db1beeba17d080e08f306830bc0ce9dd0b7bf5e0
[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 <osl.h>
16
17 #include "para.h"
18 #include "error.h"
19 #include "portable_io.h"
20 #include "fec.h"
21 #include "string.h"
22 #include "afh.h"
23 #include "afs.h"
24 #include "server.h"
25 #include "net.h"
26 #include "server.cmdline.h"
27 #include "list.h"
28 #include "send.h"
29 #include "vss.h"
30 #include "ipc.h"
31 #include "fd.h"
32 #include "sched.h"
33
34 extern struct misc_meta_data *mmd;
35
36 extern void dccp_send_init(struct sender *);
37 extern void http_send_init(struct sender *);
38 extern void udp_send_init(struct sender *);
39
40 /** The list of supported senders. */
41 struct sender senders[] = {
42 {
43 .name = "http",
44 .init = http_send_init,
45 },
46 {
47 .name = "dccp",
48 .init = dccp_send_init,
49 },
50 {
51 .name = "udp",
52 .init = udp_send_init,
53 },
54 {
55 .name = NULL,
56 }
57 };
58
59 /** The possible states of the afs socket. */
60 enum afs_socket_status {
61 /** Socket is inactive. */
62 AFS_SOCKET_READY,
63 /** Socket fd was included in the write fd set for select(). */
64 AFS_SOCKET_CHECK_FOR_WRITE,
65 /** vss wrote a request to the socket and waits for reply from afs. */
66 AFS_SOCKET_AFD_PENDING
67 };
68
69 /** The task structure for the virtual streaming system. */
70 struct vss_task {
71 /** Copied from the -announce_time command line option. */
72 struct timeval announce_tv;
73 /** End of the announcing interval. */
74 struct timeval data_send_barrier;
75 /** End of the EOF interval. */
76 struct timeval eof_barrier;
77 /** Only used if --autoplay_delay was given. */
78 struct timeval autoplay_barrier;
79 /** Used for afs-server communication. */
80 int afs_socket;
81 /** The current state of \a afs_socket. */
82 enum afs_socket_status afsss;
83 /** The memory mapped audio file. */
84 char *map;
85 /** Used by the scheduler. */
86 struct task task;
87 /** Pointer to the header of the mapped audio file. */
88 char *header_buf;
89 /** Length of the audio file header. */
90 size_t header_len;
91 /** Time between audio file headers are sent. */
92 struct timeval header_interval;
93 };
94
95 /**
96 * The list of currently connected fec clients.
97 *
98 * Senders may use \ref vss_add_fec_client() to add entries to the list.
99 */
100 static struct list_head fec_client_list;
101
102 /**
103 * Data associated with one FEC group.
104 *
105 * A FEC group consists of a fixed number of slices and this number is given by
106 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
107 * group contains a number of chunks of the current audio file.
108 *
109 * FEC slices directly correspond to the data packages sent by the paraslash
110 * senders that use FEC. Each slice is identified by its group number and its
111 * number within the group. All slices have the same size, but the last slice
112 * of the group may not be filled entirely.
113 */
114 struct fec_group {
115 /** The number of the FEC group. */
116 uint32_t num;
117 /** Number of bytes in this group. */
118 uint32_t bytes;
119 /** The first chunk of the current audio file belonging to the group. */
120 uint32_t first_chunk;
121 /** The number of chunks contained in this group. */
122 uint32_t num_chunks;
123 /** When the first chunk was sent. */
124 struct timeval start;
125 /** The duration of the full group. */
126 struct timeval duration;
127 /** The group duration divided by the number of slices. */
128 struct timeval slice_duration;
129 /** Group contains the audio file header that occupies that many slices. */
130 uint8_t num_header_slices;
131 /** Number of bytes per slice for this group. */
132 uint16_t slice_bytes;
133 };
134
135 /** A FEC client is always in one of these states. */
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 /** Needed for the last slice of the audio file header. */
171 unsigned char *extra_header_buf;
172 /** Extra slices needed to store largest chunk + header. */
173 int num_extra_slices;
174 /** Contains the FEC-encoded data. */
175 unsigned char *enc_buf;
176 /** Maximal packet size. */
177 int mps;
178 };
179
180 /**
181 * Get the chunk time of the current audio file.
182 *
183 * \return A pointer to a struct containing the chunk time, or NULL,
184 * if currently no audio file is selected.
185 */
186 struct timeval *vss_chunk_time(void)
187 {
188 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
189 mmd->afd.afhi.chunk_tv.tv_usec == 0)
190 return NULL;
191 return &mmd->afd.afhi.chunk_tv;
192 }
193
194 /**
195 * Write a fec header to a buffer.
