Merge branch 't/periodic_header_optional'
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997-2011 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 > 0) {
231 if (!fc->fcp->need_periodic_header)
232 return false;
233 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
234 return false;
235 }
236 tv_add(now, &vsst->header_interval, &fc->next_header_time);
237 return true;
238 }
239
240 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
241 {
242 if (fc->group.num > 0)
243 return true;
244 if (!vsst->header_buf)
245 return true;
246 if (vsst->header_len == 0)
247 return true;
248 if (fc->fcp->need_periodic_header)
249 return true;
250 return false;
251 }
252
253 static int num_slices(long unsigned bytes, int max_payload, int rs)
254 {
255 int ret;
256
257 assert(max_payload > 0);
258 assert(rs > 0);
259 ret = DIV_ROUND_UP(bytes, max_payload);
260 if (ret + rs > 255)
261 return -E_BAD_CT;
262 return ret;
263 }
264
265 /* set group start and group duration */
266 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
267 {
268 struct fec_group *g = &fc->group;
269 struct timeval *chunk_tv = vss_chunk_time();
270
271 if (!need_data_slices(fc, vsst))
272 ms2tv(200, &g->duration);
273 else
274 tv_scale(g->num_chunks, chunk_tv, &g->duration);
275 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
276 &g->duration, &g->slice_duration);
277 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
278 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
279 }
280
281 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
282 {
283 int k, n, ret;
284 int hs, ds, rs; /* header/data/redundant slices */
285 struct fec_client_parms *fcp = fc->fcp;
286
287 /* set mps */
288 if (fcp->init_fec) {
289 /*
290 * Set the maximum slice size to the Maximum Packet Size if the
291 * transport protocol allows to determine this value. The user
292 * can specify a slice size up to this value.
293 */
294 ret = fcp->init_fec(fc->sc);
295 if (ret < 0)
296 return ret;
297 fc->mps = ret;
298 } else
299 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
300 if (fc->mps <= FEC_HEADER_SIZE)
301 return -ERRNO_TO_PARA_ERROR(EINVAL);
302
303 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
304 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
305 if (ret < 0)
306 return ret;
307 hs = ret;
308 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
309 if (ret < 0)
310 return ret;
311 ds = ret;
312 if (fc->fcp->need_periodic_header)
313 k = hs + ds;
314 else
315 k = PARA_MAX(hs, ds);
316 if (k < fc->fcp->data_slices_per_group)
317 k = fc->fcp->data_slices_per_group;
318 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
319 n = k + rs;
320 fec_free(fc->parms);
321 ret = fec_new(k, n, &fc->parms);
322 if (ret < 0)
323 return ret;
324 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
325 fc->mps, k, n, fc->num_extra_slices);
326 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
327 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
328 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
329
330 fc->state = FEC_STATE_READY_TO_RUN;
331 fc->next_header_time.tv_sec = 0;
332 fc->stream_start = *now;
333 fc->first_stream_chunk = mmd->current_chunk;
334 return 1;
335 }
336
337 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
338 int max_bytes)
339 {
340 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
341
342 g->num_chunks = 0;
343 g->bytes = 0;
344 /*
345 * Include chunks into the group until the group duration is at least
346 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
347 * super frame) is already larger than 150ms, so a FEC group consists
348 * of exactly one chunk for these audio formats.
349 */
350 for (i = 0;; i++) {
351 const char *buf;
352 size_t len;
353 int chunk_num = g->first_chunk + i;
354
355 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
356 break;
357 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
358 break;
359 afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, &buf, &len);
360 if (g->bytes + len > max_bytes)
361 break;
362 /* Include this chunk */
363 g->bytes += len;
364 g->num_chunks++;
365 }
366 assert(g->num_chunks);
367 }
368
369 /*
370 * Compute the slice size of the next group.
371 *
372 * The FEC parameters n and k are fixed but the slice size varies per
373 * FEC group. We'd like to choose slices as small as possible to avoid
374 * unnecessary FEC calculations but large enough to guarantee that the
375 * k data slices suffice to encode the header (if needed) and the data
376 * chunk(s).
