MM-41349: CRT, fix LastUpdated semantics (#19523)

* deadcode: remove UpdateChannelLastViewedAt

* deadcode: remove ThreadStore.(Save(Multiple)|Update|Delete)

* deadcode: followThead in App.MarkChannelAsUnreadFromPost

* document ThreadMembership, Thread structs

* maintain LastUpdated consistently

Whenever we touch a `ThreadMembership` record, we should be setting `LastUpdated` to the current timestamp. The mobile client relies on this to detect changes to these records.

* simplify: never updateThreads from `App.MarkChannelAsUnreadFromPost`

Change all invocations of `ChannelStore.UpdateLastViewedAtPost` from `App.MarkChannelAsUnreadFromPost` to pass `updateThreads` as `false`. When `ChannelStore.UpdateLastViewedAtPost` was invoked with `updateThreads` as `true`, it would in turn call `ThreadStore.UpdateUnreadsByChannel` but pass `updateViewedTimestamp` as `false`. This effectively updated the `LastUpdated` field of the corresponding thread memberships but never touched any of the actual data (such as `LastViewed`).

The overall CRT feature continued to work, because `App.MarkChannelAsUnreadFromPost` directly updates the relevant thread memberships via `ThreadStore.MaintainMembership`.

* deadcode: updateThreads in ChannelStore.UpdateLastViewedAtPost

* simplify: never updateThreads from App.SendNotifications

Change all invocations of `ChannelStore.IncrementMentionCount` from
`App.SendNotifications` to pass `updateThreads` as `false`. When `ChannelStore.IncrementMentionCount` was invoked with `updateThreads` as `true`, it would in turn call `ThreadStore.UpdateUnreadsByChannel` but pass `updateViewedTimestamp` as `false`. This effectively updated the `LastUpdated` field of the corresponding thread memberships but never touched any of the actual data (such as `UnreadMentions`).

The overall CRT feature continued to work, because `App.SendNotifications` directly updates the relevant thread memberships mention counts via `ThreadStore.MaintainMembership`.

* deadcode: updateThreads in ChannelStore.IncrementMentionCount

* fix & rename ThreadStore.UpdateUnreadsByChannel

Rename `ThreadStore.UpdateUnreadsByChannel` to `ThreadStore.UpdateLastViewedByThreadIds`, making it unconditionally set the `LastViewed` for the given threads (as well as `LastUpdated`).

All previous invocations of this method that passed `updateViewedTimestamp` have been previously removed.

* unrelated gofmt -w -s changes to satisfy linter

* always set LastUpdated to model.GetMillis()

* deadcode: ThreadStore.SaveMembership

* fix TestMarkUnreadWithThreads

* GetMasterX

store/sqlstore/channel_store.go

@@ -2380,7 +2380,7 @@ func (s SqlChannelStore) UpdateLastViewedAt(channelIds []string, userId string,
 			times[t.Id] = t.LastPostAt
 		}
 		if updateThreads {
-			s.Thread().UpdateUnreadsByChannel(userId, threadsToUpdate, now, true)
+			s.Thread().UpdateLastViewedByThreadIds(userId, threadsToUpdate, now)
 		}
 		return times, nil
 	}
@@ -2425,7 +2425,7 @@ func (s SqlChannelStore) UpdateLastViewedAt(channelIds []string, userId string,
 	}
 
 	if updateThreads {
-		s.Thread().UpdateUnreadsByChannel(userId, threadsToUpdate, now, true)
+		s.Thread().UpdateLastViewedByThreadIds(userId, threadsToUpdate, now)
 	}
 	return times, nil
 }
@@ -2478,16 +2478,8 @@ func (s SqlChannelStore) CountPostsAfter(channelId string, timestamp int64, user
 // UpdateLastViewedAtPost updates a ChannelMember as if the user last read the channel at the time of the given post.
 // If the provided mentionCount is -1, the given post and all posts after it are considered to be mentions. Returns
 // an updated model.ChannelUnreadAt that can be returned to the client.
-func (s SqlChannelStore) UpdateLastViewedAtPost(unreadPost *model.Post, userID string, mentionCount, mentionCountRoot int, updateThreads bool, setUnreadCountRoot bool) (*model.ChannelUnreadAt, error) {
-	var threadsToUpdate []string
+func (s SqlChannelStore) UpdateLastViewedAtPost(unreadPost *model.Post, userID string, mentionCount, mentionCountRoot int, setUnreadCountRoot bool) (*model.ChannelUnreadAt, error) {
 	unreadDate := unreadPost.CreateAt - 1
-	if updateThreads {
-		var err error
-		threadsToUpdate, err = s.Thread().CollectThreadsWithNewerReplies(userID, []string{unreadPost.ChannelId}, unreadDate)
-		if err != nil {
-			return nil, err
-		}
-	}
 
 	unread, unreadRoot, err := s.CountPostsAfter(unreadPost.ChannelId, unreadDate, "")
 	if err != nil {
@@ -2554,22 +2546,11 @@ func (s SqlChannelStore) UpdateLastViewedAtPost(unreadPost *model.Post, userID s
 		return nil, errors.Wrapf(err, "failed to get ChannelMember with channelId=%s", unreadPost.ChannelId)
 	}
 
