annotate 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
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1
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2 /*
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3 * Copyright (C) Austin Appleby
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4 */
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5
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6
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7 #include <ngx_config.h>
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8 #include <ngx_core.h>
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9
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11 uint32_t
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12 ngx_murmur_hash2(u_char *data, size_t len)
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13 {
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14 uint32_t h, k;
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15
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16 h = 0 ^ len;
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17
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18 while (len >= 4) {
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19 k = data[0];
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20 k |= data[1] << 8;
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21 k |= data[2] << 16;
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22 k |= data[3] << 24;
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23
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24 k *= 0x5bd1e995;
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25 k ^= k >> 24;
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26 k *= 0x5bd1e995;
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27
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28 h *= 0x5bd1e995;
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29 h ^= k;
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30
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31 data += 4;
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32 len -= 4;
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33 }
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34
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35 switch (len) {
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36 case 3:
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37 h ^= data[2] << 16;
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38 case 2:
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39 h ^= data[1] << 8;
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40 case 1:
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41 h ^= data[0];
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42 h *= 0x5bd1e995;
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43 }
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44
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45 h ^= h >> 13;
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46 h *= 0x5bd1e995;
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47 h ^= h >> 15;
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48
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49 return h;
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50 }