From 8df567e822459c602212547f7f8f674ac4c198e6 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Tue, 22 Oct 2013 18:00:35 +1100
Subject: [PATCH] Fix keep-alive timer use in connection writer, and make
 connection a public type

I'm not sure if making this public is the right approach yet, but for now it's a good way to conditionally invoke methods on Client from external packages.
---
 client.go | 40 +++++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/client.go b/client.go
index 69535861..1914977f 100644
--- a/client.go
+++ b/client.go
@@ -85,7 +85,7 @@ type Request struct {
 	ChunkSpec
 }
 
-type connection struct {
+type Connection struct {
 	Socket net.Conn
 	post   chan encoding.BinaryMarshaler
 	write  chan []byte
@@ -102,23 +102,23 @@ type connection struct {
 	PeerPieces     []bool
 }
 
-func (c *connection) Close() {
+func (c *Connection) Close() {
 	c.Socket.Close()
 	close(c.post)
 }
 
-func (c *connection) PeerHasPiece(index peer_protocol.Integer) bool {
+func (c *Connection) PeerHasPiece(index peer_protocol.Integer) bool {
 	if c.PeerPieces == nil {
 		return false
 	}
 	return c.PeerPieces[index]
 }
 
-func (c *connection) Post(msg encoding.BinaryMarshaler) {
+func (c *Connection) Post(msg encoding.BinaryMarshaler) {
 	c.post <- msg
 }
 
-func (c *connection) Request(chunk Request) bool {
+func (c *Connection) Request(chunk Request) bool {
 	if len(c.Requests) >= maxRequests {
 		return false
 	}
@@ -141,7 +141,7 @@ func (c *connection) Request(chunk Request) bool {
 	return true
 }
 
-func (c *connection) SetInterested(interested bool) {
+func (c *Connection) SetInterested(interested bool) {
 	if c.Interested == interested {
 		return
 	}
@@ -161,15 +161,17 @@ var (
 	keepAliveBytes [4]byte
 )
 
-func (conn *connection) writer() {
+func (conn *Connection) writer() {
+	timer := time.NewTimer(0)
 	for {
-		timer := time.NewTimer(time.Minute)
+		if !timer.Reset(time.Minute) {
+			<-timer.C
+		}
 		var b []byte
 		select {
 		case <-timer.C:
 			b = keepAliveBytes[:]
 		case b = <-conn.write:
-			timer.Stop()
 			if b == nil {
 				return
 			}
@@ -186,7 +188,7 @@ func (conn *connection) writer() {
 	}
 }
 
-func (conn *connection) writeOptimizer() {
+func (conn *Connection) writeOptimizer() {
 	pending := list.New()
 	var nextWrite []byte
 	defer close(conn.write)
@@ -539,7 +541,7 @@ func (me *Torrent) haveAnyPieces() bool {
 }
 
 func (me *Client) runConnection(sock net.Conn, torrent *Torrent, peerId [20]byte) (err error) {
-	conn := &connection{
+	conn := &Connection{
 		Socket:     sock,
 		Choked:     true,
 		PeerChoked: true,
@@ -596,14 +598,14 @@ func (me *Client) runConnection(sock net.Conn, torrent *Torrent, peerId [20]byte
 	}
 	err = me.connectionLoop(torrent, conn)
 	if err != nil {
-		err = fmt.Errorf("during connection loop: %s", err)
+		err = fmt.Errorf("during Connection loop: %s", err)
 	}
 	me.dropConnection(torrent, conn)
 	me.mu.Unlock()
 	return
 }
 
-func (me *Client) peerGotPiece(torrent *Torrent, conn *connection, piece int) {
+func (me *Client) peerGotPiece(torrent *Torrent, conn *Connection, piece int) {
 	if conn.PeerPieces == nil {
 		conn.PeerPieces = make([]bool, len(torrent.Pieces))
 	}
@@ -617,11 +619,11 @@ func (t *Torrent) wantPiece(index int) bool {
 	return !t.Pieces[index].Complete()
 }
 
-func (me *Client) peerUnchoked(torrent *Torrent, conn *connection) {
+func (me *Client) peerUnchoked(torrent *Torrent, conn *Connection) {
 	me.replenishConnRequests(torrent, conn)
 }
 
-func (me *Client) connectionLoop(torrent *Torrent, conn *connection) error {
+func (me *Client) connectionLoop(torrent *Torrent, conn *Connection) error {
 	decoder := peer_protocol.Decoder{
 		R:         bufio.NewReader(conn.Socket),
 		MaxLength: 256 * 1024,
@@ -689,7 +691,7 @@ func (me *Client) connectionLoop(torrent *Torrent, conn *connection) error {
 	}
 }
 
-func (me *Client) dropConnection(torrent *Torrent, conn *connection) {
+func (me *Client) dropConnection(torrent *Torrent, conn *Connection) {
 	conn.Socket.Close()
 	for i0, c := range torrent.Conns {
 		if c != conn {
@@ -702,10 +704,10 @@ func (me *Client) dropConnection(torrent *Torrent, conn *connection) {
 		torrent.Conns = torrent.Conns[:i1]
 		return
 	}
-	panic("no such connection")
+	panic("no such Connection")
 }
 
-func (me *Client) addConnection(t *Torrent, c *connection) bool {
+func (me *Client) addConnection(t *Torrent, c *Connection) bool {
 	for _, c := range t.Conns {
 		if c.PeerId == c.PeerId {
 			return false
@@ -779,7 +781,7 @@ func (me *Client) WaitAll() {
 func (me *Client) Stop() {
 }
 
-func (me *Client) replenishConnRequests(torrent *Torrent, conn *connection) {
+func (me *Client) replenishConnRequests(torrent *Torrent, conn *Connection) {
 	requestHeatMap := torrent.requestHeat()
 	addRequest := func(req Request) (again bool) {
 		piece := torrent.Pieces[req.Index]
-- 
2.48.1