Simplify vss_send().
[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 };
133
134 enum fec_client_state {
135 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
136 FEC_STATE_DISABLED, /**< temporarily disabled */
137 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
138 };
139
140 /**
141 * Describes one connected FEC client.
142 */
143 struct fec_client {
144 /** Current state of the client */
145 enum fec_client_state state;
146 /** The connected sender client (transport layer). */
147 struct sender_client *sc;
148 /** Parameters requested by the client. */
149 struct fec_client_parms *fcp;
150 /** Used by the core FEC code. */
151 struct fec_parms *parms;
152 /** The position of this client in the fec client list. */
153 struct list_head node;
154 /** When the first slice for this client was sent. */
155 struct timeval stream_start;
156 /** The first chunk sent to this FEC client. */
157 int first_stream_chunk;
158 /** Describes the current group. */
159 struct fec_group group;
160 /** The current slice. */
161 uint8_t current_slice_num;
162 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
163 const unsigned char **src_data;
164 /** Last time an audio header was sent. */
165 struct timeval next_header_time;
166 /** Used for the last source pointer of an audio file. */
167 unsigned char *extra_src_buf;
168 /** Extra slices needed to store largest chunk + header. */
169 int num_extra_slices;
170 /** Contains the FEC-encoded data. */
171 unsigned char *enc_buf;
172 };
173
174 /**
175 * Get the chunk time of the current audio file.
176 *
177 * \return A pointer to a struct containing the chunk time, or NULL,
178 * if currently no audio file is selected.
179 */
180 struct timeval *vss_chunk_time(void)
181 {
182 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
183 mmd->afd.afhi.chunk_tv.tv_usec == 0)
184 return NULL;
185 return &mmd->afd.afhi.chunk_tv;
186 }
187
188 /**
189 * Write a fec header to a buffer.
190 *
191 * \param buf The buffer to write to.
192 * \param h The fec header to write.
193 */
194 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
195 {
196 char *buf = (char *)fc->enc_buf;
197 struct fec_group *g = &fc->group;
198 struct fec_client_parms *p = fc->fcp;
199
200 write_u32(buf, FEC_MAGIC);
201
202 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
203 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
204 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
205
206 write_u32(buf + 10, g->num);
207 write_u32(buf + 14, g->bytes);
208
209 write_u8(buf + 18, fc->current_slice_num);
210 write_u16(buf + 20, p->max_slice_bytes - FEC_HEADER_SIZE);
211 write_u8(buf + 22, g->first_chunk? 0 : 1);
212 write_u8(buf + 23, vsst->header_len? 1 : 0);
213 memset(buf + 24, 0, 7);
214 }
215
216 static int need_audio_header(struct fec_client *fc, struct vss_task *vsst)
217 {
218 if (!mmd->current_chunk) {
219 tv_add(now, &vsst->header_interval, &fc->next_header_time);
220 return 0;
221 }
222 if (!vsst->header_buf)
223 return 0;
224 if (!vsst->header_len)
225 return 0;
226 if (fc->group.num && tv_diff(&fc->next_header_time, now, NULL) > 0)
227 return 0;
228 tv_add(now, &vsst->header_interval, &fc->next_header_time);
229 return 1;
230 }
231
232 static int num_slices(long unsigned bytes, int mps, int rs)
233 {
234 int m = mps - FEC_HEADER_SIZE;
235 int ret;
236
237 assert(m > 0);
238 assert(rs > 0);
239 ret = (bytes + m - 1) / m;
240 if (ret + rs > 255)
241 return -E_BAD_CT;
242 return ret;
243 }
244
245 /* set group start and group duration */
246 static void set_group_timing(struct fec_client *fc, struct fec_group *g)
247 {
248 struct timeval *chunk_tv = vss_chunk_time();
249
250 tv_scale(g->num_chunks, chunk_tv, &g->duration);
251 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
252 &g->duration, &g->slice_duration);
253 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
254 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
255 }
256
257 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
258 {
259 int k, n, ret, mps;
260 int hs, ds, rs; /* header/data/redundant slices */
261 struct fec_client_parms *fcp = fc->fcp;
262
263 /* set mps */
264 if (fcp->init_fec) {
265 /*
266 * Set the maximum slice size to the Maximum Packet Size if the
267 * transport protocol allows to determine this value. The user
268 * can specify a slice size up to this value.
