added api for piece priorities

ChangeLog

@@ -1,3 +1,12 @@
+	* the following functions have been deprecated:
+	  	void torrent_handle::filter_piece(int index, bool filter) const;
+	  	void torrent_handle::filter_pieces(std::vector<bool> const& pieces) const;
+	  	bool torrent_handle::is_piece_filtered(int index) const;
+	  	std::vector<bool> torrent_handle::filtered_pieces() const;
+	  	void torrent_handle::filter_files(std::vector<bool> const& files) const;
+	  
+	  instead, use the piece_priority functions.
+	  
 	* added support for NAT-PMP
 	* added support for piece priorities. Piece filtering is now set as
 	  a priority

docs/manual.rst

@@ -1217,11 +1217,19 @@ Its declaration looks like this::
 		void resolve_countries(bool r);
 		bool resolve_countries() const;
 
+		void piece_priority(int index, int priority) const;
+		int piece_priority(int index) const;
+
+		void prioritize_pieces(std::vector<int> const& pieces) const;
+		std::vector<int> piece_priorities() const;
+
+		void prioritize_files(std::vector<int> const& files) const;
+
+		// these functions are deprecated
 		void filter_piece(int index, bool filter) const;
 		void filter_pieces(std::vector<bool> const& bitmask) const;
 		bool is_piece_filtered(int index) const;
 		std::vector<bool> filtered_pieces() const;
-
 		void filter_files(std::vector<bool> const& files) const;
       
 		bool has_metadata() const;
@@ -1236,9 +1244,10 @@ Its declaration looks like this::
 		bool operator<(torrent_handle const&) const;
 	};
 
-The default constructor will initialize the handle to an invalid state. Which means you cannot
-perform any operation on it, unless you first assign it a valid handle. If you try to perform
-any operation on an uninitialized handle, it will throw ``invalid_handle``.
+The default constructor will initialize the handle to an invalid state. Which
+means you cannot perform any operation on it, unless you first assign it a
+valid handle. If you try to perform any operation on an uninitialized handle,
+it will throw ``invalid_handle``.
 
 .. warning:: All operations on a ``torrent_handle`` may throw invalid_handle_
 	exception, in case the handle is no longer refering to a torrent. There are
@@ -1246,7 +1255,54 @@ any operation on an uninitialized handle, it will throw ``invalid_handle``.
 	Since the torrents are processed by a background thread, there is no
 	guarantee that a handle will remain valid between two calls.
 
-*TODO: document filter_piece(), filter_pieces(), is_piece_filtered(), filtered_pieces() and filter_files()*
+
+piece_priority() prioritize_pieces() piece_priorities() prioritize_files()
+--------------------------------------------------------------------------
+
+	::
+
+		void piece_priority(int index, int priority) const;
+		int piece_priority(int index) const;
+		void prioritize_pieces(std::vector<int> const& pieces) const;
+		std::vector<int> piece_priorities() const;
+		void prioritize_files(std::vector<int> const& files) const;
+
+These functions are used to set and get the prioritiy of individual pieces.
+By default all pieces have priority 1. That means that the random rarest
+first algorithm is effectively active for all pieces. You may however
+change the priority of individual pieces. There are 8 different priority
+levels:
+
+0. piece is not downloaded at all
+1. normal priority. Download order is dependent on availability
+2. higher than normal priority. Pieces are preferred over pieces with
+   the same availability, but not over pieces with lower availability
+3. pieces are as likely to be picked as partial pieces.
+4. pieces are preferred over partial pieces, but not over pieces with
+   lower availability
+5. *currently the same as 4*
+6. piece is as likely to be picked as any piece with availability 1
+7. maximum priority, availability is disregarded, the piece is preferred
+   over any other piece with lower priority
+
+The exact definitions of these priorities are implementation details, and
+subject to change. The interface guarantees that higher number means higher
+priority, and that 0 means do not download.
+
+``piece_priority`` sets or gets the priority for an individual piece,
+specified by ``index``.
+
+``prioritize_pieces`` takes a vector of integers, one integer per piece in
+the torrent. All the piece priorities will be updated with the priorities
+in the vector.
+
+``piece_priorities`` returns a vector with one element for each piece in the
+torrent. Each element is the current priority of that piece.
+
+``prioritize_files`` takes a vector that has at as many elements as there are
+files in the torrent. Each entry is the priority of that file. The function
+sets the priorities of all the pieces in the torrent based on the vector.
+
 
 file_progress()
 ---------------

include/libtorrent/piece_picker.hpp

@@ -138,18 +138,21 @@ namespace libtorrent
 		void we_have(int index);
 
