Introduce per group slice sizes.
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997-2010 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file vss.c The virtual streaming system.
8 *
9 * This contains the audio streaming code of para_server which is independent
10 * of the current audio format, audio file selector and of the activated
11 * senders.
12 */
13
14 #include <regex.h>
15 #include <dirent.h>
16 #include <osl.h>
17
18 #include "para.h"
19 #include "error.h"
20 #include "portable_io.h"
21 #include "fec.h"
22 #include "string.h"
23 #include "afh.h"
24 #include "afs.h"
25 #include "server.h"
26 #include "net.h"
27 #include "server.cmdline.h"
28 #include "list.h"
29 #include "send.h"
30 #include "vss.h"
31 #include "ipc.h"
32 #include "fd.h"
33 #include "sched.h"
34
35 extern struct misc_meta_data *mmd;
36
37 extern void dccp_send_init(struct sender *);
38 extern void http_send_init(struct sender *);
39 extern void udp_send_init(struct sender *);
40
41 /** The list of supported senders. */
42 struct sender senders[] = {
43 {
44 .name = "http",
45 .init = http_send_init,
46 },
47 {
48 .name = "dccp",
49 .init = dccp_send_init,
50 },
51 {
52 .name = "udp",
53 .init = udp_send_init,
54 },
55 {
56 .name = NULL,
57 }
58 };
59
60 /** The possible states of the afs socket. */
61 enum afs_socket_status {
62 /** Socket is inactive. */
63 AFS_SOCKET_READY,
64 /** Socket fd was included in the write fd set for select(). */
65 AFS_SOCKET_CHECK_FOR_WRITE,
66 /** vss wrote a request to the socket and waits for reply from afs. */
67 AFS_SOCKET_AFD_PENDING
68 };
69
70 /** The task structure for the virtual streaming system. */
71 struct vss_task {
72 /** Copied from the -announce_time command line option. */
73 struct timeval announce_tv;
74 /** End of the announcing interval. */
75 struct timeval data_send_barrier;
76 /** End of the EOF interval. */
77 struct timeval eof_barrier;
78 /** Only used if --autoplay_delay was given. */
79 struct timeval autoplay_barrier;
80 /** Used for afs-server communication. */
81 int afs_socket;
82 /** The current state of \a afs_socket. */
83 enum afs_socket_status afsss;
84 /** The memory mapped audio file. */
85 char *map;
86 /** Used by the scheduler. */
87 struct task task;
88 /** Pointer to the header of the mapped audio file. */
89 const char *header_buf;
90 /** Length of the audio file header. */
91 size_t header_len;
92 /** Time between audio file headers are sent. */
93 struct timeval header_interval;
94 };
95
96 /**
97 * The list of currently connected fec clients.
98 *
99 * Senders may use \ref vss_add_fec_client() to add entries to the list.
100 */
101 static struct list_head fec_client_list;
102
103 /**
104 * Data associated with one FEC group.
105 *
106 * A FEC group consists of a fixed number of slices and this number is given by
107 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
108 * group contains a number of chunks of the current audio file.
109 *
110 * FEC slices directly correspond to the data packages sent by the paraslash
111 * senders that use FEC. Each slice is identified by its group number and its
112 * number within the group. All slices have the same size, but the last slice
113 * of the group may not be filled entirely.
114 */
115 struct fec_group {
116 /** The number of the FEC group. */
117 uint32_t num;
118 /** Number of bytes in this group. */
119 uint32_t bytes;
120 /** The first chunk of the current audio file belonging to the group. */
121 uint32_t first_chunk;
122 /** The number of chunks contained in this group. */
123 uint32_t num_chunks;
124 /** When the first chunk was sent. */
125 struct timeval start;
126 /** The duration of the full group. */
127 struct timeval duration;
128 /** The group duration divided by the number of slices. */
129 struct timeval slice_duration;
130 /** Group contains the audio file header that occupies that many slices. */
131 uint8_t num_header_slices;
132 /** Number of bytes per slice for this group. */
133 uint16_t slice_bytes;
134 };
135
136 enum fec_client_state {
137 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
138 FEC_STATE_DISABLED, /**< temporarily disabled */
139 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
140 };
141
142 /**
143 * Describes one connected FEC client.
