21ac37470e4748ea407fd7bacb96dfb42f3ee55a
[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_u8(buf + 19, 0); /* unused */
215 write_u16(buf + 20, g->slice_bytes);
216 write_u8(buf + 22, g->first_chunk? 0 : 1);
217 write_u8(buf + 23, vsst->header_len? 1 : 0);
218 memset(buf + 24, 0, 8);
219 }
220
221 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
222 {
223 if (!mmd->current_chunk) {
224 tv_add(now, &vsst->header_interval, &fc->next_header_time);
225 return false;
226 }
227 if (!vsst->header_buf)
228 return false;
229 if (vsst->header_len == 0)
230 return false;
231 if (fc->group.num > 0) {
232 if (!fc->fcp->need_periodic_header)
233 return false;
234 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
235 return false;
236 }
237 tv_add(now, &vsst->header_interval, &fc->next_header_time);
238 return true;
239 }
240
241 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
242 {
243 if (fc->group.num > 0)
244 return true;
245 if (!vsst->header_buf)
246 return true;
247 if (vsst->header_len == 0)
248 return true;
249 if (fc->fcp->need_periodic_header)
250 return true;
251 return false;
252 }
253
254 static int num_slices(long unsigned bytes, int max_payload, int rs)
255 {
256 int ret;
257
258 assert(max_payload > 0);
259 assert(rs > 0);
260 ret = DIV_ROUND_UP(bytes, max_payload);
261 if (ret + rs > 255)
262 return -E_BAD_CT;
263 return ret;
264 }
265
266 /* set group start and group duration */
267 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
268 {
269 struct fec_group *g = &fc->group;
270 struct timeval *chunk_tv = vss_chunk_time();
271
272 if (!need_data_slices(fc, vsst))
273 ms2tv(200, &g->duration);
274 else
275 tv_scale(g->num_chunks, chunk_tv, &g->duration);
276 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
277 &g->duration, &g->slice_duration);
278 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
279 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
280 }
281
282 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
283 {
284 int k, n, ret;
285 int hs, ds, rs; /* header/data/redundant slices */
286 struct fec_client_parms *fcp = fc->fcp;
287
288 /* set mps */
289 if (fcp->init_fec) {
290 /*
291 * Set the maximum slice size to the Maximum Packet Size if the
292 * transport protocol allows to determine this value. The user
293 * can specify a slice size up to this value.
294 */
295 ret = fcp->init_fec(fc->sc);
296 if (ret < 0)
297 return ret;
298 fc->mps = ret;
299 } else
300 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
301 if (fc->mps <= FEC_HEADER_SIZE)
302 return -ERRNO_TO_PARA_ERROR(EINVAL);
303
304 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
305 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
306 if (ret < 0)
307 return ret;
308 hs = ret;
309 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
310 if (ret < 0)
311 return ret;
312 ds = ret;
313 if (fc->fcp->need_periodic_header)
314 k = hs + ds;
315 else
316 k = PARA_MAX(hs, ds);
317 if (k < fc->fcp->data_slices_per_group)
318 k = fc->fcp->data_slices_per_group;
319 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
320 n = k + rs;
321 fec_free(fc->parms);
322 ret = fec_new(k, n, &fc->parms);
323 if (ret < 0)
324 return ret;
325 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
326 fc->mps, k, n, fc->num_extra_slices);
327 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
328 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
329 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
330
331 fc->state = FEC_STATE_READY_TO_RUN;
332 fc->next_header_time.tv_sec = 0;
333 fc->stream_start = *now;
334 fc->first_stream_chunk = mmd->current_chunk;
335 return 1;
336 }
337
338 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
339 int max_bytes)
340 {
341 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
342
343 g->num_chunks = 0;
344 g->bytes = 0;
345 /*
346 * Include chunks into the group until the group duration is at least
347 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
348 * super frame) is already larger than 150ms, so a FEC group consists
349 * of exactly one chunk for these audio formats.
