summaryrefslogtreecommitdiffstats
path: root/src/pulsecore/memblockq.c
blob: 2fd38850e6ae404c6ab967972097063aed4a009d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
/* $Id$ */

/***
  This file is part of PulseAudio.
 
  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.
 
  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/time.h>
#include <time.h>
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include <pulse/xmalloc.h>

#include <pulsecore/log.h>
#include <pulsecore/mcalign.h>

#include "memblockq.h"

struct memblock_list {
    struct memblock_list *next, *prev;
    int64_t index;
    pa_memchunk chunk;
};

struct pa_memblockq {
    struct memblock_list *blocks, *blocks_tail;
    unsigned n_blocks;
    size_t maxlength, tlength, base, prebuf, minreq;
    int64_t read_index, write_index;
    enum { PREBUF, RUNNING } state;
    pa_memblock *silence;
    pa_mcalign *mcalign;
};

pa_memblockq* pa_memblockq_new(
        int64_t idx,
        size_t maxlength,
        size_t tlength,
        size_t base,
        size_t prebuf,
        size_t minreq,
        pa_memblock *silence) {
    
    pa_memblockq* bq;
    
    assert(base > 0);
    assert(maxlength >= base);
    
    bq = pa_xnew(pa_memblockq, 1);
    bq->blocks = bq->blocks_tail = NULL;
    bq->n_blocks = 0;

    bq->base = base;
    bq->read_index = bq->write_index = idx;

    pa_log_debug(__FILE__": memblockq requested: maxlength=%lu, tlength=%lu, base=%lu, prebuf=%lu, minreq=%lu",
        (unsigned long)maxlength, (unsigned long)tlength, (unsigned long)base, (unsigned long)prebuf, (unsigned long)minreq);

    bq->maxlength = ((maxlength+base-1)/base)*base;
    assert(bq->maxlength >= base);

    bq->tlength = ((tlength+base-1)/base)*base;
    if (!bq->tlength || bq->tlength >= bq->maxlength)
        bq->tlength = bq->maxlength;

    bq->prebuf = (prebuf == (size_t) -1) ? bq->tlength/2 : prebuf;
    bq->prebuf = ((bq->prebuf+base-1)/base)*base;
    if (bq->prebuf > bq->maxlength)
        bq->prebuf = bq->maxlength;

    bq->minreq = (minreq/base)*base;
    
    if (bq->minreq > bq->tlength - bq->prebuf)
        bq->minreq = bq->tlength - bq->prebuf;

    if (!bq->minreq)
        bq->minreq = 1;
    
    pa_log_debug(__FILE__": memblockq sanitized: maxlength=%lu, tlength=%lu, base=%lu, prebuf=%lu, minreq=%lu",
        (unsigned long)bq->maxlength, (unsigned long)bq->tlength, (unsigned long)bq->base, (unsigned long)bq->prebuf, (unsigned long)bq->minreq);

    bq->state = bq->prebuf ? PREBUF : RUNNING;
    bq->silence = silence ? pa_memblock_ref(silence) : NULL;
    bq->mcalign = NULL;
    
    return bq;
}

void pa_memblockq_free(pa_memblockq* bq) {
    assert(bq);

    pa_memblockq_flush(bq);

    if (bq->silence)
        pa_memblock_unref(bq->silence);

    if (bq->mcalign)
        pa_mcalign_free(bq->mcalign);
    
    pa_xfree(bq);
}

static void drop_block(pa_memblockq *bq, struct memblock_list *q) {
    assert(bq);
    assert(q);

    assert(bq->n_blocks >= 1);
    
    if (q->prev)
        q->prev->next = q->next;
    else
        bq->blocks = q->next;
    
    if (q->next)
        q->next->prev = q->prev;
    else
        bq->blocks_tail = q->prev;

    pa_memblock_unref(q->chunk.memblock);
    pa_xfree(q);

    bq->n_blocks--;
}

static int can_push(pa_memblockq *bq, size_t l) {
    int64_t end;

    assert(bq);

    if (bq->read_index > bq->write_index) {
        size_t d =  bq->read_index - bq->write_index;

        if (l > d)
            l -= d;
        else
            return 1;
    }

    end = bq->blocks_tail ? bq->blocks_tail->index + bq->blocks_tail->chunk.length : 0;

