vss_preselect(): Use single return.
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997-2008 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 <sys/mman.h> /* mmap */
15 #include <sys/time.h> /* gettimeofday */
16 #include <sys/types.h>
17 #include <dirent.h>
18
19 #include "para.h"
20 #include "error.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 "vss.h"
28 #include "list.h"
29 #include "send.h"
30 #include "ipc.h"
31 #include "fd.h"
32
33 static struct timeval announce_tv;
34 static struct timeval data_send_barrier;
35 static struct timeval eof_barrier;
36 static struct timeval autoplay_barrier;
37
38 extern struct misc_meta_data *mmd;
39 extern struct sender senders[];
40
41 static char *map;
42
43 /**
44 * Check if vss status flag \a P (playing) is set.
45 *
46 * \return Greater than zero if playing, zero otherwise.
47 *
48 */
49 unsigned int vss_playing(void)
50 {
51 return mmd->new_vss_status_flags & VSS_PLAYING;
52 }
53
54 /**
55 * Check if the \a N (next) status flag is set.
56 *
57 * \return Greater than zero if set, zero if not.
58 *
59 */
60 unsigned int vss_next(void)
61 {
62 return mmd->new_vss_status_flags & VSS_NEXT;
63 }
64
65 /**
66 * Check if a reposition request is pending.
67 *
68 * \return Greater than zero if true, zero otherwise.
69 *
70 */
71 unsigned int vss_repos(void)
72 {
73 return mmd->new_vss_status_flags & VSS_REPOS;
74 }
75
76 /**
77 * Check if the vss is currently paused.
78 *
79 * \return Greater than zero if paused, zero otherwise.
80 *
81 */
82 unsigned int vss_paused(void)
83 {
84 return !(mmd->new_vss_status_flags & VSS_NEXT)
85 && !(mmd->new_vss_status_flags & VSS_PLAYING);
86 }
87
88 /**
89 * Check if the vss is currently stopped.
90 *
91 * \return Greater than zero if paused, zero otherwise.
92 *
93 */
94 unsigned int vss_stopped(void)
95 {
96 return (mmd->new_vss_status_flags & VSS_NEXT)
97 && !(mmd->new_vss_status_flags & VSS_PLAYING);
98 }
99
100 /**
101 * Initialize the virtual streaming system.
102 *
103 * This also initializes all supported senders and starts streaming
104 * if the --autoplay command line flag was given.
105 */
106 void vss_init(void)
107 {
108 int i;
109 char *hn = para_hostname(), *home = para_homedir();
110 long unsigned announce_time = conf.announce_time_arg > 0?
111 conf.announce_time_arg : 300,
112 autoplay_delay = conf.autoplay_delay_arg > 0?
113 conf.autoplay_delay_arg : 0;
114 ms2tv(announce_time, &announce_tv);
115 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&announce_tv));
116 for (i = 0; senders[i].name; i++) {
117 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
118 senders[i].init(&senders[i]);
119 }
120 free(hn);
121 free(home);
122 if (conf.autoplay_given) {
123 struct timeval now, tmp;
124 mmd->vss_status_flags |= VSS_PLAYING;
125 mmd->new_vss_status_flags |= VSS_PLAYING;
126 gettimeofday(&now, NULL);
127 ms2tv(autoplay_delay, &tmp);
128 tv_add(&now, &tmp, &autoplay_barrier);
129 }
130 }
131
132 static int chk_barrier(const char *bname, const struct timeval *now,
133 const struct timeval *barrier, struct timeval *diff,
134 int print_log)
135 {
136 long ms;
137
138 if (tv_diff(now, barrier, diff) > 0)
139 return 1;
140 ms = tv2ms(diff);
141 if (print_log && ms)
142 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
143 return -1;
144 }
145
146 /*
147 * != NULL: timeout for next chunk
148 * NULL: nothing to do
149 */
150 static struct timeval *vss_compute_timeout(void)
151 {
152 static struct timeval the_timeout;
153 struct timeval now, next_chunk;
154
155 if (vss_next() && map) {
156 /* only sleep a bit, nec*/
