Function cirbuf_get_buf_tail

dpdk/lib/cmdline/cmdline_cirbuf.c:361–396

/* convert to buffer */

int
cirbuf_get_buf_tail(struct cirbuf *cbuf, char *c, unsigned int size)
{
	unsigned int n;

	if (!cbuf || !c)
		return -EINVAL;

	n = (size < CIRBUF_GET_LEN(cbuf)) ? size : CIRBUF_GET_LEN(cbuf);

	if (!n)
		return 0;

	if (cbuf->start <= cbuf->end) {
		dprintf("s[%d] -> d[%d] (%d)\n", cbuf->end - n + 1, 0, n);
		memcpy(c, cbuf->buf + cbuf->end - n + 1, n);
	}
	else {
		/* check if we need to go from end to the beginning */
		if (n <= cbuf->end + 1) {
			dprintf("s[%d] -> d[%d] (%d)\n", 0, cbuf->end - n + 1, n);
			memcpy(c, cbuf->buf + cbuf->end - n + 1, n);
		}
		else {
			dprintf("s[%d] -> d[%d] (%d)\n", 0,
				cbuf->maxlen - cbuf->start, cbuf->end + 1);
			dprintf("s[%d] -> d[%d] (%d)\n",
				cbuf->maxlen - n + cbuf->end + 1, 0, n - cbuf->end - 1);
			memcpy(c + cbuf->maxlen - cbuf->start,
					       cbuf->buf, cbuf->end + 1);
			memcpy(c, cbuf->buf + cbuf->maxlen - n + cbuf->end +1,
				   n - cbuf->end - 1);
		}
	}
	return n;
}

/* get head or get tail */