D:/opendownloadmanager/ODM-1.x/Bittorrent/libtorrent-0.12/src/kademlia/node_id.cpp

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/*
  Free Download Manager Copyright (c) 2003-2007 FreeDownloadManager.ORG
*/  


 

#include <algorithm>
#include <iomanip>
#include <cassert>
#include <boost/bind.hpp>

#include "libtorrent/kademlia/node_id.hpp"

using boost::bind;

namespace libtorrent { namespace dht
{  

node_id distance(node_id const& n1, node_id const& n2)
{
        node_id ret;
        node_id::iterator k = ret.begin();
        for (node_id::const_iterator i = n1.begin(), j = n2.begin()
                , end(n1.end()); i != end; ++i, ++j, ++k)
        {
                *k = *i ^ *j;
        }
        return ret;
} 

bool compare_ref(node_id const& n1, node_id const& n2, node_id const& ref)
{
        for (node_id::const_iterator i = n1.begin(), j = n2.begin()
                , k = ref.begin(), end(n1.end()); i != end; ++i, ++j, ++k)
        {
                boost::uint8_t lhs = (*i ^ *k);
                boost::uint8_t rhs = (*j ^ *k);
                if (lhs < rhs) return true;
                if (lhs > rhs) return false;
        }
        return false;
}  

int distance_exp(node_id const& n1, node_id const& n2)
{
        int byte = node_id::size - 1;
        for (node_id::const_iterator i = n1.begin(), j = n2.begin()
                , end(n1.end()); i != end; ++i, ++j, --byte)
        {
                assert(byte >= 0);
                boost::uint8_t t = *i ^ *j;
                if (t == 0) continue;
                
                
                
                int bit = byte * 8;
                for (int b = 7; b > 0; --b)
                        if (t >= (1 << b)) return bit + b;
                return bit;
        }

        return 0;
}

} }  

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