src/pulsecore/memblockq.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2.1 of the License,
   9   or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 #include <pulse/xmalloc.h>
  31
  32 #include <pulsecore/log.h>
  33 #include <pulsecore/mcalign.h>
  34 #include <pulsecore/macro.h>
  35 #include <pulsecore/flist.h>
  36
  37 #include "memblockq.h"
  38
  39 struct list_item {
  40     struct list_item *next, *prev;
  41     int64_t index;
  42     pa_memchunk chunk;
  43 };
  44
  45 PA_STATIC_FLIST_DECLARE(list_items, 0, pa_xfree);
  46
  47 struct pa_memblockq {
  48     struct list_item *blocks, *blocks_tail;
  49     struct list_item *current_read, *current_write;
  50     unsigned n_blocks;
  51     size_t maxlength, tlength, base, prebuf, minreq, maxrewind;
  52     int64_t read_index, write_index;
  53     pa_bool_t in_prebuf;
  54     pa_memchunk silence;
  55     pa_mcalign *mcalign;
  56     int64_t missing, requested;
  57 };
  58
  59 pa_memblockq* pa_memblockq_new(
  60         int64_t idx,
  61         size_t maxlength,
  62         size_t tlength,
  63         size_t base,
  64         size_t prebuf,
  65         size_t minreq,
  66         size_t maxrewind,
  67         pa_memchunk *silence) {
  68
  69     pa_memblockq* bq;
  70
  71     pa_assert(base > 0);
  72
  73     bq = pa_xnew(pa_memblockq, 1);
  74     bq->blocks = bq->blocks_tail = NULL;
  75     bq->current_read = bq->current_write = NULL;
  76     bq->n_blocks = 0;
  77
  78     bq->base = base;
  79     bq->read_index = bq->write_index = idx;
  80
  81     pa_log_debug("memblockq requested: maxlength=%lu, tlength=%lu, base=%lu, prebuf=%lu, minreq=%lu maxrewind=%lu",
  82                  (unsigned long) maxlength, (unsigned long) tlength, (unsigned long) base, (unsigned long) prebuf, (unsigned long) minreq, (unsigned long) maxrewind);
  83
  84     bq->missing = bq->requested = 0;
  85     bq->maxlength = bq->tlength = bq->prebuf = bq->minreq = bq->maxrewind = 0;
  86     bq->in_prebuf = TRUE;
  87
  88     pa_memblockq_set_maxlength(bq, maxlength);
  89     pa_memblockq_set_tlength(bq, tlength);
  90     pa_memblockq_set_minreq(bq, minreq);
  91     pa_memblockq_set_prebuf(bq, prebuf);
  92     pa_memblockq_set_maxrewind(bq, maxrewind);
  93
  94     pa_log_debug("memblockq sanitized: maxlength=%lu, tlength=%lu, base=%lu, prebuf=%lu, minreq=%lu maxrewind=%lu",
  95                  (unsigned long) bq->maxlength, (unsigned long) bq->tlength, (unsigned long) bq->base, (unsigned long) bq->prebuf, (unsigned long) bq->minreq, (unsigned long) bq->maxrewind);
  96
  97     if (silence) {
  98         bq->silence = *silence;
  99         pa_memblock_ref(bq->silence.memblock);
 100     } else
 101         pa_memchunk_reset(&bq->silence);
 102
 103     bq->mcalign = pa_mcalign_new(bq->base);
 104
 105     return bq;
 106 }
 107
 108 void pa_memblockq_free(pa_memblockq* bq) {
 109     pa_assert(bq);
 110
 111     pa_memblockq_silence(bq);
 112
 113     if (bq->silence.memblock)
 114         pa_memblock_unref(bq->silence.memblock);
 115
 116     if (bq->mcalign)
 117         pa_mcalign_free(bq->mcalign);
 118
 119     pa_xfree(bq);
 120 }
 121
 122 static void fix_current_read(pa_memblockq *bq) {
 123     pa_assert(bq);
 124
 125     if (PA_UNLIKELY(!bq->blocks)) {
 126         bq->current_read = NULL;
 127         return;
 128     }
 129
 130     if (PA_UNLIKELY(!bq->current_read))
 131         bq->current_read = bq->blocks;
 132
 133     /* Scan left */
 134     while (PA_UNLIKELY(bq->current_read->index > bq->read_index))
 135
 136         if (bq->current_read->prev)
 137             bq->current_read = bq->current_read->prev;
 138         else
 139             break;
 140
 141     /* Scan right */
