mastodon/app/lib/feed_manager.rb

371 lines
16 KiB
Ruby

# frozen_string_literal: true
require 'singleton'
class FeedManager
include Singleton
include Redisable
MAX_ITEMS = 400
# Must be <= MAX_ITEMS or the tracking sets will grow forever
REBLOG_FALLOFF = 40
def with_active_accounts(&block)
Account.joins(:user).where('users.current_sign_in_at > ?', User::ACTIVE_DURATION.ago).find_each(&block)
end
def key(type, id, subtype = nil)
return "feed:#{type}:#{id}" unless subtype
"feed:#{type}:#{id}:#{subtype}"
end
def filter?(timeline_type, status, receiver_id)
if timeline_type == :home
filter_from_home?(status, receiver_id, build_crutches(receiver_id, [status]))
elsif timeline_type == :mentions
filter_from_mentions?(status, receiver_id)
else
false
end
end
def push_to_home(account, status)
return false unless add_to_feed(:home, account.id, status, account.user&.aggregates_reblogs?)
trim(:home, account.id)
PushUpdateWorker.perform_async(account.id, status.id, "timeline:#{account.id}") if push_update_required?("timeline:#{account.id}")
true
end
def unpush_from_home(account, status)
return false unless remove_from_feed(:home, account.id, status, account.user&.aggregates_reblogs?)
redis.publish("timeline:#{account.id}", Oj.dump(event: :delete, payload: status.id.to_s))
true
end
def push_to_list(list, status)
if status.reply? && status.in_reply_to_account_id != status.account_id
should_filter = status.in_reply_to_account_id != list.account_id
should_filter &&= !ListAccount.where(list_id: list.id, account_id: status.in_reply_to_account_id).exists?
return false if should_filter
end
return false unless add_to_feed(:list, list.id, status, list.account.user&.aggregates_reblogs?)
trim(:list, list.id)
PushUpdateWorker.perform_async(list.account_id, status.id, "timeline:list:#{list.id}") if push_update_required?("timeline:list:#{list.id}")
true
end
def unpush_from_list(list, status)
return false unless remove_from_feed(:list, list.id, status, list.account.user&.aggregates_reblogs?)
redis.publish("timeline:list:#{list.id}", Oj.dump(event: :delete, payload: status.id.to_s))
true
end
def trim(type, account_id)
timeline_key = key(type, account_id)
reblog_key = key(type, account_id, 'reblogs')
# Remove any items past the MAX_ITEMS'th entry in our feed
redis.zremrangebyrank(timeline_key, 0, -(FeedManager::MAX_ITEMS + 1))
# Get the score of the REBLOG_FALLOFF'th item in our feed, and stop
# tracking anything after it for deduplication purposes.
falloff_rank = FeedManager::REBLOG_FALLOFF - 1
falloff_range = redis.zrevrange(timeline_key, falloff_rank, falloff_rank, with_scores: true)
falloff_score = falloff_range&.first&.last&.to_i || 0
# Get any reblogs we might have to clean up after.
redis.zrangebyscore(reblog_key, 0, falloff_score).each do |reblogged_id|
# Remove it from the set of reblogs we're tracking *first* to avoid races.
redis.zrem(reblog_key, reblogged_id)
# Just drop any set we might have created to track additional reblogs.
# This means that if this reblog is deleted, we won't automatically insert
# another reblog, but also that any new reblog can be inserted into the
# feed.
redis.del(key(type, account_id, "reblogs:#{reblogged_id}"))
end
end
def merge_into_timeline(from_account, into_account)
timeline_key = key(:home, into_account.id)
aggregate = into_account.user&.aggregates_reblogs?
query = from_account.statuses.where(visibility: [:public, :unlisted, :private]).includes(:preloadable_poll, reblog: :account).limit(FeedManager::MAX_ITEMS / 4)
if redis.zcard(timeline_key) >= FeedManager::MAX_ITEMS / 4
oldest_home_score = redis.zrange(timeline_key, 0, 0, with_scores: true).first.last.to_i
query = query.where('id > ?', oldest_home_score)
end
statuses = query.to_a
crutches = build_crutches(into_account.id, statuses)
statuses.each do |status|
next if filter_from_home?(status, into_account, crutches)
add_to_feed(:home, into_account.id, status, aggregate)
end
trim(:home, into_account.id)
end
def unmerge_from_timeline(from_account, into_account)
timeline_key = key(:home, into_account.id)
oldest_home_score = redis.zrange(timeline_key, 0, 0, with_scores: true)&.first&.last&.to_i || 0
from_account.statuses.select('id, reblog_of_id').where('id > ?', oldest_home_score).reorder(nil).find_each do |status|
remove_from_feed(:home, into_account.id, status, into_account.user&.aggregates_reblogs?)