196 *
197 * \param buf The buffer to write to.
198 * \param h The fec header to write.
199 */
200 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
201 {
202 char *buf = (char *)fc->enc_buf;
203 struct fec_group *g = &fc->group;
204 struct fec_client_parms *p = fc->fcp;
205
206 write_u32(buf, FEC_MAGIC);
207
208 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
209 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
210 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
211
212 write_u32(buf + 10, g->num);
213 write_u32(buf + 14, g->bytes);
214
215 write_u8(buf + 18, fc->current_slice_num);
216 write_u8(buf + 19, 0); /* unused */
217 write_u16(buf + 20, g->slice_bytes);
218 write_u8(buf + 22, g->first_chunk? 0 : 1);
219 write_u8(buf + 23, vsst->header_len? 1 : 0);
220 memset(buf + 24, 0, 8);
221 }
222
223 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
224 {
225 if (!mmd->current_chunk) {
226 tv_add(now, &vsst->header_interval, &fc->next_header_time);
227 return false;
228 }
229 if (!vsst->header_buf)
230 return false;
231 if (vsst->header_len == 0)
232 return false;
233 if (fc->group.num > 0) {
234 if (!fc->fcp->need_periodic_header)
235 return false;
236 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
237 return false;
238 }
239 tv_add(now, &vsst->header_interval, &fc->next_header_time);
240 return true;
241 }
242
243 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
244 {
245 if (fc->group.num > 0)
246 return true;
247 if (!vsst->header_buf)
248 return true;
249 if (vsst->header_len == 0)
250 return true;
251 if (fc->fcp->need_periodic_header)
252 return true;
253 return false;
254 }
255
256 static int num_slices(long unsigned bytes, int max_payload, int rs)
257 {
258 int ret;
259
260 assert(max_payload > 0);
261 assert(rs > 0);
262 ret = DIV_ROUND_UP(bytes, max_payload);
263 if (ret + rs > 255)
264 return -E_BAD_CT;
265 return ret;
266 }
267
268 /* set group start and group duration */
269 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
270 {
271 struct fec_group *g = &fc->group;
272 struct timeval *chunk_tv = vss_chunk_time();
273
274 if (!need_data_slices(fc, vsst))
275 ms2tv(200, &g->duration);
276 else
277 tv_scale(g->num_chunks, chunk_tv, &g->duration);
278 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
279 &g->duration, &g->slice_duration);
280 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
281 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
282 }
283
284 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
285 {
286 int k, n, ret;
287 int hs, ds, rs; /* header/data/redundant slices */
288 struct fec_client_parms *fcp = fc->fcp;
289
290 /* set mps */
291 if (fcp->init_fec) {
292 /*
293 * Set the maximum slice size to the Maximum Packet Size if the
294 * transport protocol allows to determine this value. The user
295 * can specify a slice size up to this value.
296 */
297 ret = fcp->init_fec(fc->sc);
298 if (ret < 0)
299 return ret;
300 fc->mps = ret;
301 } else
302 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
303 if (fc->mps <= FEC_HEADER_SIZE)
304 return -ERRNO_TO_PARA_ERROR(EINVAL);
305
306 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
307 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
308 if (ret < 0)
309 return ret;
310 hs = ret;
311 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
312 if (ret < 0)
313 return ret;
314 ds = ret;
315 if (fc->fcp->need_periodic_header)
316 k = hs + ds;
317 else
318 k = PARA_MAX(hs, ds);
319 if (k < fc->fcp->data_slices_per_group)
320 k = fc->fcp->data_slices_per_group;
321 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
322 n = k + rs;
323 fec_free(fc->parms);
324 ret = fec_new(k, n, &fc->parms);
325 if (ret < 0)
326 return ret;
327 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
328 fc->mps, k, n, fc->num_extra_slices);
329 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
330 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
331 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
332 fc->extra_header_buf = para_realloc(fc->extra_header_buf, fc->mps);
333
334 fc->state = FEC_STATE_READY_TO_RUN;
335 fc->next_header_time.tv_sec = 0;
336 fc->stream_start = *now;
337 fc->first_stream_chunk = mmd->current_chunk;
338 return 1;
339 }
340
341 static void vss_get_chunk(int chunk_num, struct vss_task *vsst,
342 char **buf, size_t *sz)
343 {
344 /*
345 * Chunk zero is special for header streams: It is the first portion of
346 * the audio file which consists of the audio file header. It may be
347 * arbitrary large due to embedded meta data. Audio format handlers may
348 * replace the header by a stripped one with meta data omitted which is
349 * of bounded size. We always use the stripped header for streaming
350 * rather than the unmodified header (chunk zero).
