96b2ba9eadcb71f2da13e5ccd6d00c08c328444f
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997-2010 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file vss.c The virtual streaming system.
8 *
9 * This contains the audio streaming code of para_server which is independent
10 * of the current audio format, audio file selector and of the activated
11 * senders.
12 */
13
14 #include <regex.h>
15 #include <dirent.h>
16 #include <osl.h>
17
18 #include "para.h"
19 #include "error.h"
20 #include "portable_io.h"
21 #include "fec.h"
22 #include "string.h"
23 #include "afh.h"
24 #include "afs.h"
25 #include "server.h"
26 #include "net.h"
27 #include "server.cmdline.h"
28 #include "list.h"
29 #include "send.h"
30 #include "vss.h"
31 #include "ipc.h"
32 #include "fd.h"
33 #include "sched.h"
34
35 extern struct misc_meta_data *mmd;
36
37 extern void dccp_send_init(struct sender *);
38 extern void http_send_init(struct sender *);
39 extern void udp_send_init(struct sender *);
40
41 /** The list of supported senders. */
42 struct sender senders[] = {
43 {
44 .name = "http",
45 .init = http_send_init,
46 },
47 {
48 .name = "dccp",
49 .init = dccp_send_init,
50 },
51 {
52 .name = "udp",
53 .init = udp_send_init,
54 },
55 {
56 .name = NULL,
57 }
58 };
59
60 /** The possible states of the afs socket. */
61 enum afs_socket_status {
62 /** Socket is inactive. */
63 AFS_SOCKET_READY,
64 /** Socket fd was included in the write fd set for select(). */
65 AFS_SOCKET_CHECK_FOR_WRITE,
66 /** vss wrote a request to the socket and waits for reply from afs. */
67 AFS_SOCKET_AFD_PENDING
68 };
69
70 /** The task structure for the virtual streaming system. */
71 struct vss_task {
72 /** Copied from the -announce_time command line option. */
73 struct timeval announce_tv;
74 /** End of the announcing interval. */
75 struct timeval data_send_barrier;
76 /** End of the EOF interval. */
77 struct timeval eof_barrier;
78 /** Only used if --autoplay_delay was given. */
79 struct timeval autoplay_barrier;
80 /** Used for afs-server communication. */
81 int afs_socket;
82 /** The current state of \a afs_socket. */
83 enum afs_socket_status afsss;
84 /** The memory mapped audio file. */
85 char *map;
86 /** Used by the scheduler. */
87 struct task task;
88 /** Pointer to the header of the mapped audio file. */
89 const char *header_buf;
90 /** Length of the audio file header. */
91 size_t header_len;
92 /** Time between audio file headers are sent. */
93 struct timeval header_interval;
94 };
95
96 /**
97 * The list of currently connected fec clients.
98 *
99 * Senders may use \ref vss_add_fec_client() to add entries to the list.
100 */
101 static struct list_head fec_client_list;
102
103 /**
104 * Data associated with one FEC group.
105 *
106 * A FEC group consists of a fixed number of slices and this number is given by
107 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
108 * group contains a number of chunks of the current audio file.
109 *
110 * FEC slices directly correspond to the data packages sent by the paraslash
111 * senders that use FEC. Each slice is identified by its group number and its
112 * number within the group. All slices have the same size, but the last slice
113 * of the group may not be filled entirely.
114 */
115 struct fec_group {
116 /** The number of the FEC group. */
117 uint32_t num;
118 /** Number of bytes in this group. */
119 uint32_t bytes;
120 /** The first chunk of the current audio file belonging to the group. */
121 uint32_t first_chunk;
122 /** The number of chunks contained in this group. */
123 uint32_t num_chunks;
124 /** When the first chunk was sent. */
125 struct timeval start;
126 /** The duration of the full group. */
127 struct timeval duration;
128 /** The group duration divided by the number of slices. */
129 struct timeval slice_duration;
130 /** Group contains the audio file header that occupies that many slices. */
131 uint8_t num_header_slices;
132 /** Number of bytes per slice for this group. */
133 uint16_t slice_bytes;
134 };
135
136 enum fec_client_state {
137 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
138 FEC_STATE_DISABLED, /**< temporarily disabled */
139 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
140 };
141
142 /**
143 * Describes one connected FEC client.
