nginx 0.8.31 *) Feature: now the "error_page" directive may redirect the 301 and 302 responses. *) Feature: the $geoip_city_continent_code, $geoip_latitude, and $geoip_longitude variables. Thanks to Arvind Sundararajan. *) Feature: now the ngx_http_image_filter_module deletes always EXIF and other application specific data if the data consume more than 5% of a JPEG file. *) Bugfix: nginx closed a connection if a cached response had an empty body. Thanks to Piotr Sikora. *) Bugfix: nginx might not be built by gcc 4.x if the -O2 or higher optimization option was used. Thanks to Maxim Dounin and Denis F. Latypoff. *) Bugfix: regular expressions in location were always tested in case-sensitive mode; the bug had appeared in 0.8.25. *) Bugfix: nginx cached a 304 response if there was the "If-None-Match" header line in a proxied request. Thanks to Tim Dettrick and David Kostal. *) Bugfix: nginx/Windows tried to delete a temporary file twice if the file should replace an already existent file.

/*
 * 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_ */