Mercurial > hg > nginx-vendor-current

view src/core/ngx_crc.h @ 238:a528ae0fe909 NGINX_0_4_4

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
nginx 0.4.4 *) Feature: the $scheme variable. *) Feature: the "expires" directive supports the "max" parameter. *) Feature: the "include" directive supports the "*" mask. Thanks to Jonathan Dance. *) Bugfix: the "return" directive always overrode the "error_page" response code redirected by the "error_page" directive. *) Bugfix: a segmentation fault occurred if zero-length body was in PUT method. *) Bugfix: the redirect was changed incorrectly if the variables were used in the "proxy_redirect" directive.
author Igor Sysoev <http://sysoev.ru>
date Mon, 02 Oct 2006 00:00:00 +0400
parents 74b1868dd3cd
children acd2ec3541cb
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


/* 32-bit crc16 */

static ngx_inline uint32_t ngx_crc(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_ */