Merge branch 'RC_2_0'

include/libtorrent/aux_/piece_picker.hpp

@@ -69,6 +69,20 @@ namespace libtorrent::aux {
 		bool last_piece;
 	};
 
+	// the piece picker tracks:
+	// 1. The blocks in which pieces we have sent requests for
+	// 2. Which peers we sent the requests to
+	// 3. The availability of each piece
+	// 4. The priority of each piece
+	// 5. Which blocks and pieces have been written to disk (versus being in the cache)
+	// 6. Which pieces have passed the hash check (i.e. we have them)
+	// 7. Cursors for sequential download
+	// 8. The number of pad-bytes in each piece
+	// All this in a data structure to make it cheap to pick the next piece to
+	// request from a peer.
+	// If we "have" a piece, it means it has passed the hash check. If a piece
+	// has been "flushed", it means it's been stored to disk.
+	// When saving resume data, we only care about "flushed" pieces.
 	struct TORRENT_EXTRA_EXPORT piece_picker
 	{
 		// only defined when TORRENT_PICKER_LOG is defined, used for debugging
@@ -228,11 +242,13 @@ namespace libtorrent::aux {
 		// seed
 		void we_have_all();
 
-		// This indicates that we just received this piece
-		// it means that the refcounter will indicate that
+		// A piece completes when it has passed the hash check *and* been
+		// completely written to disk. The piece picker no longer need to track
+		// the state of individual blocks
+		// The refcounter will indicate that
 		// we are not interested in this piece anymore
 		// (i.e. we don't have to maintain a refcount)
-		void we_have(piece_index_t);
+		void piece_flushed(piece_index_t);
 		void we_dont_have(piece_index_t);
 
 		// the lowest piece index we do not have
@@ -245,8 +261,14 @@ namespace libtorrent::aux {
 		void resize(std::int64_t total_size, int piece_size);
 		int num_pieces() const { return int(m_piece_map.size()); }
 
+		// returns true if we have the piece or if the piece
+		// has passed the hash check
 		bool have_piece(piece_index_t) const;
 
+		// returns true if the piece has been completely downloaded and
+		// successfully flushed to disk (i.e. "finished").
+		bool is_piece_flushed(piece_index_t) const;
+
 		bool is_downloading(piece_index_t const index) const
 		{
 			TORRENT_ASSERT(index >= piece_index_t(0));
@@ -383,10 +405,6 @@ namespace libtorrent::aux {
 		// only valid for v2 torrents
 		bool is_hashing(piece_index_t piece) const;
 
-		// returns true if we have the piece or if the piece
-		// has passed the hash check
-		bool has_piece_passed(piece_index_t) const;
-
 		// returns the number of blocks there is in the given piece
 		int blocks_in_piece(piece_index_t) const;
 
@@ -439,7 +457,7 @@ namespace libtorrent::aux {
 
 		// number of pieces whose hash has passed (but haven't necessarily
 		// been flushed to disk yet)
-		int num_passed() const { return m_num_passed; }
+		int num_have() const { return m_num_have; }
 
 		// return true if all the pieces we want have passed the hash check (but
 		// may not have been written to disk yet)
@@ -453,11 +471,11 @@ namespace libtorrent::aux {
 			// finished. Note that any piece we *have* implies it's both passed the
 			// hash check *and* been written to disk.
 			// num_pieces() - m_num_filtered - m_num_have_filtered
-			//   <= (num_passed() - m_num_have_filtered)
+			//   <= (m_num_have - m_num_have_filtered)
 			// this can be simplified. Note how m_num_have_filtered appears on both
 			// side of the equation.
 			//
-			return num_pieces() - m_num_filtered <= num_passed();
+			return num_pieces() - m_num_filtered <= m_num_have;
 		}
 
 		bool is_seeding() const { return m_num_have == num_pieces(); }
@@ -516,6 +534,9 @@ namespace libtorrent::aux {
 		int blocks_per_piece() const;
 		int piece_size(piece_index_t p) const;
 
+		void account_have(piece_index_t);
+		void account_lost(piece_index_t);
+
 		piece_extent_t extent_for(piece_index_t) const;
 		index_range<piece_index_t> extent_for(piece_extent_t) const;
 
@@ -811,9 +832,6 @@ namespace libtorrent::aux {
 		// the availability counters of the pieces
 		int m_seeds = 0;
 
-		// the number of pieces that have passed the hash check
-		int m_num_passed = 0;
-
 		// this vector contains all piece indices that are pickable
 		// sorted by priority. Pieces are in random random order
 		// among pieces with the same priority
@@ -871,7 +889,7 @@ namespace libtorrent::aux {
 		// all the subsequent pieces
 		piece_index_t m_reverse_cursor{0};
 
-		// the number of pieces we have (i.e. passed + flushed).
+		// the number of pieces we have (i.e. passed hash check).
 		// This includes pieces that we have filtered but still have
 		int m_num_have = 0;
 

include/libtorrent/aux_/torrent.hpp

@@ -836,6 +836,7 @@ namespace libtorrent::aux {
 #endif
 
 		// returns true if we have downloaded the given piece
+		// but not necessarily flushed it to disk
 		bool have_piece(piece_index_t index) const
 		{
 			if (!valid_metadata()) return false;
@@ -852,15 +853,6 @@ namespace libtorrent::aux {
 			return m_picker->have_piece(index);
 		}
 
