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/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#ifndef _NGX_CRC32_H_INCLUDED_
#define _NGX_CRC32_H_INCLUDED_
#include <ngx_config.h>
#include <ngx_core.h>
extern uint32_t *ngx_crc32_table_short;
extern uint32_t ngx_crc32_table256[];
static ngx_inline uint32_t
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_table256[(crc ^ *p++) & 0xff] ^ (crc >> 8);
}
return crc ^ 0xffffffff;
}
#define ngx_crc32_init(crc) \
crc = 0xffffffff
static ngx_inline void
ngx_crc32_update(uint32_t *crc, u_char *p, size_t len)
{
uint32_t c;
c = *crc;
while (len--) {
c = ngx_crc32_table256[(c ^ *p++) & 0xff] ^ (c >> 8);
}
*crc = c;
}
#define ngx_crc32_final(crc) \
crc ^= 0xffffffff
ngx_int_t ngx_crc32_table_init(void);
#endif /* _NGX_CRC32_H_INCLUDED_ */
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