Merge remote-tracking branch 's/master'
[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 "sched.h"
30 #include "vss.h"
31 #include "ipc.h"
32 #include "fd.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 char *buf;
365 size_t len;
366 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
367
368 if (g->first_chunk == 0) {
369 g->num_chunks = 1;
370 vss_get_chunk(0, vsst, &buf, &len);
371 g->bytes = len;
372 return;
373 }
374
375 g->num_chunks = 0;
376 g->bytes = 0;
377 /*
378 * Include chunks into the group until the group duration is at least
379 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
380 * super frame) is already larger than 150ms, so a FEC group consists
381 * of exactly one chunk for these audio formats.
382 */
383 for (i = 0;; i++) {
384 int chunk_num = g->first_chunk + i;
385
386 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
387 break;
388 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
389 break;
390 vss_get_chunk(chunk_num, vsst, &buf, &len);
391 if (g->bytes + len > max_bytes)
392 break;
393 /* Include this chunk */
394 g->bytes += len;
395 g->num_chunks++;
396 }
397 assert(g->num_chunks);
398 }
399
400 /*
401 * Compute the slice size of the next group.
402 *
403 * The FEC parameters n and k are fixed but the slice size varies per
404 * FEC group. We'd like to choose slices as small as possible to avoid
405 * unnecessary FEC calculations but large enough to guarantee that the
406 * k data slices suffice to encode the header (if needed) and the data
407 * chunk(s).
408 *
409 * Once we know the payload of the next group, we define the number s
410 * of bytes per slice for this group by
411 *
412 * s = ceil(payload / k)
413 *
414 * However, for header streams, computing s is more complicated since no
415 * overlapping of header and data slices is possible. Hence we have k >=
416 * 2 and s must satisfy
417 *
418 * (*) ceil(h / s) + ceil(d / s) <= k
419 *
420 * where h and d are payload of the header and the data chunk(s)
421 * respectively. In general there is no value for s such that (*)
422 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
423 *
424 * We use the following approach for computing a suitable value for s:
425 *
426 * Let
427 * k1 := ceil(k * min(h, d) / (h + d)),
428 * k2 := k - k1.
429 *
430 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
431 *
432 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
433 *
434 * is well-defined. Inequality (*) holds for this value of s since k1
435 * slices suffice to store min(h, d) while k2 slices suffice to store
436 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
437 * second by k2.
438 *
439 * For the above example we obtain
440 *
441 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
442 * s = max(4000 / 5, 5000 / 5) = 1000,
443 *
444 * which is optimal since a slice size of 999 bytes would already require
445 * 11 slices.
446 */
447 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
448 {
449 struct fec_group *g = &fc->group;
450 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
451 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
452 int ret, k1, k2, h, d, min, max, sum;
453 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
454 int max_group_bytes;
455
456 if (!need_audio_header(fc, vsst)) {
457 max_group_bytes = k * max_slice_bytes;
458 g->num_header_slices = 0;
459 compute_group_size(vsst, g, max_group_bytes);
460 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
461 if (g->slice_bytes == 0)
462 g->slice_bytes = 1;
463 return 1;
464 }
465 if (!need_data_slices(fc, vsst)) {
466 g->bytes = 0;
467 g->num_chunks = 0;
468 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
469 g->num_header_slices = k;
470 return 1;
471 }
472 h = vsst->header_len;
473 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
474 * max_slice_bytes;
475 compute_group_size(vsst, g, max_group_bytes);
476 d = g->bytes;
477 if (d == 0) {
478 g->slice_bytes = DIV_ROUND_UP(h, k);
479 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
480 if (ret < 0)
481 return ret;
482 g->num_header_slices = ret;
483 return 1;
484 }
485 min = PARA_MIN(h, d);
486 max = PARA_MAX(h, d);
487 sum = h + d;
488 k1 = DIV_ROUND_UP(k * min, sum);
489 k2 = k - k1;
490 assert(k1 > 0);
491 assert(k2 > 0);
492
493 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
494 /*
495 * This value of s := g->slice_bytes satisfies inequality (*) above,
496 * but it might be larger than max_slice_bytes. However, we know that
497 * max_slice_bytes are sufficient to store header and data, so:
498 */
499 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
500
501 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
502 if (ret < 0)
503 return ret;
504 g->num_header_slices = ret;
505 return 1;
506 }
507
508 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
509 {
510 int ret, i, k, n, data_slices;
511 size_t len;
512 char *buf, *p;
513 struct fec_group *g = &fc->group;
514
515 if (fc->state == FEC_STATE_NONE) {
516 ret = initialize_fec_client(fc, vsst);
517 if (ret < 0)
518 return ret;
519 g->first_chunk = mmd->current_chunk;
520 g->num = 0;
521 g->start = *now;
522 } else {
523 struct timeval tmp;
524 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
525 return 0;
526 /*
527 * Start and duration of this group depend only on the previous
528 * group. Compute the new group start as g->start += g->duration.