144 */
145 struct fec_client {
146 /** Current state of the client */
147 enum fec_client_state state;
148 /** The connected sender client (transport layer). */
149 struct sender_client *sc;
150 /** Parameters requested by the client. */
151 struct fec_client_parms *fcp;
152 /** Used by the core FEC code. */
153 struct fec_parms *parms;
154 /** The position of this client in the fec client list. */
155 struct list_head node;
156 /** When the first slice for this client was sent. */
157 struct timeval stream_start;
158 /** The first chunk sent to this FEC client. */
159 int first_stream_chunk;
160 /** Describes the current group. */
161 struct fec_group group;
162 /** The current slice. */
163 uint8_t current_slice_num;
164 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
165 const unsigned char **src_data;
166 /** Last time an audio header was sent. */
167 struct timeval next_header_time;
168 /** Used for the last source pointer of an audio file. */
169 unsigned char *extra_src_buf;
170 /** Extra slices needed to store largest chunk + header. */
171 int num_extra_slices;
172 /** Contains the FEC-encoded data. */
173 unsigned char *enc_buf;
174 /** Maximal packet size. */
175 int mps;
176 };
177
178 /**
179 * Get the chunk time of the current audio file.
180 *
181 * \return A pointer to a struct containing the chunk time, or NULL,
182 * if currently no audio file is selected.
183 */
184 struct timeval *vss_chunk_time(void)
185 {
186 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
187 mmd->afd.afhi.chunk_tv.tv_usec == 0)
188 return NULL;
189 return &mmd->afd.afhi.chunk_tv;
190 }
191
192 /**
193 * Write a fec header to a buffer.
194 *
195 * \param buf The buffer to write to.
196 * \param h The fec header to write.
197 */
198 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
199 {
200 char *buf = (char *)fc->enc_buf;
201 struct fec_group *g = &fc->group;
202 struct fec_client_parms *p = fc->fcp;
203
204 write_u32(buf, FEC_MAGIC);
205
206 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
207 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
208 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
209
210 write_u32(buf + 10, g->num);
211 write_u32(buf + 14, g->bytes);
212
213 write_u8(buf + 18, fc->current_slice_num);
214 write_u16(buf + 20, g->slice_bytes);
215 write_u8(buf + 22, g->first_chunk? 0 : 1);
216 write_u8(buf + 23, vsst->header_len? 1 : 0);
217 memset(buf + 24, 0, 7);
218 }
219
220 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
221 {
222 if (!mmd->current_chunk) {
223 tv_add(now, &vsst->header_interval, &fc->next_header_time);
224 return false;
225 }
226 if (!vsst->header_buf)
227 return false;
228 if (vsst->header_len == 0)
229 return false;
230 if (fc->group.num && tv_diff(&fc->next_header_time, now, NULL) > 0)
231 return false;
232 tv_add(now, &vsst->header_interval, &fc->next_header_time);
233 return true;
234 }
235
236 static int num_slices(long unsigned bytes, int max_payload, int rs)
237 {
238 int ret;
239
240 assert(max_payload > 0);
241 assert(rs > 0);
242 ret = DIV_ROUND_UP(bytes, max_payload);
243 if (ret + rs > 255)
244 return -E_BAD_CT;
245 return ret;
246 }
247
248 /* set group start and group duration */
249 static void set_group_timing(struct fec_client *fc, struct fec_group *g)
250 {
251 struct timeval *chunk_tv = vss_chunk_time();
252
253 tv_scale(g->num_chunks, chunk_tv, &g->duration);
254 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
255 &g->duration, &g->slice_duration);
256 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
257 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
258 }
259
260 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
261 {
262 int k, n, ret;
263 int hs, ds, rs; /* header/data/redundant slices */
264 struct fec_client_parms *fcp = fc->fcp;
265
266 /* set mps */
267 if (fcp->init_fec) {
268 /*
269 * Set the maximum slice size to the Maximum Packet Size if the
270 * transport protocol allows to determine this value. The user
271 * can specify a slice size up to this value.