 		// sets the priority of a piece.
-		// 0 is filtered, i.e. do not download
-		// 1 is normal priority
-		// 2 is high priority
-		// 3 is maximum priority (availability is ignored)
 		void set_piece_priority(int index, int prio);
 
 		// returns the priority for the piece at 'index'
 		int piece_priority(int index) const;
 
+		// returns the current piece priorities for all pieces
+		void piece_priorities(std::vector<int>& pieces) const;
+
+		// ========== start deprecation ==============
+
 		// fills the bitmask with 1's for pieces that are filtered
 		void filtered_pieces(std::vector<bool>& mask) const;
 
+		// ========== end deprecation ==============
+
 		// pieces should be the vector that represents the pieces a
 		// client has. It returns a list of all pieces that this client
 		// has and that are interesting to download. It returns them in
@@ -245,18 +248,21 @@ namespace libtorrent
 			unsigned downloading : 1;
 			// is 0 if the piece is filtered (not to be downloaded)
 			// 1 is normal priority (default)
-			// 2 is high priority
-			// 3 is maximum priority (ignores availability)
-			unsigned piece_priority : 2;
+			// 2 is higher priority than pieces at the same availability level
+			// 3 is same priority as partial pieces
+			// 4 is higher priority than partial pieces
+			// 5 and 6 same priority as availability 1 (ignores availability)
+			// 7 is maximum priority (ignores availability)
+			unsigned piece_priority : 3;
 			// index in to the piece_info vector
-			unsigned index : 19;
+			unsigned index : 18;
 
 			enum
 			{
 				// index is set to this to indicate that we have the
 				// piece. There is no entry for the piece in the
 				// buckets if this is the case.
-				we_have_index = 0x7ffff,
+				we_have_index = 0x3ffff,
 				// the priority value that means the piece is filtered
 				filter_priority = 0,
 				// the max number the peer count can hold
@@ -281,7 +287,11 @@ namespace libtorrent
 				switch (piece_priority)
 				{
 					case 2: return prio - 1;
-					case 3: return 1;
+					case 3: return (std::max)(prio / 2, 1);
+					case 4: return (std::max)(prio / 2 - 1, 1);
+					case 5:
+					case 6: return (std::min)(prio / 2 - 1, 2);
+					case 7: return 1;
 				}
 				return prio;
 			}

include/libtorrent/torrent.hpp

@@ -171,12 +171,23 @@ namespace libtorrent
 		void resume();
 		bool is_paused() const { return m_paused; }
 
+		// ============ start deprecation =============
 		void filter_piece(int index, bool filter);
 		void filter_pieces(std::vector<bool> const& bitmask);
 		bool is_piece_filtered(int index) const;
 		void filtered_pieces(std::vector<bool>& bitmask) const;
-	
 		void filter_files(std::vector<bool> const& files);
+		// ============ end deprecation =============
+
+
+		void set_piece_priority(int index, int priority);
+		int piece_priority(int index) const;
+
+		void prioritize_pieces(std::vector<int> const& pieces);
+		void piece_priorities(std::vector<int>&) const;
+
+		void prioritize_files(std::vector<int> const& files);
+
 
 		torrent_status status() const;
 		void file_progress(std::vector<float>& fp) const;

include/libtorrent/torrent_handle.hpp

@@ -188,7 +188,7 @@ namespace libtorrent
 		// the number of distributed copies of the file.
 		// note that one copy may be spread out among many peers.
 		//
-		// the whole number part tells how many copies
+		// the integer part tells how many copies
 		//   there are of the rarest piece(s)
 		//
 		// the fractional part tells the fraction of pieces that
@@ -247,17 +247,33 @@ namespace libtorrent
 		void resolve_countries(bool r);
 		bool resolve_countries() const;
 
+		// all these are deprecated, use piece
+		// priority functions instead
+
+		// ================ start deprecation ============
+
 		// marks the piece with the given index as filtered
 		// it will not be downloaded
 		void filter_piece(int index, bool filter) const;
 		void filter_pieces(std::vector<bool> const& pieces) const;
 		bool is_piece_filtered(int index) const;
 		std::vector<bool> filtered_pieces() const;
-
 		// marks the file with the given index as filtered
 		// it will not be downloaded
 		void filter_files(std::vector<bool> const& files) const;
 
