most of the metadata is now freed when a torrent becomes a seed. #44

include/libtorrent/torrent_handle.hpp

@@ -373,3 +373,4 @@ namespace libtorrent
 }
 
 #endif // TORRENT_TORRENT_HANDLE_HPP_INCLUDED
+

include/libtorrent/torrent_info.hpp

@@ -115,7 +115,11 @@ namespace libtorrent
 		std::vector<file_slice> map_block(int piece, size_type offset, int size) const;
 		peer_request map_file(int file, size_type offset, int size) const;
 		
-		std::vector<std::string> const& url_seeds() const { return m_url_seeds; }
+		std::vector<std::string> const& url_seeds() const
+		{
+			assert(!m_half_metadata);
+			return m_url_seeds;
+		}
 
 		typedef std::vector<file_entry>::const_iterator file_iterator;
 		typedef std::vector<file_entry>::const_reverse_iterator reverse_file_iterator;
@@ -135,7 +139,7 @@ namespace libtorrent
 
 		size_type total_size() const { assert(m_piece_length > 0); return m_total_size; }
 		size_type piece_length() const { assert(m_piece_length > 0); return m_piece_length; }
-		int num_pieces() const { assert(m_piece_length > 0); return (int)m_piece_hash.size(); }
+		int num_pieces() const { assert(m_piece_length > 0); return m_num_pieces; }
 		const sha1_hash& info_hash() const { return m_info_hash; }
 		const std::string& name() const { assert(m_piece_length > 0); return m_name; }
 
@@ -156,6 +160,7 @@ namespace libtorrent
 		{
 			assert(index >= 0);
 			assert(index < (int)m_piece_hash.size());
+			assert(!m_half_metadata);
 			return m_piece_hash[index];
 		}
 
@@ -171,7 +176,10 @@ namespace libtorrent
 		typedef std::vector<std::pair<std::string, int> > nodes_t;
 		
 		nodes_t const& nodes() const
-		{ return m_nodes; }
+		{
+			assert(!m_half_metadata);
+			return m_nodes;
+		}
 		
 		void add_node(std::pair<std::string, int> const& node);
 
@@ -180,6 +188,10 @@ namespace libtorrent
 		entry extra(char const* key) const
 		{ return m_extra_info[key]; }
 
+		// frees parts of the metadata that isn't
+		// used by seeds
+		void seed_free();
+
 	private:
 
 		void read_torrent_info(const entry& libtorrent);
@@ -205,6 +217,9 @@ namespace libtorrent
 		// the sum of all filesizes
 		size_type m_total_size;
 
+		// the number of pieces in the torrent
+		int m_num_pieces;
+
 		// the hash that identifies this torrent
 		// is mutable because it's calculated
 		// lazily
@@ -241,6 +256,11 @@ namespace libtorrent
 		// reproduce the info-section when sending the metadata
 		// to peers.
 		entry m_extra_info;
+
+#ifndef NDEBUG
+		// this is set to true when seed_free() is called
+		bool m_half_metadata;
+#endif
 	};
 
 }

src/metadata_transfer.cpp

@@ -106,7 +106,15 @@ namespace libtorrent { namespace
 		{
 			m_requested_metadata.resize(256, 0);
 		}
-	
+
+		virtual void on_files_checked()
+		{
+			// if the torrent is a seed, copy the metadata from
+			// the torrent before it is deallocated
+			if (m_torrent.is_seed())
+				metadata();
+		}
+
 		virtual boost::shared_ptr<peer_plugin> new_connection(
 			peer_connection* pc);
 		
@@ -211,6 +219,14 @@ namespace libtorrent { namespace
 			m_metadata_size = total_size;
 		}
 
+		void piece_pass(int)
+		{
+			// if we became a seed, copy the metadata from
+			// the torrent before it is deallocated
+			if (m_torrent.is_seed())
+				metadata();
+		}
+
 	private:
 		torrent& m_torrent;
 

src/torrent.cpp

@@ -1010,7 +1010,11 @@ namespace libtorrent
 			try { (*i)->on_piece_pass(index); } catch (std::exception&) {}
 		}
 #endif
-		if (is_seed()) m_picker.reset();
+		if (is_seed())
+		{
+			m_picker.reset();
+			m_torrent_file.seed_free();
+		}
 	}
 
 	std::string torrent::tracker_login() const
@@ -2108,9 +2112,19 @@ namespace libtorrent
 			if (m_sequenced_download_threshold > 0)
 				picker().set_sequenced_download_threshold(m_sequenced_download_threshold);
 		}
-		else
+
+#ifndef TORRENT_DISABLE_EXTENSIONS
+		for (extension_list_t::iterator i = m_extensions.begin()
+			, end(m_extensions.end()); i != end; ++i)
+		{
+			try { (*i)->on_files_checked(); } catch (std::exception&) {}
+		}
+#endif
+
+		if (is_seed())
 		{
 			m_picker.reset();
+			m_torrent_file.seed_free();
 		}
 
