fix: clear error message on channel open after restart (#273)

Author: dirkmc

channels/channels.go

@@ -217,6 +217,10 @@ func (c *Channels) Accept(chid datatransfer.ChannelID) error {
 	return c.send(chid, datatransfer.Accept)
 }
 
+func (c *Channels) ChannelOpened(chid datatransfer.ChannelID) error {
+	return c.send(chid, datatransfer.Opened)
+}
+
 func (c *Channels) TransferRequestQueued(chid datatransfer.ChannelID) error {
 	return c.send(chid, datatransfer.TransferRequestQueued)
 }

channels/channels_fsm.go

@@ -50,6 +50,16 @@ var ChannelEvents = fsm.Events{
 		chst.AddLog("")
 		return nil
 	}),
+
+	// When a channel is Opened, clear any previous error message.
+	// (eg if the channel is opened after being restarted due to a connection
+	// error)
+	fsm.Event(datatransfer.Opened).FromAny().ToJustRecord().Action(func(chst *internal.ChannelState) error {
+		chst.Message = ""
+		chst.AddLog("")
+		return nil
+	}),
+
 	fsm.Event(datatransfer.DataReceived).FromAny().ToNoChange().
 		Action(func(chst *internal.ChannelState, rcvdBlocksTotal int64) error {
 			if rcvdBlocksTotal > chst.ReceivedBlocksTotal {

events.go

@@ -107,6 +107,9 @@ const (
 
 	// RequestCancelled indicates that a transport layer request was cancelled by the request opener
 	RequestCancelled
+
+	// Opened is fired when a request for data is sent from this node to a peer
+	Opened
 )
 
 // Events are human readable names for data transfer events

impl/events.go

@@ -15,17 +15,22 @@ import (
 	"github.com/filecoin-project/go-data-transfer/registry"
 )
 
+// OnChannelOpened is called when we send a request for data to the other
+// peer on the given channel ID
 func (m *manager) OnChannelOpened(chid datatransfer.ChannelID) error {
 	log.Infof("channel %s: opened", chid)
 
+	// Check if the channel is being tracked
 	has, err := m.channels.HasChannel(chid)
 	if err != nil {
 		return err
 	}
 	if !has {
 		return datatransfer.ErrChannelNotFound
 	}
-	return nil
+
+	// Fire an event
+	return m.channels.ChannelOpened(chid)
 }
 
 // OnDataReceived is called when the transport layer reports that it has

transport.go

@@ -9,10 +9,9 @@ import (
 
 // EventsHandler are semantic data transfer events that happen as a result of graphsync hooks
 type EventsHandler interface {
-	// OnChannelOpened is called when we ask the other peer to send us data on the
-	// given channel ID
+	// OnChannelOpened is called when we send a request for data to the other
+	// peer on the given channel ID
 	// return values are:
-	// - nil = this channel is recognized
 	// - error = ignore incoming data for this channel
 	OnChannelOpened(chid ChannelID) error
 	// OnResponseReceived is called when we receive a response to a request