Mercurial > hg > nginx-quic
diff src/core/ngx_crc32.h @ 793:8d39da951bbd
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 |
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--- a/src/core/ngx_crc32.h +++ b/src/core/ngx_crc32.h @@ -12,22 +12,44 @@ #include <ngx_core.h> -extern uint32_t ngx_crc32_table[]; +extern uint32_t *ngx_crc32_table_short; +extern uint32_t ngx_crc32_table256[]; static ngx_inline uint32_t -ngx_crc32(u_char *p, size_t len) +ngx_crc32_short(u_char *p, size_t len) +{ + u_char c; + uint32_t crc; + + crc = 0xffffffff; + + while (len--) { + c = *p++; + crc = ngx_crc32_table_short[(crc ^ (c & 0xf)) & 0xf] ^ (crc >> 4); + crc = ngx_crc32_table_short[(crc ^ (c >> 4)) & 0xf] ^ (crc >> 4); + } + + return crc ^ 0xffffffff; +} + + +static ngx_inline uint32_t +ngx_crc32_long(u_char *p, size_t len) { uint32_t crc; crc = 0xffffffff; while (len--) { - crc = ngx_crc32_table[(crc ^ *p++) & 0xff] ^ (crc >> 8); + crc = ngx_crc32_table256[(crc ^ *p++) & 0xff] ^ (crc >> 8); } return crc ^ 0xffffffff; } +ngx_int_t ngx_crc32_init(ngx_pool_t *pool); + + #endif /* _NGX_CRC32_H_INCLUDED_ */