100 lines
2.7 KiB
C
100 lines
2.7 KiB
C
/*
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* Copyright 2013 Rob Kendrick <rjek@netsurf-browser.org>
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*
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* This file is part of NetSurf, http://www.netsurf-browser.org/
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*
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* NetSurf 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; version 2 of the License.
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*
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* NetSurf 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, see <http://www.gnu.org/licenses/>.
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*/
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/** \file
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* Trivial bloom filter */
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#ifndef _NETSURF_UTILS_BLOOM_H_
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#define _NETSURF_UTILS_BLOOM_H_
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#include <stdbool.h>
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#include <stddef.h>
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#include <stdint.h>
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struct bloom_filter;
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/**
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* Create a new bloom filter.
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*
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* \param size Size of bloom filter in bytes
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* \return Handle for newly-created bloom filter, or NULL
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*/
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struct bloom_filter *bloom_create(size_t size);
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/**
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* Destroy a previously-created bloom filter
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*
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* \param b Bloom filter to destroy
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*/
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void bloom_destroy(struct bloom_filter *b);
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/**
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* Insert a string of given length (may include NULs) into the filter,
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* using an internal hash function.
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*
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* \param b Bloom filter to add to
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* \param s Pointer to data
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* \param z Length of data
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*/
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void bloom_insert_str(struct bloom_filter *b, const char *s, size_t z);
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/**
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* Insert a given hash value into the filter, should you already have
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* one to hand.
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*
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* \param b Bloom filter to add to
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* \param hash Value to add
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*/
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void bloom_insert_hash(struct bloom_filter *b, uint32_t hash);
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/**
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* Search the filter for the given string, assuming it was added by
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* bloom_insert_str(). May return false-positives.
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*
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* \param b Bloom filter to search
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* \param s Pointer to data to search for
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* \param z Length of data
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*
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* \return False if never added, True if it might have been.
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*/
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bool bloom_search_str(struct bloom_filter *b, const char *s, size_t z);
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/**
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* Search the filter for the given hash value, assuming it was added by
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* bloom_insert_hash(). May return false-positives.
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*
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* \param b Bloom filter to search
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* \param hash Hash value to search for
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*
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* \return False if never added, True if it might have been.
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*/
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bool bloom_search_hash(struct bloom_filter *b, uint32_t hash);
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/**
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* Find out how many items have been added to this bloom filter. This
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* is useful for deciding the size of a new bloom filter should you
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* need to rehash it.
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*
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* \param b Bloom filter to examine
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*
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* \return Number of items that have been added
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*/
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uint32_t bloom_items(struct bloom_filter *b);
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#endif
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