discourse/app/models/topic_user.rb
Sam 335be272ff FEATURE: implement capping of new/unread
We cap new and unread at 2/5th of SiteSetting.max_tracked_new_unread

This dynamic capping is applied under 2 conditions:

1. New capping is applied once every 15 minutes in the periodical job, this effectively ensures that usually even super active sites are capped at 200 new items

2. Unread capping is applied if a user hits max_tracked_new_unread,
  meaning if new + unread == 500, we defer a job that runs within 15 minutes that will cap user at 200 unread

This logic ensures that at worst case a user gets "bad" numbers for 15 minutes and then the system goes ahead and fixes itself up
2015-09-07 12:03:17 +10:00

392 lines
14 KiB
Ruby

class TopicUser < ActiveRecord::Base
belongs_to :user
belongs_to :topic
# used for serialization
attr_accessor :post_action_data
scope :tracking, lambda { |topic_id|
where(topic_id: topic_id)
.where("COALESCE(topic_users.notification_level, :regular) >= :tracking",
regular: TopicUser.notification_levels[:regular],
tracking: TopicUser.notification_levels[:tracking])
}
# Class methods
class << self
# Enums
def notification_levels
@notification_levels ||= Enum.new(:muted, :regular, :tracking, :watching, start: 0)
end
def notification_reasons
@notification_reasons ||= Enum.new(
:created_topic,
:user_changed,
:user_interacted,
:created_post,
:auto_watch,
:auto_watch_category,
:auto_mute_category,
:auto_track_category,
:plugin_changed
)
end
def auto_track(user_id, topic_id, reason)
if TopicUser.where(user_id: user_id, topic_id: topic_id, notifications_reason_id: nil).exists?
change(user_id, topic_id,
notification_level: notification_levels[:tracking],
notifications_reason_id: reason
)
MessageBus.publish("/topic/#{topic_id}", {
notification_level_change: notification_levels[:tracking],
notifications_reason_id: reason
}, user_ids: [user_id])
end
end
# Find the information specific to a user in a forum topic
def lookup_for(user, topics)
# If the user isn't logged in, there's no last read posts
return {} if user.blank? || topics.blank?
topic_ids = topics.map(&:id)
create_lookup(TopicUser.where(topic_id: topic_ids, user_id: user.id))
end
def create_lookup(topic_users)
topic_users = topic_users.to_a
result = {}
return result if topic_users.blank?
topic_users.each { |ftu| result[ftu.topic_id] = ftu }
result
end
def get(topic, user)
topic = topic.id if topic.is_a?(Topic)
user = user.id if user.is_a?(User)
TopicUser.find_by(topic_id: topic, user_id: user)
end
# Change attributes for a user (creates a record when none is present). First it tries an update
# since there's more likely to be an existing record than not. If the update returns 0 rows affected
# it then creates the row instead.
def change(user_id, topic_id, attrs)
# Sometimes people pass objs instead of the ids. We can handle that.
topic_id = topic_id.id if topic_id.is_a?(::Topic)
user_id = user_id.id if user_id.is_a?(::User)
topic_id = topic_id.to_i
user_id = user_id.to_i
TopicUser.transaction do
attrs = attrs.dup
if attrs[:notification_level]
attrs[:notifications_changed_at] ||= DateTime.now
attrs[:notifications_reason_id] ||= TopicUser.notification_reasons[:user_changed]
end
attrs_array = attrs.to_a
attrs_sql = attrs_array.map { |t| "#{t[0]} = ?" }.join(", ")
vals = attrs_array.map { |t| t[1] }
rows = TopicUser.where(topic_id: topic_id, user_id: user_id).update_all([attrs_sql, *vals])
if rows == 0
now = DateTime.now
auto_track_after = User.select(:auto_track_topics_after_msecs).find_by(id: user_id).auto_track_topics_after_msecs
auto_track_after ||= SiteSetting.default_other_auto_track_topics_after_msecs
if auto_track_after >= 0 && auto_track_after <= (attrs[:total_msecs_viewed] || 0)
attrs[:notification_level] ||= notification_levels[:tracking]
end
TopicUser.create(attrs.merge!(user_id: user_id, topic_id: topic_id, first_visited_at: now ,last_visited_at: now))
else
observe_after_save_callbacks_for topic_id, user_id
end
end
if attrs[:notification_level]
MessageBus.publish("/topic/#{topic_id}", { notification_level_change: attrs[:notification_level] }, user_ids: [user_id])
end