350 */
351 for (i = 0;; i++) {
352 const char *buf;
353 size_t len;
354 int chunk_num = g->first_chunk + i;
355
356 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
357 break;
358 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
359 break;
360 afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, &buf, &len);
361 if (g->bytes + len > max_bytes)
362 break;
363 /* Include this chunk */
364 g->bytes += len;
365 g->num_chunks++;
366 }
367 assert(g->num_chunks);
368 }
369
370 /*
371 * Compute the slice size of the next group.
372 *
373 * The FEC parameters n and k are fixed but the slice size varies per
374 * FEC group. We'd like to choose slices as small as possible to avoid
375 * unnecessary FEC calculations but large enough to guarantee that the
376 * k data slices suffice to encode the header (if needed) and the data
377 * chunk(s).
378 *
379 * Once we know the payload of the next group, we define the number s
380 * of bytes per slice for this group by
381 *
382 * s = ceil(payload / k)
383 *
384 * However, for header streams, computing s is more complicated since no
385 * overlapping of header and data slices is possible. Hence we have k >=
386 * 2 and s must satisfy
387 *
388 * (*) ceil(h / s) + ceil(d / s) <= k
389 *
390 * where h and d are payload of the header and the data chunk(s)
391 * respectively. In general there is no value for s such that (*)
392 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
393 *
394 * We use the following approach for computing a suitable value for s:
395 *
396 * Let
397 * k1 := ceil(k * min(h, d) / (h + d)),
398 * k2 := k - k1.
399 *
400 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
401 *
402 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
403 *
404 * is well-defined. Inequality (*) holds for this value of s since k1
405 * slices suffice to store min(h, d) while k2 slices suffice to store
406 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
407 * second by k2.
408 *
409 * For the above example we obtain
410 *
411 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
412 * s = max(4000 / 5, 5000 / 5) = 1000,
413 *
414 * which is optimal since a slice size of 999 bytes would already require
415 * 11 slices.
416 */
417 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
418 {
419 struct fec_group *g = &fc->group;
420 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
421 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
422 int ret, k1, k2, h, d, min, max, sum;
423 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
424 int max_group_bytes;
425
426 if (!need_audio_header(fc, vsst)) {
427 max_group_bytes = k * max_slice_bytes;
428 g->num_header_slices = 0;
429 compute_group_size(vsst, g, max_group_bytes);
430 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
431 if (g->slice_bytes == 0)
432 g->slice_bytes = 1;
433 return 1;
434 }
435 if (!need_data_slices(fc, vsst)) {
436 g->bytes = 0;
437 g->num_chunks = 0;
438 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
439 g->num_header_slices = k;
440 return 1;
441 }
442 h = vsst->header_len;
443 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
444 * max_slice_bytes;
445 compute_group_size(vsst, g, max_group_bytes);
446 d = g->bytes;
447 if (d == 0) {
448 g->slice_bytes = DIV_ROUND_UP(h, k);
449 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
450 if (ret < 0)
451 return ret;
452 g->num_header_slices = ret;
453 return 1;
454 }
455 min = PARA_MIN(h, d);
456 max = PARA_MAX(h, d);
457 sum = h + d;
458 k1 = DIV_ROUND_UP(k * min, sum);
459 k2 = k - k1;
460 assert(k1 > 0);
461 assert(k2 > 0);
462
463 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
464 /*
465 * This value of s := g->slice_bytes satisfies inequality (*) above,
466 * but it might be larger than max_slice_bytes. However, we know that
467 * max_slice_bytes are sufficient to store header and data, so:
468 */
469 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
470
471 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
472 if (ret < 0)
473 return ret;
474 g->num_header_slices = ret;
475 return 1;
476 }
477
478 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
479 {
480 int ret, i, k, n, data_slices;
481 size_t len;
482 const char *buf;
483 struct fec_group *g = &fc->group;
484
485 if (fc->state == FEC_STATE_NONE) {
486 ret = initialize_fec_client(fc, vsst);
487 if (ret < 0)
488 return ret;
489 g->first_chunk = mmd->current_chunk;
490 g->num = 0;
491 g->start = *now;
492 } else {
493 struct timeval tmp;
494 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
495 return 0;
496 /*
497 * Start and duration of this group depend only on the previous
498 * group. Compute the new group start as g->start += g->duration.