157 the_timeout.tv_sec = 0;
158 the_timeout.tv_usec = 100;
159 return &the_timeout;
160 }
161 gettimeofday(&now, NULL);
162 if (chk_barrier("autoplay_delay", &now, &autoplay_barrier,
163 &the_timeout, 1) < 0)
164 return &the_timeout;
165 if (chk_barrier("eof", &now, &eof_barrier, &the_timeout, 1) < 0)
166 return &the_timeout;
167 if (chk_barrier("data send", &now, &data_send_barrier,
168 &the_timeout, 1) < 0)
169 return &the_timeout;
170 if (!vss_playing() || !map)
171 return NULL;
172 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
173 &mmd->stream_start, &next_chunk);
174 if (chk_barrier("chunk", &now, &next_chunk, &the_timeout, 0) < 0)
175 return &the_timeout;
176 /* chunk is due or bof */
177 the_timeout.tv_sec = 0;
178 the_timeout.tv_usec = 0;
179 return &the_timeout;
180 }
181
182 static void vss_eof(void)
183 {
184 struct timeval now;
185 int i;
186 char *tmp;
187
188 if (!map) {
189 for (i = 0; senders[i].name; i++)
190 senders[i].shutdown_clients();
191 return;
192 }
193 if (mmd->new_vss_status_flags & VSS_NOMORE)
194 mmd->new_vss_status_flags = VSS_NEXT;
195 gettimeofday(&now, NULL);
196 tv_add(&mmd->afd.afhi.eof_tv, &now, &eof_barrier);
197 munmap(map, mmd->size);
198 map = NULL;
199 mmd->chunks_sent = 0;
200 mmd->offset = 0;
201 mmd->afd.afhi.seconds_total = 0;
202 free(mmd->afd.afhi.chunk_table);
203 mmd->afd.afhi.chunk_table = NULL;
204 tmp = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_AUDIO_FILE_INFO],
205 status_item_list[SI_TAGINFO1], status_item_list[SI_TAGINFO2]);
206 strncpy(mmd->afd.afhi.info_string, tmp, sizeof(mmd->afd.afhi.info_string));
207 mmd->afd.afhi.info_string[sizeof(mmd->afd.afhi.info_string) - 1] = '\0';
208 make_empty_status_items(mmd->afd.verbose_ls_output);
209 free(tmp);
210 mmd->mtime = 0;
211 mmd->size = 0;
212 mmd->events++;
213 }
214
215 /**
216 * Get the header of the current audio file.
217 *
218 * \param buf The length of the header is stored here.
219 * \param len Points to a buffer containing the header on return.
220 *
221 * \sa afh_get_header.
222 */
223 void vss_get_header(char **buf, size_t *len)
224 {
225 afh_get_header(&mmd->afd.afhi, map, buf, len);
226 }
227
228 /**
229 * Get the list of all supported audio formats.
230 *
231 * \return Aa space separated list of all supported audio formats
232 * It is not allocated at runtime, i.e. there is no need to free
233 * the returned string in the caller.
234 */
235 const char *supported_audio_formats(void)
236 {
237 return SUPPORTED_AUDIO_FORMATS;
238 }
239
240 /**
241 * Get the chunk time of the current audio file.
242 *
243 * \return A pointer to a struct containing the chunk time, or NULL,
244 * if currently no audio file is selected.
245 */
246 struct timeval *vss_chunk_time(void)
247 {
248 if (!map)
249 return NULL;
250 return &mmd->afd.afhi.chunk_tv;
251 }
252
253 /** The possible states of the afs socket. See \ref afs_socket. */
254 enum afs_socket_status {
255 /** Socket is inactive. */
256 AFS_SOCKET_READY,
257 /** Socket fd was included in the write fd set for select(). */
258 AFS_SOCKET_CHECK_FOR_WRITE,
259 /** vss wrote a request to the socket and waits for afs to reply. */
260 AFS_SOCKET_AFD_PENDING
261 };
262
263 static enum afs_socket_status afsss;
264
265 /**
266 * Compute the timeout for para_server's main select-loop.
267 *
268 * This function gets called from para_server to determine the timeout value
269 * for its main select loop.
270 *
271 * \param rfds The set of file descriptors to be checked for reading.
272 * \param wfds The set of file descriptors to be checked for writing.
