added the ability to get scrape data from the tracker announce reply

docs/manual.rst

@@ -189,7 +189,7 @@ The basic usage is as follows:
 	* query the torrent_handles for progress (see torrent_handle_)
 	* query the session for information
 	* add and remove torrents from the session at run-time
-* destruct all torrent_handles
+* save resume data for all torrent_handles (optional)
 * destruct session object
 
 Each class and function is described in this manual.
@@ -799,6 +799,10 @@ Its declaration looks like this::
 		bool is_paused() const;
 		bool is_seed() const;
 
+		int num_complete() const;
+		int num_incomplete() const;
+		int num_downloaded() const;
+
 		bool has_metadata() const;
 
 		boost::filsystem::path save_path() const;
@@ -924,7 +928,25 @@ is_seed()
 
 Returns true if the torrent is in seed mode (i.e. if it has finished downloading).
 
+num_complete() num_incomplete() num_downloaded()
+------------------------------------------------
+
+	::
+
+		int num_complete() const;
+		int num_incomplete() const;
+		int num_downloaded() const;
+
+These members returns the optional scrape data returned by the tracker in the announce response.
+If the tracker did not return any scrape data the return value of these functions are -1. Note
+that in some cases the tracker can return some scrape data, so there is no guarantee that all
+functions returns -1 just because one of them do. ``num_complete()`` is the total number of
+seeds in the swarm. ``num_incomplete()`` is the number of downloaders in the swarm and
+``num_downloaded()`` is the number of times this torrent has been downloaded.
+
+
 has_metadata()
+--------------
 
 	::
 

include/libtorrent/torrent.hpp

@@ -150,6 +150,15 @@ namespace libtorrent
 		float ratio() const
 		{ return m_ratio; }
 
+		int num_complete() const
+		{ return m_complete; }
+
+		int num_incomplete() const
+		{ return m_incomplete; }
+
+		int num_downloaded() const
+		{ return m_downloaded; }
+	
 // --------------------------------------------
 		// PEER MANAGEMENT
 
@@ -192,7 +201,8 @@ namespace libtorrent
 		// (either http_tracker_connection or udp_tracker_connection)
 		// when this torrent got a response from its tracker request
 		// or when a failure occured
-		virtual void tracker_response(std::vector<peer_entry>& e, int interval);
+		virtual void tracker_response(std::vector<peer_entry>& e, int interval
+			, int complete, int incomplete, int downloaded);
 		virtual void tracker_request_timed_out();
 		virtual void tracker_request_error(int response_code, const std::string& str);
 
@@ -393,6 +403,12 @@ namespace libtorrent
 		// from the tracker
 		int m_duration;
 
+		// the scrape data from the tracker response, this
+		// is optional and may be -1.
+		int m_complete;
+		int m_incomplete;
+		int m_downloaded;
+		
 		std::map<address, peer_connection*> m_connections;
 
 		// this is the upload and download statistics for the whole torrent.

include/libtorrent/torrent_handle.hpp

@@ -197,6 +197,13 @@ namespace libtorrent
 		void pause();
 		void resume();
 
+		// interface for requesting tracker scrape data
+		// from tha last tracker announce response
+		// (optional, only sent by some trackers)
+		int num_complete() const;
+		int num_incomplete() const;
+		int num_downloaded() const;
+		
 		// set the interface to bind outgoing connections
 		// to.
 		void use_interface(const char* net_interface);

include/libtorrent/tracker_manager.hpp

@@ -104,7 +104,10 @@ namespace libtorrent
 		virtual ~request_callback() {}
 		virtual void tracker_response(
 			std::vector<peer_entry>& peers
-			, int interval) = 0;
+			, int interval
+			, int complete
+			, int incomplete
+			, int downloaded) = 0;
 		virtual void tracker_request_timed_out() = 0;
 		virtual void tracker_request_error(
 			int response_code

src/http_tracker_connection.cpp

@@ -542,7 +542,7 @@ namespace libtorrent
 		return ret;
 	}
 
-	void http_tracker_connection::parse(const entry& e)
+	void http_tracker_connection::parse(entry const& e)
 	{
 		if (!has_requester()) return;
 
@@ -553,13 +553,13 @@ namespace libtorrent
 
 			try
 			{
-				const entry& failure = e["failure reason"];
+				entry const& failure = e["failure reason"];
 
 				if (has_requester()) requester().tracker_request_error(
 					m_code, failure.string().c_str());
 				return;
 			}
-			catch (const type_error&) {}
+			catch (type_error const&) {}
 
 			int interval = (int)e["interval"].integer();
 
@@ -587,7 +587,7 @@ namespace libtorrent
 			}
 			else
 			{
-				const entry::list_type& l = e["peers"].list();
+				entry::list_type const& l = e["peers"].list();
 				for(entry::list_type::const_iterator i = l.begin(); i != l.end(); ++i)
 				{
 					peer_entry p = extract_peer_info(*i);
@@ -595,7 +595,23 @@ namespace libtorrent
 				}
 			}
 
