=head1 NAME

nbd_get_handle_size - return an estimate of the memory allocated for
the handle

=head1 SYNOPSIS

 #include <libnbd.h>

 ssize_t nbd_get_handle_size (
           struct nbd_handle *h
         );

=head1 DESCRIPTION

Return an estimate of the number of bytes allocated for the
handle.  The main use for this is with compacting garbage collectors
which can make a more informed decision about when to free the
handle with this information.

=head1 RETURN VALUE

This call returns an integer size E<ge> C<0>.

=head1 ERRORS

On error C<-1> is returned.

Refer to L<libnbd(3)/ERROR HANDLING>
for how to get further details of the error.

The following parameters must not be NULL: C<h>.
For more information see L<libnbd(3)/Non-NULL parameters>.

=head1 VERSION

This function first appeared in libnbd 1.24.

If you need to test if this function is available at compile time
check if the following macro is defined:

 #define LIBNBD_HAVE_NBD_GET_HANDLE_SIZE 1

=head1 SEE ALSO

L<nbd_create(3)>,
L<libnbd(3)>.

=head1 AUTHORS

Eric Blake

Richard W.M. Jones

=head1 COPYRIGHT

Copyright Red Hat
