From 53c86702a35b3f9d12993d613d17b74ebb99258d Mon Sep 17 00:00:00 2001
From: Wim <wim@42.be>
Date: Sat, 15 Dec 2018 23:11:03 +0100
Subject: [PATCH] Add wait option for populateUsers/Channels (slack) Fixes #579
 (#653)

When setting wait to true, we wait until the populating isn't in progress anymore.
This is used on startup connections where we really need the initial information
which could take a long time on big servers.
---
 bridge/slack/handlers.go | 10 +++++-----
 bridge/slack/helpers.go  | 14 ++++++++++----
 bridge/slack/slack.go    |  2 +-
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/bridge/slack/handlers.go b/bridge/slack/handlers.go
index b9011c92..40a9666a 100644
--- a/bridge/slack/handlers.go
+++ b/bridge/slack/handlers.go
@@ -75,7 +75,7 @@ func (b *Bslack) handleSlackClient(messages chan *config.Message) {
 			// When we join a channel we update the full list of users as
 			// well as the information for the channel that we joined as this
 			// should now tell that we are a member of it.
-			b.populateUsers()
+			b.populateUsers(false)
 
 			b.channelsMutex.Lock()
 			b.channelsByID[ev.Channel.ID] = &ev.Channel
@@ -83,8 +83,8 @@ func (b *Bslack) handleSlackClient(messages chan *config.Message) {
 			b.channelsMutex.Unlock()
 		case *slack.ConnectedEvent:
 			b.si = ev.Info
-			b.populateChannels()
-			b.populateUsers()
+			b.populateChannels(true)
+			b.populateUsers(true)
 		case *slack.InvalidAuthEvent:
 			b.Log.Fatalf("Invalid Token %#v", ev)
 		case *slack.ConnectionErrorEvent:
@@ -200,7 +200,7 @@ func (b *Bslack) handleMessageEvent(ev *slack.MessageEvent) (*config.Message, er
 func (b *Bslack) handleStatusEvent(ev *slack.MessageEvent, rmsg *config.Message) bool {
 	switch ev.SubType {
 	case sChannelJoined, sMemberJoined:
-		b.populateUsers()
+		b.populateUsers(false)
 		// There's no further processing needed on channel events
 		// so we return 'true'.
 		return true
@@ -208,7 +208,7 @@ func (b *Bslack) handleStatusEvent(ev *slack.MessageEvent, rmsg *config.Message)
 		rmsg.Username = sSystemUser
 		rmsg.Event = config.EventJoinLeave
 	case sChannelTopic, sChannelPurpose:
-		b.populateChannels()
+		b.populateChannels(false)
 		rmsg.Event = config.EventTopicChange
 	case sMessageChanged:
 		rmsg.Text = ev.SubMessage.Text
diff --git a/bridge/slack/helpers.go b/bridge/slack/helpers.go
index 6f049561..fb7a25d5 100644
--- a/bridge/slack/helpers.go
+++ b/bridge/slack/helpers.go
@@ -83,15 +83,18 @@ func (b *Bslack) populateUser(userID string) {
 	b.usersMutex.Unlock()
 }
 
-func (b *Bslack) populateUsers() {
+func (b *Bslack) populateUsers(wait bool) {
 	b.refreshMutex.Lock()
-	if time.Now().Before(b.earliestUserRefresh) || b.refreshInProgress {
+	if !wait && (time.Now().Before(b.earliestUserRefresh) || b.refreshInProgress) {
 		b.Log.Debugf("Not refreshing user list as it was done less than %v ago.",
 			minimumRefreshInterval)
 		b.refreshMutex.Unlock()
 
 		return
 	}
+	for b.refreshInProgress {
+		time.Sleep(time.Second)
+	}
 	b.refreshInProgress = true
 	b.refreshMutex.Unlock()
 
@@ -127,14 +130,17 @@ func (b *Bslack) populateUsers() {
 	b.refreshInProgress = false
 }
 
-func (b *Bslack) populateChannels() {
+func (b *Bslack) populateChannels(wait bool) {
 	b.refreshMutex.Lock()
-	if time.Now().Before(b.earliestChannelRefresh) || b.refreshInProgress {
+	if !wait && (time.Now().Before(b.earliestChannelRefresh) || b.refreshInProgress) {
 		b.Log.Debugf("Not refreshing channel list as it was done less than %v seconds ago.",
 			minimumRefreshInterval)
 		b.refreshMutex.Unlock()
 		return
 	}
+	for b.refreshInProgress {
+		time.Sleep(time.Second)
+	}
 	b.refreshInProgress = true
 	b.refreshMutex.Unlock()
 
diff --git a/bridge/slack/slack.go b/bridge/slack/slack.go
index 225e16e9..d8dfc62f 100644
--- a/bridge/slack/slack.go
+++ b/bridge/slack/slack.go
@@ -160,7 +160,7 @@ func (b *Bslack) JoinChannel(channel config.ChannelInfo) error {
 		return nil
 	}
 
-	b.populateChannels()
+	b.populateChannels(false)
 
 	channelInfo, err := b.getChannel(channel.Name)
 	if err != nil {