377 *
378 * Once we know the payload of the next group, we define the number s
379 * of bytes per slice for this group by
380 *
381 * s = ceil(payload / k)
382 *
383 * However, for header streams, computing s is more complicated since no
384 * overlapping of header and data slices is possible. Hence we have k >=
385 * 2 and s must satisfy
386 *
387 * (*) ceil(h / s) + ceil(d / s) <= k
388 *
389 * where h and d are payload of the header and the data chunk(s)
390 * respectively. In general there is no value for s such that (*)
391 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
392 *
393 * We use the following approach for computing a suitable value for s:
394 *
395 * Let
396 * k1 := ceil(k * min(h, d) / (h + d)),
397 * k2 := k - k1.
398 *
399 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
400 *
401 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
402 *
403 * is well-defined. Inequality (*) holds for this value of s since k1
404 * slices suffice to store min(h, d) while k2 slices suffice to store
405 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
406 * second by k2.
407 *
408 * For the above example we obtain
409 *
410 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
411 * s = max(4000 / 5, 5000 / 5) = 1000,
412 *
413 * which is optimal since a slice size of 999 bytes would already require
414 * 11 slices.
415 */
416 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
417 {
418 struct fec_group *g = &fc->group;
419 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
420 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
421 int ret, k1, k2, h, d, min, max, sum;
422 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
423 int max_group_bytes;
424
425 if (!need_audio_header(fc, vsst)) {
426 max_group_bytes = k * max_slice_bytes;
427 g->num_header_slices = 0;
428 compute_group_size(vsst, g, max_group_bytes);
429 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
430 if (g->slice_bytes == 0)
431 g->slice_bytes = 1;
432 return 1;
433 }
434 if (!need_data_slices(fc, vsst)) {
435 g->bytes = 0;
436 g->num_chunks = 0;
437 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
438 g->num_header_slices = k;
439 return 1;
440 }
441 h = vsst->header_len;
442 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
443 * max_slice_bytes;
444 compute_group_size(vsst, g, max_group_bytes);
445 d = g->bytes;
446 if (d == 0) {
447 g->slice_bytes = DIV_ROUND_UP(h, k);
448 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
449 if (ret < 0)
450 return ret;
451 g->num_header_slices = ret;
452 return 1;
453 }
454 min = PARA_MIN(h, d);
455 max = PARA_MAX(h, d);
456 sum = h + d;
457 k1 = DIV_ROUND_UP(k * min, sum);
458 k2 = k - k1;
459 assert(k1 > 0);
460 assert(k2 > 0);
461
462 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
463 /*
464 * This value of s := g->slice_bytes satisfies inequality (*) above,
465 * but it might be larger than max_slice_bytes. However, we know that
466 * max_slice_bytes are sufficient to store header and data, so:
467 */
468 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
469
470 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
471 if (ret < 0)
472 return ret;
473 g->num_header_slices = ret;
474 return 1;
475 }
476
477 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
478 {
479 int ret, i, k, n, data_slices;
480 size_t len;
481 const char *buf;
482 struct fec_group *g = &fc->group;
483
484 if (fc->state == FEC_STATE_NONE) {
485 ret = initialize_fec_client(fc, vsst);
486 if (ret < 0)
487 return ret;
488 g->first_chunk = mmd->current_chunk;
489 g->num = 0;
490 g->start = *now;
491 } else {
492 struct timeval tmp;
493 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
494 return 0;
495 /*
496 * Start and duration of this group depend only on the previous
497 * group. Compute the new group start as g->start += g->duration.
