aboutsummaryrefslogtreecommitdiff
path: root/nx-X11/programs/Xserver/record/set.c
blob: 07d911c8cca0a9e9a78f1545db764b8cda2795f6 (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
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698

/*

Copyright 1995, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.

*/

/*

    See the header set.h for a description of the set ADT.

    Implementation Strategy

    A bit vector is an obvious choice to represent the set, but may take
    too much memory, depending on the numerically largest member in the
    set.  One expected common case is for the client to ask for *all*
    protocol.  This means it would ask for minor opcodes 0 through 65535.
    Representing this as a bit vector takes 8K -- and there may be
    multiple minor opcode intervals, as many as one per major (extension)
    opcode).  In such cases, a list-of-intervals representation would be
    preferable to reduce memory consumption.  Both representations will be
    implemented, and RecordCreateSet will decide heuristically which one
    to use based on the set members.

    Note: When compiling for use in the server, do not use -DTESTING.
    When compiling for stand-alone testing of the set ADT, use -DTESTING.

*/

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#ifndef TESTING
#include "misc.h"
#else
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* stuff that you normally get from the X Server's environment */

typedef int Bool;
#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif

typedef unsigned short CARD16;

#define ALLOCATE_LOCAL malloc
#define DEALLOCATE_LOCAL free

#ifndef max
#define max(_a, _b) ( ((_a) > (_b)) ? (_a) : (_b) )
#endif

#endif /* TESTING */

#include "set.h"

#ifdef XFree86LOADER
#include "xf86_libc.h"
#include "xf86_ansic.h"
#endif

static int
maxMemberInInterval(pIntervals, nIntervals)
    RecordSetInterval *pIntervals;
    int nIntervals;
{
    int i;
    int maxMember = -1;
    for (i = 0; i < nIntervals; i++)
    {
	if (maxMember < (int)pIntervals[i].last)
	    maxMember = pIntervals[i].last;
    }
    return maxMember;
}

static void
NoopDestroySet(pSet)
    RecordSetPtr pSet;
{
}

/***************************************************************************/

/* set operations for bit vector representation */

typedef struct {
    RecordSetRec baseSet;
    int maxMember;
    /* followed by the bit vector itself */
} BitVectorSet, *BitVectorSetPtr;

#define BITS_PER_LONG (sizeof(unsigned long) * 8)

static void
BitVectorDestroySet(pSet)
    RecordSetPtr pSet;
{
    free(pSet);
}

static unsigned long
BitVectorIsMemberOfSet(pSet, pm)
    RecordSetPtr pSet;
    int pm;
{
    BitVectorSetPtr pbvs = (BitVectorSetPtr)pSet;
    unsigned long *pbitvec;

    if ((int)pm > pbvs->maxMember) return FALSE;
    pbitvec = (unsigned long *)(&pbvs[1]);
    return (pbitvec[pm / BITS_PER_LONG] & ((unsigned long)1 << (pm % BITS_PER_LONG)));
}


static int
BitVectorFindBit(pSet, iterbit, bitval)
    RecordSetPtr pSet;
    int iterbit;
    Bool bitval;
{
    BitVectorSetPtr pbvs = (BitVectorSetPtr)pSet;
    unsigned long *pbitvec = (unsigned long *)(&pbvs[1]);
    int startlong;
    int startbit;
    int walkbit;
    int maxMember;
    unsigned long skipval;
    unsigned long bits;
    unsigned long usefulbits;

    startlong = iterbit / BITS_PER_LONG;
    pbitvec  += startlong;
    startbit  = startlong * BITS_PER_LONG;
    skipval = bitval ? 0L : ~0L;
    maxMember = pbvs->maxMember;


    if (startbit > maxMember) return -1;
    bits = *pbitvec;
    usefulbits = ~(((unsigned long)1 << (iterbit - startbit)) - 1);
    if ( (bits & usefulbits) == (skipval & usefulbits) )
    {
	pbitvec++;
	startbit += BITS_PER_LONG;