269 */
270 ret = fcp->init_fec(fc->sc);
271 if (ret < 0)
272 return ret;
273 mps = ret;
274 } else
275 mps = generic_max_transport_msg_size(fc->sc->fd);
276 if (mps <= FEC_HEADER_SIZE)
277 return -ERRNO_TO_PARA_ERROR(EINVAL);
278
279 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
280 ret = num_slices(vsst->header_len, mps, rs);
281 if (ret < 0)
282 goto err;
283 hs = ret;
284 ret = num_slices(afh_get_largest_chunk_size(&mmd->afd.afhi),
285 mps, rs);
286 if (ret < 0)
287 goto err;
288 ds = ret;
289 k = ret + ds;
290 if (k < fc->fcp->data_slices_per_group)
291 k = fc->fcp->data_slices_per_group;
292 n = k + rs;
293 PARA_CRIT_LOG("hs: %d, ds: %d, rs: %d, k: %d, n: %d\n", hs, ds, rs, k, n);
294 fec_free(fc->parms);
295 ret = fec_new(k, n, &fc->parms);
296 if (ret < 0)
297 return ret;
298 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
299 PARA_NOTICE_LOG("fec parms %d:%d:%d (%d extra slices)\n",
300 mps, k, n, fc->num_extra_slices);
301 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
302 fc->enc_buf = para_realloc(fc->enc_buf, mps);
303 memset(fc->enc_buf, 0, mps);
304 fc->extra_src_buf = para_realloc(fc->extra_src_buf, mps);
305 memset(fc->extra_src_buf, 0, mps);
306
307 fc->fcp->max_slice_bytes = mps;
308 fc->state = FEC_STATE_READY_TO_RUN;
309 fc->next_header_time.tv_sec = 0;
310 fc->stream_start = *now;
311 fc->first_stream_chunk = mmd->current_chunk;
312 return 1;
313 err:
314 fec_free(fc->parms);
315 return ret;
316 }
317
318 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
319 {
320 int ret, i, k, n, data_slices;
321 size_t len;
322 const char *buf, *start_buf;
323 struct fec_group *g = &fc->group;
324 unsigned slice_bytes;
325 uint32_t max_data_size;
326
327 if (fc->state == FEC_STATE_NONE) {
328 ret = initialize_fec_client(fc, vsst);
329 if (ret < 0)
330 return ret;
331 g->first_chunk = mmd->current_chunk;
332 g->num = 0;
333 g->start = *now;
334
335 } else {
336 struct timeval tmp;
337 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
338 return 0;
339 /*
340 * Start and duration of this group depend only on the previous
341 * group. Compute the new group start as g->start += g->duration.
342 */
343 tmp = g->start;
344 tv_add(&tmp, &g->duration, &g->start);
345 set_group_timing(fc, g);
346 g->first_chunk += g->num_chunks;
347 g->num++;
348 }
349 slice_bytes = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
350 PARA_CRIT_LOG("slice_bytes: %d\n", slice_bytes);
351 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
352 n = fc->fcp->slices_per_group + fc->num_extra_slices;
353 PARA_CRIT_LOG("k: %d, n: %d\n", k, n);
354 if (need_audio_header(fc, vsst)) {
355 ret = num_slices(vsst->header_len, fc->fcp->max_slice_bytes,
356 n - k);
357 if (ret < 0)
358 return ret;
359 g->num_header_slices = ret;
360 } else
361 g->num_header_slices = 0;
362 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &start_buf,
363 &len);
364 data_slices = k - g->num_header_slices;
365 assert(data_slices);
366 max_data_size = slice_bytes * data_slices;
367 g->bytes = 0;
368 for (i = g->first_chunk; i < mmd->afd.afhi.chunks_total; i++) {
369 afh_get_chunk(i, &mmd->afd.afhi, vsst->map, &buf, &len);
370 if (g->bytes + len > max_data_size)
371 break;
372 g->bytes += len;
373 }
374 g->num_chunks = i - g->first_chunk;
375 assert(g->num_chunks);
376 fc->current_slice_num = 0;
377 if (g->num == 0)
378 set_group_timing(fc, g);
379
380 /* setup header slices */
381 buf = vsst->header_buf;
382 for (i = 0; i < g->num_header_slices; i++) {
383 fc->src_data[i] = (const unsigned char *)buf;
384 buf += slice_bytes;
385 }
386
387 /* setup data slices */
388 buf = start_buf;
389 for (i = g->num_header_slices; i < k; i++) {
390 if (buf + slice_bytes > vsst->map + mmd->size)
391 /*
392 * Can not use the memory mapped audio file for this
393 * slice as it goes beyond the map. This slice will not
394 * be fully used.