 142     while (PA_LIKELY(bq->current_read != NULL) && PA_UNLIKELY(bq->current_read->index + (int64_t) bq->current_read->chunk.length <= bq->read_index))
 143         bq->current_read = bq->current_read->next;
 144
 145     /* At this point current_read will either point at or left of the
 146        next block to play. It may be NULL in case everything in
 147        the queue was already played */
 148 }
 149
 150 static void fix_current_write(pa_memblockq *bq) {
 151     pa_assert(bq);
 152
 153     if (PA_UNLIKELY(!bq->blocks)) {
 154         bq->current_write = NULL;
 155         return;
 156     }
 157
 158     if (PA_UNLIKELY(!bq->current_write))
 159         bq->current_write = bq->blocks_tail;
 160
 161     /* Scan right */
 162     while (PA_UNLIKELY(bq->current_write->index + (int64_t) bq->current_write->chunk.length <= bq->write_index))
 163
 164         if (bq->current_write->next)
 165             bq->current_write = bq->current_write->next;
 166         else
 167             break;
 168
 169     /* Scan left */
 170     while (PA_LIKELY(bq->current_write != NULL) && PA_UNLIKELY(bq->current_write->index > bq->write_index))
 171         bq->current_write = bq->current_write->prev;
 172
 173     /* At this point current_write will either point at or right of
 174        the next block to write data to. It may be NULL in case
 175        everything in the queue is still to be played */
 176 }
 177
 178 static void drop_block(pa_memblockq *bq, struct list_item *q) {
 179     pa_assert(bq);
 180     pa_assert(q);
 181
 182     pa_assert(bq->n_blocks >= 1);
 183
 184     if (q->prev)
 185         q->prev->next = q->next;
 186     else {
 187         pa_assert(bq->blocks == q);
 188         bq->blocks = q->next;
 189     }
 190
 191     if (q->next)
 192         q->next->prev = q->prev;
 193     else {
 194         pa_assert(bq->blocks_tail == q);
 195         bq->blocks_tail = q->prev;
 196     }
 197
 198     if (bq->current_write == q)
 199         bq->current_write = q->prev;
 200
 201     if (bq->current_read == q)
 202         bq->current_read = q->next;
 203
 204     pa_memblock_unref(q->chunk.memblock);
 205
 206     if (pa_flist_push(PA_STATIC_FLIST_GET(list_items), q) < 0)
 207         pa_xfree(q);
 208
 209     bq->n_blocks--;
 210 }
 211
 212 static void drop_backlog(pa_memblockq *bq) {
 213     int64_t boundary;
 214     pa_assert(bq);
 215
 216     boundary = bq->read_index - (int64_t) bq->maxrewind;
 217
 218     while (bq->blocks && (bq->blocks->index + (int64_t) bq->blocks->chunk.length <= boundary))
 219         drop_block(bq, bq->blocks);
 220 }
 221
 222 static pa_bool_t can_push(pa_memblockq *bq, size_t l) {
 223     int64_t end;
 224
 225     pa_assert(bq);
 226
 227     if (bq->read_index > bq->write_index) {
 228         int64_t d = bq->read_index - bq->write_index;
 229
 230         if ((int64_t) l > d)
 231             l -= (size_t) d;
 232         else
 233             return TRUE;
 234     }
 235
 236     end = bq->blocks_tail ? bq->blocks_tail->index + (int64_t) bq->blocks_tail->chunk.length : bq->write_index;
 237
 238     /* Make sure that the list doesn't get too long */
 239     if (bq->write_index + (int64_t) l > end)
 240         if (bq->write_index + (int64_t) l - bq->read_index > (int64_t) bq->maxlength)
 241             return FALSE;
 242
 243     return TRUE;
 244 }
 245
 246 static void write_index_changed(pa_memblockq *bq, int64_t old_write_index, pa_bool_t account) {
 247     int64_t delta;
 248
 249     pa_assert(bq);
 250
 251     delta = bq->write_index - old_write_index;
 252
 253     if (account)
 254         bq->requested -= delta;
 255     else
 256         bq->missing -= delta;
 257
 258     /* pa_log("pushed/seeked %lli: requested counter at %lli, account=%i", (long long) delta, (long long) bq->requested, account); */