	while (startbit <= maxMember && *pbitvec == skipval)
	{
	    pbitvec++;
	    startbit += BITS_PER_LONG;
	}
	if (startbit > maxMember) return -1;
    }

    walkbit = (startbit < iterbit) ? iterbit - startbit : 0;

    bits = *pbitvec;
    while (walkbit < BITS_PER_LONG && ((!(bits & ((unsigned long)1 << walkbit))) == bitval))
	walkbit++;

    return startbit + walkbit;
}


static RecordSetIteratePtr
BitVectorIterateSet(pSet, pIter, pInterval)
    RecordSetPtr pSet;
    RecordSetIteratePtr pIter;
    RecordSetInterval *pInterval;
{
    int iterbit = (int)(long)pIter;
    int b;

    b = BitVectorFindBit(pSet, iterbit, TRUE);
    if (b == -1) return (RecordSetIteratePtr)0;
    pInterval->first = b;

    b = BitVectorFindBit(pSet, b, FALSE);
    pInterval->last = (b < 0) ? ((BitVectorSetPtr)pSet)->maxMember : b - 1;
    return (RecordSetIteratePtr)(long)(pInterval->last + 1);
}

RecordSetOperations BitVectorSetOperations = {
    BitVectorDestroySet, BitVectorIsMemberOfSet, BitVectorIterateSet };

RecordSetOperations BitVectorNoFreeOperations = {
    NoopDestroySet, BitVectorIsMemberOfSet, BitVectorIterateSet };

static int
BitVectorSetMemoryRequirements(pIntervals, nIntervals, maxMember, alignment)
    RecordSetInterval *pIntervals;
    int nIntervals;
    int maxMember;
    int *alignment;
{
    int nlongs;

    *alignment = sizeof(unsigned long);
    nlongs = (maxMember + BITS_PER_LONG) / BITS_PER_LONG;
    return (sizeof(BitVectorSet) + nlongs * sizeof(unsigned long));
}

static RecordSetPtr
BitVectorCreateSet(pIntervals, nIntervals, pMem, memsize)
    RecordSetInterval *pIntervals;
    int nIntervals;
    void *pMem;
    int memsize;
{
    BitVectorSetPtr pbvs;
    int i, j;
    unsigned long *pbitvec;

    /* allocate all storage needed by this set in one chunk */

    if (pMem)
    {
	memset(pMem, 0, memsize);
	pbvs = (BitVectorSetPtr)pMem;
	pbvs->baseSet.ops = &BitVectorNoFreeOperations;
    }
    else
    {
	pbvs = (BitVectorSetPtr)calloc(1, memsize);
	if (!pbvs) return NULL;
	pbvs->baseSet.ops = &BitVectorSetOperations;
    }

    pbvs->maxMember = maxMemberInInterval(pIntervals, nIntervals);

    /* fill in the set */

    pbitvec = (unsigned long *)(&pbvs[1]);
    for (i = 0; i < nIntervals; i++)
    {
	for (j = pIntervals[i].first; j <= (int)pIntervals[i].last; j++)
	{
	    pbitvec[j/BITS_PER_LONG] |= ((unsigned long)1 << (j % BITS_PER_LONG));
	}
    }
    return (RecordSetPtr)pbvs;
}


/***************************************************************************/

/* set operations for interval list representation */

typedef struct {
    RecordSetRec baseSet;
    int nIntervals;
    /* followed by the intervals (RecordSetInterval) */
} IntervalListSet, *IntervalListSetPtr;

static void
IntervalListDestroySet(pSet)
    RecordSetPtr pSet;
{
    free(pSet);
}

static unsigned long
IntervalListIsMemberOfSet(pSet, pm)
    RecordSetPtr pSet;
    int pm;
{
    IntervalListSetPtr prls = (IntervalListSetPtr)pSet;
    RecordSetInterval *pInterval = (RecordSetInterval *)(&prls[1]);
    int hi, lo, probe;

