include/libtorrent/kademlia/closest_nodes.hpp

   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 #ifndef CLOSEST_NODES_050323_HPP
  34 #define CLOSEST_NODES_050323_HPP
  35
  36 #include <vector>
  37
  38 #include <libtorrent/kademlia/traversal_algorithm.hpp>
  39 #include <libtorrent/kademlia/node_id.hpp>
  40 #include <libtorrent/kademlia/routing_table.hpp>
  41 #include <libtorrent/kademlia/observer.hpp>
  42 #include <libtorrent/kademlia/msg.hpp>
  43
  44 #include <boost/function.hpp>
  45
  46 namespace libtorrent { namespace dht
  47 {
  48
  49 class rpc_manager;
  50
  51 // -------- closest nodes -----------
  52
  53 class closest_nodes : public traversal_algorithm
  54 {
  55 public:
  56         typedef boost::function<
  57                 void(std::vector<node_entry> const&)
  58         > done_callback;
  59
  60         static void initiate(
  61                 node_id target
  62                 , int branch_factor
  63                 , int max_results
  64                 , routing_table& table
  65                 , rpc_manager& rpc
  66                 , done_callback const& callback
  67         );
  68
  69 private:
  70         void done();
  71         void invoke(node_id const& id, asio::ip::udp::endpoint addr);
  72
  73         closest_nodes(
  74                 node_id target
  75                 , int branch_factor
  76                 , int max_results
  77                 , routing_table& table
  78                 , rpc_manager& rpc
  79                 , done_callback const& callback
  80         );
  81
  82         done_callback m_done_callback;
  83 };
  84
  85 class closest_nodes_observer : public observer
  86 {
  87 public:
  88         closest_nodes_observer(
  89                 boost::intrusive_ptr<traversal_algorithm> const& algorithm
  90                 , node_id self
  91                 , node_id target)
  92                 : observer(algorithm->allocator())
  93                 , m_algorithm(algorithm)
  94                 , m_target(target)
  95                 , m_self(self)
  96         {}
  97         ~closest_nodes_observer();
  98
  99         void send(msg& p)
 100         {
 101                 p.info_hash = m_target;
 102         }
 103
 104         void timeout();
 105         void reply(msg const&);
 106         void abort() { m_algorithm = 0; }
 107
 108 private:
 109         boost::intrusive_ptr<traversal_algorithm> m_algorithm;
 110         node_id const m_target;
 111         node_id const m_self;
 112 };
 113
 114 } } // namespace libtorrent::dht
 115
 116 #endif // CLOSEST_NODES_050323_HPP
 117