Function sbuf_start_section

freebsd/kern/subr_sbuf.c:899–919

* Start a section. */

 * Start a section.
 */
void
sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
{

	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);

	if (!SBUF_ISSECTION(s)) {
		KASSERT(s->s_sect_len == 0,
		    ("s_sect_len != 0 when starting a section"));
		if (old_lenp != NULL)
			*old_lenp = -1;
		s->s_rec_off = s->s_len;
		SBUF_SETFLAG(s, SBUF_INSECTION);
	} else {
		KASSERT(old_lenp != NULL,
		    ("s_sect_len should be saved when starting a subsection"));
		*old_lenp = s->s_sect_len;
		s->s_sect_len = 0;
	}
}

/*
 * End the section padding to the specified length with the specified