haproxy/include/common/hash.h
Willy Tarreau a0f4271497 MEDIUM: backend: add support for the wt6 hash
This function was designed for haproxy while testing other functions
in the past. Initially it was not planned to be used given the not
very interesting numbers it showed on real URL data : it is not as
smooth as the other ones. But later tests showed that the other ones
are extremely sensible to the server count and the type of input data,
especially DJB2 which must not be used on numeric input. So in fact
this function is still a generally average performer and it can make
sense to merge it in the end, as it can provide an alternative to
sdbm+avalanche or djb2+avalanche for consistent hashing or when hashing
on numeric data such as a source IP address or a visitor identifier in
a URL parameter.
2013-11-14 16:37:50 +01:00

30 lines
1.0 KiB
C

/*
* include/common/hash.h
* Macros for different hashing function.
*
* Copyright (C) 2000-2011 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _COMMON_HASH_H_
#define _COMMON_HASH_H_
unsigned long hash_djb2(const char *key, int len);
unsigned long hash_wt6(const char *key, int len);
unsigned long hash_sdbm(const char *key, int len);
#endif /* _COMMON_HASH_H_ */