ResponsiveDownloadStrategy will readahead blocks

Test peers don't play well with short "up request" buffers, so we need to fill
these with the most likely blocks to achieve maximum download speeds.

diff --git a/client.go b/client.go
index ae246f9fa72759219c08db43e9ce5fb8083d16f4..5170db9c0c855b693bd530a6b860ad47439fa5bc 100644 (file)
--- a/client.go
+++ b/client.go
@@ -130,6 +130,7 @@ func (cl *Client) TorrentReadAt(ih InfoHash, off int64, p []byte) (n int, err er
                err = io.EOF
                return
        }
+       t.lastReadPiece = int(index)
        piece := t.Pieces[index]
        if !piece.EverHashed {
                cl.queuePieceCheck(t, index)
@@ -714,8 +715,26 @@ type ResponsiveDownloadStrategy struct{}
 func (ResponsiveDownloadStrategy) FillRequests(t *torrent, c *connection) {
        for e := t.Priorities.Front(); e != nil; e = e.Next() {
                if !c.Request(e.Value.(request)) {
+                       return
+               }
+       }
+       for i := t.lastReadPiece; i < t.lastReadPiece+5 && i < t.NumPieces(); i++ {
+               for cs := range t.Pieces[i].PendingChunkSpecs {
+                       if !c.Request(request{pp.Integer(i), cs}) {
+                               return
+                       }
+               }
+       }
+       // Then finish off incomplete pieces in order of bytes remaining.
+       for _, index := range t.piecesByPendingBytes() {
+               if t.PieceNumPendingBytes(index) == t.PieceLength(index) {
                        break
                }
+               for chunkSpec := range t.Pieces[index].PendingChunkSpecs {
+                       if !c.Request(request{index, chunkSpec}) {
+                               return
+                       }
+               }
        }
 }
 

diff --git a/torrent.go b/torrent.go
index 4f94b89bc0bb842e78c2ba907f0eeba09cab2cf8..39d85e5d7185c11f21219c51169775c2a511e37d 100644 (file)
--- a/torrent.go
+++ b/torrent.go
@@ -34,7 +34,8 @@ type torrent struct {
        Priorities *list.List
        // BEP 12 Multitracker Metadata Extension. The tracker.Client instances
        // mirror their respective URLs from the announce-list key.
-       Trackers [][]tracker.Client
+       Trackers      [][]tracker.Client
+       lastReadPiece int
 }
 
 func (t *torrent) String() string {