| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: au.c,v 1.1 2002/02/02 19:16:28 mdw Exp $ |
| 4 | * |
| 5 | * High-level audio subsystem |
| 6 | * |
| 7 | * (c) 2002 Mark Wooding |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of Jog: Programming for a jogging machine. |
| 13 | * |
| 14 | * Jog is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * Jog is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with Jog; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: au.c,v $ |
| 32 | * Revision 1.1 2002/02/02 19:16:28 mdw |
| 33 | * New audio subsystem. |
| 34 | * |
| 35 | */ |
| 36 | |
| 37 | /*----- Header files ------------------------------------------------------*/ |
| 38 | |
| 39 | #ifdef HAVE_CONFIG_H |
| 40 | # include "config.h" |
| 41 | #endif |
| 42 | |
| 43 | #include <assert.h> |
| 44 | #include <errno.h> |
| 45 | #include <stdio.h> |
| 46 | #include <stdlib.h> |
| 47 | #include <string.h> |
| 48 | |
| 49 | #include <sys/types.h> |
| 50 | #include <unistd.h> |
| 51 | #include <sys/stat.h> |
| 52 | #include <fcntl.h> |
| 53 | |
| 54 | #include <mLib/alloc.h> |
| 55 | #include <mLib/dstr.h> |
| 56 | #include <mLib/sub.h> |
| 57 | #include <mLib/sym.h> |
| 58 | #include <mLib/trace.h> |
| 59 | |
| 60 | #include "au.h" |
| 61 | #include "ausys.h" |
| 62 | #include "err.h" |
| 63 | #include "jog.h" |
| 64 | |
| 65 | /*----- Static variables --------------------------------------------------*/ |
| 66 | |
| 67 | static unsigned au_flags = 0; |
| 68 | static sym_table au_tab; /* Sample cache, by name */ |
| 69 | static const char *au_dir = AUDIODIR; /* Directory containing samples */ |
| 70 | static struct { au_data *next, *prev; } au_spare; /* Lists for sample data */ |
| 71 | static size_t au_sz, au_max; /* Size of cached samples */ |
| 72 | |
| 73 | #define AU_SPARE ((au_data*)&au_spare) |
| 74 | #define f_init 1u |
| 75 | |
| 76 | /*----- Utility functions -------------------------------------------------*/ |
| 77 | |
| 78 | /* --- @filename@ --- * |
| 79 | * |
| 80 | * Arguments: @const char *tag@ = sample tag string |
| 81 | * |
| 82 | * Returns: A pointer to a filename for the sample. |
| 83 | * |
| 84 | * Use: Converts tag strings to filenames. |
| 85 | */ |
| 86 | |
| 87 | static const char *filename(const char *tag) |
| 88 | { |
| 89 | static dstr d = DSTR_INIT; |
| 90 | |
| 91 | DRESET(&d); |
| 92 | dstr_putf(&d, "%s/%s.%s", au_dir, tag, ausys_suffix); |
| 93 | T( trace(T_AU, "au: map tag `%s' -> `%s'", tag, d.buf); ) |
| 94 | return (d.buf); |
| 95 | } |
| 96 | |
| 97 | /* --- @prune@ --- * |
| 98 | * |
| 99 | * Arguments: --- |
| 100 | * |
| 101 | * Returns: --- |
| 102 | * |
| 103 | * Use: Prunes the cache of old sample data. |
| 104 | */ |
| 105 | |
| 106 | static void prune(void) |
| 107 | { |
| 108 | T( trace(T_AU, "au: pruning cache (%lu/%lu)", |
| 109 | (unsigned long)au_sz, (unsigned long)au_max); ) |
| 110 | while (au_sz > au_max && AU_SPARE->next != AU_SPARE) { |
| 111 | au_data *a = AU_SPARE->next; |
| 112 | au_sample *s = a->s; |
| 113 | assert(!a->ref); |