-			requester().tracker_response(peer_list, interval);
+			// look for optional crape info
+			int complete = -1;
+			int incomplete = -1;
+			int downloaded = -1;
+			try
+			{
+				entry const& f = e["files"];
+				entry const& sd = f[std::string(m_req.info_hash.begin()
+					, m_req.info_hash.end())];
+				complete = sd["complete"].integer();
+				incomplete = sd["incomplete"].integer();
+				downloaded = sd["downloaded"].integer();
+			}
+			catch(type_error& e) {}
+			
+			requester().tracker_response(peer_list, interval, complete
+				, incomplete, downloaded);
 		}
 		catch(type_error& e)
 		{

src/session.cpp

@@ -132,8 +132,7 @@ namespace libtorrent { namespace detail
 				if (!t->abort)
 				{
 					boost::mutex::scoped_lock l(m_ses.m_mutex);
-					m_ses.m_torrents.insert(
-						std::make_pair(t->info_hash, t->torrent_ptr)).first;
+					m_ses.m_torrents.insert(std::make_pair(t->info_hash, t->torrent_ptr));
 					m_torrents.pop_front();
 					if (t->torrent_ptr->is_seed() && m_ses.m_alerts.should_post(alert::info))
 					{

src/torrent.cpp

@@ -160,6 +160,9 @@ namespace libtorrent
 		, m_storage(0)
 		, m_next_request(second_clock::universal_time())
 		, m_duration(1800)
+		, m_complete(-1)
+		, m_incomplete(-1)
+		, m_downloaded(-1)
 		, m_policy()
 		, m_ses(ses)
 		, m_picker(0)
@@ -203,6 +206,9 @@ namespace libtorrent
 		, m_storage(0)
 		, m_next_request(second_clock::universal_time())
 		, m_duration(1800)
+		, m_complete(-1)
+		, m_incomplete(-1)
+		, m_downloaded(-1)
 		, m_policy()
 		, m_ses(ses)
 		, m_picker(0)
@@ -271,7 +277,10 @@ namespace libtorrent
 
 	void torrent::tracker_response(
 		std::vector<peer_entry>& peer_list
-		, int interval)
+		, int interval
+		, int complete
+		, int incomplete
+		, int downloaded)
 	{
 		m_failed_trackers = 0;
 		// less than 5 minutes announce intervals
@@ -294,6 +303,10 @@ namespace libtorrent
 			m_next_request = second_clock::universal_time() + boost::posix_time::seconds(m_duration);
 		}
 
+		if (complete >= 0) m_complete = complete;
+		if (incomplete >= 0) m_incomplete = incomplete;
+		if (downloaded >= 0) m_downloaded = downloaded;
+		
 		// connect to random peers from the list
 		std::random_shuffle(peer_list.begin(), peer_list.end());
 

src/torrent_handle.cpp

@@ -271,6 +271,28 @@ namespace libtorrent
 			, bind(&torrent::resume, _1));
 	}
 
+
+	int torrent_handle::num_complete() const
+	{
+		INVARIANT_CHECK;
+		return call_member<int>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::num_complete, _1));
+	}
+
+	int torrent_handle::num_incomplete() const
+	{
+		INVARIANT_CHECK;
+		return call_member<int>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::num_incomplete, _1));
+	}
+
+	int torrent_handle::num_downloaded() const
+	{
+		INVARIANT_CHECK;
+		return call_member<int>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::num_downloaded, _1));
+	}
+	
 	void torrent_handle::set_tracker_login(std::string const& name, std::string const& password)
 	{
 		INVARIANT_CHECK;

src/udp_tracker_connection.cpp

@@ -241,18 +241,20 @@ namespace libtorrent
 		}
 		if (action != announce) return false;
 
-		if (len < 12)
+		if (len < 24)
 		{
 #ifndef NDEBUG
 			if (has_requester())
 				requester().debug_log("udp_tracker_connection: "
-				"got a message with size < 12, ignoring");
+				"got a message with size < 24, ignoring");
 #endif
 			return false;
 		}
 		int interval = detail::read_int32(buf);
-		int num_peers = (len - 12) / 6;
-		if ((len - 12) % 6 != 0)
+		int incomplete = detail::read_int32(buf);
+		int complete = detail::read_int32(buf);
+		int num_peers = (len - 24) / 6;
+		if ((len - 24) % 6 != 0)
 		{
 			if (has_requester())
 				requester().tracker_request_error(-1, "invalid tracker response");
@@ -276,7 +278,7 @@ namespace libtorrent
 			peer_list.push_back(e);
 		}
 
-		requester().tracker_response(peer_list, interval);
+		requester().tracker_response(peer_list, interval, complete, incomplete, -1);
 		return true;
 	}