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1/*
2 * Input async protocol.
3 * Copyright (c) 2015 Zhang Rui <bbcallen@gmail.com>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 *
21 * Based on libavformat/cache.c by Michael Niedermayer
22 */
23
24 /**
25 * @TODO
26 * support timeout
27 * support work with concatdec, hls
28 */
29
30#include "libavutil/avassert.h"
31#include "libavutil/avstring.h"
32#include "libavutil/error.h"
33#include "libavutil/fifo.h"
34#include "libavutil/log.h"
35#include "libavutil/opt.h"
36#include "libavutil/thread.h"
37#include "url.h"
38#include <stdint.h>
39
40#if HAVE_UNISTD_H
41#include <unistd.h>
42#endif
43
44#define BUFFER_CAPACITY (4 * 1024 * 1024)
45#define READ_BACK_CAPACITY (4 * 1024 * 1024)
46#define SHORT_SEEK_THRESHOLD (256 * 1024)
47
48typedef struct RingBuffer
49{
50 AVFifoBuffer *fifo;
51 int read_back_capacity;
52
53 int read_pos;
54} RingBuffer;
55
56typedef struct Context {
57 AVClass *class;
58 URLContext *inner;
59
60 int seek_request;
61 int64_t seek_pos;
62 int seek_whence;
63 int seek_completed;
64 int64_t seek_ret;
65
66 int inner_io_error;
67 int io_error;
68 int io_eof_reached;
69
70 int64_t logical_pos;
71 int64_t logical_size;
72 RingBuffer ring;
73
74 pthread_cond_t cond_wakeup_main;
75 pthread_cond_t cond_wakeup_background;
76 pthread_mutex_t mutex;
77 pthread_t async_buffer_thread;
78
79 int abort_request;
80 AVIOInterruptCB interrupt_callback;
81} Context;
82
83static int ring_init(RingBuffer *ring, unsigned int capacity, int read_back_capacity)
84{
85 memset(ring, 0, sizeof(RingBuffer));
86 ring->fifo = av_fifo_alloc(capacity + read_back_capacity);
87 if (!ring->fifo)
88 return AVERROR(ENOMEM);
89
90 ring->read_back_capacity = read_back_capacity;
91 return 0;
92}
93
94static void ring_destroy(RingBuffer *ring)
95{
96 av_fifo_freep(&ring->fifo);
97}
98
99static void ring_reset(RingBuffer *ring)
100{
101 av_fifo_reset(ring->fifo);
102 ring->read_pos = 0;
103}
104
105static int ring_size(RingBuffer *ring)
106{
107 return av_fifo_size(ring->fifo) - ring->read_pos;
108}
109
110static int ring_space(RingBuffer *ring)
111{
112 return av_fifo_space(ring->fifo);
113}
114
115static int ring_generic_read(RingBuffer *ring, void *dest, int buf_size, void (*func)(void*, void*, int))
116{
117 int ret;
118
119 av_assert2(buf_size <= ring_size(ring));
120 ret = av_fifo_generic_peek_at(ring->fifo, dest, ring->read_pos, buf_size, func);
121 ring->read_pos += buf_size;
122
123 if (ring->read_pos > ring->read_back_capacity) {
124 av_fifo_drain(ring->fifo, ring->read_pos - ring->read_back_capacity);
125 ring->read_pos = ring->read_back_capacity;
126 }
127
128 return ret;
129}
130
131static int ring_generic_write(RingBuffer *ring, void *src, int size, int (*func)(void*, void*, int))
132{
133 av_assert2(size <= ring_space(ring));
134 return av_fifo_generic_write(ring->fifo, src, size, func);
135}
136
137static int ring_size_of_read_back(RingBuffer *ring)
138{
139 return ring->read_pos;
140}
141
142static int ring_drain(RingBuffer *ring, int offset)
143{
144 av_assert2(offset >= -ring_size_of_read_back(ring));
145 av_assert2(offset <= -ring_size(ring));
146 ring->read_pos += offset;
147 return 0;
148}
149
150static int async_check_interrupt(void *arg)
151{
152 URLContext *h = arg;
153 Context *c = h->priv_data;
154
155 if (c->abort_request)
156 return 1;
157
158 if (ff_check_interrupt(&c->interrupt_callback))
159 c->abort_request = 1;
160
