premiere-libtorrent/include/libtorrent/kademlia/node_id.hpp

/*

Copyright (c) 2006-2012, Arvid Norberg
All rights reserved.

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modification, are permitted provided that the following conditions
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    * Redistributions in binary form must reproduce the above copyright
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      the documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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*/
#ifndef NODE_ID_HPP
#define NODE_ID_HPP

#include <algorithm>

#include <boost/cstdint.hpp>
#include "libtorrent/config.hpp"
#include "libtorrent/peer_id.hpp"
#include "libtorrent/assert.hpp"
#include "libtorrent/address.hpp"

namespace libtorrent { namespace dht
{

struct node_entry;

typedef libtorrent::sha1_hash node_id;

// returns the distance between the two nodes
// using the kademlia XOR-metric
node_id TORRENT_EXTRA_EXPORT distance(node_id const& n1, node_id const& n2);

// returns true if: distance(n1, ref) < distance(n2, ref)
bool TORRENT_EXTRA_EXPORT compare_ref(node_id const& n1, node_id const& n2, node_id const& ref);

// returns n in: 2^n <= distance(n1, n2) < 2^(n+1)
// useful for finding out which bucket a node belongs to
// the value that's returned is the number of trailing bits
// after the shared bit prefix of ``n1`` and ``n2``.
// if the first bits are different, that's 160.
int TORRENT_EXTRA_EXPORT distance_exp(node_id const& n1, node_id const& n2);

node_id TORRENT_EXTRA_EXPORT generate_id(address const& external_ip);
node_id TORRENT_EXTRA_EXPORT generate_random_id();
node_id TORRENT_EXTRA_EXPORT generate_id_impl(address const& ip_, boost::uint32_t r);

bool TORRENT_EXTRA_EXPORT verify_id(node_id const& nid, address const& source_ip);
bool TORRENT_EXTRA_EXPORT matching_prefix(node_entry const& n, int mask, int prefix, int bucket_index);
node_id TORRENT_EXTRA_EXPORT generate_prefix_mask(int bits);

} } // namespace libtorrent::dht

#endif // NODE_ID_HPP