masto-fe/app/models/concerns/account_interactions.rb
ThibG ca56527140
Add follower synchronization mechanism (#14510)
* Add support for followers synchronization on the receiving end

Check the `collectionSynchronization` attribute on `Create` and `Announce`
activities and synchronize followers from provided collection if possible.

* Add tests for followers synchronization on the receiving end

* Add support for follower synchronization on the sender's end

* Add tests for the sending end

* Switch from AS attributes to HTTP header

Replace the custom `collectionSynchronization` ActivityStreams attribute by
an HTTP header (`X-AS-Collection-Synchronization`) with the same syntax as
the `Signature` header and the following fields:
- `collectionId` to specify which collection to synchronize
- `digest` for the SHA256 hex-digest of the list of followers known on the
   receiving instance (where “receiving instance” is determined by accounts
   sharing the same host name for their ActivityPub actor `id`)
- `url` of a collection that should be fetched by the instance actor

Internally, move away from the webfinger-based `domain` attribute and use
account `uri` prefix to group accounts.

* Add environment variable to disable followers synchronization

Since the whole mechanism relies on some new preconditions that, in some
extremely rare cases, might not be met, add an environment variable
(DISABLE_FOLLOWERS_SYNCHRONIZATION) to disable the mechanism altogether and
avoid followers being incorrectly removed.

The current conditions are:
1. all managed accounts' actor `id` and inbox URL have the same URI scheme and
   netloc.
2. all accounts whose actor `id` or inbox URL share the same URI scheme and
   netloc as a managed account must be managed by the same Mastodon instance
   as well.

As far as Mastodon is concerned, breaking those preconditions require extensive
configuration changes in the reverse proxy and might also cause other issues.

Therefore, this environment variable provides a way out for people with highly
unusual configurations, and can be safely ignored for the overwhelming majority
of Mastodon administrators.

* Only set follower synchronization header on non-public statuses

This is to avoid unnecessary computations and allow Follow-related
activities to be handled by the usual codepath instead of going through
the synchronization mechanism (otherwise, any Follow/Undo/Accept activity
would trigger the synchronization mechanism even if processing the activity
itself would be enough to re-introduce synchronization)

* Change how ActivityPub::SynchronizeFollowersService handles follow requests

If the remote lists a local follower which we only know has sent a follow
request, consider the follow request as accepted instead of sending an Undo.

* Integrate review feeback

- rename X-AS-Collection-Synchronization to Collection-Synchronization
- various minor refactoring and code style changes

* Only select required fields when computing followers_hash

* Use actor URI rather than webfinger domain in synchronization endpoint

* Change hash computation to be a XOR of individual hashes

Makes it much easier to be memory-efficient, and avoid sorting discrepancy issues.

* Marginally improve followers_hash computation speed

* Further improve hash computation performances by using pluck_each
2020-10-21 18:04:09 +02:00