 259 }
 260
 261 static void read_index_changed(pa_memblockq *bq, int64_t old_read_index) {
 262     int64_t delta;
 263
 264     pa_assert(bq);
 265
 266     delta = bq->read_index - old_read_index;
 267     bq->missing += delta;
 268
 269     /* pa_log("popped %lli: missing counter at %lli", (long long) delta, (long long) bq->missing); */
 270 }
 271
 272 int pa_memblockq_push(pa_memblockq* bq, const pa_memchunk *uchunk) {
 273     struct list_item *q, *n;
 274     pa_memchunk chunk;
 275     int64_t old;
 276
 277     pa_assert(bq);
 278     pa_assert(uchunk);
 279     pa_assert(uchunk->memblock);
 280     pa_assert(uchunk->length > 0);
 281     pa_assert(uchunk->index + uchunk->length <= pa_memblock_get_length(uchunk->memblock));
 282
 283     if (uchunk->length % bq->base)
 284         return -1;
 285
 286     if (!can_push(bq, uchunk->length))
 287         return -1;
 288
 289     old = bq->write_index;
 290     chunk = *uchunk;
 291
 292     fix_current_write(bq);
 293     q = bq->current_write;
 294
 295     /* First we advance the q pointer right of where we want to
 296      * write to */
 297
 298     if (q) {
 299         while (bq->write_index + (int64_t) chunk.length > q->index)
 300             if (q->next)
 301                 q = q->next;
 302             else
 303                 break;
 304     }
 305
 306     if (!q)
 307         q = bq->blocks_tail;
 308
 309     /* We go from back to front to look for the right place to add
 310      * this new entry. Drop data we will overwrite on the way */
 311
 312     while (q) {
 313
 314         if (bq->write_index >= q->index + (int64_t) q->chunk.length)
 315             /* We found the entry where we need to place the new entry immediately after */
 316             break;
 317         else if (bq->write_index + (int64_t) chunk.length <= q->index) {
 318             /* This entry isn't touched at all, let's skip it */
 319             q = q->prev;
 320         } else if (bq->write_index <= q->index &&
 321                    bq->write_index + (int64_t) chunk.length >= q->index + (int64_t) q->chunk.length) {
 322
 323             /* This entry is fully replaced by the new entry, so let's drop it */
 324
 325             struct list_item *p;
 326             p = q;
 327             q = q->prev;
 328             drop_block(bq, p);
 329         } else if (bq->write_index >= q->index) {
 330             /* The write index points into this memblock, so let's
 331              * truncate or split it */
 332
 333             if (bq->write_index + (int64_t) chunk.length < q->index + (int64_t) q->chunk.length) {
 334
 335                 /* We need to save the end of this memchunk */
 336                 struct list_item *p;
 337                 size_t d;
 338
 339                 /* Create a new list entry for the end of thie memchunk */
 340                 if (!(p = pa_flist_pop(PA_STATIC_FLIST_GET(list_items))))
 341                     p = pa_xnew(struct list_item, 1);
 342
 343                 p->chunk = q->chunk;
 344                 pa_memblock_ref(p->chunk.memblock);
 345
 346                 /* Calculate offset */
 347                 d = (size_t) (bq->write_index + (int64_t) chunk.length - q->index);
 348                 pa_assert(d > 0);
 349
 350                 /* Drop it from the new entry */
 351                 p->index = q->index + (int64_t) d;
 352                 p->chunk.length -= d;
 353
 354                 /* Add it to the list */
 355                 p->prev = q;
 356                 if ((p->next = q->next))
 357                     q->next->prev = p;
 358                 else
 359                     bq->blocks_tail = p;
 360                 q->next = p;
 361
 362                 bq->n_blocks++;
 363             }
