added seed mode support (lazy hash checking)

include/libtorrent/bitfield.hpp

@@ -244,12 +244,14 @@ namespace libtorrent
 			if (m_size && (bits & 7)) m_bytes[(m_size + 7) / 8 - 1] &= 0xff << (7 - (bits & 7));
 		}
 
+		void free() { dealloc(); m_size = 0; }
+
 	private:
 
 		void dealloc() { if (m_own) std::free(m_bytes); m_bytes = 0; }
 		unsigned char* m_bytes;
-		int m_size; // in bits
-		bool m_own;
+		int m_size:31; // in bits
+		bool m_own:1;
 	};
 
 }

include/libtorrent/bt_peer_connection.hpp

@@ -425,6 +425,7 @@ private:
 		// the number of bytes in the send buffer
 		// that have been encrypted (only used for
 		// encrypted connections)
+public:
 		int m_encrypted_bytes;
 #endif
 

include/libtorrent/disk_io_thread.hpp

@@ -91,6 +91,7 @@ namespace libtorrent
 			, clear_read_cache
 			, abort_torrent
 			, update_settings
+			, read_and_hash
 		};
 
 		action_t action;
@@ -260,6 +261,8 @@ namespace libtorrent
 		cache_t::iterator find_cached_piece(
 			cache_t& cache, disk_io_job const& j
 			, mutex_t::scoped_lock& l);
+		int copy_from_piece(cache_t::iterator p, bool& hit
+			, disk_io_job const& j, mutex_t::scoped_lock& l);
 
 		// write cache operations
 		void flush_oldest_piece(mutex_t::scoped_lock& l);
@@ -271,13 +274,16 @@ namespace libtorrent
 		// read cache operations
 		bool clear_oldest_read_piece(cache_t::iterator ignore
 			, mutex_t::scoped_lock& l);
-		int read_into_piece(cached_piece_entry& p, int start_block, mutex_t::scoped_lock& l);
+		int read_into_piece(cached_piece_entry& p, int start_block
+			, int options, mutex_t::scoped_lock& l);
 		int cache_read_block(disk_io_job const& j, mutex_t::scoped_lock& l);
+		int cache_read_piece(disk_io_job const& j, mutex_t::scoped_lock& l);
 		void free_piece(cached_piece_entry& p, mutex_t::scoped_lock& l);
 		bool make_room(int num_blocks
 			, cache_t::iterator ignore
 			, mutex_t::scoped_lock& l);
 		int try_read_from_cache(disk_io_job const& j);
+		int read_piece_from_cache_and_hash(disk_io_job const& j, sha1_hash& h);
 
 		// this mutex only protects m_jobs, m_queue_buffer_size
 		// and m_abort

include/libtorrent/error_code.hpp

@@ -49,7 +49,8 @@ namespace libtorrent
 		enum error_code_enum
 		{
 			no_error = 0,
-			file_collision
+			file_collision,
+			failed_hash_check
 		};
 	}
 

include/libtorrent/session.hpp

@@ -173,6 +173,7 @@ namespace libtorrent
 			, duplicate_is_error(false)
 			, storage(sc)
 			, userdata(0)
+			, seed_mode(false)
 		{}
 
 		boost::intrusive_ptr<torrent_info> ti;
@@ -187,6 +188,7 @@ namespace libtorrent
 		bool duplicate_is_error;
 		storage_constructor_type storage;
 		void* userdata;
+		bool seed_mode;
 	};
 	
 	class TORRENT_EXPORT session: public boost::noncopyable, aux::eh_initializer

include/libtorrent/storage.hpp

@@ -191,7 +191,7 @@ namespace libtorrent
 		session_settings* m_settings;
 	};
 
-	typedef storage_interface* (&storage_constructor_type)(
+	typedef storage_interface* (*storage_constructor_type)(
 		file_storage const&, fs::path const&, file_pool&);
 
 	TORRENT_EXPORT storage_interface* default_storage_constructor(
@@ -234,6 +234,11 @@ namespace libtorrent
 			, boost::function<void(int, disk_io_job const&)> const& handler
 			, int priority = 0);
 
