NEWS update.
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file vss.c The virtual streaming system.
8 *
9 * This contains the audio streaming code of para_server which is independent
10 * of the current audio format, audio file selector and of the activated
11 * senders.
12 */
13
14 #include <regex.h>
15 #include <dirent.h>
16 #include <osl.h>
17
18 #include "para.h"
19 #include "error.h"
20 #include "portable_io.h"
21 #include "fec.h"
22 #include "string.h"
23 #include "afh.h"
24 #include "afs.h"
25 #include "server.h"
26 #include "net.h"
27 #include "server.cmdline.h"
28 #include "list.h"
29 #include "send.h"
30 #include "vss.h"
31 #include "ipc.h"
32 #include "fd.h"
33 #include "sched.h"
34
35 extern struct misc_meta_data *mmd;
36
37 extern void dccp_send_init(struct sender *);
38 extern void http_send_init(struct sender *);
39 extern void udp_send_init(struct sender *);
40
41 /** The list of supported senders. */
42 struct sender senders[] = {
43 {
44 .name = "http",
45 .init = http_send_init,
46 },
47 {
48 .name = "dccp",
49 .init = dccp_send_init,
50 },
51 {
52 .name = "udp",
53 .init = udp_send_init,
54 },
55 {
56 .name = NULL,
57 }
58 };
59
60 /** The possible states of the afs socket. */
61 enum afs_socket_status {
62 /** Socket is inactive. */
63 AFS_SOCKET_READY,
64 /** Socket fd was included in the write fd set for select(). */
65 AFS_SOCKET_CHECK_FOR_WRITE,
66 /** vss wrote a request to the socket and waits for reply from afs. */
67 AFS_SOCKET_AFD_PENDING
68 };
69
70 /** The task structure for the virtual streaming system. */
71 struct vss_task {
72 /** Copied from the -announce_time command line option. */
73 struct timeval announce_tv;
74 /** End of the announcing interval. */
75 struct timeval data_send_barrier;
76 /** End of the EOF interval. */
77 struct timeval eof_barrier;
78 /** Only used if --autoplay_delay was given. */
79 struct timeval autoplay_barrier;
80 /** Used for afs-server communication. */
81 int afs_socket;
82 /** The current state of \a afs_socket. */
83 enum afs_socket_status afsss;
84 /** The memory mapped audio file. */
85 char *map;
86 /** Used by the scheduler. */
87 struct task task;
88 /** Pointer to the header of the mapped audio file. */
89 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 /** 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 if (buf + g->slice_bytes <= vsst->header_buf + vsst->header_len) {
546 fc->src_data[i] = (const unsigned char *)buf;
547 buf += g->slice_bytes;
548 continue;
549 }
550 /*
551 * Can not use vss->header_buf for this slice as it
552 * goes beyond the buffer. This slice will not be fully
553 * used.
554 */
555 uint32_t payload_size = vsst->header_buf
556 + 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 compute_slice_timeout(struct timeval *timeout)
693 {
694 struct fec_client *fc;
695
696 list_for_each_entry(fc, &fec_client_list, node) {
697 struct timeval diff;
698
699 if (fc->state != FEC_STATE_READY_TO_RUN)
700 continue;
701 if (next_slice_is_due(fc, &diff)) {
702 timeout->tv_sec = 0;
703 timeout->tv_usec = 0;
704 return;
705 }
706 /* timeout = min(timeout, diff) */
707 if (tv_diff(&diff, timeout, NULL) < 0)
708 *timeout = diff;
709 }
710 }
711
712 static void set_eof_barrier(struct vss_task *vsst)
713 {
714 struct fec_client *fc;
715 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
716
717 if (!chunk_tv)
718 goto out;
719 list_for_each_entry(fc, &fec_client_list, node) {
720 struct timeval group_duration;
721
722 if (fc->state != FEC_STATE_READY_TO_RUN)
723 continue;
724 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
725 if (tv_diff(&timeout, &group_duration, NULL) < 0)
726 timeout = group_duration;
727 }
728 out:
729 tv_add(now, &timeout, &vsst->eof_barrier);
730 }
731
732 /**
733 * Check if vss status flag \a P (playing) is set.
734 *
735 * \return Greater than zero if playing, zero otherwise.
736 *
737 */
738 unsigned int vss_playing(void)
739 {
740 return mmd->new_vss_status_flags & VSS_PLAYING;
741 }
742
743 /**
744 * Check if the \a N (next) status flag is set.
745 *
746 * \return Greater than zero if set, zero if not.
747 *
748 */
749 unsigned int vss_next(void)
750 {
751 return mmd->new_vss_status_flags & VSS_NEXT;
752 }
753
754 /**
755 * Check if a reposition request is pending.