 364
 365             /* Truncate the chunk */
 366             if (!(q->chunk.length = (size_t) (bq->write_index - q->index))) {
 367                 struct list_item *p;
 368                 p = q;
 369                 q = q->prev;
 370                 drop_block(bq, p);
 371             }
 372
 373             /* We had to truncate this block, hence we're now at the right position */
 374             break;
 375         } else {
 376             size_t d;
 377
 378             pa_assert(bq->write_index + (int64_t)chunk.length > q->index &&
 379                       bq->write_index + (int64_t)chunk.length < q->index + (int64_t)q->chunk.length &&
 380                       bq->write_index < q->index);
 381
 382             /* The job overwrites the current entry at the end, so let's drop the beginning of this entry */
 383
 384             d = (size_t) (bq->write_index + (int64_t) chunk.length - q->index);
 385             q->index += (int64_t) d;
 386             q->chunk.index += d;
 387             q->chunk.length -= d;
 388
 389             q = q->prev;
 390         }
 391     }
 392
 393     if (q) {
 394         pa_assert(bq->write_index >=  q->index + (int64_t)q->chunk.length);
 395         pa_assert(!q->next || (bq->write_index + (int64_t)chunk.length <= q->next->index));
 396
 397         /* Try to merge memory blocks */
 398
 399         if (q->chunk.memblock == chunk.memblock &&
 400             q->chunk.index + q->chunk.length == chunk.index &&
 401             bq->write_index == q->index + (int64_t) q->chunk.length) {
 402
 403             q->chunk.length += chunk.length;
 404             bq->write_index += (int64_t) chunk.length;
 405             goto finish;
 406         }
 407     } else
 408         pa_assert(!bq->blocks || (bq->write_index + (int64_t)chunk.length <= bq->blocks->index));
 409
 410     if (!(n = pa_flist_pop(PA_STATIC_FLIST_GET(list_items))))
 411         n = pa_xnew(struct list_item, 1);
 412
 413     n->chunk = chunk;
 414     pa_memblock_ref(n->chunk.memblock);
 415     n->index = bq->write_index;
 416     bq->write_index += (int64_t) n->chunk.length;
 417
 418     n->next = q ? q->next : bq->blocks;
 419     n->prev = q;
 420
 421     if (n->next)
 422         n->next->prev = n;
 423     else
 424         bq->blocks_tail = n;
 425
 426     if (n->prev)
 427         n->prev->next = n;
 428     else
 429         bq->blocks = n;
 430
 431     bq->n_blocks++;
 432
 433 finish:
 434
 435     write_index_changed(bq, old, TRUE);
 436     return 0;
 437 }
 438
 439 pa_bool_t pa_memblockq_prebuf_active(pa_memblockq *bq) {
 440     pa_assert(bq);
 441
 442     if (bq->in_prebuf)
 443         return pa_memblockq_get_length(bq) < bq->prebuf;
 444     else
 445         return bq->prebuf > 0 && bq->read_index >= bq->write_index;
 446 }
 447
 448 static pa_bool_t update_prebuf(pa_memblockq *bq) {
 449     pa_assert(bq);
 450
 451     if (bq->in_prebuf) {
 452
 453         if (pa_memblockq_get_length(bq) < bq->prebuf)
 454             return TRUE;
 455
 456         bq->in_prebuf = FALSE;
 457         return FALSE;
 458     } else {
 459
 460         if (bq->prebuf > 0 && bq->read_index >= bq->write_index) {
 461             bq->in_prebuf = TRUE;
 462             return TRUE;
 463         }
 464
 465         return FALSE;
 466     }
 467 }
 468
 469 int pa_memblockq_peek(pa_memblockq* bq, pa_memchunk *chunk) {
 470     int64_t d;
 471     pa_assert(bq);
 472     pa_assert(chunk);
 473
 474     /* We need to pre-buffer */
 475     if (update_prebuf(bq))
 476         return -1;
 477
 478     fix_current_read(bq);
 479
 480     /* Do we need to spit out silence? */
 481     if (!bq->current_read || bq->current_read->index > bq->read_index) {
 482         size_t length;
 483