rescue ActiveRecord::RecordNotUnique
# In case of a race condition to insert, do nothing
end
def track_visit!(topic,user)
topic_id = topic.is_a?(Topic) ? topic.id : topic
user_id = user.is_a?(User) ? user.id : topic
now = DateTime.now
rows = TopicUser.where(topic_id: topic_id, user_id: user_id).update_all(last_visited_at: now)
if rows == 0
TopicUser.create(topic_id: topic_id, user_id: user_id, last_visited_at: now, first_visited_at: now)
else
observe_after_save_callbacks_for topic_id, user_id
end
end
# Update the last read and the last seen post count, but only if it doesn't exist.
# This would be a lot easier if psql supported some kind of upsert
def update_last_read(user, topic_id, post_number, msecs, opts={})
return if post_number.blank?
msecs = 0 if msecs.to_i < 0
args = {
user_id: user.id,
topic_id: topic_id,
post_number: post_number,
now: DateTime.now,
msecs: msecs,
tracking: notification_levels[:tracking],
threshold: SiteSetting.default_other_auto_track_topics_after_msecs
}
# In case anyone seens "highest_seen_post_number" and gets confused, like I do.
# highest_seen_post_number represents the highest_post_number of the topic when
# the user visited it. It may be out of alignment with last_read, meaning
# ... user visited the topic but did not read the posts
#
# 86400000 = 1 day
rows = exec_sql("UPDATE topic_users
SET
last_read_post_number = GREATEST(:post_number, tu.last_read_post_number),
highest_seen_post_number = t.highest_post_number,
total_msecs_viewed = LEAST(tu.total_msecs_viewed + :msecs,86400000),
notification_level =
case when tu.notifications_reason_id is null and (tu.total_msecs_viewed + :msecs) >
coalesce(u.auto_track_topics_after_msecs,:threshold) and
coalesce(u.auto_track_topics_after_msecs, :threshold) >= 0 then
:tracking
else
tu.notification_level
end
FROM topic_users tu
join topics t on t.id = tu.topic_id
join users u on u.id = :user_id
WHERE
tu.topic_id = topic_users.topic_id AND
tu.user_id = topic_users.user_id AND
tu.topic_id = :topic_id AND
tu.user_id = :user_id
RETURNING
topic_users.notification_level, tu.notification_level old_level, tu.last_read_post_number
",
args).values
if rows.length == 1
before = rows[0][1].to_i
after = rows[0][0].to_i
before_last_read = rows[0][2].to_i
if before_last_read < post_number
# The user read at least one new post
TopicTrackingState.publish_read(topic_id, post_number, user.id, after)
user.update_posts_read!(post_number - before_last_read, mobile: opts[:mobile])
end
if before != after
MessageBus.publish("/topic/#{topic_id}", { notification_level_change: after }, user_ids: [user.id])
end
end
if rows.length == 0
# The user read at least one post in a topic that they haven't viewed before.
args[:new_status] = notification_levels[:regular]
if (user.auto_track_topics_after_msecs || SiteSetting.default_other_auto_track_topics_after_msecs) == 0
args[:new_status] = notification_levels[:tracking]
end
TopicTrackingState.publish_read(topic_id, post_number, user.id, args[:new_status])
user.update_posts_read!(post_number, mobile: opts[:mobile])
exec_sql("INSERT INTO topic_users (user_id, topic_id, last_read_post_number, highest_seen_post_number, last_visited_at, first_visited_at, notification_level)
SELECT :user_id, :topic_id, :post_number, ft.highest_post_number, :now, :now, :new_status
FROM topics AS ft
JOIN users u on u.id = :user_id
WHERE ft.id = :topic_id
AND NOT EXISTS(SELECT 1
FROM topic_users AS ftu
WHERE ftu.user_id = :user_id and ftu.topic_id = :topic_id)",
args)
MessageBus.publish("/topic/#{topic_id}", { notification_level_change: args[:new_status] }, user_ids: [user.id])
end
end
def observe_after_save_callbacks_for(topic_id, user_id)
TopicUser.where(topic_id: topic_id, user_id: user_id).each do |topic_user|
UserActionObserver.instance.after_save topic_user
end
end
end
def self.update_post_action_cache(opts={})
user_id = opts[:user_id]
post_id = opts[:post_id]
topic_id = opts[:topic_id]
action_type = opts[:post_action_type]
action_type_name = "liked" if action_type == :like
action_type_name = "bookmarked" if action_type == :bookmark
raise ArgumentError, "action_type" if action_type && !action_type_name
unless action_type_name