395 */
396 break;
397 fc->src_data[i] = (const unsigned char *)buf;
398 buf += slice_bytes;
399 }
400 if (i < k) {
401 uint32_t payload_size = vsst->map + mmd->size - buf;
402 memcpy(fc->extra_src_buf, buf, payload_size);
403 fc->src_data[i] = fc->extra_src_buf;
404 i++;
405 /* use arbitrary data for all remaining slices */
406 buf = vsst->map;
407 for (; i < k; i++)
408 fc->src_data[i] = (const unsigned char *)buf;
409 }
410 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), "
411 "%d header slices, %d data slices\n",
412 g->num, g->num_chunks, g->first_chunk,
413 g->first_chunk + g->num_chunks - 1,
414 g->num_header_slices, data_slices
415 );
416 return 1;
417 }
418
419 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
420 {
421 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
422 == fc->fcp->slices_per_group + fc->num_extra_slices) {
423 int ret = setup_next_fec_group(fc, vsst);
424 if (ret == 0)
425 return 0;
426 if (ret < 0) {
427 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
428 PARA_ERROR_LOG("FEC client temporarily disabled\n");
429 fc->state = FEC_STATE_DISABLED;
430 return ret;
431 }
432 }
433 write_fec_header(fc, vsst);
434 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
435 fc->current_slice_num,
436 fc->fcp->max_slice_bytes - FEC_HEADER_SIZE);
437 return 1;
438 }
439
440 /**
441 * Return a buffer that marks the end of the stream.
442 *
443 * \param buf Result pointer.
444 * \return The length of the eof buffer.
445 *
446 * This is used for (multicast) udp streaming where closing the socket on the
447 * sender might not give rise to an eof condition at the peer.
448 */
449 size_t vss_get_fec_eof_packet(const char **buf)
450 {
451 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
452 *buf = fec_eof_packet;
453 return FEC_HEADER_SIZE;
454 }
455
456 /**
457 * Add one entry to the list of active fec clients.
458 *
459 * \param sc Generic sender_client data of the transport layer.
460 * \param fcp FEC parameters as supplied by the transport layer.
461 *
462 * \return Newly allocated fec_client struct.
463 */
464 struct fec_client *vss_add_fec_client(struct sender_client *sc,
465 struct fec_client_parms *fcp)
466 {
467 struct fec_client *fc = para_calloc(sizeof(*fc));
468
469 fc->sc = sc;
470 fc->fcp = fcp;
471 para_list_add(&fc->node, &fec_client_list);
472 return fc;
473 }
474
475 /**
476 * Remove one entry from the list of active fec clients.
477 *
478 * \param fc The client to be removed.