144 */
145 struct fec_client {
146 /** Current state of the client */
147 enum fec_client_state state;
148 /** The connected sender client (transport layer). */
149 struct sender_client *sc;
150 /** Parameters requested by the client. */
151 struct fec_client_parms *fcp;
152 /** Used by the core FEC code. */
153 struct fec_parms *parms;
154 /** The position of this client in the fec client list. */
155 struct list_head node;
156 /** When the first slice for this client was sent. */
157 struct timeval stream_start;
158 /** The first chunk sent to this FEC client. */
159 int first_stream_chunk;
160 /** Describes the current group. */
161 struct fec_group group;
162 /** The current slice. */
163 uint8_t current_slice_num;
164 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
165 const unsigned char **src_data;
166 /** Last time an audio header was sent. */
167 struct timeval next_header_time;
168 /** Used for the last source pointer of an audio file. */
169 unsigned char *extra_src_buf;
170 /** Extra slices needed to store largest chunk + header. */
171 int num_extra_slices;
172 /** Contains the FEC-encoded data. */
173 unsigned char *enc_buf;
174 /** Maximal packet size. */
175 int mps;
176 };
177
178 /**
179 * Get the chunk time of the current audio file.
180 *
181 * \return A pointer to a struct containing the chunk time, or NULL,
182 * if currently no audio file is selected.
183 */
184 struct timeval *vss_chunk_time(void)
185 {
186 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
187 mmd->afd.afhi.chunk_tv.tv_usec == 0)
188 return NULL;
189 return &mmd->afd.afhi.chunk_tv;
190 }
191
192 /**
193 * Write a fec header to a buffer.
194 *
195 * \param buf The buffer to write to.
196 * \param h The fec header to write.
197 */
198 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
199 {
200 char *buf = (char *)fc->enc_buf;
201 struct fec_group *g = &fc->group;
202 struct fec_client_parms *p = fc->fcp;
203
204 write_u32(buf, FEC_MAGIC);
205
206 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
207 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
208 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
209
210 write_u32(buf + 10, g->num);
211 write_u32(buf + 14, g->bytes);
212
213 write_u8(buf + 18, fc->current_slice_num);
214 write_u16(buf + 20, g->slice_bytes);
215 write_u8(buf + 22, g->first_chunk? 0 : 1);
216 write_u8(buf + 23, vsst->header_len? 1 : 0);
217 memset(buf + 24, 0, 7);
218 }
219
220 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
221 {
222 if (!mmd->current_chunk) {
223 tv_add(now, &vsst->header_interval, &fc->next_header_time);
224 return false;
225 }
226 if (!vsst->header_buf)
227 return false;
228 if (vsst->header_len == 0)
229 return false;
230 if (fc->group.num && tv_diff(&fc->next_header_time, now, NULL) > 0)
231 return false;
232 tv_add(now, &vsst->header_interval, &fc->next_header_time);
233 return true;
234 }
235
236 static int num_slices(long unsigned bytes, int max_payload, int rs)
237 {
238 int ret;
239
240 assert(max_payload > 0);
241 assert(rs > 0);
242 ret = DIV_ROUND_UP(bytes, max_payload);
243 if (ret + rs > 255)
244 return -E_BAD_CT;
245 return ret;
246 }
247
248 /* set group start and group duration */
249 static void set_group_timing(struct fec_client *fc, struct fec_group *g)
250 {
251 struct timeval *chunk_tv = vss_chunk_time();
252
253 tv_scale(g->num_chunks, chunk_tv, &g->duration);
254 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
255 &g->duration, &g->slice_duration);
256 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
257 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
258 }
259
260 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
261 {
262 int k, n, ret;
263 int hs, ds, rs; /* header/data/redundant slices */
264 struct fec_client_parms *fcp = fc->fcp;
265
266 /* set mps */
267 if (fcp->init_fec) {
268 /*
269 * Set the maximum slice size to the Maximum Packet Size if the
270 * transport protocol allows to determine this value. The user
271 * can specify a slice size up to this value.
