Dynamic modules. The auto/module script is extended to understand ngx_module_link=DYNAMIC. When set, it links the module as a shared object rather than statically into nginx binary. The module can later be loaded using the "load_module" directive. New auto/module parameter ngx_module_order allows to define module loading order in complex cases. By default the order is set based on ngx_module_type. 3rd party modules can be compiled dynamically using the --add-dynamic-module configure option, which will preset ngx_module_link to "DYNAMIC" before calling the module config script. Win32 support is rudimentary, and only works when using MinGW gcc (which is able to handle exports/imports automatically). In collaboration with Ruslan Ermilov.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#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_ */