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