272 */
273 ret = fcp->init_fec(fc->sc);
274 if (ret < 0)
275 return ret;
276 fc->mps = ret;
277 } else
278 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
279 if (fc->mps <= FEC_HEADER_SIZE)
280 return -ERRNO_TO_PARA_ERROR(EINVAL);
281
282 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
283 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
284 if (ret < 0)
285 return ret;
286 hs = ret;
287 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
288 if (ret < 0)
289 return ret;
290 ds = ret;
291 k = hs + ds;
292 if (k < fc->fcp->data_slices_per_group)
293 k = fc->fcp->data_slices_per_group;
294 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
295 n = k + rs;
296 fec_free(fc->parms);
297 ret = fec_new(k, n, &fc->parms);
298 if (ret < 0)
299 return ret;
300 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
301 fc->mps, k, n, fc->num_extra_slices);
302 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
303 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
304 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
305
306 fc->state = FEC_STATE_READY_TO_RUN;
307 fc->next_header_time.tv_sec = 0;
308 fc->stream_start = *now;
309 fc->first_stream_chunk = mmd->current_chunk;
310 return 1;
311 }
312
313 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
314 int max_bytes)
315 {
316 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
317
318 g->num_chunks = 0;
319 g->bytes = 0;
320 /*
321 * Include chunks into the group until the group duration is at least
322 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
323 * super frame) is already larger than 150ms, so a FEC group consists
324 * of exactly one chunk for these audio formats.
325 */
326 for (i = 0;; i++) {
327 const char *buf;
328 size_t len;
329 int chunk_num = g->first_chunk + i;
330
331 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
332 break;
333 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
334 break;
335 afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, &buf, &len);
336 if (g->bytes + len > max_bytes)
337 break;
338 /* Include this chunk */
339 g->bytes += len;
340 g->num_chunks++;
341 }
342 assert(g->num_chunks);
343 }
344
345 /*
346 * Compute the slice size of the next group.
347 *
348 * The FEC parameters n and k are fixed but the slice size varies per
349 * FEC group. We'd like to choose slices as small as possible to avoid
350 * unnecessary FEC calculations but large enough to guarantee that the
351 * k data slices suffice to encode the header (if needed) and the data
352 * chunk(s).
353 *
354 * Once we know the payload of the next group, we define the number s
355 * of bytes per slice for this group by
356 *
357 * s = ceil(payload / k)
358 *
359 * However, for header streams, computing s is more complicated since no
360 * overlapping of header and data slices is possible. Hence we have k >=
361 * 2 and s must satisfy
362 *
363 * (*) ceil(h / s) + ceil(d / s) <= k
364 *
365 * where h and d are payload of the header and the data chunk(s)
366 * respectively. In general there is no value for s such that (*)
367 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
368 *
369 * We use the following approach for computing a suitable value for s:
370 *
371 * Let
372 * k1 := ceil(k * min(h, d) / (h + d)),
373 * k2 := k - k1.
374 *
375 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
376 *
377 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
378 *
379 * is well-defined. Inequality (*) holds for this value of s since k1
380 * slices suffice to store min(h, d) while k2 slices suffice to store
381 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
382 * second by k2.
383 *
384 * For the above example we obtain
385 *
386 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
387 * s = max(4000 / 5, 5000 / 5) = 1000,
388 *
389 * which is optimal since a slice size of 999 bytes would already require
390 * 11 slices.
391 */
392 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
393 {
394 struct fec_group *g = &fc->group;
395 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
396 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
397 int ret, k1, k2, h, d, min, max, sum;
398 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
399 int max_group_bytes;
400
401 if (!need_audio_header(fc, vsst)) {
402 max_group_bytes = k * max_slice_bytes;
403 g->num_header_slices = 0;
404 compute_group_size(vsst, g, max_group_bytes);
405 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
406 if (g->slice_bytes == 0)
407 g->slice_bytes = 1;
408 return 1;
409 }
410 h = vsst->header_len;
411 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
412 * max_slice_bytes;
413 compute_group_size(vsst, g, max_group_bytes);
414 d = g->bytes;
415 if (d == 0) {
416 g->slice_bytes = DIV_ROUND_UP(h, k);
417 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
418 if (ret < 0)
419 return ret;
420 g->num_header_slices = ret;
421 return 1;
422 }
423 min = PARA_MIN(h, d);
424 max = PARA_MAX(h, d);
425 sum = h + d;
426 k1 = DIV_ROUND_UP(k * min, sum);
427 k2 = k - k1;
428 assert(k1 > 0);
429 assert(k2 > 0);
430
431 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
432 /*
433 * This value of s := g->slice_bytes satisfies inequality (*) above,
434 * but it might be larger than max_slice_bytes. However, we know that
435 * max_slice_bytes are sufficient to store header and data, so:
436 */
437 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
438
439 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
440 if (ret < 0)
441 return ret;
442 g->num_header_slices = ret;
443 return 1;
444 }
445
446 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
447 {
448 int ret, i, k, n, data_slices;
449 size_t len;
450 const char *buf;
451 struct fec_group *g = &fc->group;
452
453 if (fc->state == FEC_STATE_NONE) {
454 ret = initialize_fec_client(fc, vsst);
455 if (ret < 0)
456 return ret;
457 g->first_chunk = mmd->current_chunk;
458 g->num = 0;
459 g->start = *now;
460 } else {
461 struct timeval tmp;
462 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
463 return 0;
464 /*
465 * Start and duration of this group depend only on the previous
466 * group. Compute the new group start as g->start += g->duration.