499 */
500 tmp = g->start;
501 tv_add(&tmp, &g->duration, &g->start);
502 set_group_timing(fc, vsst);
503 g->first_chunk += g->num_chunks;
504 g->num++;
505 }
506 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
507 n = fc->fcp->slices_per_group + fc->num_extra_slices;
508
509 compute_slice_size(fc, vsst);
510 assert(g->slice_bytes > 0);
511 ret = num_slices(g->bytes, g->slice_bytes, n - k);
512 if (ret < 0)
513 return ret;
514 data_slices = ret;
515 assert(g->num_header_slices + data_slices <= k);
516 fc->current_slice_num = 0;
517 if (g->num == 0)
518 set_group_timing(fc, vsst);
519
520 /* setup header slices */
521 buf = vsst->header_buf;
522 for (i = 0; i < g->num_header_slices; i++) {
523 fc->src_data[i] = (const unsigned char *)buf;
524 buf += g->slice_bytes;
525 }
526
527 /* setup data slices */
528 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &buf, &len);
529 for (; i < g->num_header_slices + data_slices; i++) {
530 if (buf + g->slice_bytes > vsst->map + mmd->size) {
531 /*
532 * Can not use the memory mapped audio file for this
533 * slice as it goes beyond the map. This slice will not
534 * be fully used.
535 */
536 uint32_t payload_size = vsst->map + mmd->size - buf;
537 memcpy(fc->extra_src_buf, buf, payload_size);
538 if (payload_size < g->slice_bytes)
539 memset(fc->extra_src_buf + payload_size, 0,
540 g->slice_bytes - payload_size);
541 fc->src_data[i] = fc->extra_src_buf;
542 i++;
543 break;
544 }
545 fc->src_data[i] = (const unsigned char *)buf;
546 buf += g->slice_bytes;
547 }
548 if (i < k) {
549 /* use arbitrary data for all remaining slices */
550 buf = vsst->map;
551 for (; i < k; i++)
552 fc->src_data[i] = (const unsigned char *)buf;
553 }
554 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
555 g->num, g->num_chunks, g->first_chunk,
556 g->first_chunk + g->num_chunks - 1, g->bytes
557 );
558 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
559 g->slice_bytes, g->num_header_slices, data_slices
560 );
561 return 1;
562 }
563
564 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
565 {
566 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
567 == fc->fcp->slices_per_group + fc->num_extra_slices) {
568 int ret = setup_next_fec_group(fc, vsst);
569 if (ret == 0)
570 return 0;
571 if (ret < 0) {
572 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
573 PARA_ERROR_LOG("FEC client temporarily disabled\n");
574 fc->state = FEC_STATE_DISABLED;
575 return ret;
576 }
577 }
578 write_fec_header(fc, vsst);
579 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
580 fc->current_slice_num, fc->group.slice_bytes);
581 return 1;
582 }
583
584 /**
585 * Return a buffer that marks the end of the stream.
586 *
587 * \param buf Result pointer.
588 * \return The length of the eof buffer.
589 *
590 * This is used for (multicast) udp streaming where closing the socket on the
591 * sender might not give rise to an eof condition at the peer.
592 */
593 size_t vss_get_fec_eof_packet(const char **buf)
594 {
595 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
596 *buf = fec_eof_packet;
597 return FEC_HEADER_SIZE;
598 }
599
600 /**
601 * Add one entry to the list of active fec clients.
602 *
603 * \param sc Generic sender_client data of the transport layer.
604 * \param fcp FEC parameters as supplied by the transport layer.
605 *
606 * \return Newly allocated fec_client struct.
607 */
608 struct fec_client *vss_add_fec_client(struct sender_client *sc,
609 struct fec_client_parms *fcp)
610 {
611 struct fec_client *fc = para_calloc(sizeof(*fc));
612
613 fc->sc = sc;
614 fc->fcp = fcp;
615 para_list_add(&fc->node, &fec_client_list);
616 return fc;
617 }
618
619 /**
620 * Remove one entry from the list of active fec clients.
621 *
622 * \param fc The client to be removed.
