From: Matt Joiner <anacrolix@gmail.com>
Date: Sat, 13 Sep 2014 17:40:35 +0000 (+1000)
Subject: New worst conn algorithm that incorporates useful/unwanted chunk download rates
X-Git-Tag: v1.0.0~1568
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=dcc3de7a70c83b0899e1b9f4d21a73525ee1e631;p=btrtrc.git

New worst conn algorithm that incorporates useful/unwanted chunk download rates
---

diff --git a/torrent.go b/torrent.go
index 5d6b66b7..77193383 100644
--- a/torrent.go
+++ b/torrent.go
@@ -70,8 +70,10 @@ type torrent struct {
 }
 
 func (t *torrent) worstConnsHeap() (wcs *worstConns) {
-	wcs = new(worstConns)
-	*wcs = append([]*connection{}, t.Conns...)
+	wcs = &worstConns{
+		c: append([]*connection{}, t.Conns...),
+		t: t,
+	}
 	heap.Init(wcs)
 	return
 }
@@ -292,7 +294,10 @@ func (t *torrent) WriteStatus(w io.Writer) {
 	fmt.Fprintln(w)
 	fmt.Fprintf(w, "Pending peers: %d\n", len(t.Peers))
 	fmt.Fprintf(w, "Active peers: %d\n", len(t.Conns))
-	sort.Sort(worstConns(t.Conns))
+	sort.Sort(&worstConns{
+		c: t.Conns,
+		t: t,
+	})
 	for _, c := range t.Conns {
 		c.WriteStatus(w)
 	}
diff --git a/worst_conns.go b/worst_conns.go
index a1bf326b..3b26c18f 100644
--- a/worst_conns.go
+++ b/worst_conns.go
@@ -5,33 +5,52 @@ import (
 )
 
 // Implements heap functions such that [0] is the worst connection.
-type worstConns []*connection
+type worstConns struct {
+	c []*connection
+	t *torrent
+}
 
-func (me worstConns) Len() int      { return len(me) }
-func (me worstConns) Swap(i, j int) { me[i], me[j] = me[j], me[i] }
+func (me worstConns) Len() int      { return len(me.c) }
+func (me worstConns) Swap(i, j int) { me.c[i], me.c[j] = me.c[j], me.c[i] }
 
 func (me *worstConns) Pop() (ret interface{}) {
-	old := *me
+	old := me.c
 	n := len(old)
 	ret = old[n-1]
-	*me = old[:n-1]
+	me.c = old[:n-1]
 	return
 }
 
 func (me *worstConns) Push(x interface{}) {
-	*me = append(*me, x.(*connection))
+	me.c = append(me.c, x.(*connection))
+}
+
+type worstConnsSortKey struct {
+	level int
+	age   time.Duration
 }
 
-func (me worstConns) key(i int) (ret time.Duration) {
-	c := me[i]
-	return time.Duration(1+c.UnwantedChunksReceived) * time.Now().Sub(func() time.Time {
+func (me worstConnsSortKey) Less(other worstConnsSortKey) bool {
+	if me.level != other.level {
+		return me.level > other.level
+	}
+	return me.age > other.age
+}
+
+func (me worstConns) key(i int) (key worstConnsSortKey) {
+	c := me.c[i]
+	if time.Now().Sub(c.completedHandshake) >= 30*time.Second && !me.t.connHasWantedPieces(c) {
+		key.level = 1
+	}
+	key.age = time.Duration(1+3*c.UnwantedChunksReceived) * time.Now().Sub(func() time.Time {
 		if !c.lastUsefulChunkReceived.IsZero() {
 			return c.lastUsefulChunkReceived
 		}
 		return c.completedHandshake.Add(-time.Minute)
 	}()) / time.Duration(1+c.UsefulChunksReceived)
+	return
 }
 
 func (me worstConns) Less(i, j int) bool {
-	return me.key(i) > me.key(j)
+	return me.key(i).Less(me.key(j))
 }