529 */
530 tmp = g->start;
531 tv_add(&tmp, &g->duration, &g->start);
532 set_group_timing(fc, vsst);
533 g->first_chunk += g->num_chunks;
534 g->num++;
535 }
536 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
537 n = fc->fcp->slices_per_group + fc->num_extra_slices;
538
539 compute_slice_size(fc, vsst);
540 assert(g->slice_bytes > 0);
541 ret = num_slices(g->bytes, g->slice_bytes, n - k);
542 if (ret < 0)
543 return ret;
544 data_slices = ret;
545 assert(g->num_header_slices + data_slices <= k);
546 fc->current_slice_num = 0;
547 if (g->num == 0)
548 set_group_timing(fc, vsst);
549 /* setup header slices */
550 buf = vsst->header_buf;
551 for (i = 0; i < g->num_header_slices; i++) {
552 uint32_t payload_size;
553 if (buf + g->slice_bytes <= vsst->header_buf + vsst->header_len) {
554 fc->src_data[i] = (const unsigned char *)buf;
555 buf += g->slice_bytes;
556 continue;
557 }
558 /*
559 * Can not use vss->header_buf for this slice as it
560 * goes beyond the buffer. This slice will not be fully
561 * used.
562 */
563 payload_size = vsst->header_buf + vsst->header_len - buf;
564 memcpy(fc->extra_header_buf, buf, payload_size);
565 if (payload_size < g->slice_bytes)
566 memset(fc->extra_header_buf + payload_size, 0,
567 g->slice_bytes - payload_size);
568 fc->src_data[i] = fc->extra_header_buf;
569 assert(i == g->num_header_slices - 1);
570 }
571
572 /*
573 * Setup data slices. Note that for ogg streams chunk 0 points to a
574 * buffer on the heap rather than to the mapped audio file.
575 */
576 vss_get_chunk(g->first_chunk, vsst, &buf, &len);
577 for (p = buf; i < g->num_header_slices + data_slices; i++) {
578 if (p + g->slice_bytes > buf + g->bytes) {
579 /*
580 * We must make a copy for this slice since using p
581 * directly would exceed the buffer.