351 */
352 if (chunk_num == 0 && vsst->header_len > 0) {
353 *buf = vsst->header_buf; /* stripped header */
354 *sz = vsst->header_len;
355 return;
356 }
357 afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, (const char **)buf,
358 sz);
359 }
360
361 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
362 int max_bytes)
363 {
364 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
365
366 g->num_chunks = 0;
367 g->bytes = 0;
368 /*
369 * Include chunks into the group until the group duration is at least
370 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
371 * super frame) is already larger than 150ms, so a FEC group consists
372 * of exactly one chunk for these audio formats.
373 */
374 for (i = 0;; i++) {
375 char *buf;
376 size_t len;
377 int chunk_num = g->first_chunk + i;
378
379 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
380 break;
381 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
382 break;
383 vss_get_chunk(chunk_num, vsst, &buf, &len);
384 if (g->bytes + len > max_bytes)
385 break;
386 /* Include this chunk */
387 g->bytes += len;
388 g->num_chunks++;
389 }
390 assert(g->num_chunks);
391 }
392
393 /*
394 * Compute the slice size of the next group.
395 *
396 * The FEC parameters n and k are fixed but the slice size varies per
397 * FEC group. We'd like to choose slices as small as possible to avoid
398 * unnecessary FEC calculations but large enough to guarantee that the
399 * k data slices suffice to encode the header (if needed) and the data
400 * chunk(s).
401 *
402 * Once we know the payload of the next group, we define the number s
403 * of bytes per slice for this group by
404 *
405 * s = ceil(payload / k)
406 *
407 * However, for header streams, computing s is more complicated since no
408 * overlapping of header and data slices is possible. Hence we have k >=
409 * 2 and s must satisfy
410 *
411 * (*) ceil(h / s) + ceil(d / s) <= k
412 *
413 * where h and d are payload of the header and the data chunk(s)
414 * respectively. In general there is no value for s such that (*)
415 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
416 *
417 * We use the following approach for computing a suitable value for s:
418 *
419 * Let
420 * k1 := ceil(k * min(h, d) / (h + d)),
421 * k2 := k - k1.
422 *
423 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
424 *
425 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
426 *
427 * is well-defined. Inequality (*) holds for this value of s since k1
428 * slices suffice to store min(h, d) while k2 slices suffice to store
429 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
430 * second by k2.
431 *
432 * For the above example we obtain
433 *
434 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
435 * s = max(4000 / 5, 5000 / 5) = 1000,
436 *
437 * which is optimal since a slice size of 999 bytes would already require
438 * 11 slices.
439 */
440 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
441 {
442 struct fec_group *g = &fc->group;
443 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
444 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
445 int ret, k1, k2, h, d, min, max, sum;
446 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
447 int max_group_bytes;
448
449 if (!need_audio_header(fc, vsst)) {
450 max_group_bytes = k * max_slice_bytes;
451 g->num_header_slices = 0;
452 compute_group_size(vsst, g, max_group_bytes);
453 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
454 if (g->slice_bytes == 0)
455 g->slice_bytes = 1;
456 return 1;
457 }
458 if (!need_data_slices(fc, vsst)) {
459 g->bytes = 0;
460 g->num_chunks = 0;
461 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
462 g->num_header_slices = k;
463 return 1;
464 }
465 h = vsst->header_len;
466 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
467 * max_slice_bytes;
468 compute_group_size(vsst, g, max_group_bytes);
469 d = g->bytes;
470 if (d == 0) {
471 g->slice_bytes = DIV_ROUND_UP(h, k);
472 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
473 if (ret < 0)
474 return ret;
475 g->num_header_slices = ret;
476 return 1;
477 }
478 min = PARA_MIN(h, d);
479 max = PARA_MAX(h, d);
480 sum = h + d;
481 k1 = DIV_ROUND_UP(k * min, sum);
482 k2 = k - k1;
483 assert(k1 > 0);
484 assert(k2 > 0);
485
486 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
487 /*
488 * This value of s := g->slice_bytes satisfies inequality (*) above,
489 * but it might be larger than max_slice_bytes. However, we know that
490 * max_slice_bytes are sufficient to store header and data, so:
491 */
492 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
493
494 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
495 if (ret < 0)
496 return ret;
497 g->num_header_slices = ret;
498 return 1;
499 }
500
501 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
502 {
503 int ret, i, k, n, data_slices;
504 size_t len;
505 char *buf;
506 struct fec_group *g = &fc->group;
507
508 if (fc->state == FEC_STATE_NONE) {
509 ret = initialize_fec_client(fc, vsst);
510 if (ret < 0)
511 return ret;
512 g->first_chunk = mmd->current_chunk;
513 g->num = 0;
514 g->start = *now;
515 } else {
516 struct timeval tmp;
517 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
518 return 0;
519 /*
520 * Start and duration of this group depend only on the previous
521 * group. Compute the new group start as g->start += g->duration.