623 */
624 void vss_del_fec_client(struct fec_client *fc)
625 {
626 list_del(&fc->node);
627 free(fc->src_data);
628 free(fc->enc_buf);
629 free(fc->extra_src_buf);
630 fec_free(fc->parms);
631 free(fc);
632 }
633
634 /*
635 * Compute if/when next slice is due. If it isn't due yet and \a diff is
636 * not \p Null, compute the time difference next - now, where
637 *
638 * next = stream_start + (first_group_chunk - first_stream_chunk)
639 * * chunk_time + slice_num * slice_time
640 */
641 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
642 {
643 struct timeval tmp, next;
644 int ret;
645
646 if (fc->state == FEC_STATE_NONE)
647 return 1;
648 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
649 tv_add(&tmp, &fc->group.start, &next);
650 ret = tv_diff(&next, now, diff);
651 return ret < 0? 1 : 0;
652 }
653
654 static void compute_slice_timeout(struct timeval *timeout)
655 {
656 struct fec_client *fc;
657
658 list_for_each_entry(fc, &fec_client_list, node) {
659 struct timeval diff;
660
661 if (fc->state != FEC_STATE_READY_TO_RUN)
662 continue;
663 if (next_slice_is_due(fc, &diff)) {
664 timeout->tv_sec = 0;
665 timeout->tv_usec = 0;
666 return;
667 }
668 /* timeout = min(timeout, diff) */
669 if (tv_diff(&diff, timeout, NULL) < 0)
670 *timeout = diff;
671 }
672 }
673
674 static void set_eof_barrier(struct vss_task *vsst)
675 {
676 struct fec_client *fc;
677 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
678
679 if (!chunk_tv)
680 goto out;
681 list_for_each_entry(fc, &fec_client_list, node) {
682 struct timeval group_duration;
683
684 if (fc->state != FEC_STATE_READY_TO_RUN)
685 continue;
686 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
687 if (tv_diff(&timeout, &group_duration, NULL) < 0)
688 timeout = group_duration;
689 }
690 out:
691 tv_add(now, &timeout, &vsst->eof_barrier);
692 }
693
694 /**
695 * Check if vss status flag \a P (playing) is set.
696 *
697 * \return Greater than zero if playing, zero otherwise.
698 *
699 */
700 unsigned int vss_playing(void)
701 {
702 return mmd->new_vss_status_flags & VSS_PLAYING;
703 }
704
705 /**
706 * Check if the \a N (next) status flag is set.
707 *
708 * \return Greater than zero if set, zero if not.
709 *
710 */
711 unsigned int vss_next(void)
712 {
713 return mmd->new_vss_status_flags & VSS_NEXT;
714 }
715
716 /**
717 * Check if a reposition request is pending.
718 *
719 * \return Greater than zero if true, zero otherwise.
720 *
721 */
722 unsigned int vss_repos(void)
723 {
724 return mmd->new_vss_status_flags & VSS_REPOS;
725 }
726
727 /**
728 * Check if the vss is currently paused.
729 *
730 * \return Greater than zero if paused, zero otherwise.
731 *
732 */
733 unsigned int vss_paused(void)
734 {
735 return !(mmd->new_vss_status_flags & VSS_NEXT)
736 && !(mmd->new_vss_status_flags & VSS_PLAYING);
737 }
738
739 /**
740 * Check if the vss is currently stopped.
741 *
742 * \return Greater than zero if paused, zero otherwise.