272 */
273 ret = fcp->init_fec(fc->sc);
274 if (ret < 0)
275 return ret;
276 fc->mps = ret;
277 } else
278 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
279 if (fc->mps <= FEC_HEADER_SIZE)
280 return -ERRNO_TO_PARA_ERROR(EINVAL);
281
282 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
283 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
284 if (ret < 0)
285 goto err;
286 hs = ret;
287 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
288 if (ret < 0)
289 goto err;
290 ds = ret;
291 k = hs + ds;
292 if (k < fc->fcp->data_slices_per_group)
293 k = fc->fcp->data_slices_per_group;
294 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
295 n = k + rs;
296 fec_free(fc->parms);
297 ret = fec_new(k, n, &fc->parms);
298 if (ret < 0)
299 return ret;
300 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
301 fc->mps, k, n, fc->num_extra_slices);
302 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
303 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
304 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
305
306 fc->state = FEC_STATE_READY_TO_RUN;
307 fc->next_header_time.tv_sec = 0;
308 fc->stream_start = *now;
309 fc->first_stream_chunk = mmd->current_chunk;
310 return 1;
311 err:
312 fec_free(fc->parms);
313 return ret;
314 }
315
316 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
317 int max_bytes)
318 {
319 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
320
321 g->num_chunks = 0;
322 g->bytes = 0;
323 /*
324 * Include chunks into the group until the group duration is at least
325 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
326 * super frame) is already larger than 150ms, so a FEC group consists
327 * of exactly one chunk for these audio formats.
328 */
329 for (i = 0;; i++) {
330 const char *buf;
331 size_t len;
332 int chunk_num = g->first_chunk + i;
333
334 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
335 break;
336 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
337 break;
338 afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, &buf, &len);
339 if (g->bytes + len > max_bytes)
340 break;
341 /* Include this chunk */
342 g->bytes += len;
343 g->num_chunks++;
344 }
345 assert(g->num_chunks);
346 }
347
348 /*
349 * Compute the slice size of the next group.
350 *
351 * The FEC parameters n and k are fixed but the slice size varies per
352 * FEC group. We'd like to choose slices as small as possible to avoid
353 * unnecessary FEC calculations but large enough to guarantee that the
354 * k data slices suffice to encode the header (if needed) and the data
355 * chunk(s).
356 *
357 * Once we know the payload of the next group, we define the number s
358 * of bytes per slice for this group by
359 *
360 * s = ceil(payload / k)
361 *
362 * However, for header streams, computing s is more complicated since no
363 * overlapping of header and data slices is possible. Hence we have k >=
364 * 2 and s must satisfy
365 *
366 * (*) ceil(h / s) + ceil(d / s) <= k
367 *
368 * where h and d are payload of the header and the data chunk(s)
369 * respectively. In general there is no value for s such that (*)
370 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
371 *
372 * We use the following approach for computing a suitable value for s:
373 *
374 * Let
375 * k1 := ceil(k * min(h, d) / (h + d)),
376 * k2 := k - k1.
377 *
378 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
379 *
380 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
381 *
382 * is well-defined. Inequality (*) holds for this value of s since k1
383 * slices suffice to store min(h, d) while k2 slices suffice to store
384 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
385 * second by k2.
386 *
387 * For the above example we obtain
388 *
389 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
390 * s = max(4000 / 5, 5000 / 5) = 1000,
391 *
392 * which is optimal since a slice size of 999 bytes would already require
393 * 11 slices.
394 */
395 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
396 {
397 struct fec_group *g = &fc->group;
398 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
399 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
400 int ret, k1, k2, h, d, min, max, sum;
401 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
402 int max_group_bytes;
403
404 if (!need_audio_header(fc, vsst)) {
405 max_group_bytes = k * max_slice_bytes;
406 g->num_header_slices = 0;
407 compute_group_size(vsst, g, max_group_bytes);
408 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
409 if (g->slice_bytes == 0)
410 g->slice_bytes = 1;
411 return 1;
412 }
413 h = vsst->header_len;
414 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
415 * max_slice_bytes;
416 compute_group_size(vsst, g, max_group_bytes);
417 d = g->bytes;
418 if (d == 0) {
419 g->slice_bytes = DIV_ROUND_UP(h, k);
420 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
421 if (ret < 0)
422 return ret;
423 g->num_header_slices = ret;
424 return 1;
425 }
426 min = PARA_MIN(h, d);
427 max = PARA_MAX(h, d);
428 sum = h + d;
429 k1 = DIV_ROUND_UP(k * min, sum);
430 k2 = k - k1;
431 assert(k1 > 0);
432 assert(k2 > 0);
433
434 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
435 /*
436 * This value of s := g->slice_bytes satisfies inequality (*) above,
437 * but it might be larger than max_slice_bytes. However, we know that
438 * max_slice_bytes are sufficient to store header and data, so:
439 */
440 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
441
442 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
443 if (ret < 0)
444 return ret;
445 g->num_header_slices = ret;
446 return 1;
447 }
448
449 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
450 {
451 int ret, i, k, n, data_slices;
452 size_t len;
453 const char *buf;
454 struct fec_group *g = &fc->group;
455
456 if (fc->state == FEC_STATE_NONE) {
457 ret = initialize_fec_client(fc, vsst);
458 if (ret < 0)
459 return ret;
460 g->first_chunk = mmd->current_chunk;
461 g->num = 0;
462 g->start = *now;
463 } else {
464 struct timeval tmp;
465 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
466 return 0;
467 /*
468 * Start and duration of this group depend only on the previous
469 * group. Compute the new group start as g->start += g->duration.