522 */
523 tmp = g->start;
524 tv_add(&tmp, &g->duration, &g->start);
525 set_group_timing(fc, vsst);
526 g->first_chunk += g->num_chunks;
527 g->num++;
528 }
529 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
530 n = fc->fcp->slices_per_group + fc->num_extra_slices;
531
532 compute_slice_size(fc, vsst);
533 assert(g->slice_bytes > 0);
534 ret = num_slices(g->bytes, g->slice_bytes, n - k);
535 if (ret < 0)
536 return ret;
537 data_slices = ret;
538 assert(g->num_header_slices + data_slices <= k);
539 fc->current_slice_num = 0;
540 if (g->num == 0)
541 set_group_timing(fc, vsst);
542 /* setup header slices */
543 buf = vsst->header_buf;
544 for (i = 0; i < g->num_header_slices; i++) {
545 uint32_t payload_size;
546 if (buf + g->slice_bytes <= vsst->header_buf + vsst->header_len) {
547 fc->src_data[i] = (const unsigned char *)buf;
548 buf += g->slice_bytes;
549 continue;
550 }
551 /*
552 * Can not use vss->header_buf for this slice as it
553 * goes beyond the buffer. This slice will not be fully
554 * used.
555 */
556 payload_size = vsst->header_buf + vsst->header_len - buf;
557 memcpy(fc->extra_header_buf, buf, payload_size);
558 if (payload_size < g->slice_bytes)
559 memset(fc->extra_header_buf + payload_size, 0,
560 g->slice_bytes - payload_size);
561 fc->src_data[i] = fc->extra_header_buf;
562 assert(i == g->num_header_slices - 1);
563 }
564
565 /* setup data slices */
566 vss_get_chunk(g->first_chunk, vsst, &buf, &len);
567 for (; i < g->num_header_slices + data_slices; i++) {
568 if (buf + g->slice_bytes > vsst->map + mmd->size) {
569 /*
570 * Can not use the memory mapped audio file for this
571 * slice as it goes beyond the map.
572 */
573 uint32_t payload_size = vsst->map + mmd->size - buf;
574 memcpy(fc->extra_src_buf, buf, payload_size);
575 if (payload_size < g->slice_bytes)
576 memset(fc->extra_src_buf + payload_size, 0,
577 g->slice_bytes - payload_size);
578 fc->src_data[i] = fc->extra_src_buf;
579 i++;
580 break;
581 }
582 fc->src_data[i] = (const unsigned char *)buf;
583 buf += g->slice_bytes;
584 }
585 if (i < k) {
586 /* use arbitrary data for all remaining slices */
587 buf = vsst->map;
588 for (; i < k; i++)
589 fc->src_data[i] = (const unsigned char *)buf;
590 }
591 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
592 g->num, g->num_chunks, g->first_chunk,
593 g->first_chunk + g->num_chunks - 1, g->bytes
594 );
595 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
596 g->slice_bytes, g->num_header_slices, data_slices
597 );
598 return 1;
599 }
600
601 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
602 {
603 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
604 == fc->fcp->slices_per_group + fc->num_extra_slices) {
605 int ret = setup_next_fec_group(fc, vsst);
606 if (ret == 0)
607 return 0;
608 if (ret < 0) {
609 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
610 PARA_ERROR_LOG("FEC client temporarily disabled\n");
611 fc->state = FEC_STATE_DISABLED;
612 return ret;
613 }
614 }
615 write_fec_header(fc, vsst);
616 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
617 fc->current_slice_num, fc->group.slice_bytes);
618 return 1;
619 }
620
621 /**
622 * Return a buffer that marks the end of the stream.
623 *
624 * \param buf Result pointer.
625 * \return The length of the eof buffer.
626 *
627 * This is used for (multicast) udp streaming where closing the socket on the
628 * sender might not give rise to an eof condition at the peer.
