104     ring_init(ring, buffer, count)  in ring_init()  argument
105 Ring *ring;  in ring_init()
109 	(void) memset(ring, 0, sizeof (*ring));
111 	ring->size = count;
113 	ring->supply = ring->consume = ring->bottom = buffer;
115 	ring->top = ring->bottom+ring->size;
117 	ring->clearto = 0;
129 ring_mark(ring)  in ring_mark()  argument
130 	Ring *ring;  in ring_mark()
132 	ring->mark = ring_decrement(ring, ring->supply, 1);
140 ring_at_mark(ring)  in ring_at_mark()  argument
141 	Ring *ring;  in ring_at_mark()
143 	if (ring->mark == ring->consume) {
155 ring_clear_mark(ring)  in ring_clear_mark()  argument
156 	Ring *ring;  in ring_clear_mark()
158 	ring->mark = 0;
165 ring_supplied(ring, count)  in ring_supplied()  argument
166     Ring *ring;  in ring_supplied()
169     ring->supply = ring_increment(ring, ring->supply, count);
170     ring->supplytime = ++ring_clock;
177 ring_consumed(ring, count)  in ring_consumed()  argument
178 	Ring *ring;  in ring_consumed()
184 	if (ring->mark &&
185 	    (ring_subtract(ring, ring->mark, ring->consume) < count)) {
186 		ring->mark = 0;
189 	if (ring->consume < ring->clearto &&
190 	    ring->clearto <= ring->consume + count)
191 		ring->clearto = 0;
192 	else if (ring->consume + count > ring->top &&
193 	    ring->bottom <= ring->clearto &&
194 	    ring->bottom + ((ring->consume + count) - ring->top))
195 		ring->clearto = 0;
197 	ring->consume = ring_increment(ring, ring->consume, count);
198 	ring->consumetime = ++ring_clock;
202 	if (ring_empty(ring)) {
203 		ring->consume = ring->supply = ring->bottom;
214 ring_empty_count(ring)  in ring_empty_count()  argument
215 	Ring *ring;  in ring_empty_count()
217 	if (ring_empty(ring)) {	/* if empty */
218 		return (ring->size);
220 		return (ring_subtract(ring, ring->consume, ring->supply));
226 ring_empty_consecutive(ring)  in ring_empty_consecutive()  argument
227 	Ring *ring;  in ring_empty_consecutive()
229 	if ((ring->consume < ring->supply) || ring_empty(ring)) {
234 		return (ring_subtract(ring, ring->top, ring->supply));
239 		return (ring_subtract(ring, ring->consume, ring->supply));
249 ring_full_count(ring)  in ring_full_count()  argument
250 	Ring *ring;  in ring_full_count()
252 	if ((ring->mark == 0) || (ring->mark == ring->consume)) {
253 		if (ring_full(ring)) {
254 			return (ring->size);	/* nothing consumed, but full */
256 			return (ring_subtract(ring, ring->supply,
257 			    ring->consume));
260 		return (ring_subtract(ring, ring->mark, ring->consume));
269 ring_full_consecutive(ring)  in ring_full_consecutive()  argument
270 	Ring *ring;  in ring_full_consecutive()
272 	if ((ring->mark == 0) || (ring->mark == ring->consume)) {
273 		if ((ring->supply < ring->consume) || ring_full(ring)) {
274 			return (ring_subtract(ring, ring->top, ring->consume));
276 			return (ring_subtract(ring, ring->supply,
277 			    ring->consume));
280 		if (ring->mark < ring->consume) {
281 			return (ring_subtract(ring, ring->top, ring->consume));
283 			return (ring_subtract(ring, ring->mark, ring->consume));
292 ring_supply_data(ring, buffer, count)  in ring_supply_data()  argument
293 	Ring *ring;  in ring_supply_data()
300 		i = MIN(count, ring_empty_consecutive(ring));
301 		(void) memcpy(ring->supply, buffer, i);
302 		ring_supplied(ring, i);
314 ring_consume_data(ring, buffer, count)  in ring_consume_data()  argument
315 	Ring *ring;  in ring_consume_data()
322 		i = MIN(count, ring_full_consecutive(ring));
323 		memcpy(buffer, ring->consume, i);
324 		ring_consumed(ring, i);
332 ring_encrypt(ring, encryptor)  in ring_encrypt()  argument
333 	Ring *ring;  in ring_encrypt()
338 	if (ring_empty(ring) || ring->clearto == ring->supply)
341 	if ((c = ring->clearto) == NULL)
342 		c = ring->consume;
344 	s = ring->supply;
347 		(*encryptor)(c, ring->top - c);
348 		(*encryptor)(ring->bottom, s - ring->bottom);
352 	ring->clearto = ring->supply;
356 ring_clearto(ring)  in ring_clearto()  argument
357     Ring *ring;  in ring_clearto()
359     if (!ring_empty(ring))
360 	ring->clearto = ring->supply;
362 	ring->clearto = 0;