743 *
744 */
745 unsigned int vss_stopped(void)
746 {
747 return (mmd->new_vss_status_flags & VSS_NEXT)
748 && !(mmd->new_vss_status_flags & VSS_PLAYING);
749 }
750
751 static int chk_barrier(const char *bname, const struct timeval *barrier,
752 struct timeval *diff, int print_log)
753 {
754 long ms;
755
756 if (tv_diff(now, barrier, diff) > 0)
757 return 1;
758 ms = tv2ms(diff);
759 if (print_log && ms)
760 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
761 return -1;
762 }
763
764 /*
765 * != NULL: timeout for next chunk
766 * NULL: nothing to do
767 */
768 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
769 {
770 static struct timeval the_timeout;
771 struct timeval next_chunk;
772
773 if (vss_next() && vsst->map) {
774 /* only sleep a bit, nec*/
775 the_timeout.tv_sec = 0;
776 the_timeout.tv_usec = 100;
777 return &the_timeout;
778 }
779 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
780 &the_timeout, 1) < 0)
781 return &the_timeout;
782 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
783 return &the_timeout;
784 if (chk_barrier("data send", &vsst->data_send_barrier,
785 &the_timeout, 1) < 0)
786 return &the_timeout;
787 if (!vss_playing() || !vsst->map)
788 return NULL;
789 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
790 &mmd->stream_start, &next_chunk);
791 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
792 /* chunk is due or bof */
793 the_timeout.tv_sec = 0;
794 the_timeout.tv_usec = 0;
795 return &the_timeout;
796 }
797 /* compute min of current timeout and next slice time */
798 compute_slice_timeout(&the_timeout);
799 return &the_timeout;
800 }
801
802 static void vss_eof(struct vss_task *vsst)
803 {
804
805 if (!vsst->map)
806 return;
807 if (mmd->new_vss_status_flags & VSS_NOMORE)
808 mmd->new_vss_status_flags = VSS_NEXT;
809 set_eof_barrier(vsst);
810 para_munmap(vsst->map, mmd->size);
811 vsst->map = NULL;
812 mmd->chunks_sent = 0;
813 //mmd->offset = 0;
814 mmd->afd.afhi.seconds_total = 0;
815 mmd->afd.afhi.chunk_tv.tv_sec = 0;
816 mmd->afd.afhi.chunk_tv.tv_usec = 0;
817 free(mmd->afd.afhi.chunk_table);
818 mmd->afd.afhi.chunk_table = NULL;
819 mmd->mtime = 0;
820 mmd->size = 0;
821 mmd->events++;
822 }
823
824 static int need_to_request_new_audio_file(struct vss_task *vsst)
825 {
826 struct timeval diff;
827
828 if (vsst->map) /* have audio file */
829 return 0;
830 if (!vss_playing()) /* don't need one */
831 return 0;
832 if (mmd->new_vss_status_flags & VSS_NOMORE)
833 return 0;
834 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
835 return 0;
836 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
837 &diff, 1) < 0)
838 return 0;
839 return 1;
840 }
841
842 static void set_mmd_offset(void)
843 {
844 struct timeval offset;
845 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
846 mmd->offset = tv2ms(&offset);
847 }
848
849 /**
850 * Compute the timeout for the main select-loop of the scheduler.
851 *
852 * \param s Pointer to the server scheduler.
853 * \param t Pointer to the vss task structure.
854 *
855 * Before the timeout is computed, the current vss status flags are evaluated
856 * and acted upon by calling appropriate functions from the lower layers.
857 * Possible actions include
858 *
859 * - request a new audio file from afs,
860 * - shutdown of all senders (stop/pause command),
861 * - reposition the stream (ff/jmp command).
862 */
863 static void vss_pre_select(struct sched *s, struct task *t)
864 {
865 int i;
866 struct timeval *tv;
867 struct vss_task *vsst = container_of(t, struct vss_task, task);
868
869 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
870 struct fec_client *fc, *tmp;
871 for (i = 0; senders[i].name; i++)
872 if (senders[i].shutdown_clients)
873 senders[i].shutdown_clients();
874 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
875 fc->state = FEC_STATE_NONE;
876 mmd->stream_start.tv_sec = 0;