756 *
757 * \return Greater than zero if true, zero otherwise.
758 *
759 */
760 unsigned int vss_repos(void)
761 {
762 return mmd->new_vss_status_flags & VSS_REPOS;
763 }
764
765 /**
766 * Check if the vss is currently paused.
767 *
768 * \return Greater than zero if paused, zero otherwise.
769 *
770 */
771 unsigned int vss_paused(void)
772 {
773 return !(mmd->new_vss_status_flags & VSS_NEXT)
774 && !(mmd->new_vss_status_flags & VSS_PLAYING);
775 }
776
777 /**
778 * Check if the vss is currently stopped.
779 *
780 * \return Greater than zero if paused, zero otherwise.
781 *
782 */
783 unsigned int vss_stopped(void)
784 {
785 return (mmd->new_vss_status_flags & VSS_NEXT)
786 && !(mmd->new_vss_status_flags & VSS_PLAYING);
787 }
788
789 static int chk_barrier(const char *bname, const struct timeval *barrier,
790 struct timeval *diff, int print_log)
791 {
792 long ms;
793
794 if (tv_diff(now, barrier, diff) > 0)
795 return 1;
796 ms = tv2ms(diff);
797 if (print_log && ms)
798 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
799 return -1;
800 }
801
802 /*
803 * != NULL: timeout for next chunk
804 * NULL: nothing to do
805 */
806 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
807 {
808 static struct timeval the_timeout;
809 struct timeval next_chunk;
810
811 if (vss_next() && vsst->map) {
812 /* only sleep a bit, nec*/
813 the_timeout.tv_sec = 0;
814 the_timeout.tv_usec = 100;
815 return &the_timeout;
816 }
817 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
818 &the_timeout, 1) < 0)
819 return &the_timeout;
820 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
821 return &the_timeout;
822 if (chk_barrier("data send", &vsst->data_send_barrier,
823 &the_timeout, 1) < 0)
824 return &the_timeout;
825 if (!vss_playing() || !vsst->map)
826 return NULL;
827 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
828 &mmd->stream_start, &next_chunk);
829 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
830 /* chunk is due or bof */
831 the_timeout.tv_sec = 0;
832 the_timeout.tv_usec = 0;
833 return &the_timeout;
834 }
835 /* compute min of current timeout and next slice time */
836 compute_slice_timeout(&the_timeout);
837 return &the_timeout;
838 }
839
840 static void vss_eof(struct vss_task *vsst)
841 {
842
843 if (!vsst->map)
844 return;
845 if (mmd->new_vss_status_flags & VSS_NOMORE)
846 mmd->new_vss_status_flags = VSS_NEXT;
847 set_eof_barrier(vsst);
848 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
849 vsst->header_buf = NULL;
850 para_munmap(vsst->map, mmd->size);
851 vsst->map = NULL;
852 mmd->chunks_sent = 0;
853 //mmd->offset = 0;
854 mmd->afd.afhi.seconds_total = 0;
855 mmd->afd.afhi.chunk_tv.tv_sec = 0;
856 mmd->afd.afhi.chunk_tv.tv_usec = 0;
857 free(mmd->afd.afhi.chunk_table);
858 mmd->afd.afhi.chunk_table = NULL;
859 mmd->mtime = 0;
860 mmd->size = 0;
861 mmd->events++;
862 }
863
864 static int need_to_request_new_audio_file(struct vss_task *vsst)
865 {
866 struct timeval diff;
867
868 if (vsst->map) /* have audio file */
869 return 0;
870 if (!vss_playing()) /* don't need one */
871 return 0;
872 if (mmd->new_vss_status_flags & VSS_NOMORE)
873 return 0;
874 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
875 return 0;
876 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
877 &diff, 1) < 0)
878 return 0;
879 return 1;
880 }
881
882 static void set_mmd_offset(void)
883 {
884 struct timeval offset;
885 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
886 mmd->offset = tv2ms(&offset);
887 }
888
889 /**
890 * Compute the timeout for the main select-loop of the scheduler.
891 *
892 * \param s Pointer to the server scheduler.
893 * \param t Pointer to the vss task structure.
894 *
895 * Before the timeout is computed, the current vss status flags are evaluated
896 * and acted upon by calling appropriate functions from the lower layers.
897 * Possible actions include
898 *
899 * - request a new audio file from afs,
900 * - shutdown of all senders (stop/pause command),
901 * - reposition the stream (ff/jmp command).