+		void async_read_and_hash(
+			peer_request const& r
+			, boost::function<void(int, disk_io_job const&)> const& handler
+			, int priority = 0);
+
 		void async_write(
 			peer_request const& r
 			, disk_buffer_holder& buffer

include/libtorrent/torrent.hpp

@@ -83,6 +83,7 @@ namespace libtorrent
 	struct bitfield;
 	struct announce_entry;
 	struct tracker_request;
+	struct add_torrent_params;
 
 	namespace aux
 	{
@@ -118,36 +119,8 @@ namespace libtorrent
 	{
 	public:
 
-		torrent(
-			aux::session_impl& ses
-			, boost::intrusive_ptr<torrent_info> tf
-			, fs::path const& save_path
-			, tcp::endpoint const& net_interface
-			, storage_mode_t m_storage_mode
-			, int block_size
-			, storage_constructor_type sc
-			, bool paused
-			, std::vector<char>* resume_data
-			, int seq
-			, bool auto_managed);
-
-		// used with metadata-less torrents
-		// (the metadata is downloaded from the peers)
-		torrent(
-			aux::session_impl& ses
-			, char const* tracker_url
-			, sha1_hash const& info_hash
-			, char const* name
-			, fs::path const& save_path
-			, tcp::endpoint const& net_interface
-			, storage_mode_t m_storage_mode
-			, int block_size
-			, storage_constructor_type sc
-			, bool paused
-			, std::vector<char>* resume_data
-			, int seq
-			, bool auto_managed);
-
+		torrent(aux::session_impl& ses, tcp::endpoint const& net_interface
+			, int block_size, int seq, add_torrent_params const& p);
 		~torrent();
 
 #ifndef TORRENT_DISABLE_ENCRYPTION
@@ -691,6 +664,34 @@ namespace libtorrent
 
 		int sequence_number() const { return m_sequence_number; }
 
+		bool seed_mode() const { return m_seed_mode; }
+		void leave_seed_mode(bool seed)
+		{
+			if (!m_seed_mode) return;
+			m_seed_mode = false;
+			// seed is false if we turned out not
+			// to be a seed after all
+			if (!seed) force_recheck();
+			m_num_verified = 0;
+			m_verified.free();
+		}
+		bool all_verified() const
+		{ return m_num_verified == m_torrent_file->num_pieces(); }
+		bool verified_piece(int piece) const
+		{
+			TORRENT_ASSERT(piece < int(m_verified.size()));
+			TORRENT_ASSERT(piece >= 0);
+			return m_verified.get_bit(piece);
+		}
+		void verified(int piece)
+		{
+			TORRENT_ASSERT(piece < int(m_verified.size()));
+			TORRENT_ASSERT(piece >= 0);
+			TORRENT_ASSERT(m_verified.get_bit(piece) == false);
+			++m_num_verified;
+			m_verified.set_bit(piece);
+		}
+
 	private:
 
 		void on_files_deleted(int ret, disk_io_job const& j);
@@ -866,6 +867,14 @@ namespace libtorrent
 
 		fs::path m_save_path;
 
+		// each bit represents a piece. a set bit means
+		// the piece has had its hash verified. This
+		// is only used in seed mode (when m_seed_mode
+		// is true)
+		bitfield m_verified;
+		// m_num_verified = m_verified.count()
+		int m_num_verified;
+
 		// determines the storage state for this torrent.
 		storage_mode_t m_storage_mode;
 
@@ -1029,6 +1038,12 @@ namespace libtorrent
 		// is in use. i.e. one or more trackers are waiting
 		// for a reannounce
 		bool m_waiting_tracker:1;
+
+		// this means we haven't verified the file content
+		// of the files we're seeding. the m_verified bitfield
+		// indicates which pieces have been verified and which
+		// haven't
+		bool m_seed_mode:1;
 	};
 
 	inline ptime torrent::next_announce() const

include/libtorrent/torrent_handle.hpp

@@ -121,6 +121,7 @@ namespace libtorrent
 			, last_scrape(0)
 			, has_incoming(false)
 			, sparse_regions(0)
+			, seed_mode(false)
 		{}
 
 		enum state_t
@@ -274,6 +275,9 @@ namespace libtorrent
 
 		// the number of "holes" in the torrent
 		int sparse_regions;
+
+		// is true if this torrent is (still) in seed_mode
+		bool seed_mode;
 	};
 
 	struct TORRENT_EXPORT block_info