src/kademlia/closest_nodes.cpp

   1 /*
   2
   3 Copyright (c) 2006, Arvid Norberg & Daniel Wallin
   4 All rights reserved.
   5
   6 Redistribution and use in source and binary forms, with or without
   7 modification, are permitted provided that the following conditions
   8 are met:
   9
  10     * Redistributions of source code must retain the above copyright
  11       notice, this list of conditions and the following disclaimer.
  12     * Redistributions in binary form must reproduce the above copyright
  13       notice, this list of conditions and the following disclaimer in
  14       the documentation and/or other materials provided with the distribution.
  15     * Neither the name of the author nor the names of its
  16       contributors may be used to endorse or promote products derived
  17       from this software without specific prior written permission.
  18
  19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  20 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  23 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29 POSSIBILITY OF SUCH DAMAGE.
  30
  31 */
  32
  33 #include "libtorrent/pch.hpp"
  34
  35 #include <libtorrent/kademlia/closest_nodes.hpp>
  36 #include <libtorrent/kademlia/routing_table.hpp>
  37 #include <libtorrent/kademlia/rpc_manager.hpp>
  38 #include "libtorrent/assert.hpp"
  39
  40 namespace libtorrent { namespace dht
  41 {
  42
  43 closest_nodes_observer::~closest_nodes_observer()
  44 {
  45         if (m_algorithm) m_algorithm->failed(m_self, true);
  46 }
  47
  48 void closest_nodes_observer::reply(msg const& in)
  49 {
  50         if (!m_algorithm)
  51         {
  52                 TORRENT_ASSERT(false);
  53                 return;
  54         }
  55
  56         if (!in.nodes.empty())
  57         {
  58                 for (msg::nodes_t::const_iterator i = in.nodes.begin()
  59                         , end(in.nodes.end()); i != end; ++i)
  60                 {
  61                         m_algorithm->traverse(i->id, i->addr);
  62                 }
  63         }
  64         m_algorithm->finished(m_self);
  65         m_algorithm = 0;
  66 }
  67
  68 void closest_nodes_observer::timeout()
  69 {
  70         if (!m_algorithm) return;
  71         m_algorithm->failed(m_self);
  72         m_algorithm = 0;
  73 }
  74
  75
  76 closest_nodes::closest_nodes(
  77         node_id target
  78         , int branch_factor
  79         , int max_results
  80         , routing_table& table
  81         , rpc_manager& rpc
  82         , done_callback const& callback
  83 )
  84         : traversal_algorithm(
  85                 target
  86                 , branch_factor
  87                 , max_results
  88                 , table
  89                 , rpc
  90                 , table.begin()
  91                 , table.end()
  92         )
  93         , m_done_callback(callback)
  94 {
  95         boost::intrusive_ptr<closest_nodes> self(this);
  96         add_requests();
  97 }
  98
  99 void closest_nodes::invoke(node_id const& id, udp::endpoint addr)
 100 {
 101         TORRENT_ASSERT(m_rpc.allocation_size() >= sizeof(closest_nodes_observer));
 102         observer_ptr o(new (m_rpc.allocator().malloc()) closest_nodes_observer(this, id, m_target));
 103 #ifndef NDEBUG
 104         o->m_in_constructor = false;
 105 #endif
 106         m_rpc.invoke(messages::find_node, addr, o);
 107 }
 108
 109 void closest_nodes::done()
 110 {
 111         std::vector<node_entry> results;
 112         int num_results = m_max_results;
 113         for (std::vector<result>::iterator i = m_results.begin()
 114                 , end(m_results.end()); i != end && num_results > 0; ++i)
 115         {
 116                 if (i->flags & result::no_id) continue;
 117                 if ((i->flags & result::queried) == 0) continue;
 118                 results.push_back(node_entry(i->id, i->addr));
 119                 --num_results;
 120         }
 121         m_done_callback(results);
 122 }
 123
 124 void closest_nodes::initiate(
 125         node_id target
 126         , int branch_factor
 127         , int max_results
 128         , routing_table& table
 129         , rpc_manager& rpc
 130         , done_callback const& callback
 131 )
 132 {
 133         new closest_nodes(target, branch_factor, max_results, table, rpc, callback);
 134 }
 135
 136 } } // namespace libtorrent::dht
 137