902 */
903 static void vss_pre_select(struct sched *s, struct task *t)
904 {
905 int i;
906 struct timeval *tv;
907 struct vss_task *vsst = container_of(t, struct vss_task, task);
908
909 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
910 struct fec_client *fc, *tmp;
911 for (i = 0; senders[i].name; i++)
912 if (senders[i].shutdown_clients)
913 senders[i].shutdown_clients();
914 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
915 fc->state = FEC_STATE_NONE;
916 mmd->stream_start.tv_sec = 0;
917 mmd->stream_start.tv_usec = 0;
918 }
919 if (vss_next())
920 vss_eof(vsst);
921 else if (vss_paused()) {
922 if (mmd->chunks_sent)
923 set_eof_barrier(vsst);
924 mmd->chunks_sent = 0;
925 } else if (vss_repos()) {
926 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
927 set_eof_barrier(vsst);
928 mmd->chunks_sent = 0;
929 mmd->current_chunk = mmd->repos_request;
930 mmd->new_vss_status_flags &= ~VSS_REPOS;
931 set_mmd_offset();
932 }
933 if (need_to_request_new_audio_file(vsst)) {
934 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
935 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
936 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
937 } else
938 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
939 for (i = 0; senders[i].name; i++) {
940 if (!senders[i].pre_select)
941 continue;
942 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
943 }
944 tv = vss_compute_timeout(vsst);
945 if (tv)
946 sched_request_timeout(tv, s);
947 }
948
949 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
950 {
951 char control[255], buf[8];
952 struct msghdr msg = {.msg_iov = NULL};
953 struct cmsghdr *cmsg;
954 struct iovec iov;
955 int ret = 0;
956
957 *fd = -1;
958 iov.iov_base = buf;
959 iov.iov_len = sizeof(buf);
960 msg.msg_iov = &iov;
961 msg.msg_iovlen = 1;
962 msg.msg_control = control;
963 msg.msg_controllen = sizeof(control);
964 memset(buf, 0, sizeof(buf));
965 ret = recvmsg(afs_socket, &msg, 0);
966 if (ret < 0)
967 return -ERRNO_TO_PARA_ERROR(errno);
968 if (iov.iov_len != sizeof(buf))
969 return -E_AFS_SHORT_READ;
970 *code = *(uint32_t*)buf;
971 *data = *(uint32_t*)(buf + 4);
972 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
973 if (cmsg->cmsg_level != SOL_SOCKET
974 || cmsg->cmsg_type != SCM_RIGHTS)
975 continue;
976 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
977 continue;
978 *fd = *(int *)CMSG_DATA(cmsg);
979 }
980 return 1;
981 }
982
983 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
984 {
985 int ret, passed_fd, shmid;
986 uint32_t afs_code = 0, afs_data = 0;
987 struct stat statbuf;
988
989 if (!FD_ISSET(vsst->afs_socket, rfds))
990 return;
991 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
992 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
993 return;
994 if (ret < 0)
995 goto err;
996 vsst->afsss = AFS_SOCKET_READY;
997 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
998 afs_data);
999 ret = -E_NOFD;
1000 if (afs_code != NEXT_AUDIO_FILE)
1001 goto err;
1002 if (passed_fd < 0)
1003 goto err;
1004 shmid = afs_data;
1005 ret = load_afd(shmid, &mmd->afd);
1006 if (ret < 0)
1007 goto err;
1008 shm_destroy(shmid);
1009 ret = fstat(passed_fd, &statbuf);
1010 if (ret < 0) {
1011 PARA_ERROR_LOG("fstat error:\n");
1012 ret = -ERRNO_TO_PARA_ERROR(errno);
1013 goto err;
1014 }
1015 mmd->size = statbuf.st_size;
1016 mmd->mtime = statbuf.st_mtime;
1017 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
1018 0, &vsst->map);
1019 if (ret < 0)
1020 goto err;
1021 close(passed_fd);
1022 mmd->chunks_sent = 0;
1023 mmd->current_chunk = 0;
1024 mmd->offset = 0;
1025 mmd->events++;
1026 mmd->num_played++;
1027 mmd->new_vss_status_flags &= (~VSS_NEXT);
1028 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
1029 vsst->map, mmd->size, &vsst->header_buf, &vsst->header_len);
1030 return;
1031 err:
1032 free(mmd->afd.afhi.chunk_table);
1033 if (passed_fd >= 0)
1034 close(passed_fd);
1035 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1036 mmd->new_vss_status_flags = VSS_NEXT;
1037 }
1038
1039 /**
1040 * Main sending function.
1041 *
1042 * This function gets called from vss_post_select(). It checks whether the next
1043 * chunk of data should be pushed out. It obtains a pointer to the data to be
1044 * sent out as well as its length from mmd->afd.afhi. This information is then
1045 * passed to each supported sender's send() function as well as to the send()
1046 * functions of each registered fec client.