479 */
480 void vss_del_fec_client(struct fec_client *fc)
481 {
482 list_del(&fc->node);
483 free(fc->src_data);
484 free(fc->enc_buf);
485 free(fc->extra_src_buf);
486 fec_free(fc->parms);
487 free(fc);
488 }
489
490 /*
491 * Compute if/when next slice is due. If it isn't due yet and \a diff is
492 * not \p Null, compute the time difference next - now, where
493 *
494 * next = stream_start + (first_group_chunk - first_stream_chunk)
495 * * chunk_time + slice_num * slice_time
496 */
497 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
498 {
499 struct timeval tmp, next;
500 int ret;
501
502 if (fc->state == FEC_STATE_NONE)
503 return 1;
504 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
505 tv_add(&tmp, &fc->group.start, &next);
506 ret = tv_diff(&next, now, diff);
507 return ret < 0? 1 : 0;
508 }
509
510 static void compute_slice_timeout(struct timeval *timeout)
511 {
512 struct fec_client *fc;
513
514 list_for_each_entry(fc, &fec_client_list, node) {
515 struct timeval diff;
516
517 if (fc->state != FEC_STATE_READY_TO_RUN)
518 continue;
519 if (next_slice_is_due(fc, &diff)) {
520 timeout->tv_sec = 0;
521 timeout->tv_usec = 0;
522 return;
523 }
524 /* timeout = min(timeout, diff) */
525 if (tv_diff(&diff, timeout, NULL) < 0)
526 *timeout = diff;
527 }
528 }
529
530 static void set_eof_barrier(struct vss_task *vsst)
531 {
532 struct fec_client *fc;
533 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
534
535 if (!chunk_tv)
536 goto out;
537 list_for_each_entry(fc, &fec_client_list, node) {
538 struct timeval group_duration;
539
540 if (fc->state != FEC_STATE_READY_TO_RUN)
541 continue;
542 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
543 if (tv_diff(&timeout, &group_duration, NULL) < 0)
544 timeout = group_duration;
545 }
546 out:
547 tv_add(now, &timeout, &vsst->eof_barrier);
548 }
549
550 /**
551 * Check if vss status flag \a P (playing) is set.
552 *
553 * \return Greater than zero if playing, zero otherwise.
554 *
555 */
556 unsigned int vss_playing(void)
557 {
558 return mmd->new_vss_status_flags & VSS_PLAYING;
559 }
560
561 /**
562 * Check if the \a N (next) status flag is set.
563 *
564 * \return Greater than zero if set, zero if not.
565 *
566 */
567 unsigned int vss_next(void)
568 {
569 return mmd->new_vss_status_flags & VSS_NEXT;
570 }
571
572 /**
573 * Check if a reposition request is pending.
574 *
575 * \return Greater than zero if true, zero otherwise.
576 *
577 */
578 unsigned int vss_repos(void)
579 {
580 return mmd->new_vss_status_flags & VSS_REPOS;
581 }
582
583 /**
584 * Check if the vss is currently paused.
585 *
586 * \return Greater than zero if paused, zero otherwise.
587 *
588 */
589 unsigned int vss_paused(void)
590 {
591 return !(mmd->new_vss_status_flags & VSS_NEXT)
592 && !(mmd->new_vss_status_flags & VSS_PLAYING);
593 }
594
595 /**
596 * Check if the vss is currently stopped.
597 *
598 * \return Greater than zero if paused, zero otherwise.