467 */
468 tmp = g->start;
469 tv_add(&tmp, &g->duration, &g->start);
470 set_group_timing(fc, g);
471 g->first_chunk += g->num_chunks;
472 g->num++;
473 }
474 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
475 n = fc->fcp->slices_per_group + fc->num_extra_slices;
476
477 compute_slice_size(fc, vsst);
478 assert(g->slice_bytes > 0);
479 ret = num_slices(g->bytes, g->slice_bytes, n - k);
480 if (ret < 0)
481 return ret;
482 data_slices = ret;
483 assert(g->num_header_slices + data_slices <= k);
484 fc->current_slice_num = 0;
485 if (g->num == 0)
486 set_group_timing(fc, g);
487
488 /* setup header slices */
489 buf = vsst->header_buf;
490 for (i = 0; i < g->num_header_slices; i++) {
491 fc->src_data[i] = (const unsigned char *)buf;
492 buf += g->slice_bytes;
493 }
494
495 /* setup data slices */
496 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &buf, &len);
497 for (; i < g->num_header_slices + data_slices; i++) {
498 if (buf + g->slice_bytes > vsst->map + mmd->size) {
499 /*
500 * Can not use the memory mapped audio file for this
501 * slice as it goes beyond the map. This slice will not
502 * be fully used.
503 */
504 uint32_t payload_size = vsst->map + mmd->size - buf;
505 memcpy(fc->extra_src_buf, buf, payload_size);
506 if (payload_size < g->slice_bytes)
507 memset(fc->extra_src_buf + payload_size, 0,
508 g->slice_bytes - payload_size);
509 fc->src_data[i] = fc->extra_src_buf;
510 i++;
511 break;
512 }
513 fc->src_data[i] = (const unsigned char *)buf;
514 buf += g->slice_bytes;
515 }
516 if (i < k) {
517 /* use arbitrary data for all remaining slices */
518 buf = vsst->map;
519 for (; i < k; i++)
520 fc->src_data[i] = (const unsigned char *)buf;
521 }
522 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
523 g->num, g->num_chunks, g->first_chunk,
524 g->first_chunk + g->num_chunks - 1, g->bytes
525 );
526 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
527 g->slice_bytes, g->num_header_slices, data_slices
528 );
529 return 1;
530 }
531
532 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
533 {
534 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
535 == fc->fcp->slices_per_group + fc->num_extra_slices) {
536 int ret = setup_next_fec_group(fc, vsst);
537 if (ret == 0)
538 return 0;
539 if (ret < 0) {
540 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
541 PARA_ERROR_LOG("FEC client temporarily disabled\n");
542 fc->state = FEC_STATE_DISABLED;
543 return ret;
544 }
545 }
546 write_fec_header(fc, vsst);
547 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
548 fc->current_slice_num, fc->group.slice_bytes);
549 return 1;
550 }
551
552 /**
553 * Return a buffer that marks the end of the stream.
554 *
555 * \param buf Result pointer.
556 * \return The length of the eof buffer.
557 *
558 * This is used for (multicast) udp streaming where closing the socket on the
559 * sender might not give rise to an eof condition at the peer.
560 */
561 size_t vss_get_fec_eof_packet(const char **buf)
562 {
563 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
564 *buf = fec_eof_packet;
565 return FEC_HEADER_SIZE;
566 }
567
568 /**
569 * Add one entry to the list of active fec clients.
570 *
571 * \param sc Generic sender_client data of the transport layer.