498 */
499 tmp = g->start;
500 tv_add(&tmp, &g->duration, &g->start);
501 set_group_timing(fc, vsst);
502 g->first_chunk += g->num_chunks;
503 g->num++;
504 }
505 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
506 n = fc->fcp->slices_per_group + fc->num_extra_slices;
507
508 compute_slice_size(fc, vsst);
509 assert(g->slice_bytes > 0);
510 ret = num_slices(g->bytes, g->slice_bytes, n - k);
511 if (ret < 0)
512 return ret;
513 data_slices = ret;
514 assert(g->num_header_slices + data_slices <= k);
515 fc->current_slice_num = 0;
516 if (g->num == 0)
517 set_group_timing(fc, vsst);
518
519 /* setup header slices */
520 buf = vsst->header_buf;
521 for (i = 0; i < g->num_header_slices; i++) {
522 fc->src_data[i] = (const unsigned char *)buf;
523 buf += g->slice_bytes;
524 }
525
526 /* setup data slices */
527 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &buf, &len);
528 for (; i < g->num_header_slices + data_slices; i++) {
529 if (buf + g->slice_bytes > vsst->map + mmd->size) {
530 /*
531 * Can not use the memory mapped audio file for this
532 * slice as it goes beyond the map. This slice will not
533 * be fully used.
534 */
535 uint32_t payload_size = vsst->map + mmd->size - buf;
536 memcpy(fc->extra_src_buf, buf, payload_size);
537 if (payload_size < g->slice_bytes)
538 memset(fc->extra_src_buf + payload_size, 0,
539 g->slice_bytes - payload_size);
540 fc->src_data[i] = fc->extra_src_buf;
541 i++;
542 break;
543 }
544 fc->src_data[i] = (const unsigned char *)buf;
545 buf += g->slice_bytes;
546 }
547 if (i < k) {
548 /* use arbitrary data for all remaining slices */
549 buf = vsst->map;
550 for (; i < k; i++)
551 fc->src_data[i] = (const unsigned char *)buf;
552 }
553 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
554 g->num, g->num_chunks, g->first_chunk,
555 g->first_chunk + g->num_chunks - 1, g->bytes
556 );
557 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
558 g->slice_bytes, g->num_header_slices, data_slices
559 );
560 return 1;
561 }
562
563 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
564 {
565 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
566 == fc->fcp->slices_per_group + fc->num_extra_slices) {
567 int ret = setup_next_fec_group(fc, vsst);
568 if (ret == 0)
569 return 0;
570 if (ret < 0) {
571 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
572 PARA_ERROR_LOG("FEC client temporarily disabled\n");
573 fc->state = FEC_STATE_DISABLED;
574 return ret;
575 }
576 }
577 write_fec_header(fc, vsst);
578 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
579 fc->current_slice_num, fc->group.slice_bytes);
580 return 1;
581 }
582
583 /**
584 * Return a buffer that marks the end of the stream.
585 *
586 * \param buf Result pointer.
587 * \return The length of the eof buffer.
588 *
589 * This is used for (multicast) udp streaming where closing the socket on the
590 * sender might not give rise to an eof condition at the peer.
591 */
592 size_t vss_get_fec_eof_packet(const char **buf)
593 {
594 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
595 *buf = fec_eof_packet;
596 return FEC_HEADER_SIZE;
597 }
598
599 /**
600 * Add one entry to the list of active fec clients.
601 *
602 * \param sc Generic sender_client data of the transport layer.
603 * \param fcp FEC parameters as supplied by the transport layer.
604 *
605 * \return Newly allocated fec_client struct.
606 */
607 struct fec_client *vss_add_fec_client(struct sender_client *sc,
608 struct fec_client_parms *fcp)
609 {
610 struct fec_client *fc = para_calloc(sizeof(*fc));
611
612 fc->sc = sc;
613 fc->fcp = fcp;
614 para_list_add(&fc->node, &fec_client_list);
615 return fc;
616 }
617
618 /**
619 * Remove one entry from the list of active fec clients.
620 *
621 * \param fc The client to be removed.