629 */
630 size_t vss_get_fec_eof_packet(const char **buf)
631 {
632 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
633 *buf = fec_eof_packet;
634 return FEC_HEADER_SIZE;
635 }
636
637 /**
638 * Add one entry to the list of active fec clients.
639 *
640 * \param sc Generic sender_client data of the transport layer.
641 * \param fcp FEC parameters as supplied by the transport layer.
642 *
643 * \return Newly allocated fec_client struct.
644 */
645 struct fec_client *vss_add_fec_client(struct sender_client *sc,
646 struct fec_client_parms *fcp)
647 {
648 struct fec_client *fc = para_calloc(sizeof(*fc));
649
650 fc->sc = sc;
651 fc->fcp = fcp;
652 para_list_add(&fc->node, &fec_client_list);
653 return fc;
654 }
655
656 /**
657 * Remove one entry from the list of active fec clients.
658 *
659 * \param fc The client to be removed.
660 */
661 void vss_del_fec_client(struct fec_client *fc)
662 {
663 list_del(&fc->node);
664 free(fc->src_data);
665 free(fc->enc_buf);
666 free(fc->extra_src_buf);
667 free(fc->extra_header_buf);
668 fec_free(fc->parms);
669 free(fc);
670 }
671
672 /*
673 * Compute if/when next slice is due. If it isn't due yet and \a diff is
674 * not \p Null, compute the time difference next - now, where
675 *
676 * next = stream_start + (first_group_chunk - first_stream_chunk)
677 * * chunk_time + slice_num * slice_time
678 */
679 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
680 {
681 struct timeval tmp, next;
682 int ret;
683
684 if (fc->state == FEC_STATE_NONE)
685 return 1;
686 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
687 tv_add(&tmp, &fc->group.start, &next);
688 ret = tv_diff(&next, now, diff);
689 return ret < 0? 1 : 0;
690 }
691
692 static void set_eof_barrier(struct vss_task *vsst)
693 {
694 struct fec_client *fc;
695 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
696
697 if (!chunk_tv)
698 goto out;
699 list_for_each_entry(fc, &fec_client_list, node) {
700 struct timeval group_duration;
701
702 if (fc->state != FEC_STATE_READY_TO_RUN)
703 continue;
704 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
705 if (tv_diff(&timeout, &group_duration, NULL) < 0)
706 timeout = group_duration;
707 }
708 out:
709 tv_add(now, &timeout, &vsst->eof_barrier);
710 }
711
712 /**
713 * Check if vss status flag \a P (playing) is set.
714 *
715 * \return Greater than zero if playing, zero otherwise.
716 *
717 */
718 unsigned int vss_playing(void)
719 {
720 return mmd->new_vss_status_flags & VSS_PLAYING;
721 }
722
723 /**
724 * Check if the \a N (next) status flag is set.
725 *
726 * \return Greater than zero if set, zero if not.
727 *
728 */
729 unsigned int vss_next(void)
730 {
731 return mmd->new_vss_status_flags & VSS_NEXT;
732 }
733
734 /**
735 * Check if a reposition request is pending.
736 *
737 * \return Greater than zero if true, zero otherwise.
738 *
739 */
740 unsigned int vss_repos(void)
741 {
742 return mmd->new_vss_status_flags & VSS_REPOS;
743 }
744
745 /**
746 * Check if the vss is currently paused.
747 *
748 * \return Greater than zero if paused, zero otherwise.
749 *
750 */
751 unsigned int vss_paused(void)
752 {
753 return !(mmd->new_vss_status_flags & VSS_NEXT)
754 && !(mmd->new_vss_status_flags & VSS_PLAYING);
755 }
756
757 /**
758 * Check if the vss is currently stopped.
759 *
760 * \return Greater than zero if paused, zero otherwise.
761 *
762 */
763 unsigned int vss_stopped(void)
764 {
765 return (mmd->new_vss_status_flags & VSS_NEXT)
766 && !(mmd->new_vss_status_flags & VSS_PLAYING);
767 }
768
769 static int chk_barrier(const char *bname, const struct timeval *barrier,
770 struct timeval *diff, int print_log)
771 {
772 long ms;
773
774 if (tv_diff(now, barrier, diff) > 0)
775 return 1;
776 ms = tv2ms(diff);
777 if (print_log && ms)
778 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
779 return -1;
780 }
781
782 static void vss_compute_timeout(struct sched *s, struct vss_task *vsst)
783 {
784 struct timeval tv;
785 struct fec_client *fc;
786
787 if (!vss_playing() || !vsst->map)
788 return;
789 if (vss_next() && vsst->map) /* only sleep a bit, nec*/
790 return sched_request_timeout_ms(100, s);
791
792 /* Each of these barriers must have passed until we may proceed */
793 if (sched_request_barrier(&vsst->autoplay_barrier, s) == 1)
794 return;
795 if (sched_request_barrier(&vsst->eof_barrier, s) == 1)
796 return;
797 if (sched_request_barrier(&vsst->data_send_barrier, s) == 1)
798 return;
799 /*
800 * Compute the select timeout as the minimal time until the next
801 * chunk/slice is due for any client.
