Reinstate the reduce dial timeout and update some values

Fixes #263

client.go

@@ -597,7 +597,11 @@ func (cl *Client) establishOutgoingConnEx(t *Torrent, addr string, ctx context.C
 // Returns nil connection and nil error if no connection could be established
 // for valid reasons.
 func (cl *Client) establishOutgoingConn(t *Torrent, addr string) (c *connection, err error) {
-	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	ctx, cancel := context.WithTimeout(context.Background(), func() time.Duration {
+		cl.mu.RLock()
+		defer cl.mu.RUnlock()
+		return t.dialTimeout()
+	}())
 	defer cancel()
 	obfuscatedHeaderFirst := !cl.config.DisableEncryption && !cl.config.PreferNoEncryption
 	c, err = cl.establishOutgoingConnEx(t, addr, ctx, obfuscatedHeaderFirst)

config.go

@@ -93,17 +93,19 @@ type ClientConfig struct {
 	// Also see `extendedHandshakeClientVersion`.
 	Bep20 string // default "-GT0001-"
 
-	NominalDialTimeout         time.Duration // default  time.Second * 30
-	MinDialTimeout             time.Duration // default  5 * time.Second
-	EstablishedConnsPerTorrent int           // default 80
-	HalfOpenConnsPerTorrent    int           // default  80
-	TorrentPeersHighWater      int           // default 200
-	TorrentPeersLowWater       int           // default 50
+	// Peer dial timeout to use when there are limited peers.
+	NominalDialTimeout time.Duration
+	// Minimum peer dial timeout to use (even if we have lots of peers).
+	MinDialTimeout             time.Duration
+	EstablishedConnsPerTorrent int
+	HalfOpenConnsPerTorrent    int
+	TorrentPeersHighWater      int
+	TorrentPeersLowWater       int
 
 	// Limit how long handshake can take. This is to reduce the lingering
 	// impact of a few bad apples. 4s loses 1% of successful handshakes that
 	// are obtained with 60s timeout, and 5% of unsuccessful handshakes.
-	HandshakesTimeout time.Duration // default  20 * time.Second
+	HandshakesTimeout time.Duration
 
 	PublicIp4 net.IP
 	PublicIp6 net.IP
@@ -134,13 +136,13 @@ func NewDefaultClientConfig() *ClientConfig {
 		HTTPUserAgent:                  DefaultHTTPUserAgent,
 		ExtendedHandshakeClientVersion: "go.torrent dev 20150624",
 		Bep20:                          "-GT0001-",
-		NominalDialTimeout:         30 * time.Second,
+		NominalDialTimeout:             20 * time.Second,
 		MinDialTimeout:                 5 * time.Second,
 		EstablishedConnsPerTorrent:     50,
 		HalfOpenConnsPerTorrent:        25,
 		TorrentPeersHighWater:          500,
 		TorrentPeersLowWater:           50,
-		HandshakesTimeout:          20 * time.Second,
+		HandshakesTimeout:              4 * time.Second,
 		DhtStartingNodes:               dht.GlobalBootstrapAddrs,
 		ListenHost:                     func(string) string { return "" },
 		UploadRateLimiter:              unlimited,

torrent.go

@@ -1793,3 +1793,7 @@ func (t *Torrent) hashingPiece(i pieceIndex) bool {
 func (t *Torrent) pieceQueuedForHash(i pieceIndex) bool {
 	return t.piecesQueuedForHash.Get(bitmap.BitIndex(i))
 }
+
+func (t *Torrent) dialTimeout() time.Duration {
+	return reducedDialTimeout(t.cl.config.MinDialTimeout, t.cl.config.NominalDialTimeout, t.cl.halfOpenLimit, t.peers.Len())
+}