273 * \param max_fileno The highest-numbered file descriptor.
274 *
275 * Before the timeout is computed, the current vss status flags are evaluated
276 * and acted upon by calling appropriate functions from the lower layers.
277 * Possible actions include
278 *
279 * - request a new audio file from afs,
280 * - shutdown of all senders (stop/pause command),
281 * - reposition the stream (ff/jmp command).
282 *
283 * \return A pointer to a struct timeval containing the timeout for the next
284 * chunk of data to be sent, or NULL if we're not sending right now.
285 */
286 struct timeval *vss_preselect(fd_set *rfds, fd_set *wfds, int *max_fileno)
287 {
288 int i;
289 struct timeval *tv;
290
291 para_fd_set(afs_socket, rfds, max_fileno);
292 if (!map)
293 for (i = 0; senders[i].name; i++)
294 senders[i].shutdown_clients();
295 else {
296 if (vss_next()) {
297 vss_eof();
298 tv = vss_compute_timeout();
299 goto out;
300 }
301 }
302 if (vss_paused() || vss_repos()) {
303 for (i = 0; senders[i].name; i++)
304 senders[i].shutdown_clients();
305 if (map) {
306 struct timeval now;
307 gettimeofday(&now, NULL);
308 if (!vss_paused() || mmd->chunks_sent)
309 tv_add(&mmd->afd.afhi.eof_tv, &now, &eof_barrier);
310 if (vss_repos())
311 tv_add(&now, &announce_tv, &data_send_barrier);
312 }
313 mmd->chunks_sent = 0;
314 }
315 if (vss_repos()) {
316 mmd->new_vss_status_flags &= ~(VSS_REPOS);
317 mmd->current_chunk = mmd->repos_request;
318 }
319 tv = vss_compute_timeout();
320 if (tv)
321 goto out;
322 if (!map && vss_playing() &&
323 !(mmd->new_vss_status_flags & VSS_NOMORE)) {
324 if (afsss == AFS_SOCKET_READY ||
325 afsss == AFS_SOCKET_CHECK_FOR_WRITE) {
326 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
327 para_fd_set(afs_socket, wfds, max_fileno);
328 afsss = AFS_SOCKET_CHECK_FOR_WRITE;
329 }
330 }
331 out:
332 return tv;
333 }
334
335 static int recv_afs_msg(int *fd, uint32_t *code, uint32_t *data)
336 {
337 char control[255], buf[8];
338 struct msghdr msg = {.msg_iov = NULL};
339 struct cmsghdr *cmsg;
340 struct iovec iov;
341 int ret = 0;
342
343 *fd = -1;
344 iov.iov_base = buf;
345 iov.iov_len = sizeof(buf);
346 msg.msg_iov = &iov;
347 msg.msg_iovlen = 1;
348 msg.msg_control = control;
349 msg.msg_controllen = sizeof(control);
350 memset(buf, 0, sizeof(buf));
351 ret = recvmsg(afs_socket, &msg, 0);
352 if (ret < 0)
353 return -ERRNO_TO_PARA_ERROR(errno);
354 afsss = AFS_SOCKET_READY;
355 if (iov.iov_len != sizeof(buf))
356 return -E_AFS_SHORT_READ;
357 *code = *(uint32_t*)buf;
358 *data = *(uint32_t*)(buf + 4);
359 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
360 if (cmsg->cmsg_level != SOL_SOCKET
361 || cmsg->cmsg_type != SCM_RIGHTS)
362 continue;
363 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
364 continue;
365 *fd = *(int *)CMSG_DATA(cmsg);
366 }
367 return 1;
368 }
369
370 static void recv_afs_result(void)
371 {
372 int ret, passed_fd, shmid;
373 uint32_t afs_code = 0, afs_data = 0;
374 struct stat statbuf;
375 struct timeval now;
376
377 mmd->afd.afhi.chunk_table = NULL;
378 ret = recv_afs_msg(&passed_fd, &afs_code, &afs_data);
379 if (ret < 0)
380 goto err;
381 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
382 afs_data);
383 ret = -E_NOFD;
384 if (afs_code != NEXT_AUDIO_FILE)
385 goto err;
386 if (passed_fd < 0)
387 goto err;
388 shmid = afs_data;
389 ret = load_afd(shmid, &mmd->afd);
390 if (ret < 0)
391 goto err;
