view src/core/ngx_crc.h @ 640:eb208e0cf44d NGINX_1_1_4

nginx 1.1.4 *) Feature: the ngx_http_upstream_keepalive module. *) Feature: the "proxy_http_version" directive. *) Feature: the "fastcgi_keep_conn" directive. *) Feature: the "worker_aio_requests" directive. *) Bugfix: if nginx was built --with-file-aio it could not be run on Linux kernel which did not support AIO. *) Bugfix: in Linux AIO error processing. Thanks to Hagai Avrahami. *) Bugfix: reduced memory consumption for long-lived requests. *) Bugfix: the module ngx_http_mp4_module did not support 64-bit MP4 "co64" atom.
author Igor Sysoev <http://sysoev.ru>
date Tue, 20 Sep 2011 00:00:00 +0400
parents fbf2b2f66c9f
children d0f7a625f27c
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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_ */