74 lines
2.3 KiB
C++
74 lines
2.3 KiB
C++
/*
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Copyright (c) 2010, Arvid Norberg
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the distribution.
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* Neither the name of the author nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef TORRENT_BLOOM_FILTER_HPP_INCLUDED
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#define TORRENT_BLOOM_FILTER_HPP_INCLUDED
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#include <boost/cstdint.hpp>
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#include "libtorrent/peer_id.hpp" // for sha1_hash
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#include "libtorrent/config.hpp" // for sha1_hash
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namespace libtorrent
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{
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TORRENT_EXPORT void set_bit(boost::uint32_t b, boost::uint8_t* bits, int len);
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TORRENT_EXPORT bool has_bit(boost::uint32_t b, boost::uint8_t const* bits, int len);
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template <int N>
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struct bloom_filter
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{
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bool find(sha1_hash const& k) const
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{
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return has_bit(k[0], bits, N)
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&& has_bit(k[1], bits, N)
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&& has_bit(k[2], bits, N);
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}
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void set(sha1_hash const& k)
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{
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set_bit(k[0], bits, N);
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set_bit(k[1], bits, N);
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set_bit(k[2], bits, N);
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}
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void clear() { memset(bits, 0, N); }
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bloom_filter() { clear(); }
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private:
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boost::uint8_t bits[N];
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};
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}
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#endif
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