599 *
600 */
601 unsigned int vss_stopped(void)
602 {
603 return (mmd->new_vss_status_flags & VSS_NEXT)
604 && !(mmd->new_vss_status_flags & VSS_PLAYING);
605 }
606
607 static int chk_barrier(const char *bname, const struct timeval *barrier,
608 struct timeval *diff, int print_log)
609 {
610 long ms;
611
612 if (tv_diff(now, barrier, diff) > 0)
613 return 1;
614 ms = tv2ms(diff);
615 if (print_log && ms)
616 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
617 return -1;
618 }
619
620 /*
621 * != NULL: timeout for next chunk
622 * NULL: nothing to do
623 */
624 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
625 {
626 static struct timeval the_timeout;
627 struct timeval next_chunk;
628
629 if (vss_next() && vsst->map) {
630 /* only sleep a bit, nec*/
631 the_timeout.tv_sec = 0;
632 the_timeout.tv_usec = 100;
633 return &the_timeout;
634 }
635 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
636 &the_timeout, 1) < 0)
637 return &the_timeout;
638 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
639 return &the_timeout;
640 if (chk_barrier("data send", &vsst->data_send_barrier,
641 &the_timeout, 1) < 0)
642 return &the_timeout;
643 if (!vss_playing() || !vsst->map)
644 return NULL;
645 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
646 &mmd->stream_start, &next_chunk);
647 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
648 /* chunk is due or bof */
649 the_timeout.tv_sec = 0;
650 the_timeout.tv_usec = 0;
651 return &the_timeout;
652 }
653 /* compute min of current timeout and next slice time */
654 compute_slice_timeout(&the_timeout);
655 return &the_timeout;
656 }
657
658 static void vss_eof(struct vss_task *vsst)
659 {
660
661 if (!vsst->map)
662 return;
663 if (mmd->new_vss_status_flags & VSS_NOMORE)
664 mmd->new_vss_status_flags = VSS_NEXT;
665 set_eof_barrier(vsst);
666 para_munmap(vsst->map, mmd->size);
667 vsst->map = NULL;
668 mmd->chunks_sent = 0;
669 //mmd->offset = 0;
670 mmd->afd.afhi.seconds_total = 0;
671 mmd->afd.afhi.chunk_tv.tv_sec = 0;
672 mmd->afd.afhi.chunk_tv.tv_usec = 0;
673 free(mmd->afd.afhi.chunk_table);
674 mmd->afd.afhi.chunk_table = NULL;
675 mmd->mtime = 0;
676 mmd->size = 0;
677 mmd->events++;
678 }
679
680 static int need_to_request_new_audio_file(struct vss_task *vsst)
681 {
682 struct timeval diff;
683
684 if (vsst->map) /* have audio file */
685 return 0;
686 if (!vss_playing()) /* don't need one */
687 return 0;
688 if (mmd->new_vss_status_flags & VSS_NOMORE)
689 return 0;
690 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
691 return 0;
692 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
693 &diff, 1) < 0)
694 return 0;
695 return 1;
696 }
697
698 static void set_mmd_offset(void)
699 {
700 struct timeval offset;
701 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
702 mmd->offset = tv2ms(&offset);
703 }
704
705 /**
706 * Compute the timeout for the main select-loop of the scheduler.
707 *
708 * \param s Pointer to the server scheduler.
709 * \param t Pointer to the vss task structure.
710 *
711 * Before the timeout is computed, the current vss status flags are evaluated
712 * and acted upon by calling appropriate functions from the lower layers.
713 * Possible actions include
714 *
715 * - request a new audio file from afs,
716 * - shutdown of all senders (stop/pause command),
717 * - reposition the stream (ff/jmp command).
718 */
719 static void vss_pre_select(struct sched *s, struct task *t)
720 {
721 int i;
722 struct timeval *tv;
723 struct vss_task *vsst = container_of(t, struct vss_task, task);
724
725 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
726 struct fec_client *fc, *tmp;
727 for (i = 0; senders[i].name; i++)
728 if (senders[i].shutdown_clients)
729 senders[i].shutdown_clients();
730 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
731 fc->state = FEC_STATE_NONE;
732 mmd->stream_start.tv_sec = 0;
