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view src/core/ngx_crc.h @ 7943:2a7155733855

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Core: removed unnecessary restriction in hash initialization. Hash initialization ignores elements with key.data set to NULL. Nevertheless, the initial hash bucket size check didn't skip them, resulting in unnecessary restrictions on, for example, variables with long names and with the NGX_HTTP_VARIABLE_NOHASH flag. Fix is to update the initial hash bucket size check to skip elements with key.data set to NULL, similarly to how it is done in other parts of the code.
author Alexey Radkov <alexey.radkov@gmail.com>
date Thu, 19 Aug 2021 20:51:27 +0300
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_ */