Why this change?
There are two problematic queries in question here when loading
notifications in various tabs in the user menu:
```
SELECT "notifications".*
FROM "notifications"
LEFT JOIN topics ON notifications.topic_id = topics.id
WHERE "notifications"."user_id" = 1338 AND (topics.id IS NULL OR topics.deleted_at IS NULL)
ORDER BY notifications.high_priority AND NOT notifications.read DESC,
NOT notifications.read AND notifications.notification_type NOT IN (5,19,25) DESC,
notifications.created_at DESC
LIMIT 30;
```
and
```
EXPLAIN ANALYZE SELECT "notifications".*
FROM "notifications"
LEFT JOIN topics ON notifications.topic_id = topics.id
WHERE "notifications"."user_id" = 1338
AND (topics.id IS NULL OR topics.deleted_at IS NULL)
AND "notifications"."notification_type" IN (5, 19, 25)
ORDER BY notifications.high_priority AND NOT notifications.read DESC, NOT notifications.read DESC, notifications.created_at DESC LIMIT 30;
```
For a particular user, the queries takes about 40ms and 26ms
respectively on one of our production instance where the user has 10K notifications while the site has 600K notifications in total.
What does this change do?
1. Adds the `index_notifications_user_menu_ordering` index to the `notifications` table which is
indexed on `(user_id, (high_priority AND NOT read) DESC, (NOT read)
DESC, created_at DESC)`.
1. Adds a second index `index_notifications_user_menu_ordering_deprioritized_likes` to the `notifications`
table which is indexed on `(user_id, (high_priority AND NOT read) DESC, (NOT read AND notification_type NOT IN (5,19,25)) DESC, created_at DESC)`. Note that we have to hardcode the like typed notifications type here as it is being used in an ordering clause.
With the two indexes above, both queries complete in roughly 0.2ms. While I acknowledge that there will be some overhead in insert,update or delete operations. I believe this trade-off is worth it since viewing notifications in the user menu is something that is at the core of using a Discourse forum so we should optimise this experience as much as possible.
There is an edge case where the following occurs:
1. The user sets a bookmark reminder on a post/topic
2. The post/topic is changed to a PM before or after the reminder
fires, and the notification remains unread by the user
3. The user opens their bookmark reminder notification list
and they can still see the notification even though they cannot
access the topic anymore
There is a very low chance for information leaking here, since
the only thing that could be exposed is the topic title if it
changes to something sensitive.
This commit filters the bookmark unread notifications by using
the bookmarkable can_see? methods and also prevents sending
reminder notifications for bookmarks the user can no longer see.
The #pluck_first freedom patch, first introduced by @danielwaterworth has served us well, and is used widely throughout both core and plugins. It seems to have been a common enough use case that Rails 6 introduced it's own method #pick with the exact same implementation. This allows us to retire the freedom patch and switch over to the built-in ActiveRecord method.
There is no replacement for #pluck_first!, but a quick search shows we are using this in a very limited capacity, and in some cases incorrectly (by assuming a nil return rather than an exception), which can quite easily be replaced with #pick plus some extra handling.
This commit adds a new notification that gets sent to admins when the site gets new features after an upgrade/deploy. Clicking on the notification takes the admin to the admin dashboard at `/admin` where they can see the new features under the "New Features" section.
Internal topic: t/87166.
When user is watching category or tag (watching or watching first post) notifications are moved to other tab.
To achieve that and distinguish between post create to directly watched topics and indirectly watched topics, new notification type called `watching_category_or_tag` was introduced.
This commit adds non-archived group messages and `group_message_summary` notifications in the messages tab in the user menu. With this change, the messages tab in the user menu now includes 3 types of items:
1. Unread `private_message` notifications (notifications when you receive a reply in a PM)
2. Unread and read `group_message_summary` notifications (notifications when there's a new message in a group inbox that you track)
3. Non-archived personal and group messages
Unread `private_message` notifications are always shown first, followed by unread `group_message_summary` notifications, and then everything else (messages and read `group_message_summary` notifications) sorted by recency (most recent first).
Internal topic: t/72976.
Right now the experimental user menu sorts notifications the same way that the old menu does: unread high-priority notifications are shown first in reverse-chronological order followed by everything else also in reverse-chronological order. However, since the experimental user menu has dedicated tabs for some notification types and each tab displays a badge with the count of unread notifications in the tab, we feel like it makes sense to change how notifications are sorted in the experimental user menu to this:
1. unread high-priority notifications
2. unread regular notifications
3. all read notifications (both high-priority and regular)
4. within each group, notifications are sorted in reverse-chronological order (i.e. newest is shown first).