 484         /* How much silence shall we return? */
 485         if (bq->current_read)
 486             length = (size_t) (bq->current_read->index - bq->read_index);
 487         else if (bq->write_index > bq->read_index)
 488             length = (size_t) (bq->write_index - bq->read_index);
 489         else
 490             length = 0;
 491
 492         /* We need to return silence, since no data is yet available */
 493         if (bq->silence.memblock) {
 494             *chunk = bq->silence;
 495             pa_memblock_ref(chunk->memblock);
 496
 497             if (length > 0 && length < chunk->length)
 498                 chunk->length = length;
 499
 500         } else {
 501
 502             /* If the memblockq is empty, return -1, otherwise return
 503              * the time to sleep */
 504             if (length <= 0)
 505                 return -1;
 506
 507             chunk->memblock = NULL;
 508             chunk->length = length;
 509         }
 510
 511         chunk->index = 0;
 512         return 0;
 513     }
 514
 515     /* Ok, let's pass real data to the caller */
 516     *chunk = bq->current_read->chunk;
 517     pa_memblock_ref(chunk->memblock);
 518
 519     pa_assert(bq->read_index >= bq->current_read->index);
 520     d = bq->read_index - bq->current_read->index;
 521     chunk->index += (size_t) d;
 522     chunk->length -= (size_t) d;
 523
 524     return 0;
 525 }
 526
 527 int pa_memblockq_peek_fixed_size(pa_memblockq *bq, size_t block_size, pa_memchunk *chunk) {
 528     pa_memchunk tchunk, rchunk;
 529     int64_t ri;
 530     struct list_item *item;
 531
 532     pa_assert(bq);
 533     pa_assert(block_size > 0);
 534     pa_assert(chunk);
 535     pa_assert(bq->silence.memblock);
 536
 537     if (pa_memblockq_peek(bq, &tchunk) < 0)
 538         return -1;
 539
 540     if (tchunk.length >= block_size) {
 541         *chunk = tchunk;
 542         chunk->length = block_size;
 543         return 0;
 544     }
 545
 546     rchunk.memblock = pa_memblock_new(pa_memblock_get_pool(tchunk.memblock), block_size);
 547     rchunk.index = 0;
 548     rchunk.length = tchunk.length;
 549
 550     pa_memchunk_memcpy(&rchunk, &tchunk);
 551     pa_memblock_unref(tchunk.memblock);
 552
 553     rchunk.index += tchunk.length;
 554
 555     /* We don't need to call fix_current_read() here, since
 556      * pa_memblock_peek() already did that */
 557     item = bq->current_read;
 558     ri = bq->read_index + tchunk.length;
 559
 560     while (rchunk.index < block_size) {
 561
 562         if (!item || item->index > ri) {
 563             /* Do we need to append silence? */
 564             tchunk = bq->silence;
 565
 566             if (item)
 567                 tchunk.length = PA_MIN(tchunk.length, (size_t) (item->index - ri));
 568
 569         } else {
 570             int64_t d;
 571
 572             /* We can append real data! */
 573             tchunk = item->chunk;
 574
 575             d = ri - item->index;
 576             tchunk.index += (size_t) d;
 577             tchunk.length -= (size_t) d;
 578
 579             /* Go to next item for the next iteration */
 580             item = item->next;
 581         }
 582
 583         rchunk.length = tchunk.length = PA_MIN(tchunk.length, block_size - rchunk.index);
 584         pa_memchunk_memcpy(&rchunk, &tchunk);
 585
 586         rchunk.index += rchunk.length;
 587         ri += rchunk.length;
 588     }
 589
 590     rchunk.index = 0;
 591     rchunk.length = block_size;
 592
 593     *chunk = rchunk;
 594     return 0;
 595 }
 596
 597 void pa_memblockq_drop(pa_memblockq *bq, size_t length) {
 598     int64_t old;
 599     pa_assert(bq);
 600     pa_assert(length % bq->base == 0);
 601
 602     old = bq->read_index;
 603
 604     while (length > 0) {
