forked from premiere/premiere-libtorrent
70 lines
2.2 KiB
C++
70 lines
2.2 KiB
C++
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/*
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Copyright (c) 2003-2014, 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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#include "libtorrent/aux_/merkle.hpp"
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namespace libtorrent
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{
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int merkle_get_parent(int tree_node)
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{
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// node 0 doesn't have a parent
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TORRENT_ASSERT(tree_node > 0);
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return (tree_node - 1) / 2;
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}
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int merkle_get_sibling(int tree_node)
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{
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// node 0 doesn't have a sibling
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TORRENT_ASSERT(tree_node > 0);
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// even numbers have their sibling to the left
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// odd numbers have their sibling to the right
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return tree_node + (tree_node&1?1:-1);
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}
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int merkle_num_nodes(int leafs)
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{
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TORRENT_ASSERT(leafs > 0);
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return (leafs << 1) - 1;
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}
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int merkle_num_leafs(int pieces)
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{
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TORRENT_ASSERT(pieces > 0);
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// round up to nearest 2 exponent
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int ret = 1;
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while (pieces > ret) ret <<= 1;
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return ret;
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}
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}
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