+		// ================ end deprecation ============
+
+		// priority must be within the range [0, 7]
+		void piece_priority(int index, int priority) const;
+		int piece_priority(int index) const;
+
+		void prioritize_pieces(std::vector<int> const& pieces) const;
+		std::vector<int> piece_priorities() const;
+
+		void prioritize_files(std::vector<int> const& files) const;
+
+
 		// set the interface to bind outgoing connections
 		// to.
 		void use_interface(const char* net_interface) const;

src/piece_picker.cpp

@@ -649,7 +649,7 @@ namespace libtorrent
 	{
 		TORRENT_PIECE_PICKER_INVARIANT_CHECK;
 		assert(new_piece_priority >= 0);
-		assert(new_piece_priority <= 3);
+		assert(new_piece_priority <= 7);
 		assert(index >= 0);
 		assert(index < (int)m_piece_map.size());
 		
@@ -701,34 +701,7 @@ namespace libtorrent
 			move(prev_priority, p.index);
 		}
 	}
-/*	
-	// this function can be used for pieces that we don't
-	// have, but have marked as filtered (so we didn't
-	// want to download them) but later want to enable for
-	// downloading, then we call this function and it will
-	// be inserted in the available piece list again
-	void piece_picker::mark_as_unfiltered(int index)
-	{
-		TORRENT_PIECE_PICKER_INVARIANT_CHECK;
-		assert(index >= 0);
-		assert(index < (int)m_piece_map.size());
 
-		piece_pos& p = m_piece_map[index];
-		if (!p.filtered()) return;	
-		p.filtered(false);
-		if (p.index != piece_pos::we_have_index)
-		{
-			--m_num_filtered;
-			assert(m_num_filtered >= 0);
-			add(index);
-		}
-		else
-		{
-			--m_num_have_filtered;
-			assert(m_num_have_filtered >= 0);
-		}
-	}
-*/
 	int piece_picker::piece_priority(int index) const
 	{
 		assert(index >= 0);
@@ -737,6 +710,19 @@ namespace libtorrent
 		return m_piece_map[index].piece_priority;
 	}
 
+	void piece_picker::piece_priorities(std::vector<int>& pieces) const
+	{
+		pieces.resize(m_piece_map.size());
+		std::vector<int>::iterator j = pieces.begin();
+		for (std::vector<piece_pos>::const_iterator i = m_piece_map.begin(),
+			end(m_piece_map.end()); i != end; ++i, ++j)
+		{
+			*j = i->piece_priority;
+		}
+	}
+
+	// ============ start deprecation ==============
+
 	void piece_picker::filtered_pieces(std::vector<bool>& mask) const
 	{
 		mask.resize(m_piece_map.size());
@@ -747,6 +733,8 @@ namespace libtorrent
 			*j = i->filtered();
 		}
 	}
+
+	// ============ end deprecation ==============
 	
 	void piece_picker::pick_pieces(const std::vector<bool>& pieces
 		, std::vector<piece_block>& interesting_blocks

src/torrent.cpp

@@ -1022,6 +1022,134 @@ namespace libtorrent
 		return m_username + ":" + m_password;
 	}
 
+
+
+	void torrent::set_piece_priority(int index, int priority)
+	{
+		INVARIANT_CHECK;
+
+		assert(valid_metadata());
+		if (is_seed()) return;
+
+		// this call is only valid on torrents with metadata
+		assert(m_picker.get());
+		assert(index >= 0);
+		assert(index < m_torrent_file.num_pieces());
+
+		// TODO: update peer's interesting-bit
+		
+		m_picker->set_piece_priority(index, priority);
+	}
+
+	int torrent::piece_priority(int index) const
+	{
+		INVARIANT_CHECK;
+
+		assert(valid_metadata());
+		if (is_seed()) return 1;
+
+		// this call is only valid on torrents with metadata
+		assert(m_picker.get());
+		assert(index >= 0);
+		assert(index < m_torrent_file.num_pieces());
+
+		// TODO: update peer's interesting-bit
+		
+		return m_picker->piece_priority(index);
+	}
+
+	void torrent::prioritize_pieces(std::vector<int> const& pieces)
+	{
+		INVARIANT_CHECK;
+
+		// this call is only valid on torrents with metadata
+		assert(valid_metadata());
+		if (is_seed()) return;
+
+		assert(m_picker.get());
+
+		// TODO: update peer's interesting-bit
+		
+		int index = 0;
+		for (std::vector<int>::const_iterator i = pieces.begin()
+			, end(pieces.end()); i != end; ++i, ++index)
+		{
+			assert(*i >= 0);
+			assert(*i <= 7);
+			m_picker->set_piece_priority(index, *i);
+		}
+	}
+
+	void torrent::piece_priorities(std::vector<int>& pieces) const
+	{
+		INVARIANT_CHECK;
+
+		// this call is only valid on torrents with metadata
+		assert(valid_metadata());
+		if (is_seed())
+		{
+			pieces.clear();
+			pieces.resize(m_torrent_file.num_pieces(), 1);
+			return;
+		}
+
+		assert(m_picker.get());
+		m_picker->piece_priorities(pieces);
+	}
+
+	namespace
+	{
+		void set_if_greater(int& piece_prio, int file_prio)
+		{
+			if (file_prio > piece_prio) piece_prio = file_prio;
+		}
+	}
+
+	void torrent::prioritize_files(std::vector<int> const& files)
+	{
+		INVARIANT_CHECK;
+
+		// this call is only valid on torrents with metadata
+		if (!valid_metadata() || is_seed()) return;
+
+		// the bitmask need to have exactly one bit for every file
+		// in the torrent
+		assert(int(files.size()) == m_torrent_file.num_files());
+		
+		size_type position = 0;
+
+		if (m_torrent_file.num_pieces())
+		{
+			int piece_length = m_torrent_file.piece_length();
+			// initialize the piece priorities to 0, then only allow
+			// setting higher priorities
+			std::vector<int> pieces(m_torrent_file.num_pieces(), 0);
+			for (int i = 0; i < int(files.size()); ++i)
+			{
+				size_type start = position;
+				position += m_torrent_file.file_at(i).size;
+				// mark all pieces of the file with this file's priority
+				// but only if the priority is higher than the pieces
+				// already set (to avoid problems with overlapping pieces)
+				int start_piece = int(start / piece_length);
+				int last_piece = int(position / piece_length);
+				// if one piece spans several files, we might
+				// come here several times with the same start_piece, end_piece
+				std::for_each(pieces.begin() + start_piece
+					, pieces.begin() + last_piece + 1
+					, bind(&set_if_greater, _1, files[i]));
+			}
+			prioritize_pieces(pieces);
+		}
+	}
+
+
+
+
+
+
+
+
 	void torrent::filter_piece(int index, bool filter)
 	{
 		INVARIANT_CHECK;