This new sorting logic applies to all tabs in the experimental user menu, however it doesn't change anything in the old menu. With this change, if a tab in the experimental user menu shows an unread notification badge for a really old notification, it will be surfaced to the top and prevents confusing scenarios where a user sees an unread notification badge on a tab, but the tab doesn't show the unread notification because it's too old to make it to the list.
Internal topic: t72199.
Some of the changes in this PR are extracted from https://github.com/discourse/discourse/pull/17379.
Similar to the bookmarks tab in the new user menu, the messages tab also displays a mix of notifications and messages. When there are unread message notifications, the tab displays all of these notifications at the top and fills the remaining space in the menu with a list of the user's messages. The bubble/badge count on the messages tab indicates how many unread message notifications there are.
* REFACTOR: Improve support for consolidating notifications.
Before this commit, we didn't have a single way of consolidating notifications. For notifications like group summaries, we manually removed old ones before creating a new one. On the other hand, we used an after_create callback for likes and group membership requests, which caused unnecessary work, as we need to delete the record we created to replace it with a consolidated one.
We now have all the consolidation rules centralized in a single place: the consolidation planner class. Other parts of the app looking to create a consolidable notification can do so by calling Notification#consolidate_or_save!, instead of the default Notification#create! method.
Finally, we added two more rules: one for re-using existing group summaries and another for deleting duplicated dashboard problems PMs notifications when the user is tracking the moderator's inbox. Setting the threshold to one forces the planner to apply this rule every time.
I plan to add plugin support for adding custom rules in another PR to keep this one relatively small.
* DEV: Introduces a plugin API for consolidating notifications.
This commit removes the `Notification#filter_by_consolidation_data` scope since plugins could have to define their criteria. The Plan class now receives two blocks, one to query for an already consolidated notification, which we'll try to update, and another to query for existing ones to consolidate.
It also receives a consolidation window, which accepts an ActiveSupport::Duration object, and filter notifications created since that value.
Introduce the concept of "high priority notifications" which include PM and bookmark reminder notifications. Now bookmark reminder notifications act in the same way as PM notifications (float to top of recent list, show in the green bubble) and most instances of unread_private_messages in the UI have been replaced with unread_high_priority_notifications.
The user email digest is changed to just have a section about unread high priority notifications, the unread PM section has been removed.
A high_priority boolean column has been added to the Notification table and relevant indices added to account for it.
unread_private_messages has been kept on the User model purely for backwards compat, but now just returns unread_high_priority_notifications count so this may cause some inconsistencies in the UI.
* This PR implements the scheduling and notification system for bookmark reminders. Every 5 minutes a schedule runs to check any reminders that need to be sent before now, limited to **300** reminders at a time. Any leftover reminders will be sent in the next run. This is to avoid having to deal with fickle sidekiq and reminders in the far-flung future, which would necessitate having a background job anyway to clean up any missing `enqueue_at` reminders.
* If a reminder is sent its `reminder_at` time is cleared and the `reminder_last_sent_at` time is filled in. Notifications are only user-level notifications for now.
* All JavaScript and frontend code related to displaying the bookmark reminder notification is contained here. The reminder functionality is now re-enabled in the bookmark modal as well.
* This PR also implements the "Remind me next time I am at my desktop" bookmark reminder functionality. When the user is on a mobile device they are able to select this option. When they choose this option we set a key in Redis saying they have a pending at desktop reminder. The next time they change devices we check if the new device is desktop, and if it is we send reminders using a DistributedMutex. There is also a job to ensure consistency of these reminders in Redis (in case Redis drops the ball) and the at desktop reminders expire after 20 days.
* Also in this PR is a fix to delete all Bookmarks for a user via `UserDestroyer`
Introduces a new site setting `max_notifications_per_user`.
Out-of-the-box this is set to 10,000. If a user exceeds this number of
notifications, we will delete the oldest notifications keeping only 10,000.
To disable this safeguard set the setting to 0.
Enforcement happens weekly.
This is in place to protect the system from pathological states where a
single user has enormous amounts of notifications causing various queries
to time out. In practice nobody looks back more than a few hundred notifications.
This simplifies the code for refreshing notification counts. It now
unconditionally looks up the user object which protects against stale objects
in memory.
This also removes a pile of conditional logic we no longer need.
Doing .pluck(:column).first is a very common pattern in Discourse and in
most cases, a limit cause isn't being added. Instead of adding a limit
clause to all these callsites, this commit adds two new methods to
ActiveRecord::Relation:
pluck_first, equivalent to limit(1).pluck(*columns).first
and pluck_first! which, like other finder methods, raises an exception
when no record is found