470 */
471 tmp = g->start;
472 tv_add(&tmp, &g->duration, &g->start);
473 set_group_timing(fc, g);
474 g->first_chunk += g->num_chunks;
475 g->num++;
476 }
477 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
478 n = fc->fcp->slices_per_group + fc->num_extra_slices;
479
480 compute_slice_size(fc, vsst);
481 assert(g->slice_bytes > 0);
482 ret = num_slices(g->bytes, g->slice_bytes, n - k);
483 if (ret < 0)
484 return ret;
485 data_slices = ret;
486 assert(g->num_header_slices + data_slices <= k);
487 fc->current_slice_num = 0;
488 if (g->num == 0)
489 set_group_timing(fc, g);
490
491 /* setup header slices */
492 buf = vsst->header_buf;
493 for (i = 0; i < g->num_header_slices; i++) {
494 fc->src_data[i] = (const unsigned char *)buf;
495 buf += g->slice_bytes;
496 }
497
498 /* setup data slices */
499 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &buf, &len);
500 for (; i < g->num_header_slices + data_slices; i++) {
501 if (buf + g->slice_bytes > vsst->map + mmd->size) {
502 /*
503 * Can not use the memory mapped audio file for this
504 * slice as it goes beyond the map. This slice will not
505 * be fully used.
506 */
507 uint32_t payload_size = vsst->map + mmd->size - buf;
508 memcpy(fc->extra_src_buf, buf, payload_size);
509 if (payload_size < g->slice_bytes)
510 memset(fc->extra_src_buf + payload_size, 0,
511 g->slice_bytes - payload_size);
512 fc->src_data[i] = fc->extra_src_buf;
513 i++;
514 break;
515 }
516 fc->src_data[i] = (const unsigned char *)buf;
517 buf += g->slice_bytes;
518 }
519 if (i < k) {
520 /* use arbitrary data for all remaining slices */
521 buf = vsst->map;
522 for (; i < k; i++)
523 fc->src_data[i] = (const unsigned char *)buf;
524 }
525 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
526 g->num, g->num_chunks, g->first_chunk,
527 g->first_chunk + g->num_chunks - 1, g->bytes
528 );
529 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
530 g->slice_bytes, g->num_header_slices, data_slices
531 );
532 return 1;
533 }
534
535 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
536 {
537 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
538 == fc->fcp->slices_per_group + fc->num_extra_slices) {
539 int ret = setup_next_fec_group(fc, vsst);
540 if (ret == 0)
541 return 0;
542 if (ret < 0) {
543 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
544 PARA_ERROR_LOG("FEC client temporarily disabled\n");
545 fc->state = FEC_STATE_DISABLED;
546 return ret;
547 }
548 }
549 write_fec_header(fc, vsst);
550 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
551 fc->current_slice_num, fc->group.slice_bytes);
552 return 1;
553 }
554
555 /**
556 * Return a buffer that marks the end of the stream.
557 *
558 * \param buf Result pointer.
559 * \return The length of the eof buffer.
560 *
561 * This is used for (multicast) udp streaming where closing the socket on the
562 * sender might not give rise to an eof condition at the peer.
563 */
564 size_t vss_get_fec_eof_packet(const char **buf)
565 {
566 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
567 *buf = fec_eof_packet;
568 return FEC_HEADER_SIZE;
569 }
570
571 /**
572 * Add one entry to the list of active fec clients.
573 *
574 * \param sc Generic sender_client data of the transport layer.