    /* Make sure that the list doesn't get too long */
    if (bq->write_index + (int64_t)l > end)
        if (bq->write_index + l - bq->read_index > bq->maxlength)
            return 0;

    return 1;
}

int pa_memblockq_push(pa_memblockq* bq, const pa_memchunk *uchunk) {
    
    struct memblock_list *q, *n;
    pa_memchunk chunk;
    
    assert(bq);
    assert(uchunk);
    assert(uchunk->memblock);
    assert(uchunk->length > 0);
    assert(uchunk->index + uchunk->length <= uchunk->memblock->length);

    if (uchunk->length % bq->base)
        return -1;

    if (!can_push(bq, uchunk->length))
        return -1;

    chunk = *uchunk;
    
    if (bq->read_index > bq->write_index) {

        /* We currently have a buffer underflow, we need to drop some
         * incoming data */

        size_t d = bq->read_index - bq->write_index;

        if (chunk.length > d) {
            chunk.index += d;
            chunk.length -= d;
            bq->write_index = bq->read_index;
        } else {
            /* We drop the incoming data completely */
            bq->write_index += chunk.length;
            return 0;
        }
    }
    
    /* We go from back to front to look for the right place to add
     * this new entry. Drop data we will overwrite on the way */

    q = bq->blocks_tail;
    while (q) {

        if (bq->write_index >= q->index + (int64_t)q->chunk.length)
            /* We found the entry where we need to place the new entry immediately after */
            break;
        else if (bq->write_index + (int64_t)chunk.length <= q->index) {
            /* This entry isn't touched at all, let's skip it */
            q = q->prev;
        } else if (bq->write_index <= q->index &&
            bq->write_index + chunk.length >= q->index + q->chunk.length) {

            /* This entry is fully replaced by the new entry, so let's drop it */

            struct memblock_list *p;
            p = q;
            q = q->prev;
            drop_block(bq, p);
        } else if (bq->write_index >= q->index) {
            /* The write index points into this memblock, so let's
             * truncate or split it */

            if (bq->write_index + chunk.length < q->index + q->chunk.length) {

                /* We need to save the end of this memchunk */
                struct memblock_list *p;
                size_t d;

                /* Create a new list entry for the end of thie memchunk */
                p = pa_xnew(struct memblock_list, 1);
                p->chunk = q->chunk;
                pa_memblock_ref(p->chunk.memblock);

                /* Calculate offset */
                d = bq->write_index + chunk.length - q->index;
                assert(d > 0);

                /* Drop it from the new entry */
                p->index = q->index + d;
                p->chunk.length -= d;

                /* Add it to the list */
                p->prev = q;
                if ((p->next = q->next))
                    q->next->prev = p;
                else
                    bq->blocks_tail = p;
                q->next = p;

                bq->n_blocks++;
            }

            /* Truncate the chunk */
            if (!(q->chunk.length = bq->write_index - q->index)) {
                struct memblock_list *p;
                p = q;
                q = q->prev;
                drop_block(bq, p);
            }

            /* We had to truncate this block, hence we're now at the right position */
            break;
        } else {
            size_t d;

            assert(bq->write_index + (int64_t)chunk.length > q->index &&
                   bq->write_index + (int64_t)chunk.length < q->index + (int64_t)q->chunk.length &&
                   bq->write_index < q->index);
            
            /* The job overwrites the current entry at the end, so let's drop the beginning of this entry */

            d = bq->write_index + chunk.length - q->index;
            q->index += d;
            q->chunk.index += d;
            q->chunk.length -= d;
            
            q = q->prev;
        }
        
    }

    if (q) {
        assert(bq->write_index >=  q->index + (int64_t)q->chunk.length);
        assert(!q->next || (bq->write_index + (int64_t)chunk.length <= q->next->index));
               