733 mmd->stream_start.tv_usec = 0;
734 }
735 if (vss_next())
736 vss_eof(vsst);
737 else if (vss_paused()) {
738 if (mmd->chunks_sent)
739 set_eof_barrier(vsst);
740 mmd->chunks_sent = 0;
741 } else if (vss_repos()) {
742 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
743 set_eof_barrier(vsst);
744 mmd->chunks_sent = 0;
745 mmd->current_chunk = mmd->repos_request;
746 mmd->new_vss_status_flags &= ~VSS_REPOS;
747 set_mmd_offset();
748 }
749 if (need_to_request_new_audio_file(vsst)) {
750 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
751 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
752 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
753 } else
754 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
755 for (i = 0; senders[i].name; i++) {
756 if (!senders[i].pre_select)
757 continue;
758 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
759 }
760 tv = vss_compute_timeout(vsst);
761 if (tv)
762 sched_request_timeout(tv, s);
763 }
764
765 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
766 {
767 char control[255], buf[8];
768 struct msghdr msg = {.msg_iov = NULL};
769 struct cmsghdr *cmsg;
770 struct iovec iov;
771 int ret = 0;
772
773 *fd = -1;
774 iov.iov_base = buf;
775 iov.iov_len = sizeof(buf);
776 msg.msg_iov = &iov;
777 msg.msg_iovlen = 1;
778 msg.msg_control = control;
779 msg.msg_controllen = sizeof(control);
780 memset(buf, 0, sizeof(buf));
781 ret = recvmsg(afs_socket, &msg, 0);
782 if (ret < 0)
783 return -ERRNO_TO_PARA_ERROR(errno);
784 if (iov.iov_len != sizeof(buf))
785 return -E_AFS_SHORT_READ;
786 *code = *(uint32_t*)buf;
787 *data = *(uint32_t*)(buf + 4);
788 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
789 if (cmsg->cmsg_level != SOL_SOCKET
790 || cmsg->cmsg_type != SCM_RIGHTS)
791 continue;
792 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
793 continue;
794 *fd = *(int *)CMSG_DATA(cmsg);
795 }
796 return 1;
797 }
798
799 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
800 {
801 int ret, passed_fd, shmid;
802 uint32_t afs_code = 0, afs_data = 0;
803 struct stat statbuf;
804
805 if (!FD_ISSET(vsst->afs_socket, rfds))
806 return;
807 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
808 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
809 return;
810 if (ret < 0)
811 goto err;
812 vsst->afsss = AFS_SOCKET_READY;
813 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
814 afs_data);
815 ret = -E_NOFD;
816 if (afs_code != NEXT_AUDIO_FILE)
817 goto err;
818 if (passed_fd < 0)
819 goto err;
820 shmid = afs_data;
821 ret = load_afd(shmid, &mmd->afd);
822 if (ret < 0)
823 goto err;
824 shm_destroy(shmid);
825 ret = fstat(passed_fd, &statbuf);
826 if (ret < 0) {
827 PARA_ERROR_LOG("fstat error:\n");
828 ret = -ERRNO_TO_PARA_ERROR(errno);
829 goto err;
830 }
831 mmd->size = statbuf.st_size;
832 mmd->mtime = statbuf.st_mtime;
833 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
834 0, &vsst->map);
835 if (ret < 0)
836 goto err;
837 close(passed_fd);
838 mmd->chunks_sent = 0;
839 mmd->current_chunk = 0;
840 mmd->offset = 0;
841 mmd->events++;
842 mmd->num_played++;
843 mmd->new_vss_status_flags &= (~VSS_NEXT);
844 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
845 &vsst->header_len);
846 return;
847 err:
848 free(mmd->afd.afhi.chunk_table);
849 if (passed_fd >= 0)
850 close(passed_fd);
851 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
852 mmd->new_vss_status_flags = VSS_NEXT;
853 }
854
855 /**
856 * Main sending function.
857 *
858 * This function gets called from vss_post_select(). It checks whether the next
859 * chunk of data should be pushed out. It obtains a pointer to the data to be
860 * sent out as well as its length from mmd->afd.afhi. This information is then
861 * passed to each supported sender's send() function as well as to the send()
862 * functions of each registered fec client.
