Fix race condition when receiving an ActivityPub Create multiple times (#4930)

* Fix race condition when receiving an ActivityPub Create multiple times

* Use a RedisLock to avoid concurrent processing of a same Create activity
This commit is contained in:
ThibG 2017-09-14 22:26:22 +02:00 committed by Eugen Rochko
parent bdcc9e2ceb
commit 4a73615193

View file

@ -4,26 +4,31 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
def perform
return if delete_arrived_first?(object_uri) || unsupported_object_type?
status = find_existing_status
return status unless status.nil?
ApplicationRecord.transaction do
status = Status.create!(status_params)
process_tags(status)
process_attachments(status)
RedisLock.acquire(lock_options) do |lock|
if lock.acquired?
@status = find_existing_status
process_status if @status.nil?
end
end
resolve_thread(status)
distribute(status)
forward_for_reply if status.public_visibility? || status.unlisted_visibility?
status
@status
end
private
def process_status
ApplicationRecord.transaction do
@status = Status.create!(status_params)
process_tags(@status)
process_attachments(@status)
end
resolve_thread(@status)
distribute(@status)
forward_for_reply if @status.public_visibility? || @status.unlisted_visibility?
end
def find_existing_status
status = status_from_uri(object_uri)
status ||= Status.find_by(uri: @object['atomUri']) if @object['atomUri'].present?
@ -182,4 +187,8 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
return unless @json['signature'].present? && reply_to_local?
ActivityPub::RawDistributionWorker.perform_async(Oj.dump(@json), replied_to_status.account_id)
end
def lock_options
{ redis: Redis.current, key: "create:#{@object['id']}" }
end
end