From: Matt Joiner <anacrolix@gmail.com>
Date: Wed, 2 Jul 2025 05:06:34 +0000 (+1000)
Subject: Consider dirty chunks in apriori webseed request generation
X-Git-Tag: v1.59.0~53
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=d0ecabddcf9c4b617031e1e672e2630ccbcc0123;p=btrtrc.git

Consider dirty chunks in apriori webseed request generation
---

diff --git a/piece.go b/piece.go
index ce98e8a0..4d6985c1 100644
--- a/piece.go
+++ b/piece.go
@@ -155,6 +155,19 @@ func (p *Piece) chunkIndexDirty(chunk chunkIndexType) bool {
 	return p.t.dirtyChunks.Contains(p.requestIndexBegin() + chunk)
 }
 
+func (p *Piece) firstCleanChunk() (_ g.Option[chunkIndexType]) {
+	it := p.t.dirtyChunks.Iterator()
+	begin := uint32(p.requestIndexBegin())
+	end := uint32(p.requestIndexMaxEnd())
+	it.AdvanceIfNeeded(begin)
+	for next := begin; next < end; next++ {
+		if !it.HasNext() || it.Next() != next {
+			return g.Some(chunkIndexType(next - begin))
+		}
+	}
+	return
+}
+
 func (p *Piece) chunkIndexSpec(chunk chunkIndexType) ChunkSpec {
 	return chunkIndexSpec(pp.Integer(chunk), p.length(), p.chunkSize())
 }
@@ -426,9 +439,9 @@ func (p *Piece) publishStateChange() {
 	}
 }
 
-func (p *Piece) fileExtents() iter.Seq2[int, segments.Extent] {
+func (p *Piece) fileExtents(offsetIntoPiece int64) iter.Seq2[int, segments.Extent] {
 	return p.t.info.FileSegmentsIndex().LocateIter(segments.Extent{
-		p.torrentBeginOffset(),
-		segments.Int(p.length()),
+		p.torrentBeginOffset() + offsetIntoPiece,
+		int64(p.length()) - offsetIntoPiece,
 	})
 }
diff --git a/typed-roaring/bitmap.go b/typed-roaring/bitmap.go
index 7f7b1a7e..4e42dda7 100644
--- a/typed-roaring/bitmap.go
+++ b/typed-roaring/bitmap.go
@@ -46,3 +46,5 @@ func (me *Bitmap[T]) Remove(x T) {
 func (Bitmap[T]) IteratorType() Iterator[T] {
 	return Iterator[T]{}
 }
+
+// TODO: Override Bitmap.Iterator.
diff --git a/webseed-requesting.go b/webseed-requesting.go
index 0a7c0333..7a001603 100644
--- a/webseed-requesting.go
+++ b/webseed-requesting.go
@@ -180,10 +180,20 @@ func (cl *Client) iterWebseed() iter.Seq2[webseedUniqueRequestKey, webseedReques
 				value.pieces,
 				func(ih metainfo.Hash, pieceIndex int, orderState requestStrategy.PieceRequestOrderState) bool {
 					t := cl.torrentsByShortHash[ih]
-					for i, e := range t.piece(pieceIndex).fileExtents() {
+					p := t.piece(pieceIndex)
+					cleanOpt := p.firstCleanChunk()
+					if !cleanOpt.Ok {
+						// Could almost return true here, as clearly something is going on with the piece.
+						return false
+					}
+					// Pretty sure we want this and not the order state priority. That one is for
+					// client piece request order and ignores other states like hashing, marking
+					// etc. Order state priority would be faster otherwise.
+					priority := p.effectivePriority()
+					for i, e := range p.fileExtents(int64(cleanOpt.Value) * int64(t.chunkSize)) {
 						for url, ws := range t.webSeeds {
-							// Return value from this function doesn't terminate, so don't pretend
-							// it does here either.
+							// Return value from this function (RequestPieceFunc) doesn't terminate
+							// iteration, so propagate that to not handling the yield return value.
 							yield(
 								webseedUniqueRequestKey{
 									aprioriWebseedRequestKey{
@@ -194,7 +204,7 @@ func (cl *Client) iterWebseed() iter.Seq2[webseedUniqueRequestKey, webseedReques
 									e.Start,
 								},
 								webseedRequestOrderValue{
-									priority: orderState.Priority,
+									priority: priority,
 									costKey:  ws.hostKey,
 								},
 							)