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- usrloc hash fix (performace): switched to a numeric string optimized hash function (which also has very good distribution for strings) - added the new hash to core's hashes.h & changes hashes.h license to openbsd style (so that anybody can use the hash functions without being forced to gpl the code)
Andrei Pelinescu-Onciul authored on 24/11/2006 17:20:08
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@@ -3,31 +3,23 @@ |
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* |
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* Copyright (C) 2006 iptelorg GmbH |
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* |
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- * This file is part of ser, a free SIP server. |
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+ * Permission to use, copy, modify, and distribute this software for any |
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+ * purpose with or without fee is hereby granted, provided that the above |
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+ * copyright notice and this permission notice appear in all copies. |
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* |
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- * ser is free software; you can redistribute it and/or modify |
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- * it under the terms of the GNU General Public License as published by |
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- * the Free Software Foundation; either version 2 of the License, or |
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- * (at your option) any later version |
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- * |
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- * For a license to use the ser software under conditions |
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- * other than those described here, or to purchase support for this |
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- * software, please contact iptel.org by e-mail at the following addresses: |
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- * info@iptel.org |
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- * |
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- * ser is distributed in the hope that it will be useful, |
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- * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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- * GNU General Public License for more details. |
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- * |
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- * You should have received a copy of the GNU General Public License |
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- * along with this program; if not, write to the Free Software |
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- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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/* |
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* History: |
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* -------- |
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* 2006-02-02 created by andrei |
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+ * 2006-11-24 added numeric string optimized hash function (andrei) |
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*/ |
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@@ -98,6 +90,58 @@ inline static unsigned int get_hash1_raw(char* s, int len) |
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+/* a little slower than hash_* , but better distribution for |
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+ * numbers and about the same for strings */ |
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+#define hash_update_str2(s, end, p, v, h) \ |
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+ do{ \
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+ for ((p)=(s); (p)<=((end)-4); (p)+=4){ \
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+ (v)=(*(p)*16777213)+((p)[1]*65537)+((p)[2]*257)+(p)[3]; \ |
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+ (h)=16777259*(h)+((v)^((v)<<17)); \ |
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+ } \ |
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+ (v)=0; \ |
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+ for (;(p)<(end); (p)++){ (v)*=251; (v)+=*(p);} \
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+ (h)=16777259*(h)+((v)^((v)<<17)); \ |
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+ }while(0) |
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+ |
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+/* internal use: call it to adjust the h from hash_update_str */ |
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+#define hash_finish2(h) (((h)+((h)>>7))+(((h)>>13)+((h)>>23))) |
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+ |
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+ |
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+ |
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+/* a little slower than get_hash1_raw() , but better distribution for |
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+ * numbers and about the same for strings */ |
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+inline static unsigned int get_hash1_raw2(char* s, int len) |
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+{
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+ char* p; |
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+ register unsigned v; |
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+ register unsigned h; |
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+ |
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+ h=0; |
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+ |
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+ hash_update_str2(s, s+len, p, v, h); |
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+ return hash_finish2(h); |
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+} |
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+ |
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+ |
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+ |
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+/* "raw" 2 strings hash optimized for numeric strings (see above) |
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+ * returns an unsigned int (which you can use modulo table_size as hash value) |
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+ */ |
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+inline static unsigned int get_hash2_raw2(str* key1, str* key2) |
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+{
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+ char* p; |
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+ register unsigned v; |
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+ register unsigned h; |
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+ |
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+ h=0; |
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+ |
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+ hash_update_str2(key1->s, key1->s+key1->len, p, v, h); |
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+ hash_update_str2(key2->s, key2->s+key2->len, p, v, h); |
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+ return hash_finish(h); |
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+} |
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+ |
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+ |
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+ |
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/* generic, simple str keyed hash */ |
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struct str_hash_entry{
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