Use roaring.Bitmap directly for completed pieces

Looking at improving the performance around this per https://github.com/anacrolix/torrent/discussions/547#discussion-3522317.

file.go

@@ -1,6 +1,7 @@
 package torrent
 
 import (
+	"github.com/RoaringBitmap/roaring"
 	"github.com/anacrolix/missinggo/v2/bitmap"
 
 	"github.com/anacrolix/torrent/metainfo"
@@ -59,32 +60,32 @@ func fileBytesLeft(
 	fileEndPieceIndex int,
 	fileTorrentOffset int64,
 	fileLength int64,
-	torrentCompletedPieces bitmap.Bitmap,
+	torrentCompletedPieces *roaring.Bitmap,
 ) (left int64) {
 	numPiecesSpanned := fileEndPieceIndex - fileFirstPieceIndex
 	switch numPiecesSpanned {
 	case 0:
 	case 1:
-		if !torrentCompletedPieces.Get(bitmap.BitIndex(fileFirstPieceIndex)) {
+		if !torrentCompletedPieces.Contains(bitmap.BitIndex(fileFirstPieceIndex)) {
 			left += fileLength
 		}
 	default:
-		if !torrentCompletedPieces.Get(bitmap.BitIndex(fileFirstPieceIndex)) {
+		if !torrentCompletedPieces.Contains(bitmap.BitIndex(fileFirstPieceIndex)) {
 			left += torrentUsualPieceSize - (fileTorrentOffset % torrentUsualPieceSize)
 		}
-		if !torrentCompletedPieces.Get(bitmap.BitIndex(fileEndPieceIndex - 1)) {
+		if !torrentCompletedPieces.Contains(bitmap.BitIndex(fileEndPieceIndex - 1)) {
 			left += fileTorrentOffset + fileLength - int64(fileEndPieceIndex-1)*torrentUsualPieceSize
 		}
-		completedMiddlePieces := torrentCompletedPieces.Copy()
+		completedMiddlePieces := torrentCompletedPieces.Clone()
 		completedMiddlePieces.RemoveRange(0, bitmap.BitRange(fileFirstPieceIndex+1))
 		completedMiddlePieces.RemoveRange(bitmap.BitRange(fileEndPieceIndex-1), bitmap.ToEnd)
-		left += int64(numPiecesSpanned-2-pieceIndex(completedMiddlePieces.Len())) * torrentUsualPieceSize
+		left += int64(numPiecesSpanned-2-pieceIndex(completedMiddlePieces.GetCardinality())) * torrentUsualPieceSize
 	}
 	return
 }
 
 func (f *File) bytesLeft() (left int64) {
-	return fileBytesLeft(int64(f.t.usualPieceSize()), f.firstPieceIndex(), f.endPieceIndex(), f.offset, f.length, f.t._completedPieces)
+	return fileBytesLeft(int64(f.t.usualPieceSize()), f.firstPieceIndex(), f.endPieceIndex(), f.offset, f.length, &f.t._completedPieces)
 }
 
 // The relative file path for a multi-file torrent, and the torrent name for a

file_test.go

@@ -3,7 +3,7 @@ package torrent
 import (
 	"testing"
 
-	"github.com/anacrolix/missinggo/v2/bitmap"
+	"github.com/RoaringBitmap/roaring"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -28,14 +28,14 @@ type testFileBytesLeft struct {
 	endPieceIndex   int
 	fileOffset      int64
 	fileLength      int64
-	completedPieces bitmap.Bitmap
+	completedPieces roaring.Bitmap
 	expected        int64
 	name            string
 }
 
 func (me testFileBytesLeft) Run(t *testing.T) {
 	t.Run(me.name, func(t *testing.T) {
-		assert.EqualValues(t, me.expected, fileBytesLeft(me.usualPieceSize, me.firstPieceIndex, me.endPieceIndex, me.fileOffset, me.fileLength, me.completedPieces))
+		assert.EqualValues(t, me.expected, fileBytesLeft(me.usualPieceSize, me.firstPieceIndex, me.endPieceIndex, me.fileOffset, me.fileLength, &me.completedPieces))
 	})
 }
 
@@ -108,7 +108,7 @@ func TestFileBytesLeft(t *testing.T) {
 		fileOffset:      5,
 		fileLength:      7,
 		expected:        0,
-		completedPieces: func() (ret bitmap.Bitmap) {
+		completedPieces: func() (ret roaring.Bitmap) {
 			ret.AddRange(0, 5)
 			return
 		}(),

peerconn.go

@@ -646,7 +646,7 @@ func (cn *PeerConn) postBitfield() {
 		Type:     pp.Bitfield,
 		Bitfield: cn.t.bitfield(),
 	})
-	cn.sentHaves = cn.t._completedPieces.Copy()
+	cn.sentHaves = bitmap.Bitmap{cn.t._completedPieces.Clone()}
 }
 
 func (cn *PeerConn) updateRequests() {

torrent.go

@@ -18,6 +18,7 @@ import (
 	"time"
 	"unsafe"
 