802 */
803 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
804 &mmd->stream_start, &tv);
805 if (sched_request_barrier_or_min_delay(&tv, s) == 0)
806 return;
807 list_for_each_entry(fc, &fec_client_list, node) {
808 if (fc->state != FEC_STATE_READY_TO_RUN)
809 continue;
810 if (next_slice_is_due(fc, &tv))
811 return sched_min_delay(s);
812 sched_request_timeout(&tv, s);
813 }
814 }
815
816 static void vss_eof(struct vss_task *vsst)
817 {
818
819 if (!vsst->map)
820 return;
821 if (mmd->new_vss_status_flags & VSS_NOMORE)
822 mmd->new_vss_status_flags = VSS_NEXT;
823 set_eof_barrier(vsst);
824 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
825 vsst->header_buf = NULL;
826 para_munmap(vsst->map, mmd->size);
827 vsst->map = NULL;
828 mmd->chunks_sent = 0;
829 //mmd->offset = 0;
830 mmd->afd.afhi.seconds_total = 0;
831 mmd->afd.afhi.chunk_tv.tv_sec = 0;
832 mmd->afd.afhi.chunk_tv.tv_usec = 0;
833 free(mmd->afd.afhi.chunk_table);
834 mmd->afd.afhi.chunk_table = NULL;
835 mmd->mtime = 0;
836 mmd->size = 0;
837 mmd->events++;
838 }
839
840 static int need_to_request_new_audio_file(struct vss_task *vsst)
841 {
842 struct timeval diff;
843
844 if (vsst->map) /* have audio file */
845 return 0;
846 if (!vss_playing()) /* don't need one */
847 return 0;
848 if (mmd->new_vss_status_flags & VSS_NOMORE)
849 return 0;
850 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
851 return 0;
852 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
853 &diff, 1) < 0)
854 return 0;
855 return 1;
856 }
857
858 static void set_mmd_offset(void)
859 {
860 struct timeval offset;
861 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
862 mmd->offset = tv2ms(&offset);
863 }
864
865 /**
866 * Compute the timeout for the main select-loop of the scheduler.
867 *
868 * \param s Pointer to the server scheduler.
869 * \param t Pointer to the vss task structure.
870 *
871 * Before the timeout is computed, the current vss status flags are evaluated
872 * and acted upon by calling appropriate functions from the lower layers.
873 * Possible actions include
874 *
875 * - request a new audio file from afs,
876 * - shutdown of all senders (stop/pause command),
877 * - reposition the stream (ff/jmp command).
878 */
879 static void vss_pre_select(struct sched *s, struct task *t)
880 {
881 int i;
882 struct vss_task *vsst = container_of(t, struct vss_task, task);
883
884 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
885 struct fec_client *fc, *tmp;
886 for (i = 0; senders[i].name; i++)
887 if (senders[i].shutdown_clients)
888 senders[i].shutdown_clients();
889 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
890 fc->state = FEC_STATE_NONE;
891 mmd->stream_start.tv_sec = 0;
892 mmd->stream_start.tv_usec = 0;
893 }
894 if (vss_next())
895 vss_eof(vsst);
896 else if (vss_paused()) {
897 if (mmd->chunks_sent)
898 set_eof_barrier(vsst);
899 mmd->chunks_sent = 0;
900 } else if (vss_repos()) {
901 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
902 set_eof_barrier(vsst);
903 mmd->chunks_sent = 0;
904 mmd->current_chunk = mmd->repos_request;
905 mmd->new_vss_status_flags &= ~VSS_REPOS;
906 set_mmd_offset();
907 }
908 if (need_to_request_new_audio_file(vsst)) {
909 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
910 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
911 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
912 } else
913 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
914 for (i = 0; senders[i].name; i++) {
915 if (!senders[i].pre_select)
916 continue;
917 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
918 }
919 vss_compute_timeout(s, vsst);
920 }
921
922 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
923 {
924 char control[255], buf[8];
925 struct msghdr msg = {.msg_iov = NULL};
926 struct cmsghdr *cmsg;
927 struct iovec iov;
928 int ret = 0;
929
930 *fd = -1;
931 iov.iov_base = buf;
932 iov.iov_len = sizeof(buf);
933 msg.msg_iov = &iov;
934 msg.msg_iovlen = 1;
935 msg.msg_control = control;
936 msg.msg_controllen = sizeof(control);
937 memset(buf, 0, sizeof(buf));