877 mmd->stream_start.tv_usec = 0;
878 }
879 if (vss_next())
880 vss_eof(vsst);
881 else if (vss_paused()) {
882 if (mmd->chunks_sent)
883 set_eof_barrier(vsst);
884 mmd->chunks_sent = 0;
885 } else if (vss_repos()) {
886 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
887 set_eof_barrier(vsst);
888 mmd->chunks_sent = 0;
889 mmd->current_chunk = mmd->repos_request;
890 mmd->new_vss_status_flags &= ~VSS_REPOS;
891 set_mmd_offset();
892 }
893 if (need_to_request_new_audio_file(vsst)) {
894 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
895 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
896 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
897 } else
898 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
899 for (i = 0; senders[i].name; i++) {
900 if (!senders[i].pre_select)
901 continue;
902 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
903 }
904 tv = vss_compute_timeout(vsst);
905 if (tv)
906 sched_request_timeout(tv, s);
907 }
908
909 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
910 {
911 char control[255], buf[8];
912 struct msghdr msg = {.msg_iov = NULL};
913 struct cmsghdr *cmsg;
914 struct iovec iov;
915 int ret = 0;
916
917 *fd = -1;
918 iov.iov_base = buf;
919 iov.iov_len = sizeof(buf);
920 msg.msg_iov = &iov;
921 msg.msg_iovlen = 1;
922 msg.msg_control = control;
923 msg.msg_controllen = sizeof(control);
924 memset(buf, 0, sizeof(buf));
925 ret = recvmsg(afs_socket, &msg, 0);
926 if (ret < 0)
927 return -ERRNO_TO_PARA_ERROR(errno);
928 if (iov.iov_len != sizeof(buf))
929 return -E_AFS_SHORT_READ;
930 *code = *(uint32_t*)buf;
931 *data = *(uint32_t*)(buf + 4);
932 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
933 if (cmsg->cmsg_level != SOL_SOCKET
934 || cmsg->cmsg_type != SCM_RIGHTS)
935 continue;
936 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
937 continue;
938 *fd = *(int *)CMSG_DATA(cmsg);
939 }
940 return 1;
941 }
942
943 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
944 {
945 int ret, passed_fd, shmid;
946 uint32_t afs_code = 0, afs_data = 0;
947 struct stat statbuf;
948
949 if (!FD_ISSET(vsst->afs_socket, rfds))
950 return;
951 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
952 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
953 return;
954 if (ret < 0)
955 goto err;
956 vsst->afsss = AFS_SOCKET_READY;
957 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
958 afs_data);
959 ret = -E_NOFD;
960 if (afs_code != NEXT_AUDIO_FILE)
961 goto err;
962 if (passed_fd < 0)
963 goto err;
964 shmid = afs_data;
965 ret = load_afd(shmid, &mmd->afd);
966 if (ret < 0)
967 goto err;
968 shm_destroy(shmid);
969 ret = fstat(passed_fd, &statbuf);
970 if (ret < 0) {
971 PARA_ERROR_LOG("fstat error:\n");
972 ret = -ERRNO_TO_PARA_ERROR(errno);
973 goto err;
974 }
975 mmd->size = statbuf.st_size;
976 mmd->mtime = statbuf.st_mtime;
977 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
978 0, &vsst->map);
979 if (ret < 0)
980 goto err;
981 close(passed_fd);
982 mmd->chunks_sent = 0;
983 mmd->current_chunk = 0;
984 mmd->offset = 0;
985 mmd->events++;
986 mmd->num_played++;
987 mmd->new_vss_status_flags &= (~VSS_NEXT);
988 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
989 &vsst->header_len);
990 return;
991 err:
992 free(mmd->afd.afhi.chunk_table);
993 if (passed_fd >= 0)
994 close(passed_fd);
995 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
996 mmd->new_vss_status_flags = VSS_NEXT;
997 }
998
999 /**
1000 * Main sending function.
1001 *
1002 * This function gets called from vss_post_select(). It checks whether the next
1003 * chunk of data should be pushed out. It obtains a pointer to the data to be
1004 * sent out as well as its length from mmd->afd.afhi. This information is then
1005 * passed to each supported sender's send() function as well as to the send()
1006 * functions of each registered fec client.