572 * \param fcp FEC parameters as supplied by the transport layer.
573 *
574 * \return Newly allocated fec_client struct.
575 */
576 struct fec_client *vss_add_fec_client(struct sender_client *sc,
577 struct fec_client_parms *fcp)
578 {
579 struct fec_client *fc = para_calloc(sizeof(*fc));
580
581 fc->sc = sc;
582 fc->fcp = fcp;
583 para_list_add(&fc->node, &fec_client_list);
584 return fc;
585 }
586
587 /**
588 * Remove one entry from the list of active fec clients.
589 *
590 * \param fc The client to be removed.
591 */
592 void vss_del_fec_client(struct fec_client *fc)
593 {
594 list_del(&fc->node);
595 free(fc->src_data);
596 free(fc->enc_buf);
597 free(fc->extra_src_buf);
598 fec_free(fc->parms);
599 free(fc);
600 }
601
602 /*
603 * Compute if/when next slice is due. If it isn't due yet and \a diff is
604 * not \p Null, compute the time difference next - now, where
605 *
606 * next = stream_start + (first_group_chunk - first_stream_chunk)
607 * * chunk_time + slice_num * slice_time
608 */
609 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
610 {
611 struct timeval tmp, next;
612 int ret;
613
614 if (fc->state == FEC_STATE_NONE)
615 return 1;
616 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
617 tv_add(&tmp, &fc->group.start, &next);
618 ret = tv_diff(&next, now, diff);
619 return ret < 0? 1 : 0;
620 }
621
622 static void compute_slice_timeout(struct timeval *timeout)
623 {
624 struct fec_client *fc;
625
626 list_for_each_entry(fc, &fec_client_list, node) {
627 struct timeval diff;
628
629 if (fc->state != FEC_STATE_READY_TO_RUN)
630 continue;
631 if (next_slice_is_due(fc, &diff)) {
632 timeout->tv_sec = 0;
633 timeout->tv_usec = 0;
634 return;
635 }
636 /* timeout = min(timeout, diff) */
637 if (tv_diff(&diff, timeout, NULL) < 0)
638 *timeout = diff;
639 }
640 }
641
642 static void set_eof_barrier(struct vss_task *vsst)
643 {
644 struct fec_client *fc;
645 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
646
647 if (!chunk_tv)
648 goto out;
649 list_for_each_entry(fc, &fec_client_list, node) {
650 struct timeval group_duration;
651
652 if (fc->state != FEC_STATE_READY_TO_RUN)
653 continue;
654 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
655 if (tv_diff(&timeout, &group_duration, NULL) < 0)
656 timeout = group_duration;
657 }
658 out:
659 tv_add(now, &timeout, &vsst->eof_barrier);
660 }
661
662 /**
663 * Check if vss status flag \a P (playing) is set.
664 *
665 * \return Greater than zero if playing, zero otherwise.
666 *
667 */
668 unsigned int vss_playing(void)
669 {
670 return mmd->new_vss_status_flags & VSS_PLAYING;
671 }
672
673 /**
674 * Check if the \a N (next) status flag is set.
675 *
676 * \return Greater than zero if set, zero if not.
677 *
678 */
679 unsigned int vss_next(void)
680 {
681 return mmd->new_vss_status_flags & VSS_NEXT;
682 }
683
684 /**
685 * Check if a reposition request is pending.
686 *
687 * \return Greater than zero if true, zero otherwise.
688 *
689 */
690 unsigned int vss_repos(void)
691 {
692 return mmd->new_vss_status_flags & VSS_REPOS;
693 }
694
695 /**
696 * Check if the vss is currently paused.
697 *
698 * \return Greater than zero if paused, zero otherwise.
699 *
700 */
701 unsigned int vss_paused(void)
702 {
703 return !(mmd->new_vss_status_flags & VSS_NEXT)
704 && !(mmd->new_vss_status_flags & VSS_PLAYING);
705 }
706
707 /**
708 * Check if the vss is currently stopped.
709 *
710 * \return Greater than zero if paused, zero otherwise.