-		// returns true if we have downloaded the given piece
-		bool has_piece_passed(piece_index_t index) const
-		{
-			if (!valid_metadata()) return false;
-			if (index < piece_index_t(0) || index >= torrent_file().end_piece()) return false;
-			if (!has_picker()) return m_have_all;
-			return m_picker->has_piece_passed(index);
-		}
-
 #ifndef TORRENT_DISABLE_PREDICTIVE_PIECES
 		// a predictive piece is a piece that we might
 		// not have yet, but still announced to peers, anticipating that
@@ -883,6 +875,9 @@ namespace libtorrent::aux {
 
 	public:
 
+		// the number of pieces that have passed
+		// hash check, but aren't necessarily
+		// flushed to disk yet
 		int num_have() const
 		{
 			// pretend we have every piece when in seed mode
@@ -892,16 +887,6 @@ namespace libtorrent::aux {
 			return 0;
 		}
 
-		// the number of pieces that have passed
-		// hash check, but aren't necessarily
-		// flushed to disk yet
-		int num_passed() const
-		{
-			if (has_picker()) return m_picker->num_passed();
-			if (m_have_all) return m_torrent_file->num_pieces();
-			return 0;
-		}
-
 		// when we get a have message, this is called for that piece
 		void peer_has(piece_index_t index, peer_connection const* peer);
 

src/peer_connection.cpp

@@ -508,7 +508,7 @@ namespace {
 			{
 				if (m_have_piece[j]
 					&& t->piece_priority(j) > dont_download
-					&& !p.has_piece_passed(j))
+					&& !p.have_piece(j))
 				{
 					interested = true;
 #ifndef TORRENT_DISABLE_LOGGING
@@ -2050,7 +2050,7 @@ namespace {
 		// it's important to update whether we're interested in this peer before
 		// calling disconnect_if_redundant, otherwise we may disconnect even if
 		// we are interested
-		if (!t->has_piece_passed(index)
+		if (!t->have_piece(index)
 			&& !t->is_upload_only()
 			&& !is_interesting()
 			&& (!t->has_picker() || t->picker().piece_priority(index) != dont_download))
@@ -2384,7 +2384,7 @@ namespace {
 					, valid_piece_index
 						? t->torrent_file().piece_size(r.piece) : -1
 					, t->torrent_file().num_pieces()
-					, valid_piece_index ? t->has_piece_passed(r.piece) : 0
+					, valid_piece_index ? t->have_piece(r.piece) : 0
 					, static_cast<int>(m_superseed_piece[0])
 					, static_cast<int>(m_superseed_piece[1]));
 			}
@@ -2399,7 +2399,7 @@ namespace {
 				bool const peer_interested = bool(m_peer_interested);
 				t->alerts().emplace_alert<invalid_request_alert>(
 					t->get_handle(), m_remote, m_peer_id, r
-					, t->has_piece_passed(r.piece), peer_interested, true);
+					, t->user_have_piece(r.piece), peer_interested, true);
 			}
 			return;
 		}
@@ -2468,7 +2468,7 @@ namespace {
 			{
 				t->alerts().emplace_alert<invalid_request_alert>(
 					t->get_handle(), m_remote, m_peer_id, r
-					, t->has_piece_passed(r.piece)
+					, t->user_have_piece(r.piece)
 					, false, false);
 			}
 
@@ -2481,7 +2481,7 @@ namespace {
 		// is not choked
 		if (r.piece < piece_index_t(0)
 			|| r.piece >= t->torrent_file().end_piece()
-			|| (!t->has_piece_passed(r.piece)
+			|| (!t->user_have_piece(r.piece)
 #ifndef TORRENT_DISABLE_PREDICTIVE_PIECES
 				&& !t->is_predictive_piece(r.piece)
 #endif
@@ -2503,7 +2503,7 @@ namespace {
 					, valid_piece_index
 						? t->torrent_file().piece_size(r.piece) : -1
 					, ti.num_pieces()
-					, t->has_piece_passed(r.piece)
+					, t->user_have_piece(r.piece)
 					, t->block_size());
 			}
 #endif
@@ -2519,7 +2519,7 @@ namespace {
 				bool const peer_interested = bool(m_peer_interested);
 				t->alerts().emplace_alert<invalid_request_alert>(
 					t->get_handle(), m_remote, m_peer_id, r
-					, t->has_piece_passed(r.piece), peer_interested, false);
+					, t->user_have_piece(r.piece), peer_interested, false);
 			}
 
 			// every ten invalid request, remind the peer that it's choked
@@ -3489,7 +3489,7 @@ namespace {
 		// to download it, request it
 		if (index < m_have_piece.end_index()
 			&& m_have_piece[index]
-			&& !t->has_piece_passed(index)
+			&& !t->have_piece(index)
 			&& t->valid_metadata()
 			&& t->has_picker()
 			&& t->picker().piece_priority(index) > dont_download)
@@ -3974,7 +3974,7 @@ namespace {
 		{
 			auto t = m_torrent.lock();
 			TORRENT_ASSERT(t);
-			TORRENT_ASSERT(t->has_piece_passed(piece));
+			TORRENT_ASSERT(t->have_piece(piece));
 			TORRENT_ASSERT(piece < t->torrent_file().end_piece());
 		}
 #endif
@@ -5329,7 +5329,7 @@ namespace {
 				continue;
 			}
 
-			if (!t->has_piece_passed(r.piece) && !seed_mode)
+			if (!t->have_piece(r.piece) && !seed_mode)
 			{
 #ifndef TORRENT_DISABLE_PREDICTIVE_PIECES
 				// we don't have this piece yet, but we anticipate to have