view src/core/ngx_crc.h @ 622:8dc007eddbcf NGINX_1_0_1

nginx 1.0.1 *) Change: now the "split_clients" directive uses MurmurHash2 algorithm because of better distribution. Thanks to Oleg Mamontov. *) Change: now long strings starting with zero are not considered as false values. Thanks to Maxim Dounin. *) Change: now nginx uses a default listen backlog value 511 on Linux. *) Feature: the $upstream_... variables may be used in the SSI and perl modules. *) Bugfix: now nginx limits better disk cache size. Thanks to Oleg Mamontov. *) Bugfix: a segmentation fault might occur while parsing incorrect IPv4 address; the bug had appeared in 0.9.3. Thanks to Maxim Dounin. *) Bugfix: nginx could not be built by gcc 4.6 without --with-debug option. *) Bugfix: nginx could not be built on Solaris 9 and earlier; the bug had appeared in 0.9.3. Thanks to Dagobert Michelsen. *) Bugfix: $request_time variable had invalid values if subrequests were used; the bug had appeared in 0.8.47. Thanks to Igor A. Valcov.
author Igor Sysoev <http://sysoev.ru>
date Tue, 03 May 2011 00:00:00 +0400
parents fbf2b2f66c9f
children d0f7a625f27c
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


/* 32-bit crc16 */

static ngx_inline uint32_t
ngx_crc(u_char *data, size_t len)
{
    uint32_t  sum;

    for (sum = 0; len; len--) {

        /*
         * gcc 2.95.2 x86 and icc 7.1.006 compile
         * that operator into the single "rol" opcode,
         * msvc 6.0sp2 compiles it into four opcodes.
         */
        sum = sum >> 1 | sum << 31;

        sum += *data++;
    }

    return sum;
}


#endif /* _NGX_CRC_H_INCLUDED_ */