Performance optimizations to calculating bytes left in Torrent

Was generating significant overhead in cmd/torrent

diff --git a/metainfo/info.go b/metainfo/info.go
index 7fbc88e9546bfa79a2918dd6a76c683406139006..a7e23a7f07843360a2f92eff81bd278d86305ca4 100644 (file)
--- a/metainfo/info.go
+++ b/metainfo/info.go
@@ -126,9 +126,6 @@ func (info *Info) TotalLength() (ret int64) {
 }
 
 func (info *Info) NumPieces() int {
-       if len(info.Pieces)%20 != 0 {
-               panic(len(info.Pieces))
-       }
        return len(info.Pieces) / 20
 }
 

diff --git a/piece.go b/piece.go
index 7a0c2f1789f4b169c694724a9e981db478717b06..e09e00c8da5160dbcd14ffb92e53b7b88ce8c6fd 100644 (file)
--- a/piece.go
+++ b/piece.go
@@ -128,11 +128,11 @@ func (p *Piece) chunkIndexSpec(chunk int) chunkSpec {
 }
 
 func (p *Piece) numDirtyBytes() (ret pp.Integer) {
-       defer func() {
-               if ret > p.length() {
-                       panic("too many dirty bytes")
-               }
-       }()
+       // defer func() {
+       //      if ret > p.length() {
+       //              panic("too many dirty bytes")
+       //      }
+       // }()
        numRegularDirtyChunks := p.numDirtyChunks()
        if p.chunkIndexDirty(p.numChunks() - 1) {
                numRegularDirtyChunks--

diff --git a/torrent.go b/torrent.go
index 84691af65ca0a8ee10699981269841566cc53427..3374778b2c12bedd0b362fdc691faf14a896a846 100644 (file)
--- a/torrent.go
+++ b/torrent.go
@@ -558,9 +558,11 @@ func (t *Torrent) bytesMissingLocked() int64 {
 }
 
 func (t *Torrent) bytesLeft() (left int64) {
-       for i := 0; i < t.numPieces(); i++ {
-               left += int64(t.pieces[i].bytesLeft())
-       }
+       bitmap.Flip(t.completedPieces, 0, t.numPieces()).IterTyped(func(piece int) bool {
+               p := t.pieces[piece]
+               left += int64(p.length() - p.numDirtyBytes())
+               return true
+       })
        return
 }
 
@@ -658,17 +660,14 @@ type Peer struct {
        SupportsEncryption bool
 }
 
-func (t *Torrent) pieceLength(piece int) (len_ pp.Integer) {
-       if piece < 0 || piece >= t.info.NumPieces() {
-               return
-       }
+func (t *Torrent) pieceLength(piece int) pp.Integer {
        if piece == t.numPieces()-1 {
-               len_ = pp.Integer(t.length % t.info.PieceLength)
-       }
-       if len_ == 0 {
-               len_ = pp.Integer(t.info.PieceLength)
+               ret := pp.Integer(t.length % t.info.PieceLength)
+               if ret != 0 {
+                       return ret
+               }
        }
-       return
+       return pp.Integer(t.info.PieceLength)
 }
 
 func (t *Torrent) hashPiece(piece int) (ret metainfo.Hash) {