161 return c->abort_request;
162}
163
164static int wrapped_url_read(void *src, void *dst, int size)
165{
166 URLContext *h = src;
167 Context *c = h->priv_data;
168 int ret;
169
170 ret = ffurl_read(c->inner, dst, size);
171 c->inner_io_error = ret < 0 ? ret : 0;
172
173 return ret;
174}
175
176static void *async_buffer_task(void *arg)
177{
178 URLContext *h = arg;
179 Context *c = h->priv_data;
180 RingBuffer *ring = &c->ring;
181 int ret = 0;
182 int64_t seek_ret;
183
184 while (1) {
185 int fifo_space, to_copy;
186
187 pthread_mutex_lock(&c->mutex);
188 if (async_check_interrupt(h)) {
189 c->io_eof_reached = 1;
190 c->io_error = AVERROR_EXIT;
191 pthread_cond_signal(&c->cond_wakeup_main);
192 pthread_mutex_unlock(&c->mutex);
193 break;
194 }
195
196 if (c->seek_request) {
197 seek_ret = ffurl_seek(c->inner, c->seek_pos, c->seek_whence);
198 if (seek_ret >= 0) {
199 c->io_eof_reached = 0;
200 c->io_error = 0;
201 ring_reset(ring);
202 }
203
204 c->seek_completed = 1;
205 c->seek_ret = seek_ret;
206 c->seek_request = 0;
207
208
209 pthread_cond_signal(&c->cond_wakeup_main);
210 pthread_mutex_unlock(&c->mutex);
211 continue;
212 }
213
214 fifo_space = ring_space(ring);
215 if (c->io_eof_reached || fifo_space <= 0) {
216 pthread_cond_signal(&c->cond_wakeup_main);
217 pthread_cond_wait(&c->cond_wakeup_background, &c->mutex);
218 pthread_mutex_unlock(&c->mutex);
219 continue;
220 }
221 pthread_mutex_unlock(&c->mutex);
222
223 to_copy = FFMIN(4096, fifo_space);
224 ret = ring_generic_write(ring, (void *)h, to_copy, wrapped_url_read);
225
226 pthread_mutex_lock(&c->mutex);
227 if (ret <= 0) {
228 c->io_eof_reached = 1;
229 if (c->inner_io_error < 0)
230 c->io_error = c->inner_io_error;
231 }
232
233 pthread_cond_signal(&c->cond_wakeup_main);
234 pthread_mutex_unlock(&c->mutex);
235 }
236
237 return NULL;
238}
239
240static int async_open(URLContext *h, const char *arg, int flags, AVDictionary **options)
241{
242 Context *c = h->priv_data;
243 int ret;
244 AVIOInterruptCB interrupt_callback = {.callback = async_check_interrupt, .opaque = h};
245
246 av_strstart(arg, "async:", &arg);
247
248 ret = ring_init(&c->ring, BUFFER_CAPACITY, READ_BACK_CAPACITY);
249 if (ret < 0)
250 goto fifo_fail;
251
252 /* wrap interrupt callback */
253 c->interrupt_callback = h->interrupt_callback;
254 ret = ffurl_open_whitelist(&c->inner, arg, flags, &interrupt_callback, options, h->protocol_whitelist, h->protocol_blacklist, h);
255 if (ret != 0) {
256 av_log(h, AV_LOG_ERROR, "ffurl_open failed : %s, %s\n", av_err2str(ret), arg);
257 goto url_fail;
258 }
259
260 c->logical_size = ffurl_size(c->inner);
261 h->is_streamed = c->inner->is_streamed;
262
263 ret = pthread_mutex_init(&c->mutex, NULL);
264 if (ret != 0) {
265 av_log(h, AV_LOG_ERROR, "pthread_mutex_init failed : %s\n", av_err2str(ret));
266 goto mutex_fail;
267 }
268
269 ret = pthread_cond_init(&c->cond_wakeup_main, NULL);
270 if (ret != 0) {
271 av_log(h, AV_LOG_ERROR, "pthread_cond_init failed : %s\n", av_err2str(ret));
272 goto cond_wakeup_main_fail;
273 }
274
275 ret = pthread_cond_init(&c->cond_wakeup_background, NULL);
276 if (ret != 0) {
277 av_log(h, AV_LOG_ERROR, "pthread_cond_init failed : %s\n", av_err2str(ret));
278 goto cond_wakeup_background_fail;
279 }
280
281 ret = pthread_create(&c->async_buffer_thread, NULL, async_buffer_task, h);
282 if (ret) {
283 av_log(h, AV_LOG_ERROR, "pthread_create failed : %s\n", av_err2str(ret));
284 goto thread_fail;
285 }