711 *
712 */
713 unsigned int vss_stopped(void)
714 {
715 return (mmd->new_vss_status_flags & VSS_NEXT)
716 && !(mmd->new_vss_status_flags & VSS_PLAYING);
717 }
718
719 static int chk_barrier(const char *bname, const struct timeval *barrier,
720 struct timeval *diff, int print_log)
721 {
722 long ms;
723
724 if (tv_diff(now, barrier, diff) > 0)
725 return 1;
726 ms = tv2ms(diff);
727 if (print_log && ms)
728 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
729 return -1;
730 }
731
732 /*
733 * != NULL: timeout for next chunk
734 * NULL: nothing to do
735 */
736 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
737 {
738 static struct timeval the_timeout;
739 struct timeval next_chunk;
740
741 if (vss_next() && vsst->map) {
742 /* only sleep a bit, nec*/
743 the_timeout.tv_sec = 0;
744 the_timeout.tv_usec = 100;
745 return &the_timeout;
746 }
747 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
748 &the_timeout, 1) < 0)
749 return &the_timeout;
750 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
751 return &the_timeout;
752 if (chk_barrier("data send", &vsst->data_send_barrier,
753 &the_timeout, 1) < 0)
754 return &the_timeout;
755 if (!vss_playing() || !vsst->map)
756 return NULL;
757 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
758 &mmd->stream_start, &next_chunk);
759 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
760 /* chunk is due or bof */
761 the_timeout.tv_sec = 0;
762 the_timeout.tv_usec = 0;
763 return &the_timeout;
764 }
765 /* compute min of current timeout and next slice time */
766 compute_slice_timeout(&the_timeout);
767 return &the_timeout;
768 }
769
770 static void vss_eof(struct vss_task *vsst)
771 {
772
773 if (!vsst->map)
774 return;
775 if (mmd->new_vss_status_flags & VSS_NOMORE)
776 mmd->new_vss_status_flags = VSS_NEXT;
777 set_eof_barrier(vsst);
778 para_munmap(vsst->map, mmd->size);
779 vsst->map = NULL;
780 mmd->chunks_sent = 0;
781 //mmd->offset = 0;
782 mmd->afd.afhi.seconds_total = 0;
783 mmd->afd.afhi.chunk_tv.tv_sec = 0;
784 mmd->afd.afhi.chunk_tv.tv_usec = 0;
785 free(mmd->afd.afhi.chunk_table);
786 mmd->afd.afhi.chunk_table = NULL;
787 mmd->mtime = 0;
788 mmd->size = 0;
789 mmd->events++;
790 }
791
792 static int need_to_request_new_audio_file(struct vss_task *vsst)
793 {
794 struct timeval diff;
795
796 if (vsst->map) /* have audio file */
797 return 0;
798 if (!vss_playing()) /* don't need one */
799 return 0;
800 if (mmd->new_vss_status_flags & VSS_NOMORE)
801 return 0;
802 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
803 return 0;
804 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
805 &diff, 1) < 0)
806 return 0;
807 return 1;
808 }
809
810 static void set_mmd_offset(void)
811 {
812 struct timeval offset;
813 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
814 mmd->offset = tv2ms(&offset);
815 }
816
817 /**
818 * Compute the timeout for the main select-loop of the scheduler.
819 *
820 * \param s Pointer to the server scheduler.
821 * \param t Pointer to the vss task structure.
822 *
823 * Before the timeout is computed, the current vss status flags are evaluated
824 * and acted upon by calling appropriate functions from the lower layers.
825 * Possible actions include
826 *
827 * - request a new audio file from afs,
828 * - shutdown of all senders (stop/pause command),
829 * - reposition the stream (ff/jmp command).
