feat: add signal to inform clients when all archives have been downloaded and handled

This adds a new `DownloadingHistoryArchivesFinished` signal to the
family of community archive signals. It's emitted when all to be
downloaded archives have been downloaded and handled.

protocol/communities/manager.go

@@ -116,6 +116,7 @@ type Subscription struct {
 	HistoryArchivesSeedingSignal             *signal.HistoryArchivesSeedingSignal
 	HistoryArchivesUnseededSignal            *signal.HistoryArchivesUnseededSignal
 	HistoryArchiveDownloadedSignal           *signal.HistoryArchiveDownloadedSignal
+	DownloadingHistoryArchivesFinishedSignal *signal.DownloadingHistoryArchivesFinishedSignal
 }
 
 type CommunityResponse struct {

protocol/messenger_config.go

@@ -45,6 +45,7 @@ type MessengerSignalsHandler interface {
 	HistoryArchivesSeeding(communityID string)
 	HistoryArchivesUnseeded(communityID string)
 	HistoryArchiveDownloaded(communityID string, from int, to int)
+	DownloadingHistoryArchivesFinished(communityID string)
 	StatusUpdatesTimedOut(statusUpdates *[]UserStatus)
 	DiscordCategoriesAndChannelsExtracted(categories []*discord.Category, channels []*discord.Channel, oldestMessageTimestamp int64, errors map[string]*discord.ImportError)
 }

protocol/messenger_handler.go

@@ -949,6 +949,7 @@ func (m *Messenger) HandleHistoryArchiveMagnetlinkMessage(state *ReceivedMessage
 					signal.SendNewMessages(response)
 					localnotifications.PushMessages(notifications)
 				}
+				m.config.messengerSignalsHandler.DownloadingHistoryArchivesFinished(types.EncodeHex(id))
 			}()
 
 			return m.communitiesManager.UpdateMagnetlinkMessageClock(id, clock)

services/ext/signal.go

@@ -120,6 +120,10 @@ func (m *MessengerSignalsHandler) HistoryArchiveDownloaded(communityID string, f
 	signal.SendHistoryArchiveDownloaded(communityID, from, to)
 }
 
+func (m *MessengerSignalsHandler) DownloadingHistoryArchivesFinished(communityID string) {
+	signal.SendDownloadingHistoryArchivesFinished(communityID)
+}
+
 func (m *MessengerSignalsHandler) StatusUpdatesTimedOut(statusUpdates *[]protocol.UserStatus) {
 	signal.SendStatusUpdatesTimedOut(statusUpdates)
 }

signal/events_community_archives.go

@@ -27,6 +27,9 @@ const (
 	// EventHistoryArchiveDownloaded is triggered when the community member node
 	// has downloaded an individual community archive
 	EventHistoryArchiveDownloaded = "community.historyArchiveDownloaded"
+	// EventDownloadingHistoryArchivesFinished is triggered when the community member node
+	// has downloaded all archives
+	EventDownloadingHistoryArchivesFinished = "community.downloadingHistoryArchivesFinished"
 )
 
 type CreatingHistoryArchivesSignal struct {
@@ -59,6 +62,10 @@ type HistoryArchiveDownloadedSignal struct {
 	To          int    `json:"to"`
 }
 
+type DownloadingHistoryArchivesFinishedSignal struct {
+	CommunityID string `json:"communityId"`
+}
+
 func SendHistoryArchivesProtocolEnabled() {
 	send(EventHistoryArchivesProtocolEnabled, nil)
 }
@@ -102,3 +109,9 @@ func SendHistoryArchiveDownloaded(communityID string, from int, to int) {
 		To:          to,
 	})
 }
+
+func SendDownloadingHistoryArchivesFinished(communityID string) {
+	send(EventDownloadingHistoryArchivesFinished, DownloadingHistoryArchivesFinishedSignal{
+		CommunityID: communityID,
+	})
+}