286
287 return 0;
288
289thread_fail:
290 pthread_cond_destroy(&c->cond_wakeup_background);
291cond_wakeup_background_fail:
292 pthread_cond_destroy(&c->cond_wakeup_main);
293cond_wakeup_main_fail:
294 pthread_mutex_destroy(&c->mutex);
295mutex_fail:
296 ffurl_close(c->inner);
297url_fail:
298 ring_destroy(&c->ring);
299fifo_fail:
300 return ret;
301}
302
303static int async_close(URLContext *h)
304{
305 Context *c = h->priv_data;
306 int ret;
307
308 pthread_mutex_lock(&c->mutex);
309 c->abort_request = 1;
310 pthread_cond_signal(&c->cond_wakeup_background);
311 pthread_mutex_unlock(&c->mutex);
312
313 ret = pthread_join(c->async_buffer_thread, NULL);
314 if (ret != 0)
315 av_log(h, AV_LOG_ERROR, "pthread_join(): %s\n", av_err2str(ret));
316
317 pthread_cond_destroy(&c->cond_wakeup_background);
318 pthread_cond_destroy(&c->cond_wakeup_main);
319 pthread_mutex_destroy(&c->mutex);
320 ffurl_close(c->inner);
321 ring_destroy(&c->ring);
322
323 return 0;
324}
325
326static int async_read_internal(URLContext *h, void *dest, int size, int read_complete,
327 void (*func)(void*, void*, int))
328{
329 Context *c = h->priv_data;
330 RingBuffer *ring = &c->ring;
331 int to_read = size;
332 int ret = 0;
333
334 pthread_mutex_lock(&c->mutex);
335
336 while (to_read > 0) {
337 int fifo_size, to_copy;
338 if (async_check_interrupt(h)) {
339 ret = AVERROR_EXIT;
340 break;
341 }
342 fifo_size = ring_size(ring);
343 to_copy = FFMIN(to_read, fifo_size);
344 if (to_copy > 0) {
345 ring_generic_read(ring, dest, to_copy, func);
346 if (!func)
347 dest = (uint8_t *)dest + to_copy;
348 c->logical_pos += to_copy;
349 to_read -= to_copy;
350 ret = size - to_read;
351
352 if (to_read <= 0 || !read_complete)
353 break;
354 } else if (c->io_eof_reached) {
355 if (ret <= 0) {
356 if (c->io_error)
357 ret = c->io_error;
358 else
359 ret = AVERROR_EOF;
360 }
361 break;
362 }
363 pthread_cond_signal(&c->cond_wakeup_background);
364 pthread_cond_wait(&c->cond_wakeup_main, &c->mutex);
365 }
366
367 pthread_cond_signal(&c->cond_wakeup_background);
368 pthread_mutex_unlock(&c->mutex);
369
370 return ret;
371}
372
373static int async_read(URLContext *h, unsigned char *buf, int size)
374{
375 return async_read_internal(h, buf, size, 0, NULL);
376}
377
378static void fifo_do_not_copy_func(void* dest, void* src, int size) {
379 // do not copy
380}
381
382static int64_t async_seek(URLContext *h, int64_t pos, int whence)
383{
384 Context *c = h->priv_data;
385 RingBuffer *ring = &c->ring;
386 int64_t ret;
387 int64_t new_logical_pos;
388 int fifo_size;
389 int fifo_size_of_read_back;
390
391 if (whence == AVSEEK_SIZE) {
392 av_log(h, AV_LOG_TRACE, "async_seek: AVSEEK_SIZE: %"PRId64"\n", (int64_t)c->logical_size);
393 return c->logical_size;
394 } else if (whence == SEEK_CUR) {
395 av_log(h, AV_LOG_TRACE, "async_seek: %"PRId64"\n", pos);
396 new_logical_pos = pos + c->logical_pos;
397 } else if (whence == SEEK_SET){
398 av_log(h, AV_LOG_TRACE, "async_seek: %"PRId64"\n", pos);
399 new_logical_pos = pos;
400 } else {
401 return AVERROR(EINVAL);
402 }
403 if (new_logical_pos < 0)
404 return AVERROR(EINVAL);
405
406 fifo_size = ring_size(ring);
407 fifo_size_of_read_back = ring_size_of_read_back(ring);
408 if (new_logical_pos == c->logical_pos) {
409 /* current position */
410 return c->logical_pos;
411 } else if ((new_logical_pos >= (c->logical_pos - fifo_size_of_read_back)) &&
412 (new_logical_pos < (c->logical_pos + fifo_size + SHORT_SEEK_THRESHOLD))) {
