nginx 0.8.16 *) Feature: the "image_filter_transparency" directive. *) Bugfix: "addition_types" directive was incorrectly named "addtion_types". *) Bugfix: resolver cache poisoning. Thanks to Matthew Dempsky. *) Bugfix: memory leak in resolver. Thanks to Matthew Dempsky. *) Bugfix: invalid request line in $request variable was written in access_log only if error_log was set to "info" or "debug" level. *) Bugfix: in PNG alpha-channel support in the ngx_http_image_filter_module. *) Bugfix: nginx always added "Vary: Accept-Encoding" response header line, if both "gzip_static" and "gzip_vary" were on. *) Bugfix: in UTF-8 encoding support by "try_files" directive in nginx/Windows. *) Bugfix: in "post_action" directive usage; the bug had appeared in 0.8.11. Thanks to Igor Artemiev.

/*
 * 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_ */