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# frozen_string_literal: true
module StatusThreadingConcern
extend ActiveSupport::Concern
def ancestors(limit, account = nil)
find_statuses_from_tree_path(ancestor_ids(limit), account)
end
def descendants(account = nil)
find_statuses_from_tree_path(descendant_ids, account)
end
private
def ancestor_ids(limit)
key = "ancestors:#{id}"
ancestors = Rails.cache.fetch(key)
if ancestors.nil? || ancestors[:limit] < limit
ids = ancestor_statuses(limit).pluck(:id).reverse!
Rails.cache.write key, limit: limit, ids: ids
ids
else
ancestors[:ids].last(limit)
end
end
def ancestor_statuses(limit)
Status.find_by_sql([<<-SQL.squish, id: in_reply_to_id, limit: limit])
WITH RECURSIVE search_tree(id, in_reply_to_id, path)
AS (
SELECT id, in_reply_to_id, ARRAY[id]
FROM statuses
WHERE id = :id
UNION ALL
SELECT statuses.id, statuses.in_reply_to_id, path || statuses.id
FROM search_tree
JOIN statuses ON statuses.id = search_tree.in_reply_to_id
WHERE NOT statuses.id = ANY(path)
)
SELECT id
FROM search_tree
ORDER BY path
LIMIT :limit
SQL
end
def descendant_ids
descendant_statuses.pluck(:id)
end
def descendant_statuses
Status.find_by_sql([<<-SQL.squish, id: id])
WITH RECURSIVE search_tree(id, path)
AS (
SELECT id, ARRAY[id]
FROM statuses
WHERE in_reply_to_id = :id
UNION ALL
SELECT statuses.id, path || statuses.id
FROM search_tree
JOIN statuses ON statuses.in_reply_to_id = search_tree.id
WHERE NOT statuses.id = ANY(path)
)
SELECT id
FROM search_tree
ORDER BY path
SQL
end
def find_statuses_from_tree_path(ids, account)
statuses = statuses_with_accounts(ids).to_a
# FIXME: n+1 bonanza
statuses.reject! { |status| filter_from_context?(status, account) }
# Order ancestors/descendants by tree path
statuses.sort_by! { |status| ids.index(status.id) }
end
def statuses_with_accounts(ids)
Status.where(id: ids).includes(:account)
end
def filter_from_context?(status, account)
StatusFilter.new(status, account).filtered?
end
end
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