--- /dev/null
+/* Copyright (c) 2012-2017. The SimGrid Team.
+ * All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+#ifndef BITTORRENT_PEER_HPP
+#define BITTORRENT_PEER_HPP
+#include "s4u_bittorrent.hpp"
+#include <set>
+#include <unordered_map>
+
+class Connection {
+public:
+ int id; // Peer id
+ simgrid::s4u::MailboxPtr mailbox_;
+ unsigned int bitfield = 0U; // Fields
+ // int messages_count;
+ double peer_speed = 0;
+ double last_unchoke = 0;
+ int current_piece = -1;
+ bool am_interested = false; // Indicates if we are interested in something the peer has
+ bool interested = false; // Indicates if the peer is interested in one of our pieces
+ bool choked_upload = true; // Indicates if the peer is choked for the current peer
+ bool choked_download = true; // Indicates if the peer has choked the current peer
+
+ Connection(int id) : id(id), mailbox_(simgrid::s4u::Mailbox::byName(std::to_string(id))){};
+ ~Connection() = default;
+ void addSpeedValue(double speed) { peer_speed = peer_speed * 0.6 + speed * 0.4; }
+ bool hasPiece(unsigned int piece) { return bitfield & 1U << piece; }
+};
+
+class Peer {
+ int id;
+ double deadline;
+ RngStream stream;
+ simgrid::s4u::MailboxPtr mailbox_;
+ std::set<Connection*> active_peers; // active peers list
+
+ unsigned int bitfield_ = 0; // list of pieces the peer has.
+ unsigned long long bitfield_blocks = 0; // list of blocks the peer has.
+ short* pieces_count = nullptr; // number of peers that have each piece.
+ unsigned int current_pieces = 0; // current pieces the peer is downloading
+ double begin_receive_time = 0; // time when the receiving communication has begun, useful for calculating host speed.
+ int round_ = 0; // current round for the chocking algorithm.
+
+ std::unordered_map<int, Connection*> connected_peers;
+ simgrid::s4u::CommPtr comm_received = nullptr; // current comm
+ Message* message = nullptr; // current message being received
+public:
+ explicit Peer(std::vector<std::string> args);
+ ~Peer();
+ void operator()();
+
+ std::string getStatus();
+ bool hasFinished();
+ int nbInterestedPeers();
+ bool isInterestedBy(Connection* remote_peer);
+ bool isInterestedByFree(Connection* remote_peer);
+ void updateActivePeersSet(Connection* remote_peer);
+ void updateInterestedAfterReceive();
+ void updateChokedPeers();
+
+ bool hasNotPiece(unsigned int piece) { return !(bitfield_ & 1U << piece); }
+ bool hasCompletedPiece(unsigned int piece);
+ unsigned int countPieces(unsigned int bitfield);
+ /** Check that a piece is not currently being download by the peer. */
+ bool isNotDownloadingPiece(unsigned int piece) { return !(current_pieces & 1U << piece); }
+ int partiallyDownloadedPiece(Connection* remote_peer);
+ void updatePiecesCountFromBitfield(unsigned int bitfield);
+ void removeCurrentPiece(Connection* remote_peer, unsigned int current_piece);
+ void updateBitfieldBlocks(int piece, int block_index, int block_length);
+ int getFirstMissingBlockFrom(int piece);
+ int selectPieceToDownload(Connection* remote_peer);
+ void requestNewPieceTo(Connection* remote_peer);
+
+ bool getPeersFromTracker();
+ void sendHandshake(simgrid::s4u::MailboxPtr mailbox);
+ void sendBitfield(simgrid::s4u::MailboxPtr mailbox);
+ void sendPiece(simgrid::s4u::MailboxPtr mailbox, unsigned int piece, int block_index, int block_length);
+ void sendInterested(simgrid::s4u::MailboxPtr mailbox);
+ void sendChoked(simgrid::s4u::MailboxPtr mailbox);
+ void sendUnchoked(simgrid::s4u::MailboxPtr mailbox);
+ void sendNotInterested(simgrid::s4u::MailboxPtr mailbox);
+ void sendHandshakeToAllPeers();
+ void sendRequest(simgrid::s4u::MailboxPtr mailbox, unsigned int piece, int block_index, int block_length);
+ void sendHaveToAllPeers(unsigned int piece);
+ void sendRequestTo(Connection* remote_peer, unsigned int piece);
+
+ void handleMessage();
+ void leech();
+ void seed();
+};
+
+#endif /* BITTORRENT_PEER_HPP */
