Fix N+1s in grouped notifications (#31638)

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Claire 2024-09-02 11:56:00 +02:00 committed by GitHub
parent fc870c7e5a
commit a23b3747ac
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3 changed files with 88 additions and 48 deletions

View File

@ -13,7 +13,6 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
def index
with_read_replica do
@notifications = load_notifications
@group_metadata = load_group_metadata
@grouped_notifications = load_grouped_notifications
@relationships = StatusRelationshipsPresenter.new(target_statuses_from_notifications, current_user&.account_id)
@presenter = GroupedNotificationsPresenter.new(@grouped_notifications, expand_accounts: expand_accounts_param)
@ -34,7 +33,7 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
'app.notification_grouping.expand_accounts_param' => expand_accounts_param
)
render json: @presenter, serializer: REST::DedupNotificationGroupSerializer, relationships: @relationships, group_metadata: @group_metadata, expand_accounts: expand_accounts_param
render json: @presenter, serializer: REST::DedupNotificationGroupSerializer, relationships: @relationships, expand_accounts: expand_accounts_param
end
end
@ -48,7 +47,7 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
def show
@notification = current_account.notifications.without_suspended.find_by!(group_key: params[:id])
presenter = GroupedNotificationsPresenter.new([NotificationGroup.from_notification(@notification)])
presenter = GroupedNotificationsPresenter.new(NotificationGroup.from_notifications([@notification]))
render json: presenter, serializer: REST::DedupNotificationGroupSerializer
end
@ -77,22 +76,9 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
end
end
def load_group_metadata
return {} if @notifications.empty?
MastodonOTELTracer.in_span('Api::V2Alpha::NotificationsController#load_group_metadata') do
browserable_account_notifications
.where(group_key: @notifications.filter_map(&:group_key))
.where(id: (@notifications.last.id)..(@notifications.first.id))
.group(:group_key)
.pluck(:group_key, 'min(notifications.id) as min_id', 'max(notifications.id) as max_id', 'max(notifications.created_at) as latest_notification_at')
.to_h { |group_key, min_id, max_id, latest_notification_at| [group_key, { min_id: min_id, max_id: max_id, latest_notification_at: latest_notification_at }] }
end
end
def load_grouped_notifications
MastodonOTELTracer.in_span('Api::V2Alpha::NotificationsController#load_grouped_notifications') do
@notifications.map { |notification| NotificationGroup.from_notification(notification, max_id: @group_metadata.dig(notification.group_key, :max_id), grouped_types: params[:grouped_types]) }
NotificationGroup.from_notifications(@notifications, pagination_range: (@notifications.last.id)..(@notifications.first.id), grouped_types: params[:grouped_types])
end
end