830 */
831 static void vss_pre_select(struct sched *s, struct task *t)
832 {
833 int i;
834 struct timeval *tv;
835 struct vss_task *vsst = container_of(t, struct vss_task, task);
836
837 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
838 struct fec_client *fc, *tmp;
839 for (i = 0; senders[i].name; i++)
840 if (senders[i].shutdown_clients)
841 senders[i].shutdown_clients();
842 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
843 fc->state = FEC_STATE_NONE;
844 mmd->stream_start.tv_sec = 0;
845 mmd->stream_start.tv_usec = 0;
846 }
847 if (vss_next())
848 vss_eof(vsst);
849 else if (vss_paused()) {
850 if (mmd->chunks_sent)
851 set_eof_barrier(vsst);
852 mmd->chunks_sent = 0;
853 } else if (vss_repos()) {
854 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
855 set_eof_barrier(vsst);
856 mmd->chunks_sent = 0;
857 mmd->current_chunk = mmd->repos_request;
858 mmd->new_vss_status_flags &= ~VSS_REPOS;
859 set_mmd_offset();
860 }
861 if (need_to_request_new_audio_file(vsst)) {
862 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
863 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
864 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
865 } else
866 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
867 for (i = 0; senders[i].name; i++) {
868 if (!senders[i].pre_select)
869 continue;
870 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
871 }
872 tv = vss_compute_timeout(vsst);
873 if (tv)
874 sched_request_timeout(tv, s);
875 }
876
877 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
878 {
879 char control[255], buf[8];
880 struct msghdr msg = {.msg_iov = NULL};
881 struct cmsghdr *cmsg;
882 struct iovec iov;
883 int ret = 0;
884
885 *fd = -1;
886 iov.iov_base = buf;
887 iov.iov_len = sizeof(buf);
888 msg.msg_iov = &iov;
889 msg.msg_iovlen = 1;
890 msg.msg_control = control;
891 msg.msg_controllen = sizeof(control);
892 memset(buf, 0, sizeof(buf));
893 ret = recvmsg(afs_socket, &msg, 0);
894 if (ret < 0)
895 return -ERRNO_TO_PARA_ERROR(errno);
896 if (iov.iov_len != sizeof(buf))
897 return -E_AFS_SHORT_READ;
898 *code = *(uint32_t*)buf;
899 *data = *(uint32_t*)(buf + 4);
900 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
901 if (cmsg->cmsg_level != SOL_SOCKET
902 || cmsg->cmsg_type != SCM_RIGHTS)
903 continue;
904 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
905 continue;
906 *fd = *(int *)CMSG_DATA(cmsg);
907 }
908 return 1;
909 }
910
911 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
912 {
913 int ret, passed_fd, shmid;
914 uint32_t afs_code = 0, afs_data = 0;
915 struct stat statbuf;
916
917 if (!FD_ISSET(vsst->afs_socket, rfds))
918 return;
919 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
920 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
921 return;
922 if (ret < 0)
923 goto err;
924 vsst->afsss = AFS_SOCKET_READY;
925 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
926 afs_data);
927 ret = -E_NOFD;
928 if (afs_code != NEXT_AUDIO_FILE)
929 goto err;
930 if (passed_fd < 0)
931 goto err;
932 shmid = afs_data;
933 ret = load_afd(shmid, &mmd->afd);
934 if (ret < 0)
935 goto err;
936 shm_destroy(shmid);
937 ret = fstat(passed_fd, &statbuf);
938 if (ret < 0) {
939 PARA_ERROR_LOG("fstat error:\n");
940 ret = -ERRNO_TO_PARA_ERROR(errno);
941 goto err;
942 }
943 mmd->size = statbuf.st_size;
944 mmd->mtime = statbuf.st_mtime;
945 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
946 0, &vsst->map);
947 if (ret < 0)
948 goto err;
949 close(passed_fd);
950 mmd->chunks_sent = 0;
951 mmd->current_chunk = 0;
952 mmd->offset = 0;
953 mmd->events++;
954 mmd->num_played++;
955 mmd->new_vss_status_flags &= (~VSS_NEXT);
956 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
957 &vsst->header_len);
958 return;
959 err:
960 free(mmd->afd.afhi.chunk_table);
961 if (passed_fd >= 0)
962 close(passed_fd);
963 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
964 mmd->new_vss_status_flags = VSS_NEXT;
965 }
966
967 /**
968 * Main sending function.
969 *
970 * This function gets called from vss_post_select(). It checks whether the next
971 * chunk of data should be pushed out. It obtains a pointer to the data to be
972 * sent out as well as its length from mmd->afd.afhi. This information is then
973 * passed to each supported sender's send() function as well as to the send()
974 * functions of each registered fec client.
