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80 lines
1.3 KiB
C
80 lines
1.3 KiB
C
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/*
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* Copyright (C) Igor Sysoev
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* Copyright (C) Nginx, Inc.
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*/
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#ifndef _NGX_CRC32_H_INCLUDED_
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#define _NGX_CRC32_H_INCLUDED_
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#include <ngx_config.h>
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#include <ngx_core.h>
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extern uint32_t *ngx_crc32_table_short;
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extern uint32_t ngx_crc32_table256[];
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static ngx_inline uint32_t
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ngx_crc32_short(u_char *p, size_t len)
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{
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u_char c;
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uint32_t crc;
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crc = 0xffffffff;
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while (len--) {
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c = *p++;
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crc = ngx_crc32_table_short[(crc ^ (c & 0xf)) & 0xf] ^ (crc >> 4);
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crc = ngx_crc32_table_short[(crc ^ (c >> 4)) & 0xf] ^ (crc >> 4);
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}
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return crc ^ 0xffffffff;
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}
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static ngx_inline uint32_t
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ngx_crc32_long(u_char *p, size_t len)
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{
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uint32_t crc;
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crc = 0xffffffff;
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while (len--) {
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crc = ngx_crc32_table256[(crc ^ *p++) & 0xff] ^ (crc >> 8);
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}
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return crc ^ 0xffffffff;
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}
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#define ngx_crc32_init(crc) \
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crc = 0xffffffff
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static ngx_inline void
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ngx_crc32_update(uint32_t *crc, u_char *p, size_t len)
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{
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uint32_t c;
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c = *crc;
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while (len--) {
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c = ngx_crc32_table256[(c ^ *p++) & 0xff] ^ (c >> 8);
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}
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*crc = c;
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}
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#define ngx_crc32_final(crc) \
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crc ^= 0xffffffff
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ngx_int_t ngx_crc32_table_init(void);
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#endif /* _NGX_CRC32_H_INCLUDED_ */
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