view src/core/ngx_murmurhash.c @ 622:8dc007eddbcf NGINX_1_0_1

nginx 1.0.1 *) Change: now the "split_clients" directive uses MurmurHash2 algorithm because of better distribution. Thanks to Oleg Mamontov. *) Change: now long strings starting with zero are not considered as false values. Thanks to Maxim Dounin. *) Change: now nginx uses a default listen backlog value 511 on Linux. *) Feature: the $upstream_... variables may be used in the SSI and perl modules. *) Bugfix: now nginx limits better disk cache size. Thanks to Oleg Mamontov. *) Bugfix: a segmentation fault might occur while parsing incorrect IPv4 address; the bug had appeared in 0.9.3. Thanks to Maxim Dounin. *) Bugfix: nginx could not be built by gcc 4.6 without --with-debug option. *) Bugfix: nginx could not be built on Solaris 9 and earlier; the bug had appeared in 0.9.3. Thanks to Dagobert Michelsen. *) Bugfix: $request_time variable had invalid values if subrequests were used; the bug had appeared in 0.8.47. Thanks to Igor A. Valcov.
author Igor Sysoev <http://sysoev.ru>
date Tue, 03 May 2011 00:00:00 +0400
parents
children
line wrap: on
line source


/*
 * Copyright (C) Austin Appleby
 */


#include <ngx_config.h>
#include <ngx_core.h>


uint32_t
ngx_murmur_hash2(u_char *data, size_t len)
{
    uint32_t  h, k;

    h = 0 ^ len;

    while (len >= 4) {
        k  = data[0];
        k |= data[1] << 8;
        k |= data[2] << 16;
        k |= data[3] << 24;

        k *= 0x5bd1e995;
        k ^= k >> 24;
        k *= 0x5bd1e995;

        h *= 0x5bd1e995;
        h ^= k;

        data += 4;
        len -= 4;
    }

    switch (len) {
    case 3:
        h ^= data[2] << 16;
    case 2:
        h ^= data[1] << 8;
    case 1:
        h ^= data[0];
        h *= 0x5bd1e995;
    }

    h ^= h >> 13;
    h *= 0x5bd1e995;
    h ^= h >> 15;

    return h;
}