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annotate src/core/ngx_crc.h @ 201:267ea1d98683

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nginx-0.0.1-2003-11-30-23:03:18 import
author Igor Sysoev <igor@sysoev.ru>
date Sun, 30 Nov 2003 20:03:18 +0000
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children 0b67be7d4489
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267ea1d98683 nginx-0.0.1-2003-11-30-23:03:18 import
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1 #ifndef _NGX_CRC_H_INCLUDED_
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2 #define _NGX_CRC_H_INCLUDED_
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5 /* 32-bit crc16 */
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7 ngx_inline static uint32_t ngx_crc(char *data, size_t len)
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8 {
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9 uint32_t sum;
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11 for (sum = 0; len; len--) {
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12 /*
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13 * gcc 2.95.2 x86 and icc 7.1.006 compile that operator
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14 * into the single rol opcode.
267ea1d98683 nginx-0.0.1-2003-11-30-23:03:18 import
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15 * msvc 6.0sp2 compiles it into four opcodes.
267ea1d98683 nginx-0.0.1-2003-11-30-23:03:18 import
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16 */
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17 sum = sum >> 1 | sum << 31;
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19 sum += *data++;
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20 }
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22 return sum;
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23 }
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267ea1d98683 nginx-0.0.1-2003-11-30-23:03:18 import
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26 #endif /* _NGX_CRC_H_INCLUDED_ */