The function register with USRLOC a callback function to be called when some event occurs inside USRLOC.

Meaning of the parameters is as follows:

- int types - type of event for which the callback should be called (see usrloc/ul_callback.h).

- ul_cb f - callback function; see usrloc/ul_callback.h for prototype.

- void *param - some parameter to be passed to the callback each time when it is called.

### `ul_get_num_users()`

The function loops through all domains summing up the number of users.