rate limiter fix for metadata extension

include/libtorrent/peer_connection.hpp

@@ -195,6 +195,12 @@ namespace libtorrent
 		policy::peer* peer_info_struct() const
 		{ return m_peer_info; }
 
+		// used by extensions to advertise that they expect to
+		// receive a number of bytes, this will make the peer
+		// connection request more download quota from the download
+		// rate limiter
+		void extension_expect_bytes(int n) { m_extension_outstanding_bytes += n; }
+
 		enum peer_speed_t { slow = 1, medium, fast };
 		peer_speed_t peer_speed();
 
@@ -820,6 +826,10 @@ namespace libtorrent
 		// have sent to it
 		int m_outstanding_bytes;
 
+		// the number of outstanding bytes expected
+		// to be received by extensions
+		int m_extension_outstanding_bytes;
+
 		// the number of time critical requests
 		// queued up in the m_request_queue that
 		// soon will be committed to the download

src/metadata_transfer.cpp

@@ -207,6 +207,8 @@ namespace libtorrent { namespace
 				metadata();
 		}
 
+		int metadata_size() const { return m_metadata_size; }
+
 	private:
 		torrent& m_torrent;
 
@@ -285,6 +287,8 @@ namespace libtorrent { namespace
 				<< " ==> METADATA_REQUEST  [ start: " << start << " | size: " << size << " ]\n";
 #endif
 
+			m_pc.extension_expect_bytes(m_tp.metadata_size() == 0 ? 2048 : m_tp.metadata_size() * size / 255);
+
 			buffer::interval i = m_pc.allocate_send_buffer(9);
 
 			detail::write_uint32(1 + 1 + 3, i.begin);

src/peer_connection.cpp

@@ -103,6 +103,7 @@ namespace libtorrent
 		, m_receiving_block(-1, -1)
 		, m_timeout_extend(0)
 		, m_outstanding_bytes(0)
+		, m_extension_outstanding_bytes(0)
 		, m_queued_time_critical(0)
 		, m_num_pieces(0)
 		, m_timeout(m_ses.settings().peer_timeout)
@@ -236,6 +237,7 @@ namespace libtorrent
 		, m_receiving_block(-1, -1)
 		, m_timeout_extend(0)
 		, m_outstanding_bytes(0)
+		, m_extension_outstanding_bytes(0)
 		, m_queued_time_critical(0)
 		, m_num_pieces(0)
 		, m_timeout(m_ses.settings().peer_timeout)
@@ -4170,8 +4172,8 @@ namespace libtorrent
 		TORRENT_ASSERT(m_outstanding_bytes >= 0);
 		m_channel_state[download_channel] = peer_info::bw_limit;
 		m_ses.m_download_rate.request_bandwidth(self()
-			, m_outstanding_bytes + 30, priority
+			, (std::max)(m_outstanding_bytes, m_extension_outstanding_bytes) + 30
-			, bwc1, bwc2, bwc3, bwc4);
+			, priority , bwc1, bwc2, bwc3, bwc4);
 	}
 
 	void peer_connection::setup_send()
@@ -4526,6 +4528,9 @@ namespace libtorrent
 
 		int bytes_in_loop = bytes_transferred;
 
+		if (m_extension_outstanding_bytes > 0)
+			m_extension_outstanding_bytes -= (std::min)(m_extension_outstanding_bytes, int(bytes_transferred));
+
 		if (error)
 		{
 #if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING

src/ut_metadata.cpp

@@ -324,6 +324,7 @@ namespace libtorrent { namespace
 					if (!m_torrent.valid_metadata())
 					{
 						write_metadata_packet(2, piece);
+						m_pc.extension_expect_bytes(0x4000);
 						return true;
 					}
 					// TODO: put the request on the queue in some cases