582 */
583 uint32_t payload_size = buf + g->bytes - p;
584 assert(payload_size + FEC_HEADER_SIZE <= fc->mps);
585 memcpy(fc->extra_src_buf, p, payload_size);
586 if (payload_size < g->slice_bytes)
587 memset(fc->extra_src_buf + payload_size, 0,
588 g->slice_bytes - payload_size);
589 fc->src_data[i] = fc->extra_src_buf;
590 i++;
591 break;
592 }
593 fc->src_data[i] = (const unsigned char *)p;
594 p += g->slice_bytes;
595 }
596 if (i < k) {
597 /* use arbitrary data for all remaining slices */
598 buf = vsst->map;
599 for (; i < k; i++)
600 fc->src_data[i] = (const unsigned char *)buf;
601 }
602 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
603 g->num, g->num_chunks, g->first_chunk,
604 g->first_chunk + g->num_chunks - 1, g->bytes
605 );
606 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
607 g->slice_bytes, g->num_header_slices, data_slices
608 );
609 return 1;
610 }
611
612 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
613 {
614 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
615 == fc->fcp->slices_per_group + fc->num_extra_slices) {
616 int ret = setup_next_fec_group(fc, vsst);
617 if (ret == 0)
618 return 0;
619 if (ret < 0) {
620 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
621 PARA_ERROR_LOG("FEC client temporarily disabled\n");
622 fc->state = FEC_STATE_DISABLED;
623 return ret;
624 }
625 }
626 write_fec_header(fc, vsst);
627 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
628 fc->current_slice_num, fc->group.slice_bytes);
629 return 1;
630 }
631
632 /**
633 * Return a buffer that marks the end of the stream.
634 *
635 * \param buf Result pointer.
636 * \return The length of the eof buffer.
637 *
638 * This is used for (multicast) udp streaming where closing the socket on the
639 * sender might not give rise to an eof condition at the peer.
640 */
641 size_t vss_get_fec_eof_packet(const char **buf)
642 {
643 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
644 *buf = fec_eof_packet;
645 return FEC_HEADER_SIZE;
646 }
647
648 /**
649 * Add one entry to the list of active fec clients.
650 *
651 * \param sc Generic sender_client data of the transport layer.
652 * \param fcp FEC parameters as supplied by the transport layer.
653 *
654 * \return Newly allocated fec_client struct.
655 */
656 struct fec_client *vss_add_fec_client(struct sender_client *sc,
657 struct fec_client_parms *fcp)
658 {
659 struct fec_client *fc = para_calloc(sizeof(*fc));
660
661 fc->sc = sc;
662 fc->fcp = fcp;
663 para_list_add(&fc->node, &fec_client_list);
664 return fc;
665 }
666
667 /**
668 * Remove one entry from the list of active fec clients.
669 *
670 * \param fc The client to be removed.
671 */
672 void vss_del_fec_client(struct fec_client *fc)
673 {
674 list_del(&fc->node);
675 free(fc->src_data);
676 free(fc->enc_buf);
677 free(fc->extra_src_buf);
678 free(fc->extra_header_buf);
679 fec_free(fc->parms);
680 free(fc);
681 }
682
683 /*
684 * Compute if/when next slice is due. If it isn't due yet and \a diff is
685 * not \p Null, compute the time difference next - now, where
686 *
687 * next = stream_start + (first_group_chunk - first_stream_chunk)
688 * * chunk_time + slice_num * slice_time
689 */
690 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
691 {
692 struct timeval tmp, next;
693 int ret;
694
695 if (fc->state == FEC_STATE_NONE)
696 return 1;
697 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
698 tv_add(&tmp, &fc->group.start, &next);
699 ret = tv_diff(&next, now, diff);
700 return ret < 0? 1 : 0;
701 }
702
703 static void set_eof_barrier(struct vss_task *vsst)
704 {
705 struct fec_client *fc;
706 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
707
708 if (!chunk_tv)
709 goto out;
710 list_for_each_entry(fc, &fec_client_list, node) {
711 struct timeval group_duration;
712
713 if (fc->state != FEC_STATE_READY_TO_RUN)
714 continue;
715 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
716 if (tv_diff(&timeout, &group_duration, NULL) < 0)
717 timeout = group_duration;
718 }
719 out:
720 tv_add(now, &timeout, &vsst->eof_barrier);
721 }
722
723 /**
724 * Check if vss status flag \a P (playing) is set.
725 *
726 * \return Greater than zero if playing, zero otherwise.
727 *
728 */
729 unsigned int vss_playing(void)
730 {
731 return mmd->new_vss_status_flags & VSS_PLAYING;
732 }
733
734 /**
735 * Check if the \a N (next) status flag is set.