1007 */
1008 static void vss_send(struct vss_task *vsst)
1009 {
1010 int i, fec_active = 0;
1011 struct timeval due;
1012 struct fec_client *fc, *tmp_fc;
1013
1014 if (!vsst->map || !vss_playing())
1015 return;
1016 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1017 return;
1018 if (chk_barrier("data send", &vsst->data_send_barrier,
1019 &due, 1) < 0)
1020 return;
1021 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1022 if (fc->state == FEC_STATE_DISABLED)
1023 continue;
1024 if (!next_slice_is_due(fc, NULL)) {
1025 fec_active = 1;
1026 continue;
1027 }
1028 if (compute_next_fec_slice(fc, vsst) <= 0)
1029 continue;
1030 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
1031 fc->current_slice_num, fc->group.slice_bytes);
1032 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1033 fc->group.slice_bytes + FEC_HEADER_SIZE);
1034 fc->current_slice_num++;
1035 fec_active = 1;
1036 }
1037 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1038 if (!fec_active)
1039 mmd->new_vss_status_flags |= VSS_NEXT;
1040 return;
1041 }
1042 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1043 &mmd->stream_start, &due);
1044 if (tv_diff(&due, now, NULL) <= 0) {
1045 const char *buf;
1046 size_t len;
1047
1048 if (!mmd->chunks_sent) {
1049 mmd->stream_start = *now;
1050 mmd->events++;
1051 set_mmd_offset();
1052 }
1053 /*
1054 * We call the send function also in case of empty chunks as
1055 * they might have still some data queued which can be sent in
1056 * this case.
1057 */
1058 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
1059 &buf, &len);
1060 for (i = 0; senders[i].name; i++) {
1061 if (!senders[i].send)
1062 continue;
1063 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1064 buf, len, vsst->header_buf, vsst->header_len);
1065 }
1066 mmd->chunks_sent++;
1067 mmd->current_chunk++;
1068 }
1069 }
1070
1071 static void vss_post_select(struct sched *s, struct task *t)
1072 {
1073 int ret, i;
1074 struct vss_task *vsst = container_of(t, struct vss_task, task);
1075
1076
1077 if (mmd->sender_cmd_data.cmd_num >= 0) {
1078 int num = mmd->sender_cmd_data.cmd_num,
1079 sender_num = mmd->sender_cmd_data.sender_num;
1080
1081 if (senders[sender_num].client_cmds[num]) {
1082 ret = senders[sender_num].client_cmds[num]
1083 (&mmd->sender_cmd_data);
1084 if (ret < 0)
1085 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1086 }
1087 mmd->sender_cmd_data.cmd_num = -1;
1088 }
1089 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1090 recv_afs_result(vsst, &s->rfds);
1091 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1092 PARA_NOTICE_LOG("requesting new fd from afs\n");
1093 ret = send_buffer(vsst->afs_socket, "new");
1094 if (ret < 0)
1095 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1096 else
1097 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1098 }
1099 for (i = 0; senders[i].name; i++) {
1100 if (!senders[i].post_select)
1101 continue;
1102 senders[i].post_select(&s->rfds, &s->wfds);
1103 }
1104 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1105 (vss_next() && vss_playing()))
1106 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1107 vss_send(vsst);
1108 }
1109
1110 /**
1111 * Initialize the virtual streaming system task.
1112 *
1113 * \param afs_socket The fd for communication with afs.
1114 *
1115 * This also initializes all supported senders and starts streaming
1116 * if the --autoplay command line flag was given.
1117 */
1118 void init_vss_task(int afs_socket)
1119 {
1120 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1121 int i;
1122 char *hn = para_hostname(), *home = para_homedir();
1123 long unsigned announce_time = conf.announce_time_arg > 0?
1124 conf.announce_time_arg : 300,
1125 autoplay_delay = conf.autoplay_delay_arg > 0?
1126 conf.autoplay_delay_arg : 0;
1127 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1128 vsst->afs_socket = afs_socket;
1129 vsst->task.pre_select = vss_pre_select;
1130 vsst->task.post_select = vss_post_select;
1131 ms2tv(announce_time, &vsst->announce_tv);
1132 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1133 INIT_LIST_HEAD(&fec_client_list);
1134 for (i = 0; senders[i].name; i++) {
1135 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1136 senders[i].init(&senders[i]);
1137 }
1138 free(hn);
1139 free(home);
1140 mmd->sender_cmd_data.cmd_num = -1;
1141 if (conf.autoplay_given) {
1142 struct timeval tmp;
1143 mmd->vss_status_flags |= VSS_PLAYING;
1144 mmd->new_vss_status_flags |= VSS_PLAYING;
1145 ms2tv(autoplay_delay, &tmp);
1146 tv_add(now, &tmp, &vsst->autoplay_barrier);
1147 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1148 &vsst->data_send_barrier);
1149 }
1150 register_task(&vsst->task);
1151 }