622 */
623 void vss_del_fec_client(struct fec_client *fc)
624 {
625 list_del(&fc->node);
626 free(fc->src_data);
627 free(fc->enc_buf);
628 free(fc->extra_src_buf);
629 fec_free(fc->parms);
630 free(fc);
631 }
632
633 /*
634 * Compute if/when next slice is due. If it isn't due yet and \a diff is
635 * not \p Null, compute the time difference next - now, where
636 *
637 * next = stream_start + (first_group_chunk - first_stream_chunk)
638 * * chunk_time + slice_num * slice_time
639 */
640 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
641 {
642 struct timeval tmp, next;
643 int ret;
644
645 if (fc->state == FEC_STATE_NONE)
646 return 1;
647 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
648 tv_add(&tmp, &fc->group.start, &next);
649 ret = tv_diff(&next, now, diff);
650 return ret < 0? 1 : 0;
651 }
652
653 static void compute_slice_timeout(struct timeval *timeout)
654 {
655 struct fec_client *fc;
656
657 list_for_each_entry(fc, &fec_client_list, node) {
658 struct timeval diff;
659
660 if (fc->state != FEC_STATE_READY_TO_RUN)
661 continue;
662 if (next_slice_is_due(fc, &diff)) {
663 timeout->tv_sec = 0;
664 timeout->tv_usec = 0;
665 return;
666 }
667 /* timeout = min(timeout, diff) */
668 if (tv_diff(&diff, timeout, NULL) < 0)
669 *timeout = diff;
670 }
671 }
672
673 static void set_eof_barrier(struct vss_task *vsst)
674 {
675 struct fec_client *fc;
676 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
677
678 if (!chunk_tv)
679 goto out;
680 list_for_each_entry(fc, &fec_client_list, node) {
681 struct timeval group_duration;
682
683 if (fc->state != FEC_STATE_READY_TO_RUN)
684 continue;
685 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
686 if (tv_diff(&timeout, &group_duration, NULL) < 0)
687 timeout = group_duration;
688 }
689 out:
690 tv_add(now, &timeout, &vsst->eof_barrier);
691 }
692
693 /**
694 * Check if vss status flag \a P (playing) is set.
695 *
696 * \return Greater than zero if playing, zero otherwise.
697 *
698 */
699 unsigned int vss_playing(void)
700 {
701 return mmd->new_vss_status_flags & VSS_PLAYING;
702 }
703
704 /**
705 * Check if the \a N (next) status flag is set.
706 *
707 * \return Greater than zero if set, zero if not.
708 *
709 */
710 unsigned int vss_next(void)
711 {
712 return mmd->new_vss_status_flags & VSS_NEXT;
713 }
714
715 /**
716 * Check if a reposition request is pending.
717 *
718 * \return Greater than zero if true, zero otherwise.
719 *
720 */
721 unsigned int vss_repos(void)
722 {
723 return mmd->new_vss_status_flags & VSS_REPOS;
724 }
725
726 /**
727 * Check if the vss is currently paused.
728 *
729 * \return Greater than zero if paused, zero otherwise.
730 *
731 */
732 unsigned int vss_paused(void)
733 {
734 return !(mmd->new_vss_status_flags & VSS_NEXT)
735 && !(mmd->new_vss_status_flags & VSS_PLAYING);
736 }
737
738 /**
739 * Check if the vss is currently stopped.
740 *
741 * \return Greater than zero if paused, zero otherwise.