| 114 | AU_SPARE->next = a->next; |
| 115 | a->next->prev = AU_SPARE; |
| 116 | s->a = 0; |
| 117 | au_sz -= a->sz; |
| 118 | ausys_free(a); |
| 119 | T( trace(T_AU, "au: ... discarded `%s' (%lu/%lu)", SYM_NAME(s), |
| 120 | (unsigned long)au_sz, (unsigned long)au_max); ) |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | /*----- Main code ---------------------------------------------------------*/ |
| 125 | |
| 126 | /* --- @au_init@ --- * |
| 127 | * |
| 128 | * Arguments: @const char *dir@ = samples directory, or null |
| 129 | * @size_t max@ = maximum cache size |
| 130 | * |
| 131 | * Returns: --- |
| 132 | * |
| 133 | * Use: Initializes the audio subsystem. |
| 134 | */ |
| 135 | |
| 136 | void au_init(const char *dir, size_t max) |
| 137 | { |
| 138 | if (au_flags & f_init) |
| 139 | return; |
| 140 | |
| 141 | /* --- Set up the sound directory --- */ |
| 142 | |
| 143 | if (!dir) |
| 144 | dir = getenv("JOG_AUDIR"); |
| 145 | if (dir) |
| 146 | au_dir = dir; |
| 147 | |
| 148 | /* --- Initialize the sample cache --- */ |
| 149 | |
| 150 | sym_create(&au_tab); |
| 151 | AU_SPARE->next = AU_SPARE->prev = AU_SPARE; |
| 152 | au_max = max; |
| 153 | |
| 154 | /* --- Initialize the system-specific subsystem --- */ |
| 155 | |
| 156 | ausys_init(); |
| 157 | T( trace(T_AU, "au: initialized ok (dir = `%s')", au_dir); ) |
| 158 | |
| 159 | /* --- Done --- */ |
| 160 | |
| 161 | au_flags |= f_init; |
| 162 | } |
| 163 | |
| 164 | /* --- @au_shutdown@ --- * |
| 165 | * |
| 166 | * Arguments: --- |
| 167 | * |
| 168 | * Returns: --- |
| 169 | * |
| 170 | * Use: Shuts down the audio subsystem. |
| 171 | */ |
| 172 | |
| 173 | void au_shutdown(void) |
| 174 | { |
| 175 | if (!(au_flags & f_init)) |
| 176 | return; |
| 177 | ausys_shutdown(); |
| 178 | T( trace(T_AU, "au: shutdown ok"); ) |
| 179 | } |
| 180 | |
| 181 | /* --- @au_find@ --- * |
| 182 | * |
| 183 | * Arguments: @const char *tag@ = sample tag string |
| 184 | * |
| 185 | * Returns: A pointer to the sample corresponding to the tag, or null if |
| 186 | * the sample wasn't found. |
| 187 | * |
| 188 | * Use: Looks up a sample by its name. |
| 189 | */ |
| 190 | |
| 191 | au_sample *au_find(const char *tag) |
| 192 | { |
| 193 | unsigned f; |
| 194 | au_sample *s = sym_find(&au_tab, tag, -1, sizeof(*s), &f); |
| 195 | |
| 196 | if (!f) { |
| 197 | struct stat st; |
| 198 | |
| 199 | s->f = 0; |
| 200 | s->a = 0; |
| 201 | if (stat(filename(tag), &st)) |
| 202 | s->f |= AUF_NOMATCH; |
| 203 | } |
| 204 | if (s->f & AUF_NOMATCH) { |
| 205 | T( trace(T_AU, "au: sample `%s' not found%s", tag, f ? " (hit)": ""); ) |
| 206 | return (0); |
| 207 | } |
| 208 | T( trace(T_AU, "au: sample `%s' found%s", tag, f ? " (hit)" : ""); ) |
| 209 | return (s); |
| 210 | } |
| 211 | |
| 212 | /* --- @au_fetch@ --- * |
| 213 | * |
| 214 | * Arguments: @au_sample *s@ = sample pointer |
| 215 | * |
| 216 | * Returns: A pointer to the audio data for the sample. |
| 217 | * |
| 218 | * Use: Fetches a sample, and decodes it, if necessary. The decoded |
| 219 | * sample data is left with an outstanding reference to it, so |