 605
 606         /* Do not drop any data when we are in prebuffering mode */
 607         if (update_prebuf(bq))
 608             break;
 609
 610         fix_current_read(bq);
 611
 612         if (bq->current_read) {
 613             int64_t p, d;
 614
 615             /* We go through this piece by piece to make sure we don't
 616              * drop more than allowed by prebuf */
 617
 618             p = bq->current_read->index + (int64_t) bq->current_read->chunk.length;
 619             pa_assert(p >= bq->read_index);
 620             d = p - bq->read_index;
 621
 622             if (d > (int64_t) length)
 623                 d = (int64_t) length;
 624
 625             bq->read_index += d;
 626             length -= (size_t) d;
 627
 628         } else {
 629
 630             /* The list is empty, there's nothing we could drop */
 631             bq->read_index += (int64_t) length;
 632             break;
 633         }
 634     }
 635
 636     drop_backlog(bq);
 637     read_index_changed(bq, old);
 638 }
 639
 640 void pa_memblockq_rewind(pa_memblockq *bq, size_t length) {
 641     int64_t old;
 642     pa_assert(bq);
 643     pa_assert(length % bq->base == 0);
 644
 645     old = bq->read_index;
 646
 647     /* This is kind of the inverse of pa_memblockq_drop() */
 648
 649     bq->read_index -= (int64_t) length;
 650
 651     read_index_changed(bq, old);
 652 }
 653
 654 pa_bool_t pa_memblockq_is_readable(pa_memblockq *bq) {
 655     pa_assert(bq);
 656
 657     if (pa_memblockq_prebuf_active(bq))
 658         return FALSE;
 659
 660     if (pa_memblockq_get_length(bq) <= 0)
 661         return FALSE;
 662
 663     return TRUE;
 664 }
 665
 666 size_t pa_memblockq_get_length(pa_memblockq *bq) {
 667     pa_assert(bq);
 668
 669     if (bq->write_index <= bq->read_index)
 670         return 0;
 671
 672     return (size_t) (bq->write_index - bq->read_index);
 673 }
 674
 675 size_t pa_memblockq_missing(pa_memblockq *bq) {
 676     size_t l;
 677     pa_assert(bq);
 678
 679     if ((l = pa_memblockq_get_length(bq)) >= bq->tlength)
 680         return 0;
 681
 682     l = bq->tlength - l;
 683
 684     return l >= bq->minreq ? l : 0;
 685 }
 686
 687 void pa_memblockq_seek(pa_memblockq *bq, int64_t offset, pa_seek_mode_t seek, pa_bool_t account) {
 688     int64_t old;
 689     pa_assert(bq);
 690
 691     old = bq->write_index;
 692
 693     switch (seek) {
 694         case PA_SEEK_RELATIVE:
 695             bq->write_index += offset;
 696             break;
 697         case PA_SEEK_ABSOLUTE:
 698             bq->write_index = offset;
 699             break;
 700         case PA_SEEK_RELATIVE_ON_READ:
 701             bq->write_index = bq->read_index + offset;
 702             break;
 703         case PA_SEEK_RELATIVE_END:
 704             bq->write_index = (bq->blocks_tail ? bq->blocks_tail->index + (int64_t) bq->blocks_tail->chunk.length : bq->read_index) + offset;
 705             break;
 706         default:
 707             pa_assert_not_reached();
 708     }
 709
 710     drop_backlog(bq);
 711     write_index_changed(bq, old, account);
 712 }
 713
 714 void pa_memblockq_flush_write(pa_memblockq *bq, pa_bool_t account) {
 715     int64_t old;
 716     pa_assert(bq);
 717
 718     pa_memblockq_silence(bq);
 719
 720     old = bq->write_index;
 721     bq->write_index = bq->read_index;
 722
 723     pa_memblockq_prebuf_force(bq);
 724     write_index_changed(bq, old, account);
 725 }
 726
 727 void pa_memblockq_flush_read(pa_memblockq *bq) {
 728     int64_t old;
 729     pa_assert(bq);
 730
 731     pa_memblockq_silence(bq);
 732
 733     old = bq->read_index;
 734     bq->read_index = bq->write_index;
 735
 736     pa_memblockq_prebuf_force(bq);
 737     read_index_changed(bq, old);
 738 }