736 *
737 * \return Greater than zero if set, zero if not.
738 *
739 */
740 unsigned int vss_next(void)
741 {
742 return mmd->new_vss_status_flags & VSS_NEXT;
743 }
744
745 /**
746 * Check if a reposition request is pending.
747 *
748 * \return Greater than zero if true, zero otherwise.
749 *
750 */
751 unsigned int vss_repos(void)
752 {
753 return mmd->new_vss_status_flags & VSS_REPOS;
754 }
755
756 /**
757 * Check if the vss is currently paused.
758 *
759 * \return Greater than zero if paused, zero otherwise.
760 *
761 */
762 unsigned int vss_paused(void)
763 {
764 return !(mmd->new_vss_status_flags & VSS_NEXT)
765 && !(mmd->new_vss_status_flags & VSS_PLAYING);
766 }
767
768 /**
769 * Check if the vss is currently stopped.
770 *
771 * \return Greater than zero if paused, zero otherwise.
772 *
773 */
774 unsigned int vss_stopped(void)
775 {
776 return (mmd->new_vss_status_flags & VSS_NEXT)
777 && !(mmd->new_vss_status_flags & VSS_PLAYING);
778 }
779
780 static int chk_barrier(const char *bname, const struct timeval *barrier,
781 struct timeval *diff, int print_log)
782 {
783 long ms;
784
785 if (tv_diff(now, barrier, diff) > 0)
786 return 1;
787 ms = tv2ms(diff);
788 if (print_log && ms)
789 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
790 return -1;
791 }
792
793 static void vss_compute_timeout(struct sched *s, struct vss_task *vsst)
794 {
795 struct timeval tv;
796 struct fec_client *fc;
797
798 if (!vss_playing() || !vsst->map)
799 return;
800 if (vss_next() && vsst->map) /* only sleep a bit, nec*/
801 return sched_request_timeout_ms(100, s);
802
803 /* Each of these barriers must have passed until we may proceed */
804 if (sched_request_barrier(&vsst->autoplay_barrier, s) == 1)
805 return;
806 if (sched_request_barrier(&vsst->eof_barrier, s) == 1)
807 return;
808 if (sched_request_barrier(&vsst->data_send_barrier, s) == 1)
809 return;
810 /*
811 * Compute the select timeout as the minimal time until the next
812 * chunk/slice is due for any client.
813 */
814 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
815 &mmd->stream_start, &tv);
816 if (sched_request_barrier_or_min_delay(&tv, s) == 0)
817 return;
818 list_for_each_entry(fc, &fec_client_list, node) {
819 if (fc->state != FEC_STATE_READY_TO_RUN)
820 continue;
821 if (next_slice_is_due(fc, &tv))
822 return sched_min_delay(s);
823 sched_request_timeout(&tv, s);
824 }
825 }
826
827 static void vss_eof(struct vss_task *vsst)
828 {
829
830 if (!vsst->map)
831 return;
832 if (mmd->new_vss_status_flags & VSS_NOMORE)
833 mmd->new_vss_status_flags = VSS_NEXT;
834 set_eof_barrier(vsst);
835 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
836 vsst->header_buf = NULL;
837 para_munmap(vsst->map, mmd->size);
838 vsst->map = NULL;
839 mmd->chunks_sent = 0;
840 //mmd->offset = 0;
841 mmd->afd.afhi.seconds_total = 0;
842 mmd->afd.afhi.chunk_tv.tv_sec = 0;
843 mmd->afd.afhi.chunk_tv.tv_usec = 0;
844 free(mmd->afd.afhi.chunk_table);
845 mmd->afd.afhi.chunk_table = NULL;
846 mmd->mtime = 0;
847 mmd->size = 0;
848 mmd->events++;
849 }
850
851 static int need_to_request_new_audio_file(struct vss_task *vsst)
852 {
853 struct timeval diff;
854
855 if (vsst->map) /* have audio file */
856 return 0;
857 if (!vss_playing()) /* don't need one */
858 return 0;
859 if (mmd->new_vss_status_flags & VSS_NOMORE)
860 return 0;
861 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
862 return 0;
863 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
864 &diff, 1) < 0)
865 return 0;
866 return 1;
867 }
868
869 static void set_mmd_offset(void)
870 {
871 struct timeval offset;
872 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
873 mmd->offset = tv2ms(&offset);
874 }
875
876 /**
877 * Compute the timeout for the main select-loop of the scheduler.