    /* binary search */
    lo = 0; hi = prls->nIntervals - 1;
    while (lo <= hi)
    {
	probe = (hi + lo) / 2;
	if (pm >= pInterval[probe].first && pm <= pInterval[probe].last) return 1;
	else if (pm < pInterval[probe].first) hi = probe - 1;
	else				   lo = probe + 1;
    }
    return 0;
}


static RecordSetIteratePtr
IntervalListIterateSet(pSet, pIter, pIntervalReturn)
    RecordSetPtr pSet;
    RecordSetIteratePtr pIter;
    RecordSetInterval *pIntervalReturn;
{
    RecordSetInterval *pInterval = (RecordSetInterval *)pIter;
    IntervalListSetPtr prls = (IntervalListSetPtr)pSet;

    if (pInterval == NULL)
    {
	pInterval = (RecordSetInterval *)(&prls[1]);
    }

    if ( (pInterval - (RecordSetInterval *)(&prls[1])) < prls->nIntervals )
    {
	*pIntervalReturn = *pInterval;
	return (RecordSetIteratePtr)(++pInterval);
    }
    else
	return (RecordSetIteratePtr)NULL;
}

RecordSetOperations IntervalListSetOperations = {
    IntervalListDestroySet, IntervalListIsMemberOfSet, IntervalListIterateSet };

RecordSetOperations IntervalListNoFreeOperations = {
    NoopDestroySet, IntervalListIsMemberOfSet, IntervalListIterateSet };

static int
IntervalListMemoryRequirements(pIntervals, nIntervals, maxMember, alignment)
    RecordSetInterval *pIntervals;
    int nIntervals;
    int maxMember;
    int *alignment;
{
    *alignment = sizeof(unsigned long);
    return sizeof(IntervalListSet) + nIntervals * sizeof(RecordSetInterval);
}

static RecordSetPtr
IntervalListCreateSet(pIntervals, nIntervals, pMem, memsize)
    RecordSetInterval *pIntervals;
    int nIntervals;
    void *pMem;
    int memsize;
{
    IntervalListSetPtr prls;
    int i, j, k;
    RecordSetInterval *stackIntervals = NULL;
    CARD16 first;

    if (nIntervals > 0)
    {
	stackIntervals = (RecordSetInterval *)ALLOCATE_LOCAL(
				sizeof(RecordSetInterval) * nIntervals);
	if (!stackIntervals) return NULL;

	/* sort intervals, store in stackIntervals (insertion sort) */

	for (i = 0; i < nIntervals; i++)
	{
	    first = pIntervals[i].first;
	    for (j = 0; j < i; j++)
	    {
		if (first < stackIntervals[j].first)
		    break;
	    }
	    for (k = i; k > j; k--)
	    {
		stackIntervals[k] = stackIntervals[k-1];
	    }
	    stackIntervals[j] = pIntervals[i];
	}

	/* merge abutting/overlapping intervals */

	for (i = 0; i < nIntervals - 1; )
	{
	    if ( (stackIntervals[i].last + (unsigned int)1) <
		  stackIntervals[i + 1].first)
	    {
		i++; /* disjoint intervals */
	    }
	    else
	    {
		stackIntervals[i].last = max(stackIntervals[i].last,
					  stackIntervals[i + 1].last);
		nIntervals--;
		for (j = i + 1; j < nIntervals; j++)
		    stackIntervals[j] = stackIntervals[j + 1];
	    }
	}
    }

    /* allocate and fill in set structure */

    if (pMem)
    {
	prls = (IntervalListSetPtr)pMem;
	prls->baseSet.ops = &IntervalListNoFreeOperations;
    }
    else
    {
	prls = (IntervalListSetPtr)
	    malloc(sizeof(IntervalListSet) + nIntervals * sizeof(RecordSetInterval));
	if (!prls) goto bailout;
	prls->baseSet.ops = &IntervalListSetOperations;
    }
    memcpy(&prls[1], stackIntervals, nIntervals * sizeof(RecordSetInterval));
    prls->nIntervals = nIntervals;
bailout:
    if (stackIntervals) DEALLOCATE_LOCAL(stackIntervals);
    return (RecordSetPtr)prls;
}