863 */
864 static void vss_send(struct vss_task *vsst)
865 {
866 int i, fec_active = 0;
867 struct timeval due;
868 struct fec_client *fc, *tmp_fc;
869
870 if (!vsst->map || !vss_playing())
871 return;
872 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
873 return;
874 if (chk_barrier("data send", &vsst->data_send_barrier,
875 &due, 1) < 0)
876 return;
877 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
878 if (fc->state == FEC_STATE_DISABLED)
879 continue;
880 if (!next_slice_is_due(fc, NULL)) {
881 fec_active = 1;
882 continue;
883 }
884 if (compute_next_fec_slice(fc, vsst) <= 0)
885 continue;
886 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
887 fc->current_slice_num, fc->fcp->max_slice_bytes);
888 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
889 fc->fcp->max_slice_bytes);
890 fc->current_slice_num++;
891 fec_active = 1;
892 }
893 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
894 if (!fec_active)
895 mmd->new_vss_status_flags |= VSS_NEXT;
896 return;
897 }
898 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
899 &mmd->stream_start, &due);
900 if (tv_diff(&due, now, NULL) <= 0) {
901 const char *buf;
902 size_t len;
903
904 if (!mmd->chunks_sent) {
905 mmd->stream_start = *now;
906 mmd->events++;
907 set_mmd_offset();
908 }
909 /*
910 * We call the send function also in case of empty chunks as
911 * they might have still some data queued which can be sent in
912 * this case.
913 */
914 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
915 &buf, &len);
916 for (i = 0; senders[i].name; i++) {
917 if (!senders[i].send)
918 continue;
919 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
920 buf, len, vsst->header_buf, vsst->header_len);
921 }
922 mmd->chunks_sent++;
923 mmd->current_chunk++;
924 }
925 }
926
927 static void vss_post_select(struct sched *s, struct task *t)
928 {
929 int ret, i;
930 struct vss_task *vsst = container_of(t, struct vss_task, task);
931
932
933 if (mmd->sender_cmd_data.cmd_num >= 0) {
934 int num = mmd->sender_cmd_data.cmd_num,
935 sender_num = mmd->sender_cmd_data.sender_num;
936
937 if (senders[sender_num].client_cmds[num]) {
938 ret = senders[sender_num].client_cmds[num]
939 (&mmd->sender_cmd_data);
940 if (ret < 0)
941 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
942 }
943 mmd->sender_cmd_data.cmd_num = -1;
944 }
945 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
946 recv_afs_result(vsst, &s->rfds);
947 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
948 PARA_NOTICE_LOG("requesting new fd from afs\n");
949 ret = send_buffer(vsst->afs_socket, "new");
950 if (ret < 0)
951 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
952 else
953 vsst->afsss = AFS_SOCKET_AFD_PENDING;
954 }
955 for (i = 0; senders[i].name; i++) {
956 if (!senders[i].post_select)
957 continue;
958 senders[i].post_select(&s->rfds, &s->wfds);
959 }
960 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
961 (vss_next() && vss_playing()))
962 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
963 vss_send(vsst);
964 }
965
966 /**
967 * Initialize the virtual streaming system task.
968 *
969 * \param afs_socket The fd for communication with afs.
970 *
971 * This also initializes all supported senders and starts streaming
972 * if the --autoplay command line flag was given.
973 */
974 void init_vss_task(int afs_socket)
975 {
976 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
977 int i;
978 char *hn = para_hostname(), *home = para_homedir();
979 long unsigned announce_time = conf.announce_time_arg > 0?
980 conf.announce_time_arg : 300,
981 autoplay_delay = conf.autoplay_delay_arg > 0?
982 conf.autoplay_delay_arg : 0;
983 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
984 vsst->afs_socket = afs_socket;
985 vsst->task.pre_select = vss_pre_select;
986 vsst->task.post_select = vss_post_select;
987 ms2tv(announce_time, &vsst->announce_tv);
988 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
989 INIT_LIST_HEAD(&fec_client_list);
990 for (i = 0; senders[i].name; i++) {
991 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
992 senders[i].init(&senders[i]);
993 }
994 free(hn);
995 free(home);
996 mmd->sender_cmd_data.cmd_num = -1;
997 if (conf.autoplay_given) {
998 struct timeval tmp;
999 mmd->vss_status_flags |= VSS_PLAYING;
1000 mmd->new_vss_status_flags |= VSS_PLAYING;
1001 ms2tv(autoplay_delay, &tmp);
1002 tv_add(now, &tmp, &vsst->autoplay_barrier);
1003 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1004 &vsst->data_send_barrier);
1005 }
1006 register_task(&vsst->task);
1007 }