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

/*

Copyright (c) 2006-2016, Arvid Norberg
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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.
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      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
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*/
#ifndef NODE_ID_HPP
#define NODE_ID_HPP

#include <vector>
#include <cstdint>

#include <libtorrent/config.hpp>
#include <libtorrent/sha1_hash.hpp>
#include <libtorrent/address.hpp>

namespace libtorrent { namespace dht {

using node_id = libtorrent::sha1_hash;

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

// returns true if: distance(n1, ref) < distance(n2, ref)
TORRENT_EXTRA_EXPORT bool 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.
TORRENT_EXTRA_EXPORT int distance_exp(node_id const& n1, node_id const& n2);
TORRENT_EXTRA_EXPORT int min_distance_exp(node_id const& n1, std::vector<node_id> const& ids);

TORRENT_EXTRA_EXPORT node_id generate_id(address const& external_ip);
TORRENT_EXTRA_EXPORT node_id generate_random_id();
TORRENT_EXTRA_EXPORT void make_id_secret(node_id& in);
TORRENT_EXTRA_EXPORT node_id generate_secret_id();
TORRENT_EXTRA_EXPORT bool verify_secret_id(node_id const& nid);
TORRENT_EXTRA_EXPORT node_id generate_id_impl(address const& ip_, std::uint32_t r);

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

} } // namespace libtorrent::dht

#endif // NODE_ID_HPP