 		if (!m_connections_initialized)
@@ -2142,14 +2156,6 @@ namespace libtorrent
 #ifndef NDEBUG
 		m_initial_done = boost::get<0>(bytes_done());
 #endif
-
-#ifndef TORRENT_DISABLE_EXTENSIONS
-		for (extension_list_t::iterator i = m_extensions.begin()
-			, end(m_extensions.end()); i != end; ++i)
-		{
-			try { (*i)->on_files_checked(); } catch (std::exception&) {}
-		}
-#endif
 	}
 
 	alert_manager& torrent::alerts() const

src/torrent_info.cpp

@@ -219,10 +219,14 @@ namespace libtorrent
 
 	// standard constructor that parses a torrent file
 	torrent_info::torrent_info(const entry& torrent_file)
-		: m_creation_date(pt::ptime(pt::not_a_date_time))
+		: m_num_pieces(0)
+		, m_creation_date(pt::ptime(pt::not_a_date_time))
 		, m_multifile(false)
 		, m_private(false)
 		, m_extra_info(entry::dictionary_t)
+#ifndef NDEBUG
+		, m_half_metadata(false)
+#endif
 	{
 		try
 		{
@@ -241,24 +245,32 @@ namespace libtorrent
 	torrent_info::torrent_info(sha1_hash const& info_hash)
 		: m_piece_length(0)
 		, m_total_size(0)
+		, m_num_pieces(0)
 		, m_info_hash(info_hash)
 		, m_name()
 		, m_creation_date(pt::second_clock::universal_time())
 		, m_multifile(false)
 		, m_private(false)
 		, m_extra_info(entry::dictionary_t)
+#ifndef NDEBUG
+		, m_half_metadata(false)
+#endif
 	{
 	}
 
 	torrent_info::torrent_info()
 		: m_piece_length(0)
 		, m_total_size(0)
+		, m_num_pieces(0)
 		, m_info_hash(0)
 		, m_name()
 		, m_creation_date(pt::second_clock::universal_time())
 		, m_multifile(false)
 		, m_private(false)
 		, m_extra_info(entry::dictionary_t)
+#ifndef NDEBUG
+		, m_half_metadata(false)
+#endif
 	{
 	}
 
@@ -278,15 +290,15 @@ namespace libtorrent
 			}
 		}
 #endif
+		assert(!m_half_metadata);
 		m_piece_length = size;
 
-
-		int num_pieces = static_cast<int>(
+		m_num_pieces = static_cast<int>(
 			(m_total_size + m_piece_length - 1) / m_piece_length);
 		int old_num_pieces = static_cast<int>(m_piece_hash.size());
 
-		m_piece_hash.resize(num_pieces);
-		for (int i = old_num_pieces; i < num_pieces; ++i)
+		m_piece_hash.resize(m_num_pieces);
+		for (int i = old_num_pieces; i < m_num_pieces; ++i)
 		{
 			m_piece_hash[i].clear();
 		}
@@ -344,14 +356,14 @@ namespace libtorrent
 		// we want this division to round upwards, that's why we have the
 		// extra addition
 
-		int num_pieces = static_cast<int>((m_total_size + m_piece_length - 1) / m_piece_length);
-		m_piece_hash.resize(num_pieces);
+		m_num_pieces = static_cast<int>((m_total_size + m_piece_length - 1) / m_piece_length);
+		m_piece_hash.resize(m_num_pieces);
 		const std::string& hash_string = info["pieces"].string();
 
-		if ((int)hash_string.length() != num_pieces * 20)
+		if ((int)hash_string.length() != m_num_pieces * 20)
 			throw invalid_torrent_file();
 
-		for (int i = 0; i < num_pieces; ++i)
+		for (int i = 0; i < m_num_pieces; ++i)
 			std::copy(
 				hash_string.begin() + i*20
 				, hash_string.begin() + (i+1)*20
@@ -550,12 +562,12 @@ namespace libtorrent
 		if (m_piece_length == 0)
 			m_piece_length = 256 * 1024;
 
-		int num_pieces = static_cast<int>(
+		m_num_pieces = static_cast<int>(
 			(m_total_size + m_piece_length - 1) / m_piece_length);
 		int old_num_pieces = static_cast<int>(m_piece_hash.size());
 
-		m_piece_hash.resize(num_pieces);
-		if (num_pieces > old_num_pieces)
+		m_piece_hash.resize(m_num_pieces);
+		if (m_num_pieces > old_num_pieces)
 			std::for_each(m_piece_hash.begin() + old_num_pieces
 				, m_piece_hash.end(), boost::bind(&sha1_hash::clear, _1));
 	}
@@ -736,6 +748,16 @@ namespace libtorrent
 		assert(false);
 	}
 
+	void torrent_info::seed_free()
+	{
+		std::vector<std::string>().swap(m_url_seeds);
+		nodes_t().swap(m_nodes);
+		std::vector<sha1_hash>().swap(m_piece_hash);
+#ifndef NDEBUG
+		m_half_metadata = true;
+#endif
+	}
+
 // ------- start deprecation -------
 
 	void torrent_info::print(std::ostream& os) const