575 * \param fcp FEC parameters as supplied by the transport layer.
576 *
577 * \return Newly allocated fec_client struct.
578 */
579 struct fec_client *vss_add_fec_client(struct sender_client *sc,
580 struct fec_client_parms *fcp)
581 {
582 struct fec_client *fc = para_calloc(sizeof(*fc));
583
584 fc->sc = sc;
585 fc->fcp = fcp;
586 para_list_add(&fc->node, &fec_client_list);
587 return fc;
588 }
589
590 /**
591 * Remove one entry from the list of active fec clients.
592 *
593 * \param fc The client to be removed.
594 */
595 void vss_del_fec_client(struct fec_client *fc)
596 {
597 list_del(&fc->node);
598 free(fc->src_data);
599 free(fc->enc_buf);
600 free(fc->extra_src_buf);
601 fec_free(fc->parms);
602 free(fc);
603 }
604
605 /*
606 * Compute if/when next slice is due. If it isn't due yet and \a diff is
607 * not \p Null, compute the time difference next - now, where
608 *
609 * next = stream_start + (first_group_chunk - first_stream_chunk)
610 * * chunk_time + slice_num * slice_time
611 */
612 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
613 {
614 struct timeval tmp, next;
615 int ret;
616
617 if (fc->state == FEC_STATE_NONE)
618 return 1;
619 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
620 tv_add(&tmp, &fc->group.start, &next);
621 ret = tv_diff(&next, now, diff);
622 return ret < 0? 1 : 0;
623 }
624
625 static void compute_slice_timeout(struct timeval *timeout)
626 {
627 struct fec_client *fc;
628
629 list_for_each_entry(fc, &fec_client_list, node) {
630 struct timeval diff;
631
632 if (fc->state != FEC_STATE_READY_TO_RUN)
633 continue;
634 if (next_slice_is_due(fc, &diff)) {
635 timeout->tv_sec = 0;
636 timeout->tv_usec = 0;
637 return;
638 }
639 /* timeout = min(timeout, diff) */
640 if (tv_diff(&diff, timeout, NULL) < 0)
641 *timeout = diff;
642 }
643 }
644
645 static void set_eof_barrier(struct vss_task *vsst)
646 {
647 struct fec_client *fc;
648 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
649
650 if (!chunk_tv)
651 goto out;
652 list_for_each_entry(fc, &fec_client_list, node) {
653 struct timeval group_duration;
654
655 if (fc->state != FEC_STATE_READY_TO_RUN)
656 continue;
657 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
658 if (tv_diff(&timeout, &group_duration, NULL) < 0)
659 timeout = group_duration;
660 }
661 out:
662 tv_add(now, &timeout, &vsst->eof_barrier);
663 }
664
665 /**
666 * Check if vss status flag \a P (playing) is set.
667 *
668 * \return Greater than zero if playing, zero otherwise.
669 *
670 */
671 unsigned int vss_playing(void)
672 {
673 return mmd->new_vss_status_flags & VSS_PLAYING;
674 }
675
676 /**
677 * Check if the \a N (next) status flag is set.
678 *
679 * \return Greater than zero if set, zero if not.
680 *
681 */
682 unsigned int vss_next(void)
683 {
684 return mmd->new_vss_status_flags & VSS_NEXT;
685 }
686
687 /**
688 * Check if a reposition request is pending.
689 *
690 * \return Greater than zero if true, zero otherwise.
691 *
692 */
693 unsigned int vss_repos(void)
694 {
695 return mmd->new_vss_status_flags & VSS_REPOS;
696 }
697
698 /**
699 * Check if the vss is currently paused.
700 *
701 * \return Greater than zero if paused, zero otherwise.
702 *
703 */
704 unsigned int vss_paused(void)
705 {
706 return !(mmd->new_vss_status_flags & VSS_NEXT)
707 && !(mmd->new_vss_status_flags & VSS_PLAYING);
708 }
709
710 /**
711 * Check if the vss is currently stopped.
712 *
713 * \return Greater than zero if paused, zero otherwise.
