crc32.c 1.7 KB

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  1. /*
  2. +----------------------------------------------------------------------+
  3. | PHP Version 7 |
  4. +----------------------------------------------------------------------+
  5. | Copyright (c) 1997-2018 The PHP Group |
  6. +----------------------------------------------------------------------+
  7. | This source file is subject to version 3.01 of the PHP license, |
  8. | that is bundled with this package in the file LICENSE, and is |
  9. | available through the world-wide-web at the following url: |
  10. | http://www.php.net/license/3_01.txt |
  11. | If you did not receive a copy of the PHP license and are unable to |
  12. | obtain it through the world-wide-web, please send a note to |
  13. | license@php.net so we can mail you a copy immediately. |
  14. +----------------------------------------------------------------------+
  15. | Author: Rasmus Lerdorf <rasmus@php.net> |
  16. +----------------------------------------------------------------------+
  17. */
  18. #include "php.h"
  19. #include "basic_functions.h"
  20. #include "crc32.h"
  21. /* {{{ proto string crc32(string str)
  22. Calculate the crc32 polynomial of a string */
  23. PHP_NAMED_FUNCTION(php_if_crc32)
  24. {
  25. char *p;
  26. size_t nr;
  27. uint32_t crcinit = 0;
  28. register uint32_t crc;
  29. ZEND_PARSE_PARAMETERS_START(1, 1)
  30. Z_PARAM_STRING(p, nr)
  31. ZEND_PARSE_PARAMETERS_END();
  32. crc = crcinit^0xFFFFFFFF;
  33. for (; nr--; ++p) {
  34. crc = ((crc >> 8) & 0x00FFFFFF) ^ crc32tab[(crc ^ (*p)) & 0xFF ];
  35. }
  36. RETVAL_LONG(crc^0xFFFFFFFF);
  37. }
  38. /* }}} */
  39. /*
  40. * Local variables:
  41. * tab-width: 4
  42. * c-basic-offset: 4
  43. * End:
  44. * vim600: sw=4 ts=4 fdm=marker
  45. * vim<600: sw=4 ts=4
  46. */