413 int pos_delta = (int)(new_logical_pos - c->logical_pos);
414 /* fast seek */
415 av_log(h, AV_LOG_TRACE, "async_seek: fask_seek %"PRId64" from %d dist:%d/%d\n",
416 new_logical_pos, (int)c->logical_pos,
417 (int)(new_logical_pos - c->logical_pos), fifo_size);
418
419 if (pos_delta > 0) {
420 // fast seek forwards
421 async_read_internal(h, NULL, pos_delta, 1, fifo_do_not_copy_func);
422 } else {
423 // fast seek backwards
424 ring_drain(ring, pos_delta);
425 c->logical_pos = new_logical_pos;
426 }
427
428 return c->logical_pos;
429 } else if (c->logical_size <= 0) {
430 /* can not seek */
431 return AVERROR(EINVAL);
432 } else if (new_logical_pos > c->logical_size) {
433 /* beyond end */
434 return AVERROR(EINVAL);
435 }
436
437 pthread_mutex_lock(&c->mutex);
438
439 c->seek_request = 1;
440 c->seek_pos = new_logical_pos;
441 c->seek_whence = SEEK_SET;
442 c->seek_completed = 0;
443 c->seek_ret = 0;
444
445 while (1) {
446 if (async_check_interrupt(h)) {
447 ret = AVERROR_EXIT;
448 break;
449 }
450 if (c->seek_completed) {
451 if (c->seek_ret >= 0)
452 c->logical_pos = c->seek_ret;
453 ret = c->seek_ret;
454 break;
455 }
456 pthread_cond_signal(&c->cond_wakeup_background);
457 pthread_cond_wait(&c->cond_wakeup_main, &c->mutex);
458 }
459
460 pthread_mutex_unlock(&c->mutex);
461
462 return ret;
463}
464
465#define OFFSET(x) offsetof(Context, x)
466#define D AV_OPT_FLAG_DECODING_PARAM
467
468static const AVOption options[] = {
469 {NULL},
470};
471
472#undef D
473#undef OFFSET
474
475static const AVClass async_context_class = {
476 .class_name = "Async",
477 .item_name = av_default_item_name,
478 .option = options,
479 .version = LIBAVUTIL_VERSION_INT,
480};
481
482const URLProtocol ff_async_protocol = {
483 .name = "async",
484 .url_open2 = async_open,
485 .url_read = async_read,
486 .url_seek = async_seek,
487 .url_close = async_close,
488 .priv_data_size = sizeof(Context),
489 .priv_data_class = &async_context_class,
490};
491
492#if 0
493
494#define TEST_SEEK_POS (1536)
495#define TEST_STREAM_SIZE (2048)
496
497typedef struct TestContext {
498 AVClass *class;
499 int64_t logical_pos;
500 int64_t logical_size;
501
502 /* options */
503 int opt_read_error;
504} TestContext;
505
506static int async_test_open(URLContext *h, const char *arg, int flags, AVDictionary **options)
507{
508 TestContext *c = h->priv_data;
509 c->logical_pos = 0;
510 c->logical_size = TEST_STREAM_SIZE;
511 return 0;
512}
513
514static int async_test_close(URLContext *h)
515{
516 return 0;
517}
518
519static int async_test_read(URLContext *h, unsigned char *buf, int size)
520{
521 TestContext *c = h->priv_data;
522 int i;
523 int read_len = 0;
524
525 if (c->opt_read_error)
526 return c->opt_read_error;
527
528 if (c->logical_pos >= c->logical_size)
529 return AVERROR_EOF;
530
531 for (i = 0; i < size; ++i) {
532 buf[i] = c->logical_pos & 0xFF;
533
534 c->logical_pos++;
535 read_len++;
536
537 if (c->logical_pos >= c->logical_size)
538 break;
539 }
540
541 return read_len;
542}
543
544static int64_t async_test_seek(URLContext *h, int64_t pos, int whence)
545{
546 TestContext *c = h->priv_data;
547 int64_t new_logical_pos;
548
549 if (whence == AVSEEK_SIZE) {
550 return c->logical_size;
551 } else if (whence == SEEK_CUR) {
552 new_logical_pos = pos + c->logical_pos;
553 } else if (whence == SEEK_SET){
554 new_logical_pos = pos;
555 } else {
556 return AVERROR(EINVAL);
557 }
558 if (new_logical_pos < 0)
