From: Matt Joiner <anacrolix@gmail.com>
Date: Wed, 11 May 2022 04:15:33 +0000 (+1000)
Subject: Make piece states a slice and reuse it and request indexes between runs
X-Git-Tag: v1.43.0~4
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=590d1ac2656497c248ae24dffd146871663f6f4e;p=btrtrc.git

Make piece states a slice and reuse it and request indexes between runs
---

diff --git a/requesting.go b/requesting.go
index 3c204b84..98e9e88b 100644
--- a/requesting.go
+++ b/requesting.go
@@ -70,7 +70,7 @@ type (
 type desiredPeerRequests struct {
 	requestIndexes []RequestIndex
 	peer           *Peer
-	pieceStates    map[pieceIndex]request_strategy.PieceRequestOrderState
+	pieceStates    []request_strategy.PieceRequestOrderState
 }
 
 func (p *desiredPeerRequests) Len() int {
@@ -95,8 +95,8 @@ func (p *desiredPeerRequests) lessByValue(leftRequest, rightRequest RequestIndex
 			!p.peer.peerAllowedFast.Contains(rightPieceIndex),
 		)
 	}
-	leftPiece := p.pieceStates[leftPieceIndex]
-	rightPiece := p.pieceStates[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 {
@@ -193,8 +193,9 @@ func (p *Peer) getDesiredRequestState() (desired desiredRequestState) {
 	}
 	input := t.getRequestStrategyInput()
 	requestHeap := desiredPeerRequests{
-		peer:        p,
-		pieceStates: make(map[pieceIndex]request_strategy.PieceRequestOrderState),
+		peer:           p,
+		pieceStates:    t.requestPieceStates,
+		requestIndexes: t.requestIndexes,
 	}
 	request_strategy.GetRequestablePieces(
 		input,
@@ -206,6 +207,7 @@ func (p *Peer) getDesiredRequestState() (desired desiredRequestState) {
 			if !p.peerHasPiece(pieceIndex) {
 				return
 			}
+			requestHeap.pieceStates[pieceIndex] = pieceExtra
 			allowedFast := p.peerAllowedFast.Contains(pieceIndex)
 			p.t.piece(pieceIndex).undirtiedChunksIter.Iter(func(ci request_strategy.ChunkIndex) {
 				r := p.t.pieceRequestIndexOffset(pieceIndex) + ci
@@ -228,7 +230,6 @@ func (p *Peer) getDesiredRequestState() (desired desiredRequestState) {
 					return
 				}
 				requestHeap.requestIndexes = append(requestHeap.requestIndexes, r)
-				requestHeap.pieceStates[pieceIndex] = pieceExtra
 			})
 		},
 	)
@@ -256,6 +257,7 @@ func (p *Peer) maybeUpdateActualRequestState() {
 		func(_ context.Context) {
 			next := p.getDesiredRequestState()
 			p.applyRequestState(next)
+			p.t.requestIndexes = next.Requests.requestIndexes[:0]
 		},
 	)
 }
diff --git a/torrent.go b/torrent.go
index 4f06d650..dbfbea18 100644
--- a/torrent.go
+++ b/torrent.go
@@ -157,6 +157,10 @@ type Torrent struct {
 	sourcesLogger log.Logger
 
 	smartBanCache smartBanCache
+
+	// Large allocations reused between request state updates.
+	requestPieceStates []request_strategy.PieceRequestOrderState
+	requestIndexes     []RequestIndex
 }
 
 func (t *Torrent) selectivePieceAvailabilityFromPeers(i pieceIndex) (count int) {
@@ -457,6 +461,7 @@ func (t *Torrent) pieceRequestOrderKey(i int) request_strategy.PieceRequestOrder
 func (t *Torrent) onSetInfo() {
 	t.initPieceRequestOrder()
 	MakeSliceWithLength(&t.requestState, t.numChunks())
+	MakeSliceWithLength(&t.requestPieceStates, t.numPieces())
 	for i := range t.pieces {
 		p := &t.pieces[i]
 		// Need to add relativeAvailability before updating piece completion, as that may result in conns