view src/core/ngx_murmurhash.c @ 4848:a0f1d53546d4 stable-1.2

Merge of r4778, r4782, r4783, r4824, r4830, r4834: minor fixes. *) Reorder checks in ngx_shared_memory_add() for more consistent error messages. *) Added "const" to ngx_memcpy() with NGX_MEMCPY_LIMIT defined. This fixes warning produced during compilation of the ngx_http_geoip_module due to const qualifier being discarded. *) Fixed possible use of old cached times if runtime went backwards. If ngx_time_sigsafe_update() updated only ngx_cached_err_log_time, and then clock was adjusted backwards, the cached_time[slot].sec might accidentally match current seconds on next ngx_time_update() call, resulting in various cached times not being updated. Fix is to clear the cached_time[slot].sec to explicitly mark cached times are stale and need updating. *) Radix tree preallocation fix. The preallocation size was calculated incorrectly and was always 8 due to sizeof(ngx_radix_tree_t) accidentally used instead of sizeof(ngx_radix_node_t). *) Fixed overflow if ngx_slab_alloc() is called with very big "size" argument. *) Write filter: replaced unneeded loop with one to free chains. Noted by Gabor Lekeny.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 24 Sep 2012 18:34:04 +0000
parents 203eb026ec07
children f38647c651a8
line wrap: on
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/*
 * 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;
}