peer_connection.hpp

LINUX下

		{
			m_send_buffer.append_buffer(buffer, size, size, destructor);
#ifdef TORRENT_STATS
			m_ses.m_buffer_usage_logger << log_time() << " append_send_buffer: " << size << std::endl;
			m_ses.log_buffer_usage();
#endif
		}

#ifndef TORRENT_DISABLE_RESOLVE_COUNTRIES	
		void set_country(char const* c)
		{
			TORRENT_ASSERT(strlen(c) == 2);
			m_country[0] = c[0];
			m_country[1] = c[1];
		}
		bool has_country() const { return m_country[0] != 0; }
#endif

		int send_buffer_size() const
		{ return m_send_buffer.size(); }

		int send_buffer_capacity() const
		{ return m_send_buffer.capacity(); }

	protected:

		virtual void get_specific_peer_info(peer_info& p) const = 0;

		virtual void write_choke() = 0;
		virtual void write_unchoke() = 0;
		virtual void write_interested() = 0;
		virtual void write_not_interested() = 0;
		virtual void write_request(peer_request const& r) = 0;
		virtual void write_cancel(peer_request const& r) = 0;
		virtual void write_have(int index) = 0;
		virtual void write_keepalive() = 0;
		virtual void write_piece(peer_request const& r, char* buffer) = 0;
		
		virtual void write_reject_request(peer_request const& r) = 0;
		virtual void write_allow_fast(int piece) = 0;

		virtual void on_connected() = 0;
		virtual void on_tick() {}
	
		virtual void on_receive(asio::error_code const& error
			, std::size_t bytes_transferred) = 0;
		virtual void on_sent(asio::error_code const& error
			, std::size_t bytes_transferred) = 0;

#ifndef TORRENT_DISABLE_ENCRYPTION
		buffer::interval wr_recv_buffer()
		{
			if (m_recv_buffer.empty()) return buffer::interval(0,0);
			return buffer::interval(&m_recv_buffer[0]
				, &m_recv_buffer[0] + m_recv_pos);
		}
#endif
		
		buffer::const_interval receive_buffer() const
		{
			if (m_recv_buffer.empty()) return buffer::const_interval(0,0);
			return buffer::const_interval(&m_recv_buffer[0]
				, &m_recv_buffer[0] + m_recv_pos);
		}

		void cut_receive_buffer(int size, int packet_size);

		void reset_recv_buffer(int packet_size);
		int packet_size() const { return m_packet_size; }

		bool packet_finished() const
		{
			return m_packet_size <= m_recv_pos;
		}

		void setup_receive();

		void attach_to_torrent(sha1_hash const& ih);

		bool verify_piece(peer_request const& p) const;

		// the bandwidth channels, upload and download
		// keeps track of the current quotas
		bandwidth_limit m_bandwidth_limit[num_channels];

		// statistics about upload and download speeds
		// and total amount of uploads and downloads for
		// this peer
		stat m_statistics;

		// a back reference to the session
		// the peer belongs to.
		aux::session_impl& m_ses;

		// called from the main loop when this connection has any
		// work to do.
		void on_send_data(asio::error_code const& error
			, std::size_t bytes_transferred);
		void on_receive_data(asio::error_code const& error
			, std::size_t bytes_transferred);

		// this is the limit on the number of outstanding requests
		// we have to this peer. This is initialized to the settings
		// in the session_settings structure. But it may be lowered
		// if the peer is known to require a smaller limit (like BitComet).
		// or if the extended handshake sets a limit.
		// web seeds also has a limit on the queue size.
		int m_max_out_request_queue;

		void set_timeout(int s) { m_timeout = s; }

#ifndef TORRENT_DISABLE_EXTENSIONS
		typedef std::list<boost::shared_ptr<peer_plugin> > extension_list_t;
		extension_list_t m_extensions;
#endif

#ifndef TORRENT_DISABLE_RESOLVE_COUNTRIES	
		// in case the session settings is set
		// to resolve countries, this is set to
		// the two character country code this
		// peer resides in.
		char m_country[2];
#endif

	private:

		void fill_send_buffer();
		void on_disk_read_complete(int ret, disk_io_job const& j, peer_request r);
		void on_disk_write_complete(int ret, disk_io_job const& j
			, peer_request r, boost::shared_ptr<torrent> t);

		// the timeout in seconds
		int m_timeout;

		// the time when we last got a part of a
		// piece packet from this peer
		ptime m_last_piece;
		// the time we sent a request to
		// this peer the last time
		ptime m_last_request;
		// the time we received the last
		// piece request from the peer
		ptime m_last_incoming_request;
		// the time when we unchoked this peer
		ptime m_last_unchoke;

		int m_packet_size;
		int m_recv_pos;
		buffer m_recv_buffer;

		chained_buffer m_send_buffer;

		// the number of bytes we are currently reading
		// from disk, that will be added to the send
		// buffer as soon as they complete
		int m_reading_bytes;
		
		// timeouts
		ptime m_last_receive;
		ptime m_last_sent;

		boost::shared_ptr<socket_type> m_socket;
		// this is the peer we're actually talking to
		// it may not necessarily be the peer we're
		// connected to, in case we use a proxy
		tcp::endpoint m_remote;
		
		// this is the torrent this connection is
		// associated with. If the connection is an
		// incoming conncetion, this is set to zero
		// until the info_hash is received. Then it's
		// set to the torrent it belongs to.
		boost::weak_ptr<torrent> m_torrent;
		// is true if it was we that connected to the peer
		// and false if we got an incoming connection
		// could be considered: true = local, false = remote
		bool m_active;