742 *
743 */
744 unsigned int vss_stopped(void)
745 {
746 return (mmd->new_vss_status_flags & VSS_NEXT)
747 && !(mmd->new_vss_status_flags & VSS_PLAYING);
748 }
749
750 static int chk_barrier(const char *bname, const struct timeval *barrier,
751 struct timeval *diff, int print_log)
752 {
753 long ms;
754
755 if (tv_diff(now, barrier, diff) > 0)
756 return 1;
757 ms = tv2ms(diff);
758 if (print_log && ms)
759 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
760 return -1;
761 }
762
763 /*
764 * != NULL: timeout for next chunk
765 * NULL: nothing to do
766 */
767 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
768 {
769 static struct timeval the_timeout;
770 struct timeval next_chunk;
771
772 if (vss_next() && vsst->map) {
773 /* only sleep a bit, nec*/
774 the_timeout.tv_sec = 0;
775 the_timeout.tv_usec = 100;
776 return &the_timeout;
777 }
778 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
779 &the_timeout, 1) < 0)
780 return &the_timeout;
781 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
782 return &the_timeout;
783 if (chk_barrier("data send", &vsst->data_send_barrier,
784 &the_timeout, 1) < 0)
785 return &the_timeout;
786 if (!vss_playing() || !vsst->map)
787 return NULL;
788 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
789 &mmd->stream_start, &next_chunk);
790 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
791 /* chunk is due or bof */
792 the_timeout.tv_sec = 0;
793 the_timeout.tv_usec = 0;
794 return &the_timeout;
795 }
796 /* compute min of current timeout and next slice time */
797 compute_slice_timeout(&the_timeout);
798 return &the_timeout;
799 }
800
801 static void vss_eof(struct vss_task *vsst)
802 {
803
804 if (!vsst->map)
805 return;
806 if (mmd->new_vss_status_flags & VSS_NOMORE)
807 mmd->new_vss_status_flags = VSS_NEXT;
808 set_eof_barrier(vsst);
809 para_munmap(vsst->map, mmd->size);
810 vsst->map = NULL;
811 mmd->chunks_sent = 0;
812 //mmd->offset = 0;
813 mmd->afd.afhi.seconds_total = 0;
814 mmd->afd.afhi.chunk_tv.tv_sec = 0;
815 mmd->afd.afhi.chunk_tv.tv_usec = 0;
816 free(mmd->afd.afhi.chunk_table);
817 mmd->afd.afhi.chunk_table = NULL;
818 mmd->mtime = 0;
819 mmd->size = 0;
820 mmd->events++;
821 }
822
823 static int need_to_request_new_audio_file(struct vss_task *vsst)
824 {
825 struct timeval diff;
826
827 if (vsst->map) /* have audio file */
828 return 0;
829 if (!vss_playing()) /* don't need one */
830 return 0;
831 if (mmd->new_vss_status_flags & VSS_NOMORE)
832 return 0;
833 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
834 return 0;
835 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
836 &diff, 1) < 0)
837 return 0;
838 return 1;
839 }
840
841 static void set_mmd_offset(void)
842 {
843 struct timeval offset;
844 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
845 mmd->offset = tv2ms(&offset);
846 }
847
848 /**
849 * Compute the timeout for the main select-loop of the scheduler.
850 *
851 * \param s Pointer to the server scheduler.
852 * \param t Pointer to the vss task structure.
853 *
854 * Before the timeout is computed, the current vss status flags are evaluated
855 * and acted upon by calling appropriate functions from the lower layers.
856 * Possible actions include
857 *
858 * - request a new audio file from afs,
859 * - shutdown of all senders (stop/pause command),
860 * - reposition the stream (ff/jmp command).
861 */
862 static void vss_pre_select(struct sched *s, struct task *t)
863 {
864 int i;
865 struct timeval *tv;
866 struct vss_task *vsst = container_of(t, struct vss_task, task);
867
868 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
869 struct fec_client *fc, *tmp;
870 for (i = 0; senders[i].name; i++)
871 if (senders[i].shutdown_clients)
872 senders[i].shutdown_clients();
873 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
874 fc->state = FEC_STATE_NONE;
875 mmd->stream_start.tv_sec = 0;
876 mmd->stream_start.tv_usec = 0;
877 }
878 if (vss_next())
879 vss_eof(vsst);
880 else if (vss_paused()) {
881 if (mmd->chunks_sent)
882 set_eof_barrier(vsst);
883 mmd->chunks_sent = 0;
884 } else if (vss_repos()) {
885 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
886 set_eof_barrier(vsst);
887 mmd->chunks_sent = 0;
888 mmd->current_chunk = mmd->repos_request;
889 mmd->new_vss_status_flags &= ~VSS_REPOS;
890 set_mmd_offset();
891 }
892 if (need_to_request_new_audio_file(vsst)) {
893 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
894 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
895 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
896 } else
897 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