#ifdef TESTING
typedef enum {
  BitVectorImplementation, IntervalListImplementation} RecordSetImplementation;

RecordSetImplementation _RecordSetImpl;

static void
_RecordForceSetImplementation(setimpl)
    RecordSetImplementation setimpl;
{
    _RecordSetImpl = setimpl;
}
#endif

typedef RecordSetPtr (*RecordCreateSetProcPtr)(
    RecordSetInterval *pIntervals,
    int nIntervals,
    void *pMem,
    int memsize
);

static int
_RecordSetMemoryRequirements(pIntervals, nIntervals, alignment, ppCreateSet)
    RecordSetInterval *pIntervals;
    int nIntervals;
    int *alignment;
    RecordCreateSetProcPtr *ppCreateSet;
{
    int bmsize, rlsize, bma, rla;
    int maxMember;

    /* find maximum member of set so we know how big to make the bit vector */
    maxMember = maxMemberInInterval(pIntervals, nIntervals);

    bmsize = BitVectorSetMemoryRequirements(pIntervals, nIntervals, maxMember,
					    &bma);
    rlsize = IntervalListMemoryRequirements(pIntervals, nIntervals, maxMember,
					    &rla);
#ifdef TESTING
    if (_RecordSetImpl == BitVectorImplementation)
#else
    if ( ( (nIntervals > 1) && (maxMember <= 255) )
	|| (bmsize < rlsize) )
#endif
    {
	*alignment = bma;
	*ppCreateSet = BitVectorCreateSet;
	return bmsize;
    }
    else
    {
	*alignment = rla;
	*ppCreateSet = IntervalListCreateSet;
	return rlsize;
    }
}

/***************************************************************************/

/* user-visible functions */

int
RecordSetMemoryRequirements(pIntervals, nIntervals, alignment)
    RecordSetInterval *pIntervals;
    int nIntervals;
    int *alignment;
{
    RecordCreateSetProcPtr pCreateSet;
    return _RecordSetMemoryRequirements(pIntervals, nIntervals, alignment,
					&pCreateSet);
}

RecordSetPtr
RecordCreateSet(pIntervals, nIntervals, pMem, memsize)
    RecordSetInterval *pIntervals;
    int nIntervals;
    void *pMem;
    int memsize;
{
    RecordCreateSetProcPtr pCreateSet;
    int alignment;
    int size;

    size = _RecordSetMemoryRequirements(pIntervals, nIntervals, &alignment,
					&pCreateSet);
    if (pMem)
    {
	if ( ((long)pMem & (alignment-1) ) || memsize < size)
	    return NULL;
    }
    return (*pCreateSet)(pIntervals, nIntervals, pMem, size);
}

/***************************************************************************/

#ifdef TESTING

/*

Test Strategy

Having two set representations is convenient for testing because we
can play them against each other.  The test code will be able to
specify which implementation to use.  This breaks the encapsulation,
but that seems acceptable for testing.  The crux of the test loop
looks like this:

loop:
    generate random list of Intervals

    create set A using bit vector implementation
    create set B using Interval list implementation

    for each possible set member
        if set A and set B disagree on whether this is a member    error;

    iterate over both sets, comparing the intervals returned by each.
    if intervals or number of intervals are different    error;

    iterate over intervals of set A
	for i = interval.first to interval.last
	    if i is not a member of set B	error;

    iterate over intervals of set B
	for i = interval.first to interval.last
	    if i is not a member of set A	error;

    destroy sets A, B

*/

int GenerateRandomIntervals(pIntervals, maxintervals)
    RecordSetInterval *pIntervals;
    int maxintervals;
{
    int i, nIntervals;

    nIntervals = rand() % maxintervals;

    for (i = 0; i < nIntervals; i++)
    {
	pIntervals[i].first = rand();
	pIntervals[i].last  = pIntervals[i].first + rand();
    }
    return nIntervals;
}