		// remote peer's id
		peer_id m_peer_id;

		// other side says that it's interested in downloading
		// from us.
		bool m_peer_interested;

		// the other side has told us that it won't send anymore
		// data to us for a while
		bool m_peer_choked;

		// the peer has pieces we are interested in
		bool m_interesting;

		// we have choked the upload to the peer
		bool m_choked;

		// this is set to true if the connection timed
		// out or closed the connection. In that
		// case we will not try to reconnect to
		// this peer
		bool m_failed;

		// if this is set to true, the peer will not
		// request bandwidth from the limiter, but instead
		// just send and receive as much as possible.
		bool m_ignore_bandwidth_limits;

		// the pieces the other end have
		std::vector<bool> m_have_piece;
		// this is set to true when a have_all
		// message is received. This information
		// is used to fill the bitmask in init()
		bool m_have_all;

		// the number of pieces this peer
		// has. Must be the same as
		// std::count(m_have_piece.begin(),
		// m_have_piece.end(), true)
		int m_num_pieces;

		// the queue of requests we have got
		// from this peer
		std::deque<peer_request> m_requests;

		// the blocks we have reserved in the piece
		// picker and will request from this peer.
		std::deque<piece_block> m_request_queue;
		
		// the queue of blocks we have requested
		// from this peer
		std::deque<piece_block> m_download_queue;
		
		// the number of request we should queue up
		// at the remote end.
		int m_desired_queue_size;

		// the amount of data this peer has been given
		// as free upload. This is distributed from
		// peers from which we get free download
		// this will be negative on a peer from which
		// we get free download, and positive on peers
		// that we give the free upload, to keep the balance.
		size_type m_free_upload;

		// if this is true, this peer is assumed to handle all piece
		// requests in fifo order. All skipped blocks are re-requested
		// immediately instead of having a looser requirement
		// where blocks can be sent out of order. The default is to
		// allow non-fifo order.
		bool m_assume_fifo;

		// the number of invalid piece-requests
		// we have got from this peer. If the request
		// queue gets empty, and there have been
		// invalid requests, we can assume the
		// peer is waiting for those pieces.
		// we can then clear its download queue
		// by sending choke, unchoke.
		int m_num_invalid_requests;

		// this is true if this connection has been added
		// to the list of connections that will be closed.
		bool m_disconnecting;

		// the time when this peer sent us a not_interested message
		// the last time.
		ptime m_became_uninterested;

		// the time when we sent a not_interested message to
		// this peer the last time.
		ptime m_became_uninteresting;

		// this is true until this socket has become
		// writable for the first time (i.e. the
		// connection completed). While connecting
		// the timeout will not be triggered. This is
		// because windows XP SP2 may delay connection
		// attempts, which means that the connection
		// may not even have been attempted when the
		// time out is reached.
		bool m_connecting;

		// This is true until connect is called on the
		// peer_connection's socket. It is false on incoming
		// connections.
		bool m_queued;

		// these are true when there's a asynchronous write
		// or read operation in progress. Or an asyncronous bandwidth
		// request is in progress.
		bool m_writing;
		bool m_reading;

		// if set to non-zero, this peer will always prefer
		// to request entire n pieces, rather than blocks.
		// where n is the value of this variable.
		// if it is 0, the download rate limit setting
		// will be used to determine if whole pieces
		// are preferred.
		int m_prefer_whole_pieces;
		
		// if this is true, the blocks picked by the piece
		// picker will be merged before passed to the
		// request function. i.e. subsequent blocks are
		// merged into larger blocks. This is used by
		// the http-downloader, to request whole pieces
		// at a time.
		bool m_request_large_blocks;
		
		// this is the priority with which this peer gets
		// download bandwidth quota assigned to it.
		int m_priority;

		int m_upload_limit;
		int m_download_limit;

		// this peer's peer info struct. This may
		// be 0, in case the connection is incoming
		// and hasn't been added to a torrent yet.
		policy::peer* m_peer_info;

		// this is a measurement of how fast the peer
		// it allows some variance without changing
		// back and forth between states
		peer_speed_t m_speed;

		// the ticket id from the connection queue.
		// This is used to identify the connection
		// so that it can be removed from the queue
		// once the connection completes
		int m_connection_ticket;
		
		// bytes downloaded since last second
		// timer timeout; used for determining 
		// approx download rate
		int m_remote_bytes_dled;

		// approximate peer download rate
		int m_remote_dl_rate;

		// a timestamp when the remote download rate
		// was last updated
		ptime m_remote_dl_update;

		// the pieces we will send to the peer
		// if requested (regardless of choke state)
		std::set<int> m_accept_fast;

		// the pieces the peer will send us if
		// requested (regardless of choke state)
		std::vector<int> m_allowed_fast;

		// pieces that has been suggested to be
		// downloaded from this peer
		std::vector<int> m_suggested_pieces;

		// the number of bytes send to the disk-io
		// thread that hasn't yet been completely written.
		int m_outstanding_writing_bytes;

		// if this is true, the disconnection
		// timestamp is not updated when the connection
		// is closed. This means the time until we can
		// reconnect to this peer is shorter, and likely
		// immediate.
		bool m_fast_reconnect;
		
#ifndef NDEBUG
	public:
		bool m_in_constructor;
#endif
	};
}

#endif // TORRENT_PEER_CONNECTION_HPP_INCLUDED