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comparison src/core/ngx_crc32.h @ 793:8d39da951bbd

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split ngx_crc32() to short and long version
author Igor Sysoev <igor@sysoev.ru>
date Thu, 19 Oct 2006 09:57:49 +0000
parents f9a971440614
children 45df22906c12
comparison
equal deleted inserted replaced
792:99858705b03f 793:8d39da951bbd
10 10
11 #include <ngx_config.h> 11 #include <ngx_config.h>
12 #include <ngx_core.h> 12 #include <ngx_core.h>
13 13
14 14
15 extern uint32_t ngx_crc32_table[]; 15 extern uint32_t *ngx_crc32_table_short;
16 extern uint32_t ngx_crc32_table256[];
16 17
17 18
18 static ngx_inline uint32_t 19 static ngx_inline uint32_t
19 ngx_crc32(u_char *p, size_t len) 20 ngx_crc32_short(u_char *p, size_t len)
21 {
22 u_char c;
23 uint32_t crc;
24
25 crc = 0xffffffff;
26
27 while (len--) {
28 c = *p++;
29 crc = ngx_crc32_table_short[(crc ^ (c & 0xf)) & 0xf] ^ (crc >> 4);
30 crc = ngx_crc32_table_short[(crc ^ (c >> 4)) & 0xf] ^ (crc >> 4);
31 }
32
33 return crc ^ 0xffffffff;
34 }
35
36
37 static ngx_inline uint32_t
38 ngx_crc32_long(u_char *p, size_t len)
20 { 39 {
21 uint32_t crc; 40 uint32_t crc;
22 41
23 crc = 0xffffffff; 42 crc = 0xffffffff;
24 43
25 while (len--) { 44 while (len--) {
26 crc = ngx_crc32_table[(crc ^ *p++) & 0xff] ^ (crc >> 8); 45 crc = ngx_crc32_table256[(crc ^ *p++) & 0xff] ^ (crc >> 8);
27 } 46 }
28 47
29 return crc ^ 0xffffffff; 48 return crc ^ 0xffffffff;
30 } 49 }
31 50
32 51
52 ngx_int_t ngx_crc32_init(ngx_pool_t *pool);
53
54
33 #endif /* _NGX_CRC32_H_INCLUDED_ */ 55 #endif /* _NGX_CRC32_H_INCLUDED_ */