#define MAXINTERVALS 100

int main(argc, argv)
    int argc;
    char **argv;
{
    RecordSetPtr bs, rs;
    RecordSetInterval br, rr;
    RecordSetIteratePtr bi, ri;
    CARD16 i;
    int testcount;
    RecordSetInterval intervals[MAXINTERVALS];
    int nIntervals;
    int bsize, rsize;
    int balign, ralign;
    int pad;

    for (testcount = 0; 1; testcount++)
    {
	nIntervals = GenerateRandomIntervals(intervals, MAXINTERVALS);
	printf("%d nIntervals %d\n", testcount, nIntervals);

	if (testcount & 1)
	{
	    _RecordForceSetImplementation(BitVectorImplementation);
	    bsize = RecordSetMemoryRequirements(intervals, nIntervals, &balign);
	    _RecordForceSetImplementation(IntervalListImplementation);
	    rsize = RecordSetMemoryRequirements(intervals, nIntervals, &ralign);
	    pad = (ralign - (bsize & (ralign - 1))) & (ralign - 1);
	    bs = (RecordSetPtr)malloc(bsize + pad + rsize );
	    if (!bs)
	    {
		fprintf(stderr, "%d: failed to alloc memory for  sets\n",
			testcount);
		continue;
	    }
	    rs = (RecordSetPtr)(((char *)bs) + bsize + pad);
	}
	else
	{
	    bs = rs = NULL;
	    bsize = rsize = 0;
	}

	_RecordForceSetImplementation(BitVectorImplementation);
	bs = RecordCreateSet(intervals, nIntervals, bs, bsize);
	_RecordForceSetImplementation(IntervalListImplementation);
	rs = RecordCreateSet(intervals, nIntervals, rs, rsize);

	if (!bs || !rs)
	{
	    fprintf(stderr, "%d: failed to create sets\n", testcount);
	    continue;
	}

	for (i = 0; i < 65535; i++)
	{
	    unsigned long b, r;

	    b = RecordIsMemberOfSet(bs, i);
	    r = RecordIsMemberOfSet(rs, i);
	    if ( (b && !r) || (!b && r) )
	    {
		fprintf(stderr, "%d: isMemberOfSet %d\n",
			testcount, (int)i);
	    }
	}

	bi = RecordIterateSet(bs, NULL, &br);
	ri = RecordIterateSet(rs, NULL, &rr);

	while (bi && ri)
	{
	    if ( (rr.first != br.first) || (rr.last != br.last) )
	    {
		fprintf(stderr, "%d: iterateSet interval value mismatch\n",
			testcount);
	    }
	    bi = RecordIterateSet(bs, bi, &br);
	    ri = RecordIterateSet(rs, ri, &rr);
	}
	if (bi != ri)
	{
	    fprintf(stderr, "%d: iterateSet interval count mismatch\n",
		    testcount);
	}
	

	bi = NULL;
	while (bi = RecordIterateSet(bs, bi, &br))
	{
	    for (i = br.first; i <= br.last; i++)
	    {
		if (!RecordIsMemberOfSet(rs, i))
		{
		    fprintf(stderr, "%d: iterateSet b / isMemberOfSet r %d\n",
			    testcount, (int)i);
		}
	    }
	}

	ri = NULL;
	while (ri = RecordIterateSet(rs, ri, &rr))
	{
	    for (i = rr.first; i <= rr.last; i++)
	    {
		if (!RecordIsMemberOfSet(bs, i) )
		{
		    fprintf(stderr, "%d: iterateSet r / isMemberOfSet b %d\n",
			    testcount, (int)i);
		}
	    }
	}

	RecordDestroySet(bs);
	RecordDestroySet(rs);

	if (testcount & 1)
	{
	    free(bs);
	}
    }
}

#endif /* TESTING */