+	"github.com/RoaringBitmap/roaring"
 	"github.com/anacrolix/dht/v2"
 	"github.com/anacrolix/log"
 	"github.com/anacrolix/missinggo/iter"
@@ -131,7 +132,7 @@ type Torrent struct {
 	// file priorities and completion states elsewhere.
 	_pendingPieces prioritybitmap.PriorityBitmap
 	// A cache of completed piece indices.
-	_completedPieces bitmap.Bitmap
+	_completedPieces roaring.Bitmap
 	// Pieces that need to be hashed.
 	piecesQueuedForHash bitmap.Bitmap
 	activePieceHashes   int
@@ -252,7 +253,7 @@ func (t *Torrent) setChunkSize(size pp.Integer) {
 }
 
 func (t *Torrent) pieceComplete(piece pieceIndex) bool {
-	return t._completedPieces.Get(bitmap.BitIndex(piece))
+	return t._completedPieces.Contains(bitmap.BitIndex(piece))
 }
 
 func (t *Torrent) pieceCompleteUncached(piece pieceIndex) storage.Completion {
@@ -755,9 +756,13 @@ func (t *Torrent) bytesMissingLocked() int64 {
 	return t.bytesLeft()
 }
 
+func iterFlipped(b *roaring.Bitmap, end uint64, cb func(uint32) bool) {
+	roaring.Flip(b, 0, end).Iterate(cb)
+}
+
 func (t *Torrent) bytesLeft() (left int64) {
-	bitmap.Flip(t._completedPieces, 0, bitmap.BitRange(t.numPieces())).IterTyped(func(piece int) bool {
-		p := &t.pieces[piece]
+	iterFlipped(&t._completedPieces, uint64(t.numPieces()), func(x uint32) bool {
+		p := t.piece(pieceIndex(x))
 		left += int64(p.length() - p.numDirtyBytes())
 		return true
 	})
@@ -792,7 +797,7 @@ func (t *Torrent) numPieces() pieceIndex {
 }
 
 func (t *Torrent) numPiecesCompleted() (num pieceIndex) {
-	return pieceIndex(t._completedPieces.Len())
+	return pieceIndex(t._completedPieces.GetCardinality())
 }
 
 func (t *Torrent) close() (err error) {
@@ -838,7 +843,7 @@ func (t *Torrent) writeChunk(piece int, begin int64, data []byte) (err error) {
 
 func (t *Torrent) bitfield() (bf []bool) {
 	bf = make([]bool, t.numPieces())
-	t._completedPieces.IterTyped(func(piece int) (again bool) {
+	t._completedPieces.Iterate(func(piece uint32) (again bool) {
 		bf[piece] = true
 		return true
 	})
@@ -895,14 +900,14 @@ func (t *Torrent) hashPiece(piece pieceIndex) (ret metainfo.Hash, err error) {
 }
 
 func (t *Torrent) haveAnyPieces() bool {
-	return t._completedPieces.Len() != 0
+	return t._completedPieces.GetCardinality() != 0
 }
 
 func (t *Torrent) haveAllPieces() bool {
 	if !t.haveInfo() {
 		return false
 	}
-	return t._completedPieces.Len() == bitmap.BitRange(t.numPieces())
+	return t._completedPieces.GetCardinality() == bitmap.BitRange(t.numPieces())
 }
 
 func (t *Torrent) havePiece(index pieceIndex) bool {
@@ -1238,7 +1243,12 @@ func (t *Torrent) updatePieceCompletion(piece pieceIndex) bool {
 	changed := cached != uncached
 	complete := uncached.Complete
 	p.storageCompletionOk = uncached.Ok
-	t._completedPieces.Set(bitmap.BitIndex(piece), complete)
+	x := uint32(piece)
+	if complete {
+		t._completedPieces.Add(x)
+	} else {
+		t._completedPieces.Remove(x)
+	}
 	if complete && len(p.dirtiers) != 0 {
 		t.logger.Printf("marked piece %v complete but still has dirtiers", piece)
 	}
@@ -1347,7 +1357,7 @@ func (t *Torrent) bytesCompleted() int64 {
 	if !t.haveInfo() {
 		return 0
 	}
-	return t.info.TotalLength() - t.bytesLeft()
+	return *t.length - t.bytesLeft()
 }
 
 func (t *Torrent) SetInfoBytes(b []byte) (err error) {

torrent_test.go

@@ -98,7 +98,7 @@ func BenchmarkUpdatePiecePriorities(b *testing.B) {
 	}
 	assert.Len(b, t.readers, 7)
 	for i := 0; i < t.numPieces(); i += 3 {
-		t._completedPieces.Set(bitmap.BitIndex(i), true)
+		t._completedPieces.Add(bitmap.BitIndex(i))
 	}
 	t.DownloadPieces(0, t.numPieces())
 	for range iter.N(b.N) {