Don't allocate pieces map unless necessary when filling responsive requests

diff --git a/download_strategies.go b/download_strategies.go
index bc7287594a4ec233ac7833f9342df40db432135a..e0e79814e0d79ef31e9b3bd44262ef83e27fceb6 100644 (file)
--- a/download_strategies.go
+++ b/download_strategies.go
@@ -176,6 +176,9 @@ type requestFiller struct {
 
 // Wrapper around connection.request that tracks request heat.
 func (me *requestFiller) request(req request) bool {
+       if me.pieces == nil {
+               me.pieces = make(map[int]struct{})
+       }
        me.pieces[int(req.Index)] = struct{}{}
        if me.c.RequestPending(req) {
                return true
@@ -330,7 +333,7 @@ func (me *requestFiller) readahead() bool {
 }
 
 func (me *responsiveDownloadStrategy) FillRequests(t *torrent, c *connection) (pieces []int) {
-       rf := requestFiller{c, t, me, make(map[int]struct{}, t.NumPieces())}
+       rf := requestFiller{c: c, t: t, s: me}
        rf.Run()
        for p := range rf.pieces {
                pieces = append(pieces, p)