update_post_action_cache(opts.merge(post_action_type: :like))
update_post_action_cache(opts.merge(post_action_type: :bookmark))
return
end
builder = SqlBuilder.new <<SQL
UPDATE topic_users tu
SET #{action_type_name} = x.state
FROM (
SELECT CASE WHEN EXISTS (
SELECT 1
FROM post_actions pa
JOIN posts p on p.id = pa.post_id
JOIN topics t ON t.id = p.topic_id
WHERE pa.deleted_at IS NULL AND
p.deleted_at IS NULL AND
t.deleted_at IS NULL AND
pa.post_action_type_id = :action_type_id AND
tu2.topic_id = t.id AND
tu2.user_id = pa.user_id
LIMIT 1
) THEN true ELSE false END state, tu2.topic_id, tu2.user_id
FROM topic_users tu2
/*where*/
) x
WHERE x.topic_id = tu.topic_id AND x.user_id = tu.user_id AND x.state != tu.#{action_type_name}
SQL
if user_id
builder.where("tu2.user_id = :user_id", user_id: user_id)
end
if topic_id
builder.where("tu2.topic_id = :topic_id", topic_id: topic_id)
end
if post_id
builder.where("tu2.topic_id IN (SELECT topic_id FROM posts WHERE id = :post_id)", post_id: post_id)
builder.where("tu2.user_id IN (SELECT user_id FROM post_actions
WHERE post_id = :post_id AND
post_action_type_id = :action_type_id)")
end
builder.exec(action_type_id: PostActionType.types[action_type])
end
# cap number of unread topics at count, bumping up highest_seen / last_read if needed
def self.cap_unread!(user_id, count)
sql = <<SQL
UPDATE topic_users tu
SET last_read_post_number = max_number,
highest_seen_post_number = max_number
FROM (
SELECT MAX(post_number) max_number, p.topic_id FROM posts p
WHERE deleted_at IS NULL
GROUP BY p.topic_id
) m
WHERE tu.user_id = :user_id AND
m.topic_id = tu.topic_id AND
tu.topic_id IN (
#{TopicTrackingState.report_raw_sql(skip_new: true, select: "topics.id")}
offset :count
)
SQL
TopicUser.exec_sql(sql, user_id: user_id, count: count)
end
def self.unread_cap_key
"unread_cap_user".freeze
end
def self.cap_unread_later(user_id)
$redis.hset TopicUser.unread_cap_key, user_id, ""
end
def self.cap_unread_backlog!
$redis.hkeys(unread_cap_key).map(&:to_i).each do |user_id|
cap_unread!(user_id, (SiteSetting.max_tracked_new_unread * (2/5.0)).to_i)
$redis.hdel unread_cap_key, user_id
end
end
def self.ensure_consistency!(topic_id=nil)
update_post_action_cache(topic_id: topic_id)
# TODO this needs some reworking, when we mark stuff skipped
# we up these numbers so they are not in-sync
# the simple fix is to add a column here, but table is already quite big
# long term we want to split up topic_users and allow for this better
builder = SqlBuilder.new <<SQL
UPDATE topic_users t
SET
last_read_post_number = LEAST(GREATEST(last_read, last_read_post_number), max_post_number),
highest_seen_post_number = LEAST(max_post_number,GREATEST(t.highest_seen_post_number, last_read))
FROM (
SELECT topic_id, user_id, MAX(post_number) last_read
FROM post_timings
GROUP BY topic_id, user_id
) as X
JOIN (
SELECT p.topic_id, MAX(p.post_number) max_post_number from posts p
GROUP BY p.topic_id
) as Y on Y.topic_id = X.topic_id
/*where*/
SQL
builder.where <<SQL
X.topic_id = t.topic_id AND
X.user_id = t.user_id AND
(
last_read_post_number <> LEAST(GREATEST(last_read, last_read_post_number), max_post_number) OR
highest_seen_post_number <> LEAST(max_post_number,GREATEST(t.highest_seen_post_number, last_read))
)
SQL
if topic_id
builder.where("t.topic_id = :topic_id", topic_id: topic_id)
end
builder.exec
end
end
# == Schema Information
#
# Table name: topic_users
#
# user_id :integer not null
# topic_id :integer not null
# posted :boolean default(FALSE), not null
# last_read_post_number :integer
# highest_seen_post_number :integer
# last_visited_at :datetime
# first_visited_at :datetime
# notification_level :integer default(1), not null
# notifications_changed_at :datetime
# notifications_reason_id :integer
# total_msecs_viewed :integer default(0), not null
# cleared_pinned_at :datetime
# id :integer not null, primary key
# last_emailed_post_number :integer
# liked :boolean default(FALSE)
# bookmarked :boolean default(FALSE)
#
# Indexes
#
# index_topic_users_on_topic_id_and_user_id (topic_id,user_id) UNIQUE
# index_topic_users_on_user_id_and_topic_id (user_id,topic_id) UNIQUE
#