fedibird-fe/app/services/remove_status_service.rb
Eugen Rochko 6ff67be0f6
Add a spam check (#11217)
* Add a spam check

* Use Nilsimsa to generate locality-sensitive hashes and compare using Levenshtein distance

* Add more tests

* Add exemption when the message is a reply to something that mentions the sender

* Use Nilsimsa Compare Value instead of Levenshtein distance

* Use MD5 for messages shorter than 10 characters

* Add message to automated report, do not add non-public statuses to
automated report, add trust level to accounts and make unsilencing
raise the trust level to prevent repeated spam checks on that account

* Expire spam check data after 3 months

* Add support for local statuses, reduce expiration to 1 week, always create a report

* Add content warnings to the spam check and exempt empty statuses

* Change Nilsimsa threshold to 95 and make sure removed statuses are removed from the spam check

* Add all matched statuses into automatic report
2019-07-13 16:45:50 +02:00

153 lines
4.6 KiB
Ruby

# frozen_string_literal: true
class RemoveStatusService < BaseService
include Redisable
include Payloadable
def call(status, **options)
@payload = Oj.dump(event: :delete, payload: status.id.to_s)
@status = status
@account = status.account
@tags = status.tags.pluck(:name).to_a
@mentions = status.active_mentions.includes(:account).to_a
@reblogs = status.reblogs.includes(:account).to_a
@options = options
RedisLock.acquire(lock_options) do |lock|
if lock.acquired?
remove_from_self if status.account.local?
remove_from_followers
remove_from_lists
remove_from_affected
remove_reblogs
remove_from_hashtags
remove_from_public
remove_from_media if status.media_attachments.any?
remove_from_spam_check
@status.destroy!
else
raise Mastodon::RaceConditionError
end
end
# There is no reason to send out Undo activities when the
# cause is that the original object has been removed, since
# original object being removed implicitly removes reblogs
# of it. The Delete activity of the original is forwarded
# separately.
return if !@account.local? || @options[:original_removed]
remove_from_remote_followers
remove_from_remote_affected
end
private
def remove_from_self
FeedManager.instance.unpush_from_home(@account, @status)
end
def remove_from_followers
@account.followers_for_local_distribution.reorder(nil).find_each do |follower|
FeedManager.instance.unpush_from_home(follower, @status)
end
end
def remove_from_lists
@account.lists_for_local_distribution.select(:id, :account_id).reorder(nil).find_each do |list|
FeedManager.instance.unpush_from_list(list, @status)
end
end
def remove_from_affected
@mentions.map(&:account).select(&:local?).each do |account|
redis.publish("timeline:#{account.id}", @payload)
end
end
def remove_from_remote_affected
# People who got mentioned in the status, or who
# reblogged it from someone else might not follow
# the author and wouldn't normally receive the
# delete notification - so here, we explicitly
# send it to them
target_accounts = (@mentions.map(&:account).reject(&:local?) + @reblogs.map(&:account).reject(&:local?))
target_accounts << @status.reblog.account if @status.reblog? && !@status.reblog.account.local?
target_accounts.uniq!(&:id)
# ActivityPub
ActivityPub::DeliveryWorker.push_bulk(target_accounts.select(&:activitypub?).uniq(&:preferred_inbox_url)) do |target_account|
[signed_activity_json, @account.id, target_account.preferred_inbox_url]
end
end
def remove_from_remote_followers
# ActivityPub
ActivityPub::DeliveryWorker.push_bulk(@account.followers.inboxes) do |inbox_url|
[signed_activity_json, @account.id, inbox_url]
end
relay! if relayable?
end
def relayable?
@status.public_visibility?
end
def relay!
ActivityPub::DeliveryWorker.push_bulk(Relay.enabled.pluck(:inbox_url)) do |inbox_url|
[signed_activity_json, @account.id, inbox_url]
end
end
def signed_activity_json
@signed_activity_json ||= Oj.dump(serialize_payload(@status, @status.reblog? ? ActivityPub::UndoAnnounceSerializer : ActivityPub::DeleteSerializer, signer: @account))
end
def remove_reblogs
# We delete reblogs of the status before the original status,
# because once original status is gone, reblogs will disappear
# without us being able to do all the fancy stuff
@reblogs.each do |reblog|
RemoveStatusService.new.call(reblog, original_removed: true)
end
end
def remove_from_hashtags
@account.featured_tags.where(tag_id: @status.tags.pluck(:id)).each do |featured_tag|
featured_tag.decrement(@status.id)
end
return unless @status.public_visibility?
@tags.each do |hashtag|
redis.publish("timeline:hashtag:#{hashtag}", @payload)
redis.publish("timeline:hashtag:#{hashtag}:local", @payload) if @status.local?
end
end
def remove_from_public
return unless @status.public_visibility?
redis.publish('timeline:public', @payload)
redis.publish('timeline:public:local', @payload) if @status.local?
end
def remove_from_media
return unless @status.public_visibility?
redis.publish('timeline:public:media', @payload)
redis.publish('timeline:public:local:media', @payload) if @status.local?
end
def remove_from_spam_check
redis.zremrangebyscore("spam_check:#{@status.account_id}", @status.id, @status.id)
end
def lock_options
{ redis: Redis.current, key: "distribute:#{@status.id}" }
end
end