-	if updateThreads {
-		s.Thread().UpdateUnreadsByChannel(userID, threadsToUpdate, unreadDate, false)
-	}
 	return result, nil
 }
 
-func (s SqlChannelStore) IncrementMentionCount(channelId string, userId string, updateThreads, isRoot bool) error {
+func (s SqlChannelStore) IncrementMentionCount(channelId string, userId string, isRoot bool) error {
 	now := model.GetMillis()
-	var threadsToUpdate []string
-	if updateThreads {
-		var err error
-		threadsToUpdate, err = s.Thread().CollectThreadsWithNewerReplies(userId, []string{channelId}, now)
-		if err != nil {
-			return err
-		}
-	}
 	rootInc := 0
 	if isRoot {
 		rootInc = 1
@@ -2587,9 +2568,6 @@ func (s SqlChannelStore) IncrementMentionCount(channelId string, userId string,
 	if err != nil {
 		return errors.Wrapf(err, "failed to Update ChannelMembers with channelId=%s and userId=%s", channelId, userId)
 	}
-	if updateThreads {
-		s.Thread().UpdateUnreadsByChannel(userId, threadsToUpdate, now, false)
-	}
 	return nil
 }
 

store/sqlstore/thread_store.go

@@ -6,7 +6,6 @@ package sqlstore
 import (
 	"context"
 	"database/sql"
-	"encoding/json"
 	"strconv"
 	"sync"
 	"time"
@@ -32,70 +31,6 @@ func newSqlThreadStore(sqlStore *SqlStore) store.ThreadStore {
 	}
 }
 
-func threadSliceColumns() []string {
-	return []string{"PostId", "ChannelId", "LastReplyAt", "ReplyCount", "Participants"}
-}
-
-func threadToSlice(thread *model.Thread) []interface{} {
-	return []interface{}{
-		thread.PostId,
-		thread.ChannelId,
-		thread.LastReplyAt,
-		thread.ReplyCount,
-		model.ArrayToJSON(thread.Participants),
-	}
-}
-
-func (s *SqlThreadStore) SaveMultiple(threads []*model.Thread) ([]*model.Thread, int, error) {
-	builder := s.getQueryBuilder().
-		Insert("Threads").
-		Columns(threadSliceColumns()...)
-	for _, thread := range threads {
-		builder = builder.Values(threadToSlice(thread)...)
-	}
-	query, args, err := builder.ToSql()
-	if err != nil {
-		return nil, -1, errors.Wrap(err, "thread_tosql")
-	}
-
-	if _, err := s.GetMasterX().Exec(query, args...); err != nil {
-		return nil, -1, errors.Wrap(err, "failed to save Post")
-	}
-
-	return threads, -1, nil
-}
-
-func (s *SqlThreadStore) Save(thread *model.Thread) (*model.Thread, error) {
-	threads, _, err := s.SaveMultiple([]*model.Thread{thread})
-	if err != nil {
-		return nil, err
-	}
-	return threads[0], nil
-}
-
-func (s *SqlThreadStore) Update(thread *model.Thread) (*model.Thread, error) {
-	jsonParticipants, err := json.Marshal(thread.Participants)
-	if err != nil {
-		return nil, errors.Wrap(err, "failed marshaling thread participants")
-	}
-	query, args, err := s.getQueryBuilder().
-		Update("Threads").
-		Set("ChannelId", thread.ChannelId).
-		Set("ReplyCount", thread.ReplyCount).
-		Set("LastReplyAt", thread.LastReplyAt).
-		Set("Participants", string(jsonParticipants)).
-		Where(sq.Eq{"PostId": thread.PostId}).
-		ToSql()
-	if err != nil {
-		return nil, errors.Wrap(err, "thread_tosql")
-	}
-	if _, err := s.GetMasterX().Exec(query, args...); err != nil {
-		return nil, errors.Wrapf(err, "failed to update thread with id=%s", thread.PostId)
-	}
-
-	return thread, nil
-}
-
 func (s *SqlThreadStore) Get(id string) (*model.Thread, error) {
 	var thread model.Thread
 	query, args, err := s.getQueryBuilder().
@@ -575,6 +510,9 @@ func (s *SqlThreadStore) GetThreadForUser(teamId string, threadMembership *model
 
 	return result, nil
 }
+
+// MarkAllAsReadInChannels marks all threads for the given user in the given channels as read from
+// the current time.
 func (s *SqlThreadStore) MarkAllAsReadInChannels(userID string, channelIDs []string) error {
 	threadIDs := []string{}
 