975 */
976 static void vss_send(struct vss_task *vsst)
977 {
978 int i, fec_active = 0;
979 struct timeval due;
980 struct fec_client *fc, *tmp_fc;
981
982 if (!vsst->map || !vss_playing())
983 return;
984 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
985 return;
986 if (chk_barrier("data send", &vsst->data_send_barrier,
987 &due, 1) < 0)
988 return;
989 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
990 if (fc->state == FEC_STATE_DISABLED)
991 continue;
992 if (!next_slice_is_due(fc, NULL)) {
993 fec_active = 1;
994 continue;
995 }
996 if (compute_next_fec_slice(fc, vsst) <= 0)
997 continue;
998 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
999 fc->current_slice_num, fc->group.slice_bytes);
1000 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1001 fc->group.slice_bytes + FEC_HEADER_SIZE);
1002 fc->current_slice_num++;
1003 fec_active = 1;
1004 }
1005 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1006 if (!fec_active)
1007 mmd->new_vss_status_flags |= VSS_NEXT;
1008 return;
1009 }
1010 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1011 &mmd->stream_start, &due);
1012 if (tv_diff(&due, now, NULL) <= 0) {
1013 const char *buf;
1014 size_t len;
1015
1016 if (!mmd->chunks_sent) {
1017 mmd->stream_start = *now;
1018 mmd->events++;
1019 set_mmd_offset();
1020 }
1021 /*
1022 * We call the send function also in case of empty chunks as
1023 * they might have still some data queued which can be sent in
1024 * this case.
1025 */
1026 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
1027 &buf, &len);
1028 for (i = 0; senders[i].name; i++) {
1029 if (!senders[i].send)
1030 continue;
1031 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1032 buf, len, vsst->header_buf, vsst->header_len);
1033 }
1034 mmd->chunks_sent++;
1035 mmd->current_chunk++;
1036 }
1037 }
1038
1039 static void vss_post_select(struct sched *s, struct task *t)
1040 {
1041 int ret, i;
1042 struct vss_task *vsst = container_of(t, struct vss_task, task);
1043
1044
1045 if (mmd->sender_cmd_data.cmd_num >= 0) {
1046 int num = mmd->sender_cmd_data.cmd_num,
1047 sender_num = mmd->sender_cmd_data.sender_num;
1048
1049 if (senders[sender_num].client_cmds[num]) {
1050 ret = senders[sender_num].client_cmds[num]
1051 (&mmd->sender_cmd_data);
1052 if (ret < 0)
1053 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1054 }
1055 mmd->sender_cmd_data.cmd_num = -1;
1056 }
1057 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1058 recv_afs_result(vsst, &s->rfds);
1059 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1060 PARA_NOTICE_LOG("requesting new fd from afs\n");
1061 ret = send_buffer(vsst->afs_socket, "new");
1062 if (ret < 0)
1063 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1064 else
1065 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1066 }
1067 for (i = 0; senders[i].name; i++) {
1068 if (!senders[i].post_select)
1069 continue;
1070 senders[i].post_select(&s->rfds, &s->wfds);
1071 }
1072 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1073 (vss_next() && vss_playing()))
1074 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1075 vss_send(vsst);
1076 }
1077
1078 /**
1079 * Initialize the virtual streaming system task.
1080 *
1081 * \param afs_socket The fd for communication with afs.
1082 *
1083 * This also initializes all supported senders and starts streaming
1084 * if the --autoplay command line flag was given.
1085 */
1086 void init_vss_task(int afs_socket)
1087 {
1088 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1089 int i;
1090 char *hn = para_hostname(), *home = para_homedir();
1091 long unsigned announce_time = conf.announce_time_arg > 0?
1092 conf.announce_time_arg : 300,
1093 autoplay_delay = conf.autoplay_delay_arg > 0?
1094 conf.autoplay_delay_arg : 0;
1095 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1096 vsst->afs_socket = afs_socket;
1097 vsst->task.pre_select = vss_pre_select;
1098 vsst->task.post_select = vss_post_select;
1099 ms2tv(announce_time, &vsst->announce_tv);
1100 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1101 INIT_LIST_HEAD(&fec_client_list);
1102 for (i = 0; senders[i].name; i++) {
1103 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1104 senders[i].init(&senders[i]);
1105 }
1106 free(hn);
1107 free(home);
1108 mmd->sender_cmd_data.cmd_num = -1;
1109 if (conf.autoplay_given) {
1110 struct timeval tmp;
1111 mmd->vss_status_flags |= VSS_PLAYING;
1112 mmd->new_vss_status_flags |= VSS_PLAYING;
1113 ms2tv(autoplay_delay, &tmp);
1114 tv_add(now, &tmp, &vsst->autoplay_barrier);
1115 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1116 &vsst->data_send_barrier);
1117 }
1118 register_task(&vsst->task);
1119 }