878 *
879 * \param s Pointer to the server scheduler.
880 * \param t Pointer to the vss task structure.
881 *
882 * Before the timeout is computed, the current vss status flags are evaluated
883 * and acted upon by calling appropriate functions from the lower layers.
884 * Possible actions include
885 *
886 * - request a new audio file from afs,
887 * - shutdown of all senders (stop/pause command),
888 * - reposition the stream (ff/jmp command).
889 */
890 static void vss_pre_select(struct sched *s, struct task *t)
891 {
892 int i;
893 struct vss_task *vsst = container_of(t, struct vss_task, task);
894
895 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
896 struct fec_client *fc, *tmp;
897 for (i = 0; senders[i].name; i++)
898 if (senders[i].shutdown_clients)
899 senders[i].shutdown_clients();
900 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
901 fc->state = FEC_STATE_NONE;
902 mmd->stream_start.tv_sec = 0;
903 mmd->stream_start.tv_usec = 0;
904 }
905 if (vss_next())
906 vss_eof(vsst);
907 else if (vss_paused()) {
908 if (mmd->chunks_sent)
909 set_eof_barrier(vsst);
910 mmd->chunks_sent = 0;
911 } else if (vss_repos()) {
912 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
913 set_eof_barrier(vsst);
914 mmd->chunks_sent = 0;
915 mmd->current_chunk = mmd->repos_request;
916 mmd->new_vss_status_flags &= ~VSS_REPOS;
917 set_mmd_offset();
918 }
919 if (need_to_request_new_audio_file(vsst)) {
920 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
921 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
922 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
923 } else
924 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
925 for (i = 0; senders[i].name; i++) {
926 if (!senders[i].pre_select)
927 continue;
928 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
929 }
930 vss_compute_timeout(s, vsst);
931 }
932
933 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
934 {
935 char control[255], buf[8];
936 struct msghdr msg = {.msg_iov = NULL};
937 struct cmsghdr *cmsg;
938 struct iovec iov;
939 int ret = 0;
940
941 *fd = -1;
942 iov.iov_base = buf;
943 iov.iov_len = sizeof(buf);
944 msg.msg_iov = &iov;
945 msg.msg_iovlen = 1;
946 msg.msg_control = control;
947 msg.msg_controllen = sizeof(control);
948 memset(buf, 0, sizeof(buf));
949 ret = recvmsg(afs_socket, &msg, 0);
950 if (ret < 0)
951 return -ERRNO_TO_PARA_ERROR(errno);
952 if (iov.iov_len != sizeof(buf))
953 return -E_AFS_SHORT_READ;
954 *code = *(uint32_t*)buf;
955 *data = *(uint32_t*)(buf + 4);
956 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
957 if (cmsg->cmsg_level != SOL_SOCKET
958 || cmsg->cmsg_type != SCM_RIGHTS)
959 continue;
960 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
961 continue;
962 *fd = *(int *)CMSG_DATA(cmsg);
963 }
964 return 1;
965 }
966
967 #ifndef MAP_POPULATE
968 #define MAP_POPULATE 0
969 #endif
970
971 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
972 {
973 int ret, passed_fd, shmid;
974 uint32_t afs_code = 0, afs_data = 0;
975 struct stat statbuf;
976
977 if (!FD_ISSET(vsst->afs_socket, rfds))
978 return;
979 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
980 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
