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Diffstat (limited to 'app/models/account_statuses_cleanup_policy.rb')
| -rw-r--r-- | app/models/account_statuses_cleanup_policy.rb | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/app/models/account_statuses_cleanup_policy.rb b/app/models/account_statuses_cleanup_policy.rb new file mode 100644 index 000000000..705ccff54 --- /dev/null +++ b/app/models/account_statuses_cleanup_policy.rb @@ -0,0 +1,171 @@ +# frozen_string_literal: true + +# == Schema Information +# +# Table name: account_statuses_cleanup_policies +# +# id :bigint not null, primary key +# account_id :bigint not null +# enabled :boolean default(TRUE), not null +# min_status_age :integer default(1209600), not null +# keep_direct :boolean default(TRUE), not null +# keep_pinned :boolean default(TRUE), not null +# keep_polls :boolean default(FALSE), not null +# keep_media :boolean default(FALSE), not null +# keep_self_fav :boolean default(TRUE), not null +# keep_self_bookmark :boolean default(TRUE), not null +# min_favs :integer +# min_reblogs :integer +# created_at :datetime not null +# updated_at :datetime not null +# +class AccountStatusesCleanupPolicy < ApplicationRecord + include Redisable + + ALLOWED_MIN_STATUS_AGE = [ + 2.weeks.seconds, + 1.month.seconds, + 2.months.seconds, + 3.months.seconds, + 6.months.seconds, + 1.year.seconds, + 2.years.seconds, + ].freeze + + EXCEPTION_BOOLS = %w(keep_direct keep_pinned keep_polls keep_media keep_self_fav keep_self_bookmark).freeze + EXCEPTION_THRESHOLDS = %w(min_favs min_reblogs).freeze + + # Depending on the cleanup policy, the query to discover the next + # statuses to delete my get expensive if the account has a lot of old + # statuses otherwise excluded from deletion by the other exceptions. + # + # Therefore, `EARLY_SEARCH_CUTOFF` is meant to be the maximum number of + # old statuses to be considered for deletion prior to checking exceptions. + # + # This is used in `compute_cutoff_id` to provide a `max_id` to + # `statuses_to_delete`. + EARLY_SEARCH_CUTOFF = 5_000 + + belongs_to :account + + validates :min_status_age, inclusion: { in: ALLOWED_MIN_STATUS_AGE } + validates :min_favs, numericality: { greater_than_or_equal_to: 1, allow_nil: true } + validates :min_reblogs, numericality: { greater_than_or_equal_to: 1, allow_nil: true } + validate :validate_local_account + + before_save :update_last_inspected + + def statuses_to_delete(limit = 50, max_id = nil, min_id = nil) + scope = account.statuses + scope.merge!(old_enough_scope(max_id)) + scope = scope.where(Status.arel_table[:id].gteq(min_id)) if min_id.present? + scope.merge!(without_popular_scope) unless min_favs.nil? && min_reblogs.nil? + scope.merge!(without_direct_scope) if keep_direct? + scope.merge!(without_pinned_scope) if keep_pinned? + scope.merge!(without_poll_scope) if keep_polls? + scope.merge!(without_media_scope) if keep_media? + scope.merge!(without_self_fav_scope) if keep_self_fav? + scope.merge!(without_self_bookmark_scope) if keep_self_bookmark? + + scope.reorder(id: :asc).limit(limit) + end + + # This computes a toot id such that: + # - the toot would be old enough to be candidate for deletion + # - there are at most EARLY_SEARCH_CUTOFF toots between the last inspected toot and this one + # + # The idea is to limit expensive SQL queries when an account has lots of toots excluded from + # deletion, while not starting anew on each run. + def compute_cutoff_id + min_id = last_inspected || 0 + max_id = Mastodon::Snowflake.id_at(min_status_age.seconds.ago, with_random: false) + subquery = account.statuses.where(Status.arel_table[:id].gteq(min_id)).where(Status.arel_table[:id].lteq(max_id)) + subquery = subquery.select(:id).reorder(id: :asc).limit(EARLY_SEARCH_CUTOFF) + + # We're textually interpolating a subquery here as ActiveRecord seem to not provide + # a way to apply the limit to the subquery + Status.connection.execute("SELECT MAX(id) FROM (#{subquery.to_sql}) t").values.first.first + end + + # The most important thing about `last_inspected` is that any toot older than it is guaranteed + # not to be kept by the policy regardless of its age. + def record_last_inspected(last_id) + redis.set("account_cleanup:#{account.id}", last_id, ex: 1.week.seconds) + end + + def last_inspected + redis.get("account_cleanup:#{account.id}")&.to_i + end + + def invalidate_last_inspected(status, action) + last_value = last_inspected + return if last_value.nil? || status.id > last_value || status.account_id != account_id + + case action + when :unbookmark + return unless keep_self_bookmark? + when :unfav + return unless keep_self_fav? + when :unpin + return unless keep_pinned? + end + + record_last_inspected(status.id) + end + + private + + def update_last_inspected + if EXCEPTION_BOOLS.map { |name| attribute_change_to_be_saved(name) }.compact.include?([true, false]) + # Policy has been widened in such a way that any previously-inspected status + # may need to be deleted, so we'll have to start again. + redis.del("account_cleanup:#{account.id}") + end + if EXCEPTION_THRESHOLDS.map { |name| attribute_change_to_be_saved(name) }.compact.any? { |old, new| old.present? && (new.nil? || new > old) } + redis.del("account_cleanup:#{account.id}") + end + end + + def validate_local_account + errors.add(:account, :invalid) unless account&.local? + end + + def without_direct_scope + Status.where.not(visibility: :direct) + end + + def old_enough_scope(max_id = nil) + # Filtering on `id` rather than `min_status_age` ago will treat + # non-snowflake statuses as older than they really are, but Mastodon + # has switched to snowflake IDs significantly over 2 years ago anyway. + max_id = [max_id, Mastodon::Snowflake.id_at(min_status_age.seconds.ago, with_random: false)].compact.min + Status.where(Status.arel_table[:id].lteq(max_id)) + end + + def without_self_fav_scope + Status.where('NOT EXISTS (SELECT * FROM favourites fav WHERE fav.account_id = statuses.account_id AND fav.status_id = statuses.id)') + end + + def without_self_bookmark_scope + Status.where('NOT EXISTS (SELECT * FROM bookmarks bookmark WHERE bookmark.account_id = statuses.account_id AND bookmark.status_id = statuses.id)') + end + + def without_pinned_scope + Status.where('NOT EXISTS (SELECT * FROM status_pins pin WHERE pin.account_id = statuses.account_id AND pin.status_id = statuses.id)') + end + + def without_media_scope + Status.where('NOT EXISTS (SELECT * FROM media_attachments media WHERE media.status_id = statuses.id)') + end + + def without_poll_scope + Status.where(poll_id: nil) + end + + def without_popular_scope + scope = Status.left_joins(:status_stat) + scope = scope.where('COALESCE(status_stats.reblogs_count, 0) <= ?', min_reblogs) unless min_reblogs.nil? + scope = scope.where('COALESCE(status_stats.favourites_count, 0) <= ?', min_favs) unless min_favs.nil? + scope + end +end |