714 *
715 */
716 unsigned int vss_stopped(void)
717 {
718 return (mmd->new_vss_status_flags & VSS_NEXT)
719 && !(mmd->new_vss_status_flags & VSS_PLAYING);
720 }
721
722 static int chk_barrier(const char *bname, const struct timeval *barrier,
723 struct timeval *diff, int print_log)
724 {
725 long ms;
726
727 if (tv_diff(now, barrier, diff) > 0)
728 return 1;
729 ms = tv2ms(diff);
730 if (print_log && ms)
731 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
732 return -1;
733 }
734
735 /*
736 * != NULL: timeout for next chunk
737 * NULL: nothing to do
738 */
739 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
740 {
741 static struct timeval the_timeout;
742 struct timeval next_chunk;
743
744 if (vss_next() && vsst->map) {
745 /* only sleep a bit, nec*/
746 the_timeout.tv_sec = 0;
747 the_timeout.tv_usec = 100;
748 return &the_timeout;
749 }
750 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
751 &the_timeout, 1) < 0)
752 return &the_timeout;
753 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
754 return &the_timeout;
755 if (chk_barrier("data send", &vsst->data_send_barrier,
756 &the_timeout, 1) < 0)
757 return &the_timeout;
758 if (!vss_playing() || !vsst->map)
759 return NULL;
760 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
761 &mmd->stream_start, &next_chunk);
762 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
763 /* chunk is due or bof */
764 the_timeout.tv_sec = 0;
765 the_timeout.tv_usec = 0;
766 return &the_timeout;
767 }
768 /* compute min of current timeout and next slice time */
769 compute_slice_timeout(&the_timeout);
770 return &the_timeout;
771 }
772
773 static void vss_eof(struct vss_task *vsst)
774 {
775
776 if (!vsst->map)
777 return;
778 if (mmd->new_vss_status_flags & VSS_NOMORE)
779 mmd->new_vss_status_flags = VSS_NEXT;
780 set_eof_barrier(vsst);
781 para_munmap(vsst->map, mmd->size);
782 vsst->map = NULL;
783 mmd->chunks_sent = 0;
784 //mmd->offset = 0;
785 mmd->afd.afhi.seconds_total = 0;
786 mmd->afd.afhi.chunk_tv.tv_sec = 0;
787 mmd->afd.afhi.chunk_tv.tv_usec = 0;
788 free(mmd->afd.afhi.chunk_table);
789 mmd->afd.afhi.chunk_table = NULL;
790 mmd->mtime = 0;
791 mmd->size = 0;
792 mmd->events++;
793 }
794
795 static int need_to_request_new_audio_file(struct vss_task *vsst)
796 {
797 struct timeval diff;
798
799 if (vsst->map) /* have audio file */
800 return 0;
801 if (!vss_playing()) /* don't need one */
802 return 0;
803 if (mmd->new_vss_status_flags & VSS_NOMORE)
804 return 0;
805 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
806 return 0;
807 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
808 &diff, 1) < 0)
809 return 0;
810 return 1;
811 }
812
813 static void set_mmd_offset(void)
814 {
815 struct timeval offset;
816 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
817 mmd->offset = tv2ms(&offset);
818 }
819
820 /**
821 * Compute the timeout for the main select-loop of the scheduler.
822 *
823 * \param s Pointer to the server scheduler.
824 * \param t Pointer to the vss task structure.
825 *
826 * Before the timeout is computed, the current vss status flags are evaluated
827 * and acted upon by calling appropriate functions from the lower layers.
828 * Possible actions include
829 *
830 * - request a new audio file from afs,
831 * - shutdown of all senders (stop/pause command),
832 * - reposition the stream (ff/jmp command).
