sparsemap/examples/ex_3.c

#include <assert.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>

#include "../include/sparsemap.h"

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wvariadic-macros"
#define __diag(...)                                                \
  do {                                                             \
    fprintf(stderr, "%s:%d:%s(): ", __FILE__, __LINE__, __func__); \
    fprintf(stderr, __VA_ARGS__);                                  \
  } while (0)
#pragma GCC diagnostic pop

#define SEED

/* https://burtleburtle.net/bob/rand/smallprng.html */
typedef struct rnd_ctx {
  uint32_t a;
  uint32_t b;
  uint32_t c;
  uint32_t d;
} rnd_ctx_t;
#define __rot(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
uint32_t
__random(rnd_ctx_t *x)
{
  uint32_t e = x->a - __rot(x->b, 27);
  x->a = x->b ^ __rot(x->c, 17);
  x->b = x->c + x->d;
  x->c = x->d + e;
  x->d = e + x->a;
  return x->d;
}

void
__random_seed(rnd_ctx_t *x, uint32_t seed)
{
  uint32_t i;
  x->a = 0xf1ea5eed, x->b = x->c = x->d = seed;
  for (i = 0; i < 20; ++i) {
    (void)__random(x);
  }
}

void
shuffle(rnd_ctx_t *prng, int *array, size_t n)
{
  size_t i, j;

  if (n > 1) {
    for (i = n - 1; i > 0; i--) {
      j = (unsigned int)(__random(prng) % (i + 1));
      // XOR swap algorithm
      if (i != j) { // avoid self-swap leading to zero-ing the element
        array[i] = array[i] ^ array[j];
        array[j] = array[i] ^ array[j];
        array[i] = array[i] ^ array[j];
      }
    }
  }
}

int
main(void)
{
  int i = 0;
  rnd_ctx_t prng;
  int array[1024] = { 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, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708, 709,
    710, 711, 712, 713, 714, 715, 716, 717, 718, 719, 720, 721, 722, 723, 724,
    725, 726, 727, 728, 729, 730, 731, 732, 733, 734, 735, 736, 737, 738, 739,
    740, 741, 742, 743, 744, 745, 746, 747, 748, 749, 750, 751, 752, 753, 754,
    755, 756, 757, 758, 759, 760, 761, 762, 763, 764, 765, 766, 767, 768, 769,
    770, 771, 772, 773, 774, 775, 776, 777, 778, 779, 780, 781, 782, 783, 784,
    785, 786, 787, 788, 789, 790, 791, 792, 793, 794, 795, 796, 797, 798, 799,
    800, 801, 802, 803, 804, 805, 806, 807, 808, 809, 810, 811, 812, 813, 814,
    815, 816, 817, 818, 819, 820, 821, 822, 823, 824, 825, 826, 827, 828, 829,
    830, 831, 832, 833, 834, 835, 836, 837, 838, 839, 840, 841, 842, 843, 844,
    845, 846, 847, 848, 849, 850, 851, 852, 853, 854, 855, 856, 857, 858, 859,
    860, 861, 862, 863, 864, 865, 866, 867, 868, 869, 870, 871, 872, 873, 874,
    875, 876, 877, 878, 879, 880, 881, 882, 883, 884, 885, 886, 887, 888, 889,
    890, 891, 892, 893, 894, 895, 896, 897, 898, 899, 900, 901, 902, 903, 904,
    905, 906, 907, 908, 909, 910, 911, 912, 913, 914, 915, 916, 917, 918, 919,
    920, 921, 922, 923, 924, 925, 926, 927, 928, 929, 930, 931, 932, 933, 934,
    935, 936, 937, 938, 939, 940, 941, 942, 943, 944, 945, 946, 947, 948, 949,
    950, 951, 952, 953, 954, 955, 956, 957, 958, 959, 960, 961, 962, 963, 964,
    965, 966, 967, 968, 969, 970, 971, 972, 973, 974, 975, 976, 977, 978, 979,
    980, 981, 982, 983, 984, 985, 986, 987, 988, 989, 990, 991, 992, 993, 994,
    995, 996, 997, 998, 999, 1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007,
    1008, 1009, 1010, 1011, 1012, 1013, 1014, 1015, 1016, 1017, 1018, 1019,
    1020, 1021, 1022, 1023, 1024 };

  // disable buffering
  setbuf(stderr, 0);

  // seed the PRNG
#ifdef SEED
  __random_seed(&prng, 8675309);
#else
  __random_seed(&prng, (unsigned int)time(NULL) ^ getpid());
#endif

  // randomize setting the bits on
  shuffle(&prng, array, 1024);

  // start with a 1KiB buffer, 1024 bits
  uint8_t *buf = calloc(1024, sizeof(uint8_t));

  // create the sparse bitmap
  sparsemap_t *map = sparsemap(buf, sizeof(uint8_t) * 1024, 0);

  // set all the bits on in a random order
  for (i = 0; i < 1024; i++) {
    __diag("set %d\n", array[i]);
    sparsemap_set(map, array[i], true);
    assert(sparsemap_is_set(map, array[i]) == true);
  }

  sparsemap_set(map, 1025, true);
  assert(sparsemap_is_set(map, 1025) == true);

  return 0;
}