view src/core/ngx_crc.h @ 5047:852f40088278 stable-1.2

Merge of r4968, r4969, r4977, r4980, r4981, r4990: geo fixes. *) Geo: improved ngx_http_geo_block() code readability. *) Geo: fixed the "ranges" without ranges case. The following configuration returned an empty value for $geo: geo $geo { ranges; default default; } *) Fixed return type of internal function that allocates radix tree nodes. *) There's no need to normalize address returned by ngx_ptocidr(). *) Geo: ensure that default entry is always present. If 0.0.0.0/32 entry was present and there was no explicit "default", we failed to add an empty string as a default value. *) Trailing whitespace fix.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 11 Feb 2013 12:26:33 +0000
parents d620f497c50f
children
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/*
 * 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_ */