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src/core/ngx_crc32.c - nginx-1.31.4 nginx/ @ 8d9666701

Global variables defined

Functions defined

Source code


  2. /*
  3. * Copyright (C) Igor Sysoev
  4. * Copyright (C) Nginx, Inc.
  5. */


  8. #include <ngx_config.h>
  9. #include <ngx_core.h>


  12. /*
  13. * The code and lookup tables are based on the algorithm
  14. * described at http://www.w3.org/TR/PNG/
  15. *
  16. * The 256 element lookup table takes 1024 bytes, and it may be completely
  17. * cached after processing about 30-60 bytes of data.  So for short data
  18. * we use the 16 element lookup table that takes only 64 bytes and align it
  19. * to CPU cache line size.  Of course, the small table adds code inside
  20. * CRC32 loop, but the cache misses overhead is bigger than overhead of
  21. * the additional code.  For example, ngx_crc32_short() of 16 bytes of data
  22. * takes half as much CPU clocks than ngx_crc32_long().
  23. */


  26. ‌static uint32_t  ngx_crc32_table16[] = {
  27.     0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
  28.     0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
  29.     0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
  30.     0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
  31. };


  34. ‌uint32_t  ngx_crc32_table256[] = {
  35.     0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
  36.     0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
  37.     0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
  38.     0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
  39.     0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
  40.     0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
  41.     0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
  42.     0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
  43.     0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
  44.     0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
  45.     0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
  46.     0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
  47.     0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
  48.     0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
  49.     0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
  50.     0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
  51.     0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
  52.     0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
  53.     0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
  54.     0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
  55.     0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
  56.     0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
  57.     0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
  58.     0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
  59.     0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
  60.     0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
  61.     0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
  62.     0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
  63.     0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
  64.     0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  65.     0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
  66.     0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
  67.     0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
  68.     0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
  69.     0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
  70.     0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
  71.     0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
  72.     0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
  73.     0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
  74.     0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
  75.     0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
  76.     0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
  77.     0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
  78.     0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
  79.     0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
  80.     0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
  81.     0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
  82.     0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
  83.     0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
  84.     0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
  85.     0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
  86.     0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
  87.     0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
  88.     0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
  89.     0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
  90.     0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
  91.     0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
  92.     0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
  93.     0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
  94.     0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
  95.     0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
  96.     0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
  97.     0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
  98.     0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
  99. };


  102. ‌uint32_t *ngx_crc32_table_short = ngx_crc32_table16;


  105. /*
  106. * CRC32c (Castagnoli93) lookup table, based on the algorithm
  107. * described at RFC 4960, Appendix B
  108. */

  110. ‌uint32_t  ngx_crc32c_table256[] = {
  111.     0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4,
  112.     0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb,
  113.     0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b,
  114.     0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24,
  115.     0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b,
  116.     0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
  117.     0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54,
  118.     0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b,
  119.     0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a,
  120.     0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35,
  121.     0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5,
  122.     0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
  123.     0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45,
  124.     0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a,
  125.     0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a,
  126.     0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595,
  127.     0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48,
  128.     0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
  129.     0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687,
  130.     0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198,
  131.     0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927,
  132.     0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38,
  133.     0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8,
  134.     0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
  135.     0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096,
  136.     0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789,
  137.     0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859,
  138.     0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46,
  139.     0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9,
  140.     0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
  141.     0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36,
  142.     0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829,
  143.     0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c,
  144.     0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93,
  145.     0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043,
  146.     0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
  147.     0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3,
  148.     0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc,
  149.     0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c,
  150.     0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033,
  151.     0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652,
  152.     0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
  153.     0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d,
  154.     0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982,
  155.     0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d,
  156.     0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622,
  157.     0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2,
  158.     0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
  159.     0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530,
  160.     0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f,
  161.     0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff,
  162.     0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0,
  163.     0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f,
  164.     0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
  165.     0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90,
  166.     0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f,
  167.     0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee,
  168.     0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1,
  169.     0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321,
  170.     0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
  171.     0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81,
  172.     0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e,
  173.     0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e,
  174.     0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351
  175. };


  178. ngx_int_t
  179. ‌ngx_crc32_table_init(void)
  180. {
  181.     void  *p;

  183.     if (((uintptr_t) ngx_crc32_table_short
  184.           & ~((uintptr_t) ngx_cacheline_size - 1))
  185.         == (uintptr_t) ngx_crc32_table_short)
  186.     {
  187.         return NGX_OK;
  188.     }

  190.     p = ngx_alloc(16 * sizeof(uint32_t) + ngx_cacheline_size, ngx_cycle->log);
  191.     if (p == NULL) {
  192.         return NGX_ERROR;
  193.     }

  195.     p = ngx_align_ptr(p, ngx_cacheline_size);

  197.     ngx_memcpy(p, ngx_crc32_table16, 16 * sizeof(uint32_t));

  199.     ngx_crc32_table_short = p;

  201.     return NGX_OK;
  202. }

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