938 ret = recvmsg(afs_socket, &msg, 0);
939 if (ret < 0)
940 return -ERRNO_TO_PARA_ERROR(errno);
941 if (iov.iov_len != sizeof(buf))
942 return -E_AFS_SHORT_READ;
943 *code = *(uint32_t*)buf;
944 *data = *(uint32_t*)(buf + 4);
945 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
946 if (cmsg->cmsg_level != SOL_SOCKET
947 || cmsg->cmsg_type != SCM_RIGHTS)
948 continue;
949 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
950 continue;
951 *fd = *(int *)CMSG_DATA(cmsg);
952 }
953 return 1;
954 }
955
956 #ifndef MAP_POPULATE
957 #define MAP_POPULATE 0
958 #endif
959
960 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
961 {
962 int ret, passed_fd, shmid;
963 uint32_t afs_code = 0, afs_data = 0;
964 struct stat statbuf;
965
966 if (!FD_ISSET(vsst->afs_socket, rfds))
967 return;
968 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
969 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
970 return;
971 if (ret < 0)
972 goto err;
973 vsst->afsss = AFS_SOCKET_READY;
974 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
975 afs_data);
976 ret = -E_NOFD;
977 if (afs_code != NEXT_AUDIO_FILE)
978 goto err;
979 if (passed_fd < 0)
980 goto err;
981 shmid = afs_data;
982 ret = load_afd(shmid, &mmd->afd);
983 if (ret < 0)
984 goto err;
985 shm_destroy(shmid);
986 ret = fstat(passed_fd, &statbuf);
987 if (ret < 0) {
988 PARA_ERROR_LOG("fstat error:\n");
989 ret = -ERRNO_TO_PARA_ERROR(errno);
990 goto err;
991 }
992 mmd->size = statbuf.st_size;
993 mmd->mtime = statbuf.st_mtime;
994 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
995 passed_fd, 0, &vsst->map);
996 if (ret < 0)
997 goto err;
998 close(passed_fd);
999 mmd->chunks_sent = 0;
1000 mmd->current_chunk = 0;
1001 mmd->offset = 0;
1002 mmd->events++;
1003 mmd->num_played++;
1004 mmd->new_vss_status_flags &= (~VSS_NEXT);
1005 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
1006 vsst->map, mmd->size, &vsst->header_buf, &vsst->header_len);
1007 return;
1008 err:
1009 free(mmd->afd.afhi.chunk_table);
1010 if (passed_fd >= 0)
1011 close(passed_fd);
1012 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1013 mmd->new_vss_status_flags = VSS_NEXT;
1014 }
1015
1016 /**
1017 * Main sending function.
1018 *
1019 * This function gets called from vss_post_select(). It checks whether the next
1020 * chunk of data should be pushed out. It obtains a pointer to the data to be
1021 * sent out as well as its length from mmd->afd.afhi. This information is then
1022 * passed to each supported sender's send() function as well as to the send()
1023 * functions of each registered fec client.
1024 */
1025 static void vss_send(struct vss_task *vsst)
1026 {
1027 int i, fec_active = 0;
1028 struct timeval due;
1029 struct fec_client *fc, *tmp_fc;
1030
1031 if (!vsst->map || !vss_playing())
1032 return;
1033 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1034 return;
1035 if (chk_barrier("data send", &vsst->data_send_barrier,
1036 &due, 1) < 0)
1037 return;
1038 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1039 if (fc->state == FEC_STATE_DISABLED)
1040 continue;
1041 if (!next_slice_is_due(fc, NULL)) {
1042 fec_active = 1;
1043 continue;
1044 }
1045 if (compute_next_fec_slice(fc, vsst) <= 0)
1046 continue;
1047 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
1048 fc->current_slice_num, fc->group.slice_bytes);
1049 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1050 fc->group.slice_bytes + FEC_HEADER_SIZE);
1051 fc->current_slice_num++;
1052 fec_active = 1;
1053 }
1054 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1055 if (!fec_active)
1056 mmd->new_vss_status_flags |= VSS_NEXT;
1057 return;
1058 }
1059 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1060 &mmd->stream_start, &due);
1061 if (tv_diff(&due, now, NULL) <= 0) {
1062 char *buf;
1063 size_t len;
1064
1065 if (!mmd->chunks_sent) {
1066 mmd->stream_start = *now;
1067 mmd->events++;
1068 set_mmd_offset();
1069 }
1070 /*
1071 * We call the send function also in case of empty chunks as
1072 * they might have still some data queued which can be sent in
1073 * this case.
