Fixing bulk loading perf issue (#4974)

api/post.go

@@ -573,8 +573,15 @@ func getExplicitMentions(message string, keywords map[string][]string) (map[stri
 }
 
 func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *model.Channel) []string {
+	mentionedUsersList := make([]string, 0)
+	var fchan store.StoreChannel
+	var senderUsername string
+
+	if post.IsSystemMessage() {
+		senderUsername = c.T("system.message.name")
+	} else {
 		pchan := Srv.Store.User().GetProfilesInChannel(channel.Id, -1, -1, true)
-	fchan := Srv.Store.FileInfo().GetForPost(post.Id)
+		fchan = Srv.Store.FileInfo().GetForPost(post.Id)
 
 		var profileMap map[string]*model.User
 		if result := <-pchan; result.Err != nil {
@@ -648,14 +655,13 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 			// find which users in the channel are set up to always receive mobile notifications
 			for _, profile := range profileMap {
 				if profile.NotifyProps["push"] == model.USER_NOTIFY_ALL &&
-				(post.UserId != profile.Id || post.Props["from_webhook"] == "true") &&
+					(post.UserId != profile.Id || post.Props["from_webhook"] == "true") {
-				!post.IsSystemMessage() {
 					allActivityPushUserIds = append(allActivityPushUserIds, profile.Id)
 				}
 			}
 		}
 
-	mentionedUsersList := make([]string, 0, len(mentionedUserIds))
+		mentionedUsersList = make([]string, 0, len(mentionedUserIds))
 		for id := range mentionedUserIds {
 			mentionedUsersList = append(mentionedUsersList, id)
 			updateMentionChans = append(updateMentionChans, Srv.Store.Channel().IncrementMentionCount(post.ChannelId, id))
@@ -665,9 +671,7 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 		senderName := make(map[string]string)
 		for _, id := range mentionedUsersList {
 			senderName[id] = ""
-		if post.IsSystemMessage() {
+			if profile, ok := profileMap[post.UserId]; ok {
-			senderName[id] = c.T("system.message.name")
-		} else if profile, ok := profileMap[post.UserId]; ok {
 				if value, ok := post.Props["override_username"]; ok && post.Props["from_webhook"] == "true" {
 					senderName[id] = value.(string)
 				} else {
@@ -683,7 +687,6 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 			}
 		}
 
-	var senderUsername string
 		if value, ok := post.Props["override_username"]; ok && post.Props["from_webhook"] == "true" {
 			senderUsername = value.(string)
 		} else {
@@ -821,6 +824,7 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 				}
 			}
 		}
+	}
 
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POSTED, "", post.ChannelId, "", nil)
 	message.Add("post", post.ToJson())
@@ -830,7 +834,7 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 	message.Add("sender_name", senderUsername)
 	message.Add("team_id", team.Id)
 
-	if len(post.FileIds) != 0 {
+	if len(post.FileIds) != 0 && fchan != nil {
 		message.Add("otherFile", "true")
 
 		var infos []*model.FileInfo