nginx 0.7.52 *) Feature: the first native Windows binary release. *) Bugfix: in processing HEAD method while caching. *) Bugfix: in processing the "If-Modified-Since", "If-Range", etc. client request header lines while caching. *) Bugfix: now the "Set-Cookie" and "P3P" header lines are hidden in cacheable responses. *) Bugfix: if nginx was built with the ngx_http_perl_module and with a perl which supports threads, then during a master process exit the message "panic: MUTEX_LOCK" might be issued. *) Bugfix: nginx could not be built --without-http-cache; the bug had appeared in 0.7.48. *) Bugfix: nginx could not be built on platforms different from i386, amd64, sparc, and ppc; the bug had appeared in 0.7.42.

/*
 * 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_ */