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Raw Reader with uint32_t parsing

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  1. #include <stdio.h>
  2. #include <unistd.h>
  3. #include <string.h>
  4. #include <assert.h>
  5. #include <inttypes.h>
  6.  
  7. typedef unsigned int uint_t;
  8.  
  9. class RawReader
  10. {
  11. 	static const uint_t RBUF_SIZE = 8192;
  12. 	char rbuf[RBUF_SIZE];
  13.  
  14. 	char *rlim, *rpos;
  15. 	int rrlen, reof;
  16.  
  17. 	char* read_more(char *rpos)
  18. 	{
  19. 		int l, s, t;
  20. 		char *p;
  21.  
  22. 		if (reof)
  23. 			return rpos;
  24.  
  25. 		l = rrlen - (rpos - rbuf);
  26. 		if (rpos != rbuf)
  27. 			memmove(rbuf, rpos, l);
  28. 		rpos = rbuf;
  29. 		p = rbuf + l;
  30. 		t = sizeof(rbuf) - l;
  31. 		s = read(0, p, t);
  32. 		if (s < 0)
  33. 			s = 0;
  34. 		rrlen = l + s;
  35. 		rlim = rpos + rrlen;
  36. 		if (s <= 0) {
  37. 			reof = 1;
  38. 		}
  39.  
  40. 		return rpos;
  41. 	}
  42.  
  43.  public:
  44. 	void init(void)
  45. 	{
  46. 		rrlen = 0;
  47. 		reof = 0;
  48. 		rlim = rbuf;
  49. 		rpos = rbuf;
  50. 	}
  51.  
  52. 	inline int rnextf() { return *rpos++; }
  53.  
  54. 	inline int rnext()
  55. 	{
  56. 		if (rlim - rpos <= 0)
  57. 			rpos = read_more(rpos);
  58. 		return (rlim - rpos > 0) ? rnextf() : -1;
  59. 	}
  60.  
  61. 	inline uint32_t getu32()
  62. 	{
  63. 		if (rlim - rpos < 12)
  64. 			rpos = read_more(rpos);
  65.  
  66. 		uint32_t v;
  67. 		do {
  68. 			v = rnextf() - '0';
  69. 		} while (v >= 10);
  70.  
  71. 		uint32_t res = v;
  72.  
  73. 		for (;;) {
  74. 			v = rnextf() - '0';
  75. 			if (v >= 10)
  76. 				break;
  77. 			res = res * 10 + v;
  78. 		}
  79.  
  80. 		return res;
  81. 	}
  82.  
  83. };

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