nginx 0.8.1 *) Feature: the "updating" parameter in "proxy_cache_use_stale" and "fastcgi_cache_use_stale" directives. *) Bugfix: the "If-Modified-Since", "If-Range", etc. client request header lines were passed to backend while caching if no "proxy_set_header" directive was used with any parameters. *) Bugfix: the "Set-Cookie" and "P3P" response header lines were not hidden while caching if no "proxy_hide_header/fastcgi_hide_header" directives were used with any parameters. *) Bugfix: the ngx_http_image_filter_module did not support GIF87a format. Thanks to Denis Ilyinyh. *) Bugfix: nginx could not be built modules on Solaris 10 and early; the bug had appeared in 0.7.56.

/*
 * 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_ */