From: Matt Joiner <anacrolix@gmail.com>
Date: Mon, 9 May 2022 09:37:35 +0000 (+1000)
Subject: Reuse piece order state for request ordering
X-Git-Tag: v1.43.0~7
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=f235c8ea51e0cddc0be5ff8370345a54282fda4f;p=btrtrc.git

Reuse piece order state for request ordering
---

diff --git a/request-strategy/order.go b/request-strategy/order.go
index c276da91..8bdfe188 100644
--- a/request-strategy/order.go
+++ b/request-strategy/order.go
@@ -43,7 +43,10 @@ func pieceOrderLess(i, j *pieceRequestOrderItem) multiless.Computation {
 var packageExpvarMap = expvar.NewMap("request-strategy")
 
 // Calls f with requestable pieces in order.
-func GetRequestablePieces(input Input, pro *PieceRequestOrder, f func(ih metainfo.Hash, pieceIndex int)) {
+func GetRequestablePieces(
+	input Input, pro *PieceRequestOrder,
+	f func(ih metainfo.Hash, pieceIndex int, orderState PieceRequestOrderState),
+) {
 	// Storage capacity left for this run, keyed by the storage capacity pointer on the storage
 	// TorrentImpl. A nil value means no capacity limit.
 	var storageLeft *int64
@@ -70,7 +73,7 @@ func GetRequestablePieces(input Input, pro *PieceRequestOrder, f func(ih metainf
 			return true
 		}
 		allTorrentsUnverifiedBytes += pieceLength
-		f(ih, _i.key.Index)
+		f(ih, _i.key.Index, _i.state)
 		return true
 	})
 	return
diff --git a/requesting.go b/requesting.go
index 7b6152fd..ece5dc39 100644
--- a/requesting.go
+++ b/requesting.go
@@ -70,6 +70,7 @@ type (
 type desiredPeerRequests struct {
 	requestIndexes []RequestIndex
 	peer           *Peer
+	pieceStates    map[pieceIndex]request_strategy.PieceRequestOrderState
 }
 
 func (p *desiredPeerRequests) Len() int {
@@ -94,16 +95,16 @@ func (p *desiredPeerRequests) lessByValue(leftRequest, rightRequest RequestIndex
 			!p.peer.peerAllowedFast.Contains(rightPieceIndex),
 		)
 	}
-	leftPiece := t.piece(leftPieceIndex)
-	rightPiece := t.piece(rightPieceIndex)
+	leftPiece := p.pieceStates[leftPieceIndex]
+	rightPiece := p.pieceStates[rightPieceIndex]
 	// Putting this first means we can steal requests from lesser-performing peers for our first few
 	// new requests.
 	priority := func() piecePriority {
 		// Technically we would be happy with the cached priority here, except we don't actually
 		// cache it anymore, and Torrent.piecePriority just does another lookup of *Piece to resolve
 		// the priority through Piece.purePriority, which is probably slower.
-		leftPriority := leftPiece.purePriority()
-		rightPriority := rightPiece.purePriority()
+		leftPriority := leftPiece.Priority
+		rightPriority := rightPiece.Priority
 		ml = ml.Int(
 			-int(leftPriority),
 			-int(rightPriority),
@@ -147,8 +148,8 @@ func (p *desiredPeerRequests) lessByValue(leftRequest, rightRequest RequestIndex
 		ml = ml.CmpInt64(rightLast.Sub(leftLast).Nanoseconds())
 	}
 	ml = ml.Int(
-		leftPiece.relativeAvailability,
-		rightPiece.relativeAvailability)
+		leftPiece.Availability,
+		rightPiece.Availability)
 	if priority == PiecePriorityReadahead {
 		// TODO: For readahead in particular, it would be even better to consider distance from the
 		// reader position so that reads earlier in a torrent don't starve reads later in the
@@ -191,12 +192,13 @@ func (p *Peer) getDesiredRequestState() (desired desiredRequestState) {
 	}
 	input := p.t.getRequestStrategyInput()
 	requestHeap := desiredPeerRequests{
-		peer: p,
+		peer:        p,
+		pieceStates: make(map[pieceIndex]request_strategy.PieceRequestOrderState),
 	}
 	request_strategy.GetRequestablePieces(
 		input,
 		p.t.getPieceRequestOrder(),
-		func(ih InfoHash, pieceIndex int) {
+		func(ih InfoHash, pieceIndex int, pieceExtra request_strategy.PieceRequestOrderState) {
 			if ih != p.t.infoHash {
 				return
 			}
@@ -225,6 +227,7 @@ func (p *Peer) getDesiredRequestState() (desired desiredRequestState) {
 					return
 				}
 				requestHeap.requestIndexes = append(requestHeap.requestIndexes, r)
+				requestHeap.pieceStates[pieceIndex] = pieceExtra
 			})
 		},
 	)