View File

@ -1,38 +1,49 @@
# frozen_string_literal: true
class NotificationGroup < ActiveModelSerializers::Model
attributes :group_key, :sample_accounts, :notifications_count, :notification, :most_recent_notification_id
attributes :group_key, :sample_accounts, :notifications_count, :notification, :most_recent_notification_id, :pagination_data
# Try to keep this consistent with `app/javascript/mastodon/models/notification_group.ts`
SAMPLE_ACCOUNTS_SIZE = 8
def self.from_notification(notification, max_id: nil, grouped_types: nil)
def self.from_notifications(notifications, pagination_range: nil, grouped_types: nil)
return [] if notifications.empty?
grouped_types = grouped_types.presence&.map(&:to_sym) || Notification::GROUPABLE_NOTIFICATION_TYPES
groupable = notification.group_key.present? && grouped_types.include?(notification.type)
if groupable
# TODO: caching, and, if caching, preloading
scope = notification.account.notifications.where(group_key: notification.group_key)
scope = scope.where(id: ..max_id) if max_id.present?
grouped_notifications = notifications.filter { |notification| notification.group_key.present? && grouped_types.include?(notification.type) }
group_keys = grouped_notifications.pluck(:group_key)
# Ideally, we would not load accounts for each notification group
most_recent_notifications = scope.order(id: :desc).includes(:from_account).take(SAMPLE_ACCOUNTS_SIZE)
most_recent_id = most_recent_notifications.first.id
sample_accounts = most_recent_notifications.map(&:from_account)
notifications_count = scope.count
else
most_recent_id = notification.id
sample_accounts = [notification.from_account]
notifications_count = 1
end
groups_data = load_groups_data(notifications.first.account_id, group_keys, pagination_range: pagination_range)
accounts_map = Account.where(id: groups_data.values.pluck(1).flatten).index_by(&:id)
notifications.map do |notification|
if notification.group_key.present? && grouped_types.include?(notification.type)
most_recent_notification_id, sample_account_ids, count, *raw_pagination_data = groups_data[notification.group_key]
pagination_data = raw_pagination_data.empty? ? nil : { min_id: raw_pagination_data[0], latest_notification_at: raw_pagination_data[1] }
NotificationGroup.new(
notification: notification,
group_key: groupable ? notification.group_key : "ungrouped-#{notification.id}",
sample_accounts: sample_accounts,
notifications_count: notifications_count,
most_recent_notification_id: most_recent_id
group_key: notification.group_key,
sample_accounts: sample_account_ids.map { |id| accounts_map[id] },
notifications_count: count,
most_recent_notification_id: most_recent_notification_id,
pagination_data: pagination_data
)
else
pagination_data = pagination_range.blank? ? nil : { min_id: notification.id, latest_notification_at: notification.created_at }
NotificationGroup.new(
notification: notification,
group_key: "ungrouped-#{notification.id}",
sample_accounts: [notification.from_account],
notifications_count: 1,
most_recent_notification_id: notification.id,
pagination_data: pagination_data
)
end
end
end
delegate :type,
@ -41,4 +52,50 @@ class NotificationGroup < ActiveModelSerializers::Model
:account_relationship_severance_event,
:account_warning,
to: :notification, prefix: false
class << self
private
def load_groups_data(account_id, group_keys, pagination_range: nil)
return {} if group_keys.empty?
if pagination_range.present?
binds = [
account_id,
SAMPLE_ACCOUNTS_SIZE,
pagination_range.begin,
pagination_range.end,
ActiveRecord::Relation::QueryAttribute.new('group_keys', group_keys, ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Array.new(ActiveModel::Type::String.new)),
]
ActiveRecord::Base.connection.select_all(<<~SQL.squish, 'grouped_notifications', binds).cast_values.to_h { |k, *values| [k, values] }
SELECT
groups.group_key,
(SELECT id FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key AND id <= $4 ORDER BY id DESC LIMIT 1),
array(SELECT from_account_id FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key AND id <= $4 ORDER BY id DESC LIMIT $2),
(SELECT count(*) FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key AND id <= $4) AS notifications_count,
(SELECT id FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key AND id >= $3 ORDER BY id ASC LIMIT 1) AS min_id,
(SELECT created_at FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key AND id <= $4 ORDER BY id DESC LIMIT 1)
FROM
unnest($5::text[]) AS groups(group_key);
SQL
else
binds = [
account_id,
SAMPLE_ACCOUNTS_SIZE,
ActiveRecord::Relation::QueryAttribute.new('group_keys', group_keys, ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Array.new(ActiveModel::Type::String.new)),
]
ActiveRecord::Base.connection.select_all(<<~SQL.squish, 'grouped_notifications', binds).cast_values.to_h { |k, *values| [k, values] }
SELECT
groups.group_key,
(SELECT id FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key ORDER BY id DESC LIMIT 1),
array(SELECT from_account_id FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key ORDER BY id DESC LIMIT $2),
(SELECT count(*) FROM notifications WHERE notifications.account_id = $1 AND notifications.group_key = groups.group_key) AS notifications_count
FROM
unnest($3::text[]) AS groups(group_key);
SQL
end
end
end
end

View File

@ -39,21 +39,18 @@ class REST::NotificationGroupSerializer < ActiveModel::Serializer
end
def page_min_id
range = instance_options[:group_metadata][object.group_key]
range.present? ? range[:min_id].to_s : object.notification.id.to_s
object.pagination_data[:min_id].to_s
end
def page_max_id
range = instance_options[:group_metadata][object.group_key]
range.present? ? range[:max_id].to_s : object.notification.id.to_s
object.most_recent_notification_id.to_s
end
def latest_page_notification_at
range = instance_options[:group_metadata][object.group_key]
range.present? ? range[:latest_notification_at] : object.notification.created_at
object.pagination_data[:latest_notification_at]
end
def paginated?
!instance_options[:group_metadata].nil?
object.pagination_data.present?
end
end