Function libzt::zts_get_pending_data_size

pub unsafe extern "C" fn zts_get_pending_data_size(fd: c_int) -> c_int

@brief Return the number of bytes available to read from the network buffer

@param fd Socket file descriptor @return Number of bytes to read if successful, ZTS_ERR_SERVICE if the node experiences a problem, ZTS_ERR_ARG if invalid argument. Sets zts_errno