| 220 | * it won't be freed. This is used internally by @au_queue@, |
| 221 | * before passing the fetched sample data to the system-specific |
| 222 | * layer for playback. It can also be used to lock sample data |
| 223 | * in memory (e.g., for the `abort' error message), or (by |
| 224 | * freeing it immediately afterwards) to prefetch a sample which |
| 225 | * will be used soon, to reduce the latency before the sample is |
| 226 | * heard. |
| 227 | */ |
| 228 | |
| 229 | au_data *au_fetch(au_sample *s) |
| 230 | { |
| 231 | dstr d = DSTR_INIT; |
| 232 | struct stat st; |
| 233 | const char *fn; |
| 234 | size_t n; |
| 235 | ssize_t r; |
| 236 | au_data *a; |
| 237 | int fd; |
| 238 | |
| 239 | /* --- If we already have the sample data --- * |
| 240 | * |
| 241 | * If it's currently languishing in the spare bin, rescue it. If this |
| 242 | * doesn't work, we can release the audio lock, because nothing else messes |
| 243 | * with the spare list. |
| 244 | */ |
| 245 | |
| 246 | ausys_lock(); |
| 247 | a = s->a; |
| 248 | if (a) { |
| 249 | if (!a->ref) { |
| 250 | assert(a->next); |
| 251 | a->prev->next = a->next; |
| 252 | a->next->prev = a->prev; |
| 253 | a->next = a->prev = 0; |
| 254 | } |
| 255 | a->ref++; |
| 256 | T( trace(T_AU, "au: reusing sample `%s'", SYM_NAME(s)); ) |
| 257 | ausys_unlock(); |
| 258 | return (a); |
| 259 | } |
| 260 | ausys_unlock(); |
| 261 | |
| 262 | /* --- Read the file --- * |
| 263 | * |
| 264 | * Buffered I/O will just involve more copying. |
| 265 | */ |
| 266 | |
| 267 | T( trace(T_AU, "au: fetching sample `%s'", SYM_NAME(s)); ) |
| 268 | fn = filename(SYM_NAME(s)); |
| 269 | if ((fd = open(fn, O_RDONLY)) < 0) { |
| 270 | err_report(ERR_AUDIO, ERRAU_OPEN, errno, |
| 271 | "couldn't open sample `%s': %s", fn, strerror(errno)); |
| 272 | goto fail_0; |
| 273 | } |
| 274 | if (fstat(fd, &st)) { |
| 275 | err_report(ERR_AUDIO, ERRAU_OPEN, errno, |
| 276 | "couldn't fstat `%s': %s", fn, strerror(errno)); |
| 277 | goto fail_1; |
| 278 | } |
| 279 | n = st.st_size + 1; |
| 280 | if (n < 4096) |
| 281 | n = 4096; |
| 282 | for (;;) { |
| 283 | dstr_ensure(&d, n); |
| 284 | again: |
| 285 | if ((r = read(fd, d.buf + d.len, n)) < 0) { |
| 286 | if (errno == EWOULDBLOCK || errno == EAGAIN || errno == EINTR) |
| 287 | goto again; |
| 288 | err_report(ERR_AUDIO, ERRAU_OPEN, errno, |
| 289 | "couldn't read `%s': %s", fn, strerror(errno)); |
| 290 | goto fail_1; |
| 291 | } |
| 292 | if (!r) |
| 293 | break; |
| 294 | d.len += r; |
| 295 | n -= r; |
| 296 | if (!n) |
| 297 | n = d.len; |
| 298 | } |
| 299 | close(fd); |
| 300 | |
| 301 | /* --- Convert it into internal form --- */ |
| 302 | |
| 303 | if ((a = ausys_decode(s, d.buf, d.len)) == 0) |
| 304 | goto fail_0; |
| 305 | au_sz += a->sz; |
| 306 | a->ref = 1; |
| 307 | a->next = a->prev = 0; |
| 308 | a->s = s; |
| 309 | s->a = a; |
| 310 | |
| 311 | /* --- Done --- */ |
| 312 | |
| 313 | ausys_lock(); |
| 314 | prune(); |
| 315 | ausys_unlock(); |
| 316 | goto done; |
| 317 | done: |
| 318 | dstr_destroy(&d); |