833 */
834 static void vss_pre_select(struct sched *s, struct task *t)
835 {
836 int i;
837 struct timeval *tv;
838 struct vss_task *vsst = container_of(t, struct vss_task, task);
839
840 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
841 struct fec_client *fc, *tmp;
842 for (i = 0; senders[i].name; i++)
843 if (senders[i].shutdown_clients)
844 senders[i].shutdown_clients();
845 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
846 fc->state = FEC_STATE_NONE;
847 mmd->stream_start.tv_sec = 0;
848 mmd->stream_start.tv_usec = 0;
849 }
850 if (vss_next())
851 vss_eof(vsst);
852 else if (vss_paused()) {
853 if (mmd->chunks_sent)
854 set_eof_barrier(vsst);
855 mmd->chunks_sent = 0;
856 } else if (vss_repos()) {
857 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
858 set_eof_barrier(vsst);
859 mmd->chunks_sent = 0;
860 mmd->current_chunk = mmd->repos_request;
861 mmd->new_vss_status_flags &= ~VSS_REPOS;
862 set_mmd_offset();
863 }
864 if (need_to_request_new_audio_file(vsst)) {
865 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
866 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
867 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
868 } else
869 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
870 for (i = 0; senders[i].name; i++) {
871 if (!senders[i].pre_select)
872 continue;
873 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
874 }
875 tv = vss_compute_timeout(vsst);
876 if (tv)
877 sched_request_timeout(tv, s);
878 }
879
880 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
881 {
882 char control[255], buf[8];
883 struct msghdr msg = {.msg_iov = NULL};
884 struct cmsghdr *cmsg;
885 struct iovec iov;
886 int ret = 0;
887
888 *fd = -1;
889 iov.iov_base = buf;
890 iov.iov_len = sizeof(buf);
891 msg.msg_iov = &iov;
892 msg.msg_iovlen = 1;
893 msg.msg_control = control;
894 msg.msg_controllen = sizeof(control);
895 memset(buf, 0, sizeof(buf));
896 ret = recvmsg(afs_socket, &msg, 0);
897 if (ret < 0)
898 return -ERRNO_TO_PARA_ERROR(errno);
899 if (iov.iov_len != sizeof(buf))
900 return -E_AFS_SHORT_READ;
901 *code = *(uint32_t*)buf;
902 *data = *(uint32_t*)(buf + 4);
903 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
904 if (cmsg->cmsg_level != SOL_SOCKET
905 || cmsg->cmsg_type != SCM_RIGHTS)
906 continue;
907 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
908 continue;
909 *fd = *(int *)CMSG_DATA(cmsg);
910 }
911 return 1;
912 }
913
914 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
915 {
916 int ret, passed_fd, shmid;
917 uint32_t afs_code = 0, afs_data = 0;
918 struct stat statbuf;
919
920 if (!FD_ISSET(vsst->afs_socket, rfds))
921 return;
922 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
923 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
924 return;
925 if (ret < 0)
926 goto err;
927 vsst->afsss = AFS_SOCKET_READY;
928 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
929 afs_data);
930 ret = -E_NOFD;
931 if (afs_code != NEXT_AUDIO_FILE)
932 goto err;
933 if (passed_fd < 0)
934 goto err;
935 shmid = afs_data;
936 ret = load_afd(shmid, &mmd->afd);
937 if (ret < 0)
938 goto err;
939 shm_destroy(shmid);
940 ret = fstat(passed_fd, &statbuf);
941 if (ret < 0) {
942 PARA_ERROR_LOG("fstat error:\n");
943 ret = -ERRNO_TO_PARA_ERROR(errno);
944 goto err;
945 }
946 mmd->size = statbuf.st_size;
947 mmd->mtime = statbuf.st_mtime;
948 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
949 0, &vsst->map);
950 if (ret < 0)
951 goto err;
952 close(passed_fd);
953 mmd->chunks_sent = 0;
954 mmd->current_chunk = 0;
955 mmd->offset = 0;
956 mmd->events++;
957 mmd->num_played++;
958 mmd->new_vss_status_flags &= (~VSS_NEXT);
959 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
960 &vsst->header_len);
961 return;
962 err:
963 free(mmd->afd.afhi.chunk_table);
964 if (passed_fd >= 0)
965 close(passed_fd);
966 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
967 mmd->new_vss_status_flags = VSS_NEXT;
968 }
969
970 /**
971 * Main sending function.
972 *
973 * This function gets called from vss_post_select(). It checks whether the next
974 * chunk of data should be pushed out. It obtains a pointer to the data to be
975 * sent out as well as its length from mmd->afd.afhi. This information is then
976 * passed to each supported sender's send() function as well as to the send()
977 * functions of each registered fec client.