1074 */
1075 vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1076 for (i = 0; senders[i].name; i++) {
1077 if (!senders[i].send)
1078 continue;
1079 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1080 buf, len, vsst->header_buf, vsst->header_len);
1081 }
1082 /*
1083 * Prefault next chunk(s)
1084 *
1085 * If the backing device of the memory-mapped audio file is
1086 * slow and read-ahead is turned off or prevented for some
1087 * reason, e.g. due to memory pressure, it may take much longer
1088 * than the chunk interval to get the next chunk on the wire,
1089 * causing buffer underruns on the client side. Mapping the
1090 * file with MAP_POPULATE seems to help a bit, but it does not
1091 * eliminate the delays completely. Moreover, it is supported
1092 * only on Linux. So we do our own read-ahead here.
1093 */
1094 if (mmd->current_chunk > 0) { /* chunk 0 might be on the heap */
1095 buf += len;
1096 for (i = 0; i < 5 && buf < vsst->map + mmd->size; i++) {
1097 __a_unused volatile char x = *buf;
1098 buf += 4096;
1099 }
1100 }
1101 mmd->chunks_sent++;
1102 mmd->current_chunk++;
1103 }
1104 }
1105
1106 static void vss_post_select(struct sched *s, struct task *t)
1107 {
1108 int ret, i;
1109 struct vss_task *vsst = container_of(t, struct vss_task, task);
1110
1111
1112 if (mmd->sender_cmd_data.cmd_num >= 0) {
1113 int num = mmd->sender_cmd_data.cmd_num,
1114 sender_num = mmd->sender_cmd_data.sender_num;
1115
1116 if (senders[sender_num].client_cmds[num]) {
1117 ret = senders[sender_num].client_cmds[num]
1118 (&mmd->sender_cmd_data);
1119 if (ret < 0)
1120 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1121 }
1122 mmd->sender_cmd_data.cmd_num = -1;
1123 }
1124 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1125 recv_afs_result(vsst, &s->rfds);
1126 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1127 PARA_NOTICE_LOG("requesting new fd from afs\n");
1128 ret = send_buffer(vsst->afs_socket, "new");
1129 if (ret < 0)
1130 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1131 else
1132 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1133 }
1134 for (i = 0; senders[i].name; i++) {
1135 if (!senders[i].post_select)
1136 continue;
1137 senders[i].post_select(&s->rfds, &s->wfds);
1138 }
1139 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1140 (vss_next() && vss_playing()))
1141 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1142 vss_send(vsst);
1143 }
1144
1145 /**
1146 * Initialize the virtual streaming system task.
1147 *
1148 * \param afs_socket The fd for communication with afs.
1149 *
1150 * This also initializes all supported senders and starts streaming
1151 * if the --autoplay command line flag was given.
1152 */
1153 void init_vss_task(int afs_socket)
1154 {
1155 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1156 int i;
1157 char *hn = para_hostname(), *home = para_homedir();
1158 long unsigned announce_time = conf.announce_time_arg > 0?
1159 conf.announce_time_arg : 300,
1160 autoplay_delay = conf.autoplay_delay_arg > 0?
1161 conf.autoplay_delay_arg : 0;
1162 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1163 vsst->afs_socket = afs_socket;
1164 vsst->task.pre_select = vss_pre_select;
1165 vsst->task.post_select = vss_post_select;
1166 ms2tv(announce_time, &vsst->announce_tv);
1167 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1168 INIT_LIST_HEAD(&fec_client_list);
1169 for (i = 0; senders[i].name; i++) {
1170 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1171 senders[i].init(&senders[i]);
1172 }
1173 free(hn);
1174 free(home);
1175 mmd->sender_cmd_data.cmd_num = -1;
1176 if (conf.autoplay_given) {
1177 struct timeval tmp;
1178 mmd->vss_status_flags |= VSS_PLAYING;
1179 mmd->new_vss_status_flags |= VSS_PLAYING;
1180 ms2tv(autoplay_delay, &tmp);
1181 tv_add(now, &tmp, &vsst->autoplay_barrier);
1182 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1183 &vsst->data_send_barrier);
1184 }
1185 sprintf(vsst->task.status, "vss task");
1186 register_task(&vsst->task);
1187 }