| 319 | return (a); |
| 320 | |
| 321 | /* --- Tidy up after botched file I/O --- */ |
| 322 | |
| 323 | fail_1: |
| 324 | close(fd); |
| 325 | fail_0: |
| 326 | dstr_destroy(&d); |
| 327 | return (0); |
| 328 | } |
| 329 | |
| 330 | /* --- @au_queue@ --- * |
| 331 | * |
| 332 | * Arguments: @au_sample *s@ = sample pointer |
| 333 | * |
| 334 | * Returns: Zero on success, nonzero on failure. |
| 335 | * |
| 336 | * Use: Queues a sample to be played. |
| 337 | */ |
| 338 | |
| 339 | int au_queue(au_sample *s) |
| 340 | { |
| 341 | au_data *a; |
| 342 | |
| 343 | assert(s); |
| 344 | if ((a = au_fetch(s)) == 0) |
| 345 | return (-1); |
| 346 | T( trace(T_AU, "au: queuing sample `%s'", SYM_NAME(s)); ) |
| 347 | ausys_queue(s->a); |
| 348 | return (0); |
| 349 | } |
| 350 | |
| 351 | /* --- @au_free@, @au_free_unlocked@ --- * |
| 352 | * |
| 353 | * Arguments: @au_data *a@ = pointer to audio data block |
| 354 | * |
| 355 | * Returns: --- |
| 356 | * |
| 357 | * Use: Frees a sample data block when it's no longer required. |
| 358 | */ |
| 359 | |
| 360 | void au_free(au_data *a) |
| 361 | { |
| 362 | ausys_lock(); |
| 363 | au_free_unlocked(a); |
| 364 | ausys_unlock(); |
| 365 | } |
| 366 | |
| 367 | void au_free_unlocked(au_data *a) |
| 368 | { |
| 369 | /* --- If the sample is unreferenced, throw it in the spare bin --- * |
| 370 | * |
| 371 | * This can be called from a background audio processing thread, so we need |
| 372 | * to acquire the lock. |
| 373 | */ |
| 374 | |
| 375 | assert(a->ref); |
| 376 | assert(!a->next); |
| 377 | assert(!a->prev); |
| 378 | a->ref--; |
| 379 | if (a->ref) { |
| 380 | T( trace(T_AU, "au: drop ref to `%s' (other refs remain)", |
| 381 | SYM_NAME(a->s)); ) |
| 382 | ; |
| 383 | } else { |
| 384 | a->next = AU_SPARE; |
| 385 | a->prev = AU_SPARE->prev; |
| 386 | AU_SPARE->prev->next = a; |
| 387 | AU_SPARE->prev = a; |
| 388 | T( trace(T_AU, "au: drop last ref to `%s'", SYM_NAME(a->s)); ) |
| 389 | prune(); |
| 390 | } |
| 391 | } |
| 392 | |
| 393 | /* --- @au_play@, @au_tryplay@ --- * |
| 394 | * |
| 395 | * Arguments: @const char *tag@ = sample tag string |
| 396 | * |
| 397 | * Returns: Zero on success, nonzero on failure. |
| 398 | * |
| 399 | * Use: Convenience functions for queueing samples by tag. |
| 400 | * If @au_tryplay@ cannot find the requested sample, it returns |
| 401 | * a zero value; if @au_play@ cannot find the sample, it reports |
| 402 | * an error. |
| 403 | */ |
| 404 | |
| 405 | int au_tryplay(const char *tag) |
| 406 | { |
| 407 | au_sample *s; |
| 408 | |
| 409 | if (!(au_flags & f_init)) |
| 410 | return (0); |
| 411 | if ((s = au_find(tag)) == 0 || au_queue(s)) |
| 412 | return (-1); |
| 413 | return (0); |
| 414 | } |
| 415 | |
| 416 | int au_play(const char *tag) |
| 417 | { |
| 418 | int rc; |
| 419 | |
| 420 | if ((rc = au_tryplay(tag)) != 0) |
| 421 | err_report(ERR_AUDIO, ERRAU_NOTFOUND, 0, "sample `%s' not found", tag); |
| 422 | return (rc); |
| 423 | } |
| 424 | |
| 425 | /*----- That's all, folks -------------------------------------------------*/ |