view src/core/ngx_crc.h @ 230:38e7b94d63ac NGINX_0_4_0

nginx 0.4.0 *) Change in internal API: the HTTP modules initialization was moved from the init module phase to the HTTP postconfiguration phase. *) Change: now the request body is not read beforehand for the ngx_http_perl_module: it's required to start the reading using the $r->has_request_body method. *) Feature: the ngx_http_perl_module supports the DECLINED return code. *) Feature: the ngx_http_dav_module supports the incoming "Date" header line for the PUT method. *) Feature: the "ssi" directive is available inside the "if" block. *) Bugfix: a segmentation fault occurred if there was an "index" directive with variables and the first index name was without variables; bug appeared in 0.1.29.
author Igor Sysoev <http://sysoev.ru>
date Wed, 30 Aug 2006 00:00:00 +0400
parents 74b1868dd3cd
children acd2ec3541cb
line wrap: on
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/*
 * 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_ */