Reduce dial timeouts when there are lots of peers in the backlog

diff --git a/client.go b/client.go
index c3e99d0c511b934d255707980be8f3e6ad21c0de..d1d25288e400fa979109cd2bff402a6259439542 100644 (file)
--- a/client.go
+++ b/client.go
@@ -387,6 +387,10 @@ func doDial(dial func() (net.Conn, error), ch chan dialResult, utp bool) {
        }
 }
 
+func reducedDialTimeout(max time.Duration, halfOpenLimit int, pendingPeers int) time.Duration {
+       return max / time.Duration((pendingPeers+halfOpenLimit)/halfOpenLimit)
+}
+
 // Start the process of connecting to the given peer for the given torrent if
 // appropriate.
 func (me *Client) initiateConn(peer Peer, t *torrent) {
@@ -405,6 +409,7 @@ func (me *Client) initiateConn(peer Peer, t *torrent) {
                // this address so that peers associate our local address with our
                // listen address.
 
+               dialTimeout := reducedDialTimeout(dialTimeout, me.halfOpenLimit, len(t.Peers))
                // Initiate connections via TCP and UTP simultaneously. Use the first
                // one that succeeds.
                left := 2

diff --git a/client_test.go b/client_test.go
index 3dcb6c34a1419d8793a9932f5c7509bbcb448480..05d08e694dfaea7f42bb0f59ffc4d7e91ae0ca60 100644 (file)
--- a/client_test.go
+++ b/client_test.go
@@ -3,6 +3,7 @@ package torrent
 import (
        "os"
        "testing"
+       "time"
 
        "bitbucket.org/anacrolix/go.torrent/testutil"
        "bitbucket.org/anacrolix/go.torrent/util"
@@ -75,3 +76,24 @@ func TestUnmarshalPEXMsg(t *testing.T) {
                t.FailNow()
        }
 }
+
+func TestReducedDialTimeout(t *testing.T) {
+       for _, _case := range []struct {
+               Max             time.Duration
+               HalfOpenLimit   int
+               PendingPeers    int
+               ExpectedReduced time.Duration
+       }{
+               {dialTimeout, 40, 0, dialTimeout},
+               {dialTimeout, 40, 1, dialTimeout},
+               {dialTimeout, 40, 39, dialTimeout},
+               {dialTimeout, 40, 40, dialTimeout / 2},
+               {dialTimeout, 40, 80, dialTimeout / 3},
+               {dialTimeout, 40, 4000, dialTimeout / 101},
+       } {
+               reduced := reducedDialTimeout(_case.Max, _case.HalfOpenLimit, _case.PendingPeers)
+               if reduced != _case.ExpectedReduced {
+                       t.Fatalf("expected %s, got %s", _case.ExpectedReduced, reduced)
+               }
+       }
+}