898 for (i = 0; senders[i].name; i++) {
899 if (!senders[i].pre_select)
900 continue;
901 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
902 }
903 tv = vss_compute_timeout(vsst);
904 if (tv)
905 sched_request_timeout(tv, s);
906 }
907
908 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
909 {
910 char control[255], buf[8];
911 struct msghdr msg = {.msg_iov = NULL};
912 struct cmsghdr *cmsg;
913 struct iovec iov;
914 int ret = 0;
915
916 *fd = -1;
917 iov.iov_base = buf;
918 iov.iov_len = sizeof(buf);
919 msg.msg_iov = &iov;
920 msg.msg_iovlen = 1;
921 msg.msg_control = control;
922 msg.msg_controllen = sizeof(control);
923 memset(buf, 0, sizeof(buf));
924 ret = recvmsg(afs_socket, &msg, 0);
925 if (ret < 0)
926 return -ERRNO_TO_PARA_ERROR(errno);
927 if (iov.iov_len != sizeof(buf))
928 return -E_AFS_SHORT_READ;
929 *code = *(uint32_t*)buf;
930 *data = *(uint32_t*)(buf + 4);
931 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
932 if (cmsg->cmsg_level != SOL_SOCKET
933 || cmsg->cmsg_type != SCM_RIGHTS)
934 continue;
935 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
936 continue;
937 *fd = *(int *)CMSG_DATA(cmsg);
938 }
939 return 1;
940 }
941
942 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
943 {
944 int ret, passed_fd, shmid;
945 uint32_t afs_code = 0, afs_data = 0;
946 struct stat statbuf;
947
948 if (!FD_ISSET(vsst->afs_socket, rfds))
949 return;
950 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
951 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
952 return;
953 if (ret < 0)
954 goto err;
955 vsst->afsss = AFS_SOCKET_READY;
956 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
957 afs_data);
958 ret = -E_NOFD;
959 if (afs_code != NEXT_AUDIO_FILE)
960 goto err;
961 if (passed_fd < 0)
962 goto err;
963 shmid = afs_data;
964 ret = load_afd(shmid, &mmd->afd);
965 if (ret < 0)
966 goto err;
967 shm_destroy(shmid);
968 ret = fstat(passed_fd, &statbuf);
969 if (ret < 0) {
970 PARA_ERROR_LOG("fstat error:\n");
971 ret = -ERRNO_TO_PARA_ERROR(errno);
972 goto err;
973 }
974 mmd->size = statbuf.st_size;
975 mmd->mtime = statbuf.st_mtime;
976 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
977 0, &vsst->map);
978 if (ret < 0)
979 goto err;
980 close(passed_fd);
981 mmd->chunks_sent = 0;
982 mmd->current_chunk = 0;
983 mmd->offset = 0;
984 mmd->events++;
985 mmd->num_played++;
986 mmd->new_vss_status_flags &= (~VSS_NEXT);
987 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
988 &vsst->header_len);
989 return;
990 err:
991 free(mmd->afd.afhi.chunk_table);
992 if (passed_fd >= 0)
993 close(passed_fd);
994 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
995 mmd->new_vss_status_flags = VSS_NEXT;
996 }
997
998 /**
999 * Main sending function.
1000 *
1001 * This function gets called from vss_post_select(). It checks whether the next
1002 * chunk of data should be pushed out. It obtains a pointer to the data to be
1003 * sent out as well as its length from mmd->afd.afhi. This information is then
1004 * passed to each supported sender's send() function as well as to the send()
1005 * functions of each registered fec client.
1006 */
1007 static void vss_send(struct vss_task *vsst)
1008 {
1009 int i, fec_active = 0;
1010 struct timeval due;
1011 struct fec_client *fc, *tmp_fc;
1012
1013 if (!vsst->map || !vss_playing())
1014 return;
1015 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1016 return;
1017 if (chk_barrier("data send", &vsst->data_send_barrier,
1018 &due, 1) < 0)
1019 return;
1020 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1021 if (fc->state == FEC_STATE_DISABLED)
1022 continue;
1023 if (!next_slice_is_due(fc, NULL)) {
1024 fec_active = 1;
1025 continue;
1026 }
1027 if (compute_next_fec_slice(fc, vsst) <= 0)
1028 continue;
1029 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
1030 fc->current_slice_num, fc->group.slice_bytes);
1031 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1032 fc->group.slice_bytes + FEC_HEADER_SIZE);
1033 fc->current_slice_num++;
1034 fec_active = 1;
1035 }
1036 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1037 if (!fec_active)
1038 mmd->new_vss_status_flags |= VSS_NEXT;
1039 return;
1040 }
1041 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1042 &mmd->stream_start, &due);
1043 if (tv_diff(&due, now, NULL) <= 0) {
1044 const char *buf;
1045 size_t len;
1046
1047 if (!mmd->chunks_sent) {
1048 mmd->stream_start = *now;
1049 mmd->events++;
1050 set_mmd_offset();
1051 }
1052 /*
1053 * We call the send function also in case of empty chunks as
1054 * they might have still some data queued which can be sent in
1055 * this case.