        /* Try to merge memory blocks */
        
        if (q->chunk.memblock == chunk.memblock &&
            q->chunk.index + (int64_t)q->chunk.length == chunk.index &&
            bq->write_index == q->index + (int64_t)q->chunk.length) {
            
            q->chunk.length += chunk.length;
            bq->write_index += chunk.length;
            return 0;
        }
    } else
        assert(!bq->blocks || (bq->write_index + (int64_t)chunk.length <= bq->blocks->index));


    n = pa_xnew(struct memblock_list, 1);
    n->chunk = chunk;
    pa_memblock_ref(n->chunk.memblock);
    n->index = bq->write_index;
    bq->write_index += n->chunk.length;

    n->next = q ? q->next : bq->blocks;
    n->prev = q;

    if (n->next)
        n->next->prev = n;
    else
        bq->blocks_tail = n;

    if (n->prev)
        n->prev->next = n;
    else
        bq->blocks = n;
    
    bq->n_blocks++;
    return 0;
}

int pa_memblockq_peek(pa_memblockq* bq, pa_memchunk *chunk) {
    assert(bq);
    assert(chunk);

    if (bq->state == PREBUF) {

        /* We need to pre-buffer */
        if (pa_memblockq_get_length(bq) < bq->prebuf)
            return -1;

        bq->state = RUNNING;

    } else if (bq->prebuf > 0 && bq->read_index >= bq->write_index) {

        /* Buffer underflow protection */
        bq->state = PREBUF;
        return -1;
    }
    
    /* Do we need to spit out silence? */
    if (!bq->blocks || bq->blocks->index > bq->read_index) {

        size_t length;

        /* How much silence shall we return? */
        length = bq->blocks ? bq->blocks->index - bq->read_index : 0;

        /* We need to return silence, since no data is yet available */
        if (bq->silence) {
            chunk->memblock = pa_memblock_ref(bq->silence);

            if (!length || length > chunk->memblock->length)
                length = chunk->memblock->length;
                
            chunk->length = length;
        } else {

            /* If the memblockq is empty, return -1, otherwise return
             * the time to sleep */
            if (!bq->blocks)
                return -1;
            
            chunk->memblock = NULL;
            chunk->length = length;
        }

        chunk->index = 0;
        return 0;
    }

    /* Ok, let's pass real data to the caller */
    assert(bq->blocks->index == bq->read_index);
    
    *chunk = bq->blocks->chunk;
    pa_memblock_ref(chunk->memblock);

    return 0;
}

void pa_memblockq_drop(pa_memblockq *bq, const pa_memchunk *chunk, size_t length) {
    assert(bq);
    assert(length % bq->base == 0);

    assert(!chunk || length <= chunk->length);

    if (chunk) {

        if (bq->blocks && bq->blocks->index == bq->read_index) {
            /* The first item in queue is valid */

            /* Does the chunk match with what the user supplied us? */
            if (memcmp(chunk, &bq->blocks->chunk, sizeof(pa_memchunk)) != 0)
                return;

        } else {
            size_t l;

            /* The first item in the queue is not yet relevant */

            assert(!bq->blocks || bq->blocks->index > bq->read_index);
            l = bq->blocks ? bq->blocks->index - bq->read_index : 0;

            if (bq->silence) {

                if (!l || l > bq->silence->length)
                    l = bq->silence->length;

            }

            /* Do the entries still match? */
            if (chunk->index != 0 || chunk->length != l || chunk->memblock != bq->silence)
                return;
        }
    }

    while (length > 0) {

        if (bq->blocks) {
            size_t d;

            assert(bq->blocks->index >= bq->read_index);

            d = (size_t) (bq->blocks->index - bq->read_index);
            
            if (d >= length) {
                /* The first block is too far in the future */
                
                bq->read_index += length;
                break;
            } else {
                
                length -= d;
                bq->read_index += d;
            }

            assert(bq->blocks->index == bq->read_index);

            if (bq->blocks->chunk.length <= length) {
                /* We need to drop the full block */

                length -= bq->blocks->chunk.length;
                bq->read_index += bq->blocks->chunk.length;

                drop_block(bq, bq->blocks);
            } else {
                /* Only the start of this block needs to be dropped */

                bq->blocks->chunk.index += length;
                bq->blocks->chunk.length -= length;
                bq->blocks->index += length;
                bq->read_index += length;
                break;
            }
            