978 */
979 static void vss_send(struct vss_task *vsst)
980 {
981 int i, fec_active = 0;
982 struct timeval due;
983 struct fec_client *fc, *tmp_fc;
984
985 if (!vsst->map || !vss_playing())
986 return;
987 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
988 return;
989 if (chk_barrier("data send", &vsst->data_send_barrier,
990 &due, 1) < 0)
991 return;
992 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
993 if (fc->state == FEC_STATE_DISABLED)
994 continue;
995 if (!next_slice_is_due(fc, NULL)) {
996 fec_active = 1;
997 continue;
998 }
999 if (compute_next_fec_slice(fc, vsst) <= 0)
1000 continue;
1001 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
1002 fc->current_slice_num, fc->group.slice_bytes);
1003 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1004 fc->group.slice_bytes + FEC_HEADER_SIZE);
1005 fc->current_slice_num++;
1006 fec_active = 1;
1007 }
1008 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1009 if (!fec_active)
1010 mmd->new_vss_status_flags |= VSS_NEXT;
1011 return;
1012 }
1013 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1014 &mmd->stream_start, &due);
1015 if (tv_diff(&due, now, NULL) <= 0) {
1016 const char *buf;
1017 size_t len;
1018
1019 if (!mmd->chunks_sent) {
1020 mmd->stream_start = *now;
1021 mmd->events++;
1022 set_mmd_offset();
1023 }
1024 /*
1025 * We call the send function also in case of empty chunks as
1026 * they might have still some data queued which can be sent in
1027 * this case.
1028 */
1029 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
1030 &buf, &len);
1031 for (i = 0; senders[i].name; i++) {
1032 if (!senders[i].send)
1033 continue;
1034 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1035 buf, len, vsst->header_buf, vsst->header_len);
1036 }
1037 mmd->chunks_sent++;
1038 mmd->current_chunk++;
1039 }
1040 }
1041
1042 static void vss_post_select(struct sched *s, struct task *t)
1043 {
1044 int ret, i;
1045 struct vss_task *vsst = container_of(t, struct vss_task, task);
1046
1047
1048 if (mmd->sender_cmd_data.cmd_num >= 0) {
1049 int num = mmd->sender_cmd_data.cmd_num,
1050 sender_num = mmd->sender_cmd_data.sender_num;
1051
1052 if (senders[sender_num].client_cmds[num]) {
1053 ret = senders[sender_num].client_cmds[num]
1054 (&mmd->sender_cmd_data);
1055 if (ret < 0)
1056 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1057 }
1058 mmd->sender_cmd_data.cmd_num = -1;
1059 }
1060 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1061 recv_afs_result(vsst, &s->rfds);
1062 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1063 PARA_NOTICE_LOG("requesting new fd from afs\n");
1064 ret = send_buffer(vsst->afs_socket, "new");
1065 if (ret < 0)
1066 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1067 else
1068 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1069 }
1070 for (i = 0; senders[i].name; i++) {
1071 if (!senders[i].post_select)
1072 continue;
1073 senders[i].post_select(&s->rfds, &s->wfds);
1074 }
1075 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1076 (vss_next() && vss_playing()))
1077 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1078 vss_send(vsst);
1079 }
1080
1081 /**
1082 * Initialize the virtual streaming system task.
1083 *
1084 * \param afs_socket The fd for communication with afs.
1085 *
1086 * This also initializes all supported senders and starts streaming
1087 * if the --autoplay command line flag was given.
1088 */
1089 void init_vss_task(int afs_socket)
1090 {
1091 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1092 int i;
1093 char *hn = para_hostname(), *home = para_homedir();
1094 long unsigned announce_time = conf.announce_time_arg > 0?
1095 conf.announce_time_arg : 300,
1096 autoplay_delay = conf.autoplay_delay_arg > 0?
1097 conf.autoplay_delay_arg : 0;
1098 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1099 vsst->afs_socket = afs_socket;
1100 vsst->task.pre_select = vss_pre_select;
1101 vsst->task.post_select = vss_post_select;
1102 ms2tv(announce_time, &vsst->announce_tv);
1103 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1104 INIT_LIST_HEAD(&fec_client_list);
1105 for (i = 0; senders[i].name; i++) {
1106 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1107 senders[i].init(&senders[i]);
1108 }
1109 free(hn);
1110 free(home);
1111 mmd->sender_cmd_data.cmd_num = -1;
1112 if (conf.autoplay_given) {
1113 struct timeval tmp;
1114 mmd->vss_status_flags |= VSS_PLAYING;
1115 mmd->new_vss_status_flags |= VSS_PLAYING;
1116 ms2tv(autoplay_delay, &tmp);
1117 tv_add(now, &tmp, &vsst->autoplay_barrier);
1118 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1119 &vsst->data_send_barrier);
1120 }
1121 register_task(&vsst->task);
1122 }