1047 */
1048 static void vss_send(struct vss_task *vsst)
1049 {
1050 int i, fec_active = 0;
1051 struct timeval due;
1052 struct fec_client *fc, *tmp_fc;
1053
1054 if (!vsst->map || !vss_playing())
1055 return;
1056 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1057 return;
1058 if (chk_barrier("data send", &vsst->data_send_barrier,
1059 &due, 1) < 0)
1060 return;
1061 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1062 if (fc->state == FEC_STATE_DISABLED)
1063 continue;
1064 if (!next_slice_is_due(fc, NULL)) {
1065 fec_active = 1;
1066 continue;
1067 }
1068 if (compute_next_fec_slice(fc, vsst) <= 0)
1069 continue;
1070 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
1071 fc->current_slice_num, fc->group.slice_bytes);
1072 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1073 fc->group.slice_bytes + FEC_HEADER_SIZE);
1074 fc->current_slice_num++;
1075 fec_active = 1;
1076 }
1077 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1078 if (!fec_active)
1079 mmd->new_vss_status_flags |= VSS_NEXT;
1080 return;
1081 }
1082 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1083 &mmd->stream_start, &due);
1084 if (tv_diff(&due, now, NULL) <= 0) {
1085 char *buf;
1086 size_t len;
1087
1088 if (!mmd->chunks_sent) {
1089 mmd->stream_start = *now;
1090 mmd->events++;
1091 set_mmd_offset();
1092 }
1093 /*
1094 * We call the send function also in case of empty chunks as
1095 * they might have still some data queued which can be sent in
1096 * this case.
1097 */
1098 vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1099 for (i = 0; senders[i].name; i++) {
1100 if (!senders[i].send)
1101 continue;
1102 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1103 buf, len, vsst->header_buf, vsst->header_len);
1104 }
1105 mmd->chunks_sent++;
1106 mmd->current_chunk++;
1107 }
1108 }
1109
1110 static void vss_post_select(struct sched *s, struct task *t)
1111 {
1112 int ret, i;
1113 struct vss_task *vsst = container_of(t, struct vss_task, task);
1114
1115
1116 if (mmd->sender_cmd_data.cmd_num >= 0) {
1117 int num = mmd->sender_cmd_data.cmd_num,
1118 sender_num = mmd->sender_cmd_data.sender_num;
1119
1120 if (senders[sender_num].client_cmds[num]) {
1121 ret = senders[sender_num].client_cmds[num]
1122 (&mmd->sender_cmd_data);
1123 if (ret < 0)
1124 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1125 }
1126 mmd->sender_cmd_data.cmd_num = -1;
1127 }
1128 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1129 recv_afs_result(vsst, &s->rfds);
1130 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1131 PARA_NOTICE_LOG("requesting new fd from afs\n");
1132 ret = send_buffer(vsst->afs_socket, "new");
1133 if (ret < 0)
1134 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1135 else
1136 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1137 }
1138 for (i = 0; senders[i].name; i++) {
1139 if (!senders[i].post_select)
1140 continue;
1141 senders[i].post_select(&s->rfds, &s->wfds);
1142 }
1143 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1144 (vss_next() && vss_playing()))
1145 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1146 vss_send(vsst);
1147 }
1148
1149 /**
1150 * Initialize the virtual streaming system task.
1151 *
1152 * \param afs_socket The fd for communication with afs.
1153 *
1154 * This also initializes all supported senders and starts streaming
1155 * if the --autoplay command line flag was given.
1156 */
1157 void init_vss_task(int afs_socket)
1158 {
1159 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1160 int i;
1161 char *hn = para_hostname(), *home = para_homedir();
1162 long unsigned announce_time = conf.announce_time_arg > 0?
1163 conf.announce_time_arg : 300,
1164 autoplay_delay = conf.autoplay_delay_arg > 0?
1165 conf.autoplay_delay_arg : 0;
1166 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1167 vsst->afs_socket = afs_socket;
1168 vsst->task.pre_select = vss_pre_select;
1169 vsst->task.post_select = vss_post_select;
1170 ms2tv(announce_time, &vsst->announce_tv);
1171 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1172 INIT_LIST_HEAD(&fec_client_list);
1173 for (i = 0; senders[i].name; i++) {
1174 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1175 senders[i].init(&senders[i]);
1176 }
1177 free(hn);
1178 free(home);
1179 mmd->sender_cmd_data.cmd_num = -1;
1180 if (conf.autoplay_given) {
1181 struct timeval tmp;
1182 mmd->vss_status_flags |= VSS_PLAYING;
1183 mmd->new_vss_status_flags |= VSS_PLAYING;
1184 ms2tv(autoplay_delay, &tmp);
1185 tv_add(now, &tmp, &vsst->autoplay_barrier);
1186 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1187 &vsst->data_send_barrier);
1188 }
1189 sprintf(vsst->task.status, "vss task");
1190 register_task(&vsst->task);
1191 }