        } else {

            /* The list is empty, there's nothing we could drop */
            bq->read_index += length;
            break;
        }
    }
}

int pa_memblockq_is_readable(pa_memblockq *bq) {
    assert(bq);

    if (bq->prebuf > 0) {
        size_t l = pa_memblockq_get_length(bq);
        
        if (bq->state == PREBUF && l < bq->prebuf)
            return 0;

        if (l <= 0)
            return 0;
    }

    return 1;
}

int pa_memblockq_is_writable(pa_memblockq *bq, size_t length) {
    assert(bq);

    if (length % bq->base)
        return 0;
    
    return pa_memblockq_get_length(bq) + length <= bq->tlength;
}

size_t pa_memblockq_get_length(pa_memblockq *bq) {
    assert(bq);

    if (bq->write_index <= bq->read_index)
        return 0;
    
    return (size_t) (bq->write_index - bq->read_index);
}

size_t pa_memblockq_missing(pa_memblockq *bq) {
    size_t l;
    assert(bq);

    if ((l = pa_memblockq_get_length(bq)) >= bq->tlength)
        return 0;

    l = bq->tlength - l;
    return (l >= bq->minreq) ? l : 0;
}

size_t pa_memblockq_get_minreq(pa_memblockq *bq) {
    assert(bq);

    return bq->minreq;
}

void pa_memblockq_seek(pa_memblockq *bq, int64_t offset, pa_seek_mode_t seek) {
    assert(bq);

    switch (seek) {
        case PA_SEEK_RELATIVE:
            bq->write_index += offset;
            return;
        case PA_SEEK_ABSOLUTE:
            bq->write_index = offset;
            return;
        case PA_SEEK_RELATIVE_ON_READ:
            bq->write_index = bq->read_index + offset;
            return;
        case PA_SEEK_RELATIVE_END:
            bq->write_index = (bq->blocks_tail ? bq->blocks_tail->index + (int64_t)bq->blocks_tail->chunk.length : bq->read_index) + offset;
            return;
    }

    assert(0);
}

void pa_memblockq_flush(pa_memblockq *bq) {
    assert(bq);
    
    while (bq->blocks)
        drop_block(bq, bq->blocks);

    assert(bq->n_blocks == 0);

    bq->write_index = bq->read_index;

    pa_memblockq_prebuf_force(bq);
}

size_t pa_memblockq_get_tlength(pa_memblockq *bq) {
    assert(bq);
    
    return bq->tlength;
}

int64_t pa_memblockq_get_read_index(pa_memblockq *bq) {
    assert(bq);
    return bq->read_index;
}

int64_t pa_memblockq_get_write_index(pa_memblockq *bq) {
    assert(bq);
    return bq->write_index;
}

int pa_memblockq_push_align(pa_memblockq* bq, const pa_memchunk *chunk) {
    pa_memchunk rchunk;

    assert(bq);
    assert(chunk && bq->base);
 	
    if (bq->base == 1)
        return pa_memblockq_push(bq, chunk);
 	
    if (!bq->mcalign)
        bq->mcalign = pa_mcalign_new(bq->base);

    if (!can_push(bq, pa_mcalign_csize(bq->mcalign, chunk->length)))
        return -1;
    
    pa_mcalign_push(bq->mcalign, chunk);
 	
    while (pa_mcalign_pop(bq->mcalign, &rchunk) >= 0) {
        int r;
        r = pa_memblockq_push(bq, &rchunk);
        pa_memblock_unref(rchunk.memblock);

        if (r < 0)
            return -1;
    }

    return 0;
}

void pa_memblockq_shorten(pa_memblockq *bq, size_t length) {
    size_t l;
    assert(bq);

    l = pa_memblockq_get_length(bq);

    if (l > length)
        pa_memblockq_drop(bq, NULL, l - length);
}

void pa_memblockq_prebuf_disable(pa_memblockq *bq) {
    assert(bq);

    if (bq->state == PREBUF)
        bq->state = RUNNING;
}

void pa_memblockq_prebuf_force(pa_memblockq *bq) {
    assert(bq);

    if (bq->state == RUNNING && bq->prebuf > 0)
        bq->state = PREBUF;
}

size_t pa_memblockq_get_maxlength(pa_memblockq *bq) {
    assert(bq);

    return bq->maxlength;
}

size_t pa_memblockq_get_prebuf(pa_memblockq *bq) {
    assert(bq);

    return bq->prebuf;
}