559 return AVERROR(EINVAL);
560
561 c->logical_pos = new_logical_pos;
562 return new_logical_pos;
563}
564
565#define OFFSET(x) offsetof(TestContext, x)
566#define D AV_OPT_FLAG_DECODING_PARAM
567
568static const AVOption async_test_options[] = {
569 { "async-test-read-error", "cause read fail",
570 OFFSET(opt_read_error), AV_OPT_TYPE_INT, { .i64 = 0 }, INT_MIN, INT_MAX, .flags = D },
571 {NULL},
572};
573
574#undef D
575#undef OFFSET
576
577static const AVClass async_test_context_class = {
578 .class_name = "Async-Test",
579 .item_name = av_default_item_name,
580 .option = async_test_options,
581 .version = LIBAVUTIL_VERSION_INT,
582};
583
584const URLProtocol ff_async_test_protocol = {
585 .name = "async-test",
586 .url_open2 = async_test_open,
587 .url_read = async_test_read,
588 .url_seek = async_test_seek,
589 .url_close = async_test_close,
590 .priv_data_size = sizeof(TestContext),
591 .priv_data_class = &async_test_context_class,
592};
593
594int main(void)
595{
596 URLContext *h = NULL;
597 int i;
598 int ret;
599 int64_t size;
600 int64_t pos;
601 int64_t read_len;
602 unsigned char buf[4096];
603 AVDictionary *opts = NULL;
604
605 ffurl_register_protocol(&ff_async_protocol);
606 ffurl_register_protocol(&ff_async_test_protocol);
607
608 /*
609 * test normal read
610 */
611 ret = ffurl_open(&h, "async:async-test:", AVIO_FLAG_READ, NULL, NULL);
612 printf("open: %d\n", ret);
613
614 size = ffurl_size(h);
615 printf("size: %"PRId64"\n", size);
616
617 pos = ffurl_seek(h, 0, SEEK_CUR);
618 read_len = 0;
619 while (1) {
620 ret = ffurl_read(h, buf, sizeof(buf));
621 if (ret == AVERROR_EOF) {
622 printf("read-error: AVERROR_EOF at %"PRId64"\n", ffurl_seek(h, 0, SEEK_CUR));
623 break;
624 }
625 else if (ret == 0)
626 break;
627 else if (ret < 0) {
628 printf("read-error: %d at %"PRId64"\n", ret, ffurl_seek(h, 0, SEEK_CUR));
629 goto fail;
630 } else {
631 for (i = 0; i < ret; ++i) {
632 if (buf[i] != (pos & 0xFF)) {
633 printf("read-mismatch: actual %d, expecting %d, at %"PRId64"\n",
634 (int)buf[i], (int)(pos & 0xFF), pos);
635 break;
636 }
637 pos++;
638 }
639 }
640
641 read_len += ret;
642 }
643 printf("read: %"PRId64"\n", read_len);
644
645 /*
646 * test normal seek
647 */
648 ret = ffurl_read(h, buf, 1);
649 printf("read: %d\n", ret);
650
651 pos = ffurl_seek(h, TEST_SEEK_POS, SEEK_SET);
652 printf("seek: %"PRId64"\n", pos);
653
654 read_len = 0;
655 while (1) {
656 ret = ffurl_read(h, buf, sizeof(buf));
657 if (ret == AVERROR_EOF)
658 break;
659 else if (ret == 0)
660 break;
661 else if (ret < 0) {
662 printf("read-error: %d at %"PRId64"\n", ret, ffurl_seek(h, 0, SEEK_CUR));
663 goto fail;
664 } else {
665 for (i = 0; i < ret; ++i) {
666 if (buf[i] != (pos & 0xFF)) {
667 printf("read-mismatch: actual %d, expecting %d, at %"PRId64"\n",
668 (int)buf[i], (int)(pos & 0xFF), pos);
669 break;
670 }
671 pos++;
672 }
673 }
674
675 read_len += ret;
676 }
677 printf("read: %"PRId64"\n", read_len);
678
679 ret = ffurl_read(h, buf, 1);
680 printf("read: %d\n", ret);
681
682 /*
683 * test read error
684 */
685 ffurl_close(h);
686 av_dict_set_int(&opts, "async-test-read-error", -10000, 0);
687 ret = ffurl_open(&h, "async:async-test:", AVIO_FLAG_READ, NULL, &opts);
688 printf("open: %d\n", ret);
689
690 ret = ffurl_read(h, buf, 1);
691 printf("read: %d\n", ret);
692
693fail:
694 av_dict_free(&opts);
695 ffurl_close(h);
696 return 0;
697}
698
699#endif
700
generated by cgit at 2024-05-17 02:30:21 (GMT)