src/torrent_handle.cpp

@@ -330,6 +330,57 @@ namespace libtorrent
 			, bind(&torrent::set_sequenced_download_threshold, _1, threshold));
 	}
 
+	std::string torrent_handle::name() const
+	{
+		INVARIANT_CHECK;
+		return call_member<std::string>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::name, _1));
+	}
+
+
+	void torrent_handle::piece_priority(int index, int priority) const
+	{
+		INVARIANT_CHECK;
+	
+		call_member<void>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::set_piece_priority, _1, index, priority));
+	}
+
+	int torrent_handle::piece_priority(int index) const
+	{
+		INVARIANT_CHECK;
+	
+		return call_member<int>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::piece_priority, _1, index));
+	}
+
+	void torrent_handle::prioritize_pieces(std::vector<int> const& pieces) const
+	{
+		INVARIANT_CHECK;
+
+		call_member<void>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::prioritize_pieces, _1, boost::cref(pieces)));
+	}
+
+	std::vector<int> torrent_handle::piece_priorities() const
+	{
+		INVARIANT_CHECK;
+		std::vector<int> ret;
+		call_member<void>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::piece_priorities, _1, boost::ref(ret)));
+		return ret;
+	}
+
+	void torrent_handle::prioritize_files(std::vector<int> const& files) const
+	{
+		INVARIANT_CHECK;
+	
+		call_member<void>(m_ses, m_chk, m_info_hash
+			, bind(&torrent::prioritize_files, _1, boost::cref(files)));
+	}
+
+// ============ start deprecation ===============
+
 	void torrent_handle::filter_piece(int index, bool filter) const
 	{
 		INVARIANT_CHECK;
@@ -341,7 +392,7 @@ namespace libtorrent
 	{
 		INVARIANT_CHECK;
 		call_member<void>(m_ses, m_chk, m_info_hash
-			, bind(&torrent::filter_pieces, _1, pieces));
+			, bind(&torrent::filter_pieces, _1, boost::cref(pieces)));
 	}
 
 	bool torrent_handle::is_piece_filtered(int index) const
@@ -351,13 +402,6 @@ namespace libtorrent
 			, bind(&torrent::is_piece_filtered, _1, index));
 	}
 
-	std::string torrent_handle::name() const
-	{
-		INVARIANT_CHECK;
-		return call_member<std::string>(m_ses, m_chk, m_info_hash
-			, bind(&torrent::name, _1));
-	}
-
 	std::vector<bool> torrent_handle::filtered_pieces() const
 	{
 		INVARIANT_CHECK;
@@ -374,6 +418,9 @@ namespace libtorrent
 			, bind(&torrent::filter_files, _1, files));
 	}
 
+// ============ end deprecation ===============
+
+
 	std::vector<announce_entry> const& torrent_handle::trackers() const
 	{
 		INVARIANT_CHECK;