981 return;
982 if (ret < 0)
983 goto err;
984 vsst->afsss = AFS_SOCKET_READY;
985 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
986 afs_data);
987 ret = -E_NOFD;
988 if (afs_code != NEXT_AUDIO_FILE)
989 goto err;
990 if (passed_fd < 0)
991 goto err;
992 shmid = afs_data;
993 ret = load_afd(shmid, &mmd->afd);
994 if (ret < 0)
995 goto err;
996 shm_destroy(shmid);
997 ret = fstat(passed_fd, &statbuf);
998 if (ret < 0) {
999 PARA_ERROR_LOG("fstat error:\n");
1000 ret = -ERRNO_TO_PARA_ERROR(errno);
1001 goto err;
1002 }
1003 mmd->size = statbuf.st_size;
1004 mmd->mtime = statbuf.st_mtime;
1005 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
1006 passed_fd, 0, &vsst->map);
1007 if (ret < 0)
1008 goto err;
1009 close(passed_fd);
1010 mmd->chunks_sent = 0;
1011 mmd->current_chunk = 0;
1012 mmd->offset = 0;
1013 mmd->events++;
1014 mmd->num_played++;
1015 mmd->new_vss_status_flags &= (~VSS_NEXT);
1016 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
1017 vsst->map, mmd->size, &vsst->header_buf, &vsst->header_len);
1018 return;
1019 err:
1020 free(mmd->afd.afhi.chunk_table);
1021 if (passed_fd >= 0)
1022 close(passed_fd);
1023 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1024 mmd->new_vss_status_flags = VSS_NEXT;
1025 }
1026
1027 /**
1028 * Main sending function.
1029 *
1030 * This function gets called from vss_post_select(). It checks whether the next
1031 * chunk of data should be pushed out. It obtains a pointer to the data to be
1032 * sent out as well as its length from mmd->afd.afhi. This information is then
1033 * passed to each supported sender's send() function as well as to the send()
1034 * functions of each registered fec client.
1035 */
1036 static void vss_send(struct vss_task *vsst)
1037 {
1038 int i, fec_active = 0;
1039 struct timeval due;
1040 struct fec_client *fc, *tmp_fc;
1041
1042 if (!vsst->map || !vss_playing())
1043 return;
1044 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1045 return;
1046 if (chk_barrier("data send", &vsst->data_send_barrier,
1047 &due, 1) < 0)
1048 return;
1049 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1050 if (fc->state == FEC_STATE_DISABLED)
1051 continue;
1052 if (!next_slice_is_due(fc, NULL)) {
1053 fec_active = 1;
1054 continue;
1055 }
1056 if (compute_next_fec_slice(fc, vsst) <= 0)
1057 continue;
1058 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
1059 fc->current_slice_num, fc->group.slice_bytes);
1060 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1061 fc->group.slice_bytes + FEC_HEADER_SIZE);
1062 fc->current_slice_num++;
1063 fec_active = 1;
1064 }
1065 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1066 if (!fec_active)
1067 mmd->new_vss_status_flags |= VSS_NEXT;
1068 return;
1069 }
1070 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1071 &mmd->stream_start, &due);
1072 if (tv_diff(&due, now, NULL) <= 0) {
1073 char *buf;
1074 size_t len;
1075
1076 if (!mmd->chunks_sent) {
1077 mmd->stream_start = *now;
1078 mmd->events++;
1079 set_mmd_offset();
1080 }
1081 /*
1082 * We call the send function also in case of empty chunks as
1083 * they might have still some data queued which can be sent in
1084 * this case.