1056 */
1057 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
1058 &buf, &len);
1059 for (i = 0; senders[i].name; i++) {
1060 if (!senders[i].send)
1061 continue;
1062 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1063 buf, len, vsst->header_buf, vsst->header_len);
1064 }
1065 mmd->chunks_sent++;
1066 mmd->current_chunk++;
1067 }
1068 }
1069
1070 static void vss_post_select(struct sched *s, struct task *t)
1071 {
1072 int ret, i;
1073 struct vss_task *vsst = container_of(t, struct vss_task, task);
1074
1075
1076 if (mmd->sender_cmd_data.cmd_num >= 0) {
1077 int num = mmd->sender_cmd_data.cmd_num,
1078 sender_num = mmd->sender_cmd_data.sender_num;
1079
1080 if (senders[sender_num].client_cmds[num]) {
1081 ret = senders[sender_num].client_cmds[num]
1082 (&mmd->sender_cmd_data);
1083 if (ret < 0)
1084 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1085 }
1086 mmd->sender_cmd_data.cmd_num = -1;
1087 }
1088 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1089 recv_afs_result(vsst, &s->rfds);
1090 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1091 PARA_NOTICE_LOG("requesting new fd from afs\n");
1092 ret = send_buffer(vsst->afs_socket, "new");
1093 if (ret < 0)
1094 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1095 else
1096 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1097 }
1098 for (i = 0; senders[i].name; i++) {
1099 if (!senders[i].post_select)
1100 continue;
1101 senders[i].post_select(&s->rfds, &s->wfds);
1102 }
1103 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1104 (vss_next() && vss_playing()))
1105 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1106 vss_send(vsst);
1107 }
1108
1109 /**
1110 * Initialize the virtual streaming system task.
1111 *
1112 * \param afs_socket The fd for communication with afs.
1113 *
1114 * This also initializes all supported senders and starts streaming
1115 * if the --autoplay command line flag was given.
1116 */
1117 void init_vss_task(int afs_socket)
1118 {
1119 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1120 int i;
1121 char *hn = para_hostname(), *home = para_homedir();
1122 long unsigned announce_time = conf.announce_time_arg > 0?
1123 conf.announce_time_arg : 300,
1124 autoplay_delay = conf.autoplay_delay_arg > 0?
1125 conf.autoplay_delay_arg : 0;
1126 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1127 vsst->afs_socket = afs_socket;
1128 vsst->task.pre_select = vss_pre_select;
1129 vsst->task.post_select = vss_post_select;
1130 ms2tv(announce_time, &vsst->announce_tv);
1131 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1132 INIT_LIST_HEAD(&fec_client_list);
1133 for (i = 0; senders[i].name; i++) {
1134 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1135 senders[i].init(&senders[i]);
1136 }
1137 free(hn);
1138 free(home);
1139 mmd->sender_cmd_data.cmd_num = -1;
1140 if (conf.autoplay_given) {
1141 struct timeval tmp;
1142 mmd->vss_status_flags |= VSS_PLAYING;
1143 mmd->new_vss_status_flags |= VSS_PLAYING;
1144 ms2tv(autoplay_delay, &tmp);
1145 tv_add(now, &tmp, &vsst->autoplay_barrier);
1146 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1147 &vsst->data_send_barrier);
1148 }
1149 register_task(&vsst->task);
1150 }