272 lines
9.7 KiB
Ruby

# frozen_string_literal: true
module AccountInteractions
extend ActiveSupport::Concern
class_methods do
def following_map(target_account_ids, account_id)
Follow.where(target_account_id: target_account_ids, account_id: account_id).each_with_object({}) do |follow, mapping|
mapping[follow.target_account_id] = {
reblogs: follow.show_reblogs?,
notify: follow.notify?,
}
end
end
def followed_by_map(target_account_ids, account_id)
follow_mapping(Follow.where(account_id: target_account_ids, target_account_id: account_id), :account_id)
end
def blocking_map(target_account_ids, account_id)
follow_mapping(Block.where(target_account_id: target_account_ids, account_id: account_id), :target_account_id)
end
def blocked_by_map(target_account_ids, account_id)
follow_mapping(Block.where(account_id: target_account_ids, target_account_id: account_id), :account_id)
end
def muting_map(target_account_ids, account_id)
Mute.where(target_account_id: target_account_ids, account_id: account_id).each_with_object({}) do |mute, mapping|
mapping[mute.target_account_id] = {
notifications: mute.hide_notifications?,
}
end
end
def requested_map(target_account_ids, account_id)
FollowRequest.where(target_account_id: target_account_ids, account_id: account_id).each_with_object({}) do |follow_request, mapping|
mapping[follow_request.target_account_id] = {
reblogs: follow_request.show_reblogs?,
notify: follow_request.notify?,
}
end
end
def endorsed_map(target_account_ids, account_id)
follow_mapping(AccountPin.where(account_id: account_id, target_account_id: target_account_ids), :target_account_id)
end
def account_note_map(target_account_ids, account_id)
AccountNote.where(target_account_id: target_account_ids, account_id: account_id).each_with_object({}) do |note, mapping|
mapping[note.target_account_id] = {
comment: note.comment,
}
end
end
def domain_blocking_map(target_account_ids, account_id)
accounts_map = Account.where(id: target_account_ids).select('id, domain').each_with_object({}) { |a, h| h[a.id] = a.domain }
blocked_domains = domain_blocking_map_by_domain(accounts_map.values.compact, account_id)
accounts_map.reduce({}) { |h, (id, domain)| h.merge(id => blocked_domains[domain]) }
end
def domain_blocking_map_by_domain(target_domains, account_id)
follow_mapping(AccountDomainBlock.where(account_id: account_id, domain: target_domains), :domain)
end
private
def follow_mapping(query, field)
query.pluck(field).each_with_object({}) { |id, mapping| mapping[id] = true }
end
end
included do
# Follow relations
has_many :follow_requests, dependent: :destroy
has_many :active_relationships, class_name: 'Follow', foreign_key: 'account_id', dependent: :destroy
has_many :passive_relationships, class_name: 'Follow', foreign_key: 'target_account_id', dependent: :destroy
has_many :following, -> { order('follows.id desc') }, through: :active_relationships, source: :target_account
has_many :followers, -> { order('follows.id desc') }, through: :passive_relationships, source: :account
# Block relationships
has_many :block_relationships, class_name: 'Block', foreign_key: 'account_id', dependent: :destroy
has_many :blocking, -> { order('blocks.id desc') }, through: :block_relationships, source: :target_account
has_many :blocked_by_relationships, class_name: 'Block', foreign_key: :target_account_id, dependent: :destroy
has_many :blocked_by, -> { order('blocks.id desc') }, through: :blocked_by_relationships, source: :account
# Mute relationships
has_many :mute_relationships, class_name: 'Mute', foreign_key: 'account_id', dependent: :destroy
has_many :muting, -> { order('mutes.id desc') }, through: :mute_relationships, source: :target_account
has_many :muted_by_relationships, class_name: 'Mute', foreign_key: :target_account_id, dependent: :destroy
has_many :muted_by, -> { order('mutes.id desc') }, through: :muted_by_relationships, source: :account
has_many :conversation_mutes, dependent: :destroy
has_many :domain_blocks, class_name: 'AccountDomainBlock', dependent: :destroy
has_many :announcement_mutes, dependent: :destroy
end
def follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false)
rel = active_relationships.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit)
.find_or_create_by!(target_account: other_account)
rel.show_reblogs = reblogs unless reblogs.nil?
rel.notify = notify unless notify.nil?
rel.save! if rel.changed?
remove_potential_friendship(other_account)
rel
end
def request_follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false)
rel = follow_requests.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit)
.find_or_create_by!(target_account: other_account)
rel.show_reblogs = reblogs unless reblogs.nil?
rel.notify = notify unless notify.nil?
rel.save! if rel.changed?
remove_potential_friendship(other_account)
rel
end
def block!(other_account, uri: nil)
remove_potential_friendship(other_account)
block_relationships.create_with(uri: uri)
.find_or_create_by!(target_account: other_account)
end
def mute!(other_account, notifications: nil, duration: 0)
notifications = true if notifications.nil?
mute = mute_relationships.create_with(hide_notifications: notifications).find_or_initialize_by(target_account: other_account)
mute.expires_in = duration.zero? ? nil : duration
mute.save!
remove_potential_friendship(other_account)
# When toggling a mute between hiding and allowing notifications, the mute will already exist, so the find_or_create_by! call will return the existing Mute without updating the hide_notifications attribute. Therefore, we check that hide_notifications? is what we want and set it if it isn't.
if mute.hide_notifications? != notifications
mute.update!(hide_notifications: notifications)
end
mute
end
def mute_conversation!(conversation)
conversation_mutes.find_or_create_by!(conversation: conversation)
end
def block_domain!(other_domain)
domain_blocks.find_or_create_by!(domain: other_domain)
end
def unfollow!(other_account)
follow = active_relationships.find_by(target_account: other_account)
follow&.destroy
end
def unblock!(other_account)
block = block_relationships.find_by(target_account: other_account)
block&.destroy
end
def unmute!(other_account)
mute = mute_relationships.find_by(target_account: other_account)
mute&.destroy
end
def unmute_conversation!(conversation)
mute = conversation_mutes.find_by(conversation: conversation)
mute&.destroy!
end
def unblock_domain!(other_domain)
block = domain_blocks.find_by(domain: other_domain)
block&.destroy
end
def following?(other_account)
active_relationships.where(target_account: other_account).exists?
end
def blocking?(other_account)
block_relationships.where(target_account: other_account).exists?
end
def domain_blocking?(other_domain)
domain_blocks.where(domain: other_domain).exists?
end
def muting?(other_account)
mute_relationships.where(target_account: other_account).exists?
end
def muting_conversation?(conversation)
conversation_mutes.where(conversation: conversation).exists?
end
def muting_notifications?(other_account)
mute_relationships.where(target_account: other_account, hide_notifications: true).exists?
end
def muting_reblogs?(other_account)
active_relationships.where(target_account: other_account, show_reblogs: false).exists?
end
def requested?(other_account)
follow_requests.where(target_account: other_account).exists?
end
def favourited?(status)
status.proper.favourites.where(account: self).exists?
end
def bookmarked?(status)
status.proper.bookmarks.where(account: self).exists?
end
def reblogged?(status)
status.proper.reblogs.where(account: self).exists?
end
def pinned?(status)
status_pins.where(status: status).exists?
end
def endorsed?(account)
account_pins.where(target_account: account).exists?
end
def followers_for_local_distribution
followers.local
.joins(:user)
.where('users.current_sign_in_at > ?', User::ACTIVE_DURATION.ago)
end
def lists_for_local_distribution
lists.joins(account: :user)
.where('users.current_sign_in_at > ?', User::ACTIVE_DURATION.ago)
end
def remote_followers_hash(url_prefix)
Rails.cache.fetch("followers_hash:#{id}:#{url_prefix}") do
digest = "\x00" * 32
followers.where(Account.arel_table[:uri].matches(url_prefix + '%', false, true)).pluck_each(:uri) do |uri|
Xorcist.xor!(digest, Digest::SHA256.digest(uri))
end
digest.unpack('H*')[0]
end
end
def local_followers_hash
Rails.cache.fetch("followers_hash:#{id}:local") do
digest = "\x00" * 32
followers.where(domain: nil).pluck_each(:username) do |username|
Xorcist.xor!(digest, Digest::SHA256.digest(ActivityPub::TagManager.instance.uri_for_username(username)))
end
digest.unpack('H*')[0]
end
end
private
def remove_potential_friendship(other_account, mutual = false)
PotentialFriendshipTracker.remove(id, other_account.id)
PotentialFriendshipTracker.remove(other_account.id, id) if mutual
end
end