@@ -599,6 +537,7 @@ func (s *SqlThreadStore) MarkAllAsReadInChannels(userID string, channelIDs []str
 		Where(sq.Eq{"UserId": userID}).
 		Set("LastViewed", timestamp).
 		Set("UnreadMentions", 0).
+		Set("LastUpdated", model.GetMillis()).
 		ToSql()
 	if _, err := s.GetMasterX().Exec(query, args...); err != nil {
 		return errors.Wrapf(err, "failed to update thread read state for user id=%s", userID)
@@ -606,6 +545,9 @@ func (s *SqlThreadStore) MarkAllAsReadInChannels(userID string, channelIDs []str
 	return nil
 
 }
+
+// MarkAllAsRead marks all threads for the given user in the given team as read from the current
+// time.
 func (s *SqlThreadStore) MarkAllAsRead(userId, teamId string) error {
 	memberships, err := s.GetMembershipsForUser(userId, teamId)
 	if err != nil {
@@ -622,6 +564,7 @@ func (s *SqlThreadStore) MarkAllAsRead(userId, teamId string) error {
 		Where(sq.Eq{"UserId": userId}).
 		Set("LastViewed", timestamp).
 		Set("UnreadMentions", 0).
+		Set("LastUpdated", model.GetMillis()).
 		ToSql()
 	if _, err := s.GetMasterX().Exec(query, args...); err != nil {
 		return errors.Wrapf(err, "failed to update thread read state for user id=%s", userId)
@@ -629,12 +572,14 @@ func (s *SqlThreadStore) MarkAllAsRead(userId, teamId string) error {
 	return nil
 }
 
+// MarkAsRead marks the given thread for the given user as unread from the given timestamp.
 func (s *SqlThreadStore) MarkAsRead(userId, threadId string, timestamp int64) error {
 	query, args, _ := s.getQueryBuilder().
 		Update("ThreadMemberships").
 		Where(sq.Eq{"UserId": userId}).
 		Where(sq.Eq{"PostId": threadId}).
 		Set("LastViewed", timestamp).
+		Set("LastUpdated", model.GetMillis()).
 		ToSql()
 	if _, err := s.GetMasterX().Exec(query, args...); err != nil {
 		return errors.Wrapf(err, "failed to update thread read state for user id=%s thread_id=%v", userId, threadId)
@@ -642,19 +587,6 @@ func (s *SqlThreadStore) MarkAsRead(userId, threadId string, timestamp int64) er
 	return nil
 }
 
-func (s *SqlThreadStore) Delete(threadId string) error {
-	query, args, _ := s.getQueryBuilder().Delete("Threads").Where(sq.Eq{"PostId": threadId}).ToSql()
-	if _, err := s.GetMasterX().Exec(query, args...); err != nil {
-		return errors.Wrap(err, "failed to update threads")
-	}
-
-	return nil
-}
-
-func (s *SqlThreadStore) SaveMembership(membership *model.ThreadMembership) (*model.ThreadMembership, error) {
-	return s.saveMembership(s.GetMasterX(), membership)
-}
-
 func (s *SqlThreadStore) saveMembership(ex sqlxExecutor, membership *model.ThreadMembership) (*model.ThreadMembership, error) {
 	query, args, err := s.getQueryBuilder().
 		Insert("ThreadMemberships").
@@ -875,19 +807,20 @@ func (s *SqlThreadStore) CollectThreadsWithNewerReplies(userId string, channelId
 	return changedThreads, nil
 }
 
-func (s *SqlThreadStore) UpdateUnreadsByChannel(userId string, changedThreads []string, timestamp int64, updateViewedTimestamp bool) error {
-	if len(changedThreads) == 0 {
+// UpdateLastViewedByThreadIds marks the given threads as read up to the given timestamp. If there
+// are no newer posts, it effectively marks the thread as read. If there are newer posts, say
+// because the user explicitly marked a past post as unread, the thread will be considered unread
+// past the given timestamp.
+func (s *SqlThreadStore) UpdateLastViewedByThreadIds(userId string, threadIds []string, timestamp int64) error {
+	if len(threadIds) == 0 {
 		return nil
 	}
 
 	qb := s.getQueryBuilder().
 		Update("ThreadMemberships").
-		Where(sq.Eq{"UserId": userId, "PostId": changedThreads}).
-		Set("LastUpdated", timestamp)
-
-	if updateViewedTimestamp {
-		qb = qb.Set("LastViewed", timestamp)
-	}
+		Where(sq.Eq{"UserId": userId, "PostId": threadIds}).
+		Set("LastViewed", timestamp).
+		Set("LastUpdated", model.GetMillis())
 	updateQuery, updateArgs, _ := qb.ToSql()
 
 	if _, err := s.GetMasterX().Exec(updateQuery, updateArgs...); err != nil {