 739
 740 size_t pa_memblockq_get_tlength(pa_memblockq *bq) {
 741     pa_assert(bq);
 742
 743     return bq->tlength;
 744 }
 745
 746 size_t pa_memblockq_get_minreq(pa_memblockq *bq) {
 747     pa_assert(bq);
 748
 749     return bq->minreq;
 750 }
 751
 752 size_t pa_memblockq_get_maxrewind(pa_memblockq *bq) {
 753     pa_assert(bq);
 754
 755     return bq->maxrewind;
 756 }
 757
 758 int64_t pa_memblockq_get_read_index(pa_memblockq *bq) {
 759     pa_assert(bq);
 760
 761     return bq->read_index;
 762 }
 763
 764 int64_t pa_memblockq_get_write_index(pa_memblockq *bq) {
 765     pa_assert(bq);
 766
 767     return bq->write_index;
 768 }
 769
 770 int pa_memblockq_push_align(pa_memblockq* bq, const pa_memchunk *chunk) {
 771     pa_memchunk rchunk;
 772
 773     pa_assert(bq);
 774     pa_assert(chunk);
 775
 776     if (bq->base == 1)
 777         return pa_memblockq_push(bq, chunk);
 778
 779     if (!can_push(bq, pa_mcalign_csize(bq->mcalign, chunk->length)))
 780         return -1;
 781
 782     pa_mcalign_push(bq->mcalign, chunk);
 783
 784     while (pa_mcalign_pop(bq->mcalign, &rchunk) >= 0) {
 785         int r;
 786         r = pa_memblockq_push(bq, &rchunk);
 787         pa_memblock_unref(rchunk.memblock);
 788
 789         if (r < 0) {
 790             pa_mcalign_flush(bq->mcalign);
 791             return -1;
 792         }
 793     }
 794
 795     return 0;
 796 }
 797
 798 void pa_memblockq_prebuf_disable(pa_memblockq *bq) {
 799     pa_assert(bq);
 800
 801     bq->in_prebuf = FALSE;
 802 }
 803
 804 void pa_memblockq_prebuf_force(pa_memblockq *bq) {
 805     pa_assert(bq);
 806
 807     if (bq->prebuf > 0)
 808         bq->in_prebuf = TRUE;
 809 }
 810
 811 size_t pa_memblockq_get_maxlength(pa_memblockq *bq) {
 812     pa_assert(bq);
 813
 814     return bq->maxlength;
 815 }
 816
 817 size_t pa_memblockq_get_prebuf(pa_memblockq *bq) {
 818     pa_assert(bq);
 819
 820     return bq->prebuf;
 821 }
 822
 823 size_t pa_memblockq_pop_missing(pa_memblockq *bq) {
 824     size_t l;
 825
 826     pa_assert(bq);
 827
 828 /*     pa_log("pop: %lli", bq->missing); */
 829
 830     if (bq->missing <= 0)
 831         return 0;
 832
 833     l = (size_t) bq->missing;
 834
 835     bq->requested += bq->missing;
 836     bq->missing = 0;
 837
 838     /* pa_log("sent %lli: request counter is at %lli", (long long) l, (long long) bq->requested); */
 839
 840     return l;
 841 }
 842
 843 void pa_memblockq_set_maxlength(pa_memblockq *bq, size_t maxlength) {
 844     pa_assert(bq);
 845
 846     bq->maxlength = ((maxlength+bq->base-1)/bq->base)*bq->base;
 847
 848     if (bq->maxlength < bq->base)
 849         bq->maxlength = bq->base;
 850
 851     if (bq->tlength > bq->maxlength)
 852         pa_memblockq_set_tlength(bq, bq->maxlength);
 853 }
 854
 855 void pa_memblockq_set_tlength(pa_memblockq *bq, size_t tlength) {
 856     size_t old_tlength;
 857     pa_assert(bq);
 858
 859     if (tlength <= 0 || tlength == (size_t) -1)
 860         tlength = bq->maxlength;
 861
 862     old_tlength = bq->tlength;
 863     bq->tlength = ((tlength+bq->base-1)/bq->base)*bq->base;
 864
 865     if (bq->tlength > bq->maxlength)
 866         bq->tlength = bq->maxlength;
 867
 868     if (bq->minreq > bq->tlength)
 869         pa_memblockq_set_minreq(bq, bq->tlength);
 870
 871     if (bq->prebuf > bq->tlength+bq->base-bq->minreq)
 872         pa_memblockq_set_prebuf(bq, bq->tlength+bq->base-bq->minreq);
 873
 874     bq->missing += (int64_t) bq->tlength - (int64_t) old_tlength;
 875 }
 876
 877 void pa_memblockq_set_minreq(pa_memblockq *bq, size_t minreq) {
 878     pa_assert(bq);
 879
 880     bq->minreq = (minreq/bq->base)*bq->base;
 881
 882     if (bq->minreq > bq->tlength)
 883         bq->minreq = bq->tlength;