1085 */
1086 vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1087 for (i = 0; senders[i].name; i++) {
1088 if (!senders[i].send)
1089 continue;
1090 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1091 buf, len, vsst->header_buf, vsst->header_len);
1092 }
1093 /*
1094 * Prefault next chunk(s)
1095 *
1096 * If the backing device of the memory-mapped audio file is
1097 * slow and read-ahead is turned off or prevented for some
1098 * reason, e.g. due to memory pressure, it may take much longer
1099 * than the chunk interval to get the next chunk on the wire,
1100 * causing buffer underruns on the client side. Mapping the
1101 * file with MAP_POPULATE seems to help a bit, but it does not
1102 * eliminate the delays completely. Moreover, it is supported
1103 * only on Linux. So we do our own read-ahead here.
1104 */
1105 if (mmd->current_chunk > 0) { /* chunk 0 might be on the heap */
1106 buf += len;
1107 for (i = 0; i < 5 && buf < vsst->map + mmd->size; i++) {
1108 __a_unused volatile char x = *buf;
1109 buf += 4096;
1110 }
1111 }
1112 mmd->chunks_sent++;
1113 mmd->current_chunk++;
1114 }
1115 }
1116
1117 static void vss_post_select(struct sched *s, struct task *t)
1118 {
1119 int ret, i;
1120 struct vss_task *vsst = container_of(t, struct vss_task, task);
1121
1122
1123 if (mmd->sender_cmd_data.cmd_num >= 0) {
1124 int num = mmd->sender_cmd_data.cmd_num,
1125 sender_num = mmd->sender_cmd_data.sender_num;
1126
1127 if (senders[sender_num].client_cmds[num]) {
1128 ret = senders[sender_num].client_cmds[num]
1129 (&mmd->sender_cmd_data);
1130 if (ret < 0)
1131 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1132 }
1133 mmd->sender_cmd_data.cmd_num = -1;
1134 }
1135 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1136 recv_afs_result(vsst, &s->rfds);
1137 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1138 PARA_NOTICE_LOG("requesting new fd from afs\n");
1139 ret = send_buffer(vsst->afs_socket, "new");
1140 if (ret < 0)
1141 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1142 else
1143 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1144 }
1145 for (i = 0; senders[i].name; i++) {
1146 if (!senders[i].post_select)
1147 continue;
1148 senders[i].post_select(&s->rfds, &s->wfds);
1149 }
1150 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1151 (vss_next() && vss_playing()))
1152 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1153 vss_send(vsst);
1154 }
1155
1156 /**
1157 * Initialize the virtual streaming system task.
1158 *
1159 * \param afs_socket The fd for communication with afs.
1160 * \param s The scheduler to register the vss task to.
1161 *
1162 * This also initializes all supported senders and starts streaming
1163 * if the --autoplay command line flag was given.
1164 */
1165 void init_vss_task(int afs_socket, struct sched *s)
1166 {
1167 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1168 int i;
1169 char *hn = para_hostname(), *home = para_homedir();
1170 long unsigned announce_time = conf.announce_time_arg > 0?
1171 conf.announce_time_arg : 300,
1172 autoplay_delay = conf.autoplay_delay_arg > 0?
1173 conf.autoplay_delay_arg : 0;
1174 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1175 vsst->afs_socket = afs_socket;
1176 vsst->task.pre_select = vss_pre_select;
1177 vsst->task.post_select = vss_post_select;
1178 ms2tv(announce_time, &vsst->announce_tv);
1179 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1180 INIT_LIST_HEAD(&fec_client_list);
1181 for (i = 0; senders[i].name; i++) {
1182 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1183 senders[i].init(&senders[i]);
1184 }
1185 free(hn);
1186 free(home);
1187 mmd->sender_cmd_data.cmd_num = -1;
1188 if (conf.autoplay_given) {
1189 struct timeval tmp;
1190 mmd->vss_status_flags |= VSS_PLAYING;
1191 mmd->new_vss_status_flags |= VSS_PLAYING;
1192 ms2tv(autoplay_delay, &tmp);
1193 tv_add(now, &tmp, &vsst->autoplay_barrier);
1194 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1195 &vsst->data_send_barrier);
1196 }
1197 sprintf(vsst->task.status, "vss task");
1198 register_task(s, &vsst->task);
1199 }