update_usermeta() WordPress Function

function update_usermeta( $user_id, $meta_key, $meta_value ) {
	_deprecated_function( __FUNCTION__, '3.0.0', 'update_user_meta()' );
	global $wpdb;
	if ( !is_numeric( $user_id ) )
		return false;
	$meta_key = preg_replace('|[^a-z0-9_]|i', '', $meta_key);

	/** @todo Might need fix because usermeta data is assumed to be already escaped */
	if ( is_string($meta_value) )
		$meta_value = stripslashes($meta_value);
	$meta_value = maybe_serialize($meta_value);

	if (empty($meta_value)) {
		return delete_usermeta($user_id, $meta_key);
	}

	$cur = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->usermeta WHERE user_id = %d AND meta_key = %s", $user_id, $meta_key) );

	if ( $cur )
		do_action( 'update_usermeta', $cur->umeta_id, $user_id, $meta_key, $meta_value );

	if ( !$cur )
		$wpdb->insert($wpdb->usermeta, compact('user_id', 'meta_key', 'meta_value') );
	elseif ( $cur->meta_value != $meta_value )
		$wpdb->update($wpdb->usermeta, compact('meta_value'), compact('user_id', 'meta_key') );
	else
		return false;

	clean_user_cache( $user_id );
	wp_cache_delete( $user_id, 'user_meta' );

	if ( !$cur )
		do_action( 'added_usermeta', $wpdb->insert_id, $user_id, $meta_key, $meta_value );
	else
		do_action( 'updated_usermeta', $cur->umeta_id, $user_id, $meta_key, $meta_value );

	return true;
}
Uses	Description
wp-includes/cache.php:wp_cache_delete()	Removes the cache contents matching key and group.
wp-includes/deprecated.php:delete_usermeta()	Remove user meta data.
wp-includes/functions.php:_deprecated_function()	Mark a function as deprecated and inform when it has been used.
wp-includes/functions.php:maybe_serialize()	Serialize data, if needed.
wp-includes/plugin.php:do_action()	Calls the callback functions that have been added to an action hook.
wp-includes/user.php:clean_user_cache()	Cleans all user caches.
wp-includes/wp-db.php:wpdb::get_row()	Retrieves one row from the database.
wp-includes/wp-db.php:wpdb::insert()	Inserts a row into the table.
wp-includes/wp-db.php:wpdb::update()	Updates a row in the table.
wp-includes/wp-db.php:wpdb::prepare()	Prepares a SQL query for safe execution.