392 shm_destroy(shmid);
393 ret = fstat(passed_fd, &statbuf);
394 if (ret < 0) {
395 PARA_ERROR_LOG("fstat error:\n");
396 ret = -ERRNO_TO_PARA_ERROR(errno);
397 goto err;
398 }
399 mmd->size = statbuf.st_size;
400 mmd->mtime = statbuf.st_mtime;
401 map = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE,
402 passed_fd, 0);
403 close(passed_fd);
404 mmd->chunks_sent = 0;
405 mmd->current_chunk = 0;
406 mmd->offset = 0;
407 mmd->events++;
408 mmd->num_played++;
409 mmd->new_vss_status_flags &= (~VSS_NEXT);
410 gettimeofday(&now, NULL);
411 tv_add(&now, &announce_tv, &data_send_barrier);
412 return;
413 err:
414 free(mmd->afd.afhi.chunk_table);
415 if (passed_fd >= 0)
416 close(passed_fd);
417 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
418 mmd->new_vss_status_flags = VSS_NEXT;
419 }
420
421 void vss_post_select(fd_set *rfds, fd_set *wfds)
422 {
423 int ret;
424
425 if (FD_ISSET(afs_socket, rfds))
426 recv_afs_result();
427 if (afsss != AFS_SOCKET_CHECK_FOR_WRITE || !FD_ISSET(afs_socket, wfds))
428 return;
429 PARA_NOTICE_LOG("requesting new fd from afs\n");
430 ret = send_buffer(afs_socket, "new");
431 afsss = AFS_SOCKET_AFD_PENDING;
432 }
433 /**
434 * Get the data of the given chunk.
435 *
436 * \param chunk_num The number of the desired chunk.
437 * \param buf Chunk data.
438 * \param len Chunk length in bytes.
439 *
440 * \return Standard.
441 */
442 int vss_get_chunk(long unsigned chunk_num, char **buf, size_t *len)
443 {
444 if (!map || !vss_playing())
445 return -E_CHUNK;
446 if (chunk_num >= mmd->afd.afhi.chunks_total)
447 return -E_CHUNK;
448 afh_get_chunk(chunk_num, &mmd->afd.afhi, map, buf, len);
449 return 1;
450 }
451
452 /**
453 * Main sending function.
454 *
455 * This function gets called from para_server as soon as the next chunk of data
456 * should be pushed out. It obtains a pointer to the data to be sent out as
457 * well as its length from mmd->afd.afhi. This information is then passed to
458 * each supported sender's send() function which is supposed to send out the data
459 * to all connected clients.
460 */
461 void vss_send_chunk(void)
462 {
463 int i;
464 struct timeval now, due;
465 char *buf;
466 size_t len;
467
468 if (!map || !vss_playing())
469 return;
470 gettimeofday(&now, NULL);
471 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
472 &mmd->stream_start, &due);
473 if (tv_diff(&due, &now, NULL) > 0)
474 return;
475 if (chk_barrier("eof", &now, &eof_barrier, &due, 1) < 0)
476 return;
477 if (chk_barrier("data send", &now, &data_send_barrier,
478 &due, 1) < 0)
479 return;
480 mmd->new_vss_status_flags &= ~VSS_REPOS;
481 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
482 mmd->new_vss_status_flags |= VSS_NEXT;
483 return vss_eof();
484 }
485 /*
486 * We call the send function also in case of empty chunks as they
487 * might have still some data queued which can be sent in this case.
488 */
489 if (!mmd->chunks_sent) {
490 struct timeval tmp;
491 gettimeofday(&mmd->stream_start, NULL);
492 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &tmp);
493 mmd->offset = tv2ms(&tmp);
494 mmd->events++;
495 }
496 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, map, &buf, &len);
497 for (i = 0; senders[i].name; i++)
498 senders[i].send(mmd->current_chunk, mmd->chunks_sent, buf, len);
499 mmd->new_vss_status_flags |= VSS_PLAYING;
500 mmd->chunks_sent++;
501 mmd->current_chunk++;
502 }