 884
 885     if (bq->minreq < bq->base)
 886         bq->minreq = bq->base;
 887
 888     if (bq->prebuf > bq->tlength+bq->base-bq->minreq)
 889         pa_memblockq_set_prebuf(bq, bq->tlength+bq->base-bq->minreq);
 890 }
 891
 892 void pa_memblockq_set_prebuf(pa_memblockq *bq, size_t prebuf) {
 893     pa_assert(bq);
 894
 895     if (prebuf == (size_t) -1)
 896         prebuf = bq->tlength+bq->base-bq->minreq;
 897
 898     bq->prebuf = ((prebuf+bq->base-1)/bq->base)*bq->base;
 899
 900     if (prebuf > 0 && bq->prebuf < bq->base)
 901         bq->prebuf = bq->base;
 902
 903     if (bq->prebuf > bq->tlength+bq->base-bq->minreq)
 904         bq->prebuf = bq->tlength+bq->base-bq->minreq;
 905
 906     if (bq->prebuf <= 0 || pa_memblockq_get_length(bq) >= bq->prebuf)
 907         bq->in_prebuf = FALSE;
 908 }
 909
 910 void pa_memblockq_set_maxrewind(pa_memblockq *bq, size_t maxrewind) {
 911     pa_assert(bq);
 912
 913     bq->maxrewind = (maxrewind/bq->base)*bq->base;
 914 }
 915
 916 void pa_memblockq_apply_attr(pa_memblockq *bq, const pa_buffer_attr *a) {
 917     pa_assert(bq);
 918     pa_assert(a);
 919
 920     pa_memblockq_set_maxlength(bq, a->maxlength);
 921     pa_memblockq_set_tlength(bq, a->tlength);
 922     pa_memblockq_set_prebuf(bq, a->prebuf);
 923     pa_memblockq_set_minreq(bq, a->minreq);
 924 }
 925
 926 void pa_memblockq_get_attr(pa_memblockq *bq, pa_buffer_attr *a) {
 927     pa_assert(bq);
 928     pa_assert(a);
 929
 930     a->maxlength = (uint32_t) pa_memblockq_get_maxlength(bq);
 931     a->tlength = (uint32_t) pa_memblockq_get_tlength(bq);
 932     a->prebuf = (uint32_t) pa_memblockq_get_prebuf(bq);
 933     a->minreq = (uint32_t) pa_memblockq_get_minreq(bq);
 934 }
 935
 936 int pa_memblockq_splice(pa_memblockq *bq, pa_memblockq *source) {
 937
 938     pa_assert(bq);
 939     pa_assert(source);
 940
 941     pa_memblockq_prebuf_disable(bq);
 942
 943     for (;;) {
 944         pa_memchunk chunk;
 945
 946         if (pa_memblockq_peek(source, &chunk) < 0)
 947             return 0;
 948
 949         pa_assert(chunk.length > 0);
 950
 951         if (chunk.memblock) {
 952
 953             if (pa_memblockq_push_align(bq, &chunk) < 0) {
 954                 pa_memblock_unref(chunk.memblock);
 955                 return -1;
 956             }
 957
 958             pa_memblock_unref(chunk.memblock);
 959         } else
 960             pa_memblockq_seek(bq, (int64_t) chunk.length, PA_SEEK_RELATIVE, TRUE);
 961
 962         pa_memblockq_drop(bq, chunk.length);
 963     }
 964 }
 965
 966 void pa_memblockq_willneed(pa_memblockq *bq) {
 967     struct list_item *q;
 968
 969     pa_assert(bq);
 970
 971     fix_current_read(bq);
 972
 973     for (q = bq->current_read; q; q = q->next)
 974         pa_memchunk_will_need(&q->chunk);
 975 }
 976
 977 void pa_memblockq_set_silence(pa_memblockq *bq, pa_memchunk *silence) {
 978     pa_assert(bq);
 979
 980     if (bq->silence.memblock)
 981         pa_memblock_unref(bq->silence.memblock);
 982
 983     if (silence) {
 984         bq->silence = *silence;
 985         pa_memblock_ref(bq->silence.memblock);
 986     } else
 987         pa_memchunk_reset(&bq->silence);
 988 }
 989
 990 pa_bool_t pa_memblockq_is_empty(pa_memblockq *bq) {
 991     pa_assert(bq);
 992
 993     return !bq->blocks;
 994 }
 995
 996 void pa_memblockq_silence(pa_memblockq *bq) {
 997     pa_assert(bq);
 998
 999     while (bq->blocks)
1000         drop_block(bq, bq->blocks);
1001
1002     pa_assert(bq->n_blocks == 0);
1003 }
1004
1005 unsigned pa_memblockq_get_nblocks(pa_memblockq *bq) {
1006     pa_assert(bq);
1007
1008     return bq->n_blocks;
1009 }
1010
1011 size_t pa_memblockq_get_base(pa_memblockq *bq) {
1012     pa_assert(bq);
1013
1014     return bq->base;
1015 }