b28ff39f42
sizes and numbers of hash functions In order to make the bloom filter logic more future proof communicate bloom filter parameters from the original bus creator to the clients, and allow them to be variable within certain ranges.
44 lines
1.4 KiB
C
44 lines
1.4 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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#pragma once
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/***
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This file is part of systemd.
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Copyright 2013 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <sys/types.h>
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/*
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* Our default bloom filter has the following parameters:
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*
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* m=512 (bits in the filter)
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* k=8 (hash functions)
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*
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* We use SipHash24 as hash function with a number of (originally
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* randomized) but fixed hash keys.
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*
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*/
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#define DEFAULT_BLOOM_SIZE (512/8) /* m: filter size */
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#define DEFAULT_BLOOM_N_HASH 8 /* k: number of hash functions */
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void bloom_add_pair(uint64_t filter[], size_t size, unsigned n_hash, const char *a, const char *b);
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void bloom_add_prefixes(uint64_t filter[], size_t size, unsigned n_hash, const char *a, const char *b, char sep);
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bool bloom_validate_parameters(size_t size, unsigned n_hash);
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