end
end
def clear_from_timeline(account, target_account)
timeline_key = key(:home, account.id)
timeline_status_ids = redis.zrange(timeline_key, 0, -1)
target_statuses = Status.where(id: timeline_status_ids, account: target_account)
target_statuses.each do |status|
unpush_from_home(account, status)
end
end
def populate_feed(account)
limit = FeedManager::MAX_ITEMS / 2
aggregate = account.user&.aggregates_reblogs?
timeline_key = key(:home, account.id)
account.statuses.where.not(visibility: :direct).limit(limit).each do |status|
add_to_feed(:home, account.id, status, aggregate)
end
account.following.includes(:account_stat).find_each do |target_account|
if redis.zcard(timeline_key) >= limit
oldest_home_score = redis.zrange(timeline_key, 0, 0, with_scores: true).first.last.to_i
last_status_score = Mastodon::Snowflake.id_at(account.last_status_at)
# If the feed is full and this account has not posted more recently
# than the last item on the feed, then we can skip the whole account
# because none of its statuses would stay on the feed anyway
next if last_status_score < oldest_home_score
end
statuses = target_account.statuses.where(visibility: [:public, :unlisted, :private]).includes(:preloadable_poll, reblog: :account).limit(limit)
crutches = build_crutches(account.id, statuses)
statuses.each do |status|
next if filter_from_home?(status, account.id, crutches)
add_to_feed(:home, account.id, status, aggregate)
end
trim(:home, account.id)
end
end
private
def push_update_required?(timeline_id)
redis.exists("subscribed:#{timeline_id}")
end
def blocks_or_mutes?(receiver_id, account_ids, context)
Block.where(account_id: receiver_id, target_account_id: account_ids).any? ||
(context == :home ? Mute.where(account_id: receiver_id, target_account_id: account_ids).any? : Mute.where(account_id: receiver_id, target_account_id: account_ids, hide_notifications: true).any?)
end
def filter_from_home?(status, receiver_id, crutches)
return false if receiver_id == status.account_id
return true if status.reply? && (status.in_reply_to_id.nil? || status.in_reply_to_account_id.nil?)
return true if phrase_filtered?(status, receiver_id, :home)
check_for_blocks = crutches[:active_mentions][status.id] || []
check_for_blocks.concat([status.account_id])
if status.reblog?
check_for_blocks.concat([status.reblog.account_id])
check_for_blocks.concat(crutches[:active_mentions][status.reblog_of_id] || [])
end
return true if check_for_blocks.any? { |target_account_id| crutches[:blocking][target_account_id] || crutches[:muting][target_account_id] }
if status.reply? && !status.in_reply_to_account_id.nil? # Filter out if it's a reply
should_filter = !crutches[:following][status.in_reply_to_account_id] # and I'm not following the person it's a reply to
should_filter &&= receiver_id != status.in_reply_to_account_id # and it's not a reply to me
should_filter &&= status.account_id != status.in_reply_to_account_id # and it's not a self-reply
return !!should_filter
elsif status.reblog? # Filter out a reblog
should_filter = crutches[:hiding_reblogs][status.account_id] # if the reblogger's reblogs are suppressed
should_filter ||= crutches[:blocked_by][status.reblog.account_id] # or if the author of the reblogged status is blocking me
should_filter ||= crutches[:domain_blocking][status.reblog.account.domain] # or the author's domain is blocked
return !!should_filter
end
false
end
def filter_from_mentions?(status, receiver_id)
return true if receiver_id == status.account_id
return true if phrase_filtered?(status, receiver_id, :notifications)
# This filter is called from NotifyService, but already after the sender of
# the notification has been checked for mute/block. Therefore, it's not
# necessary to check the author of the toot for mute/block again
check_for_blocks = status.active_mentions.pluck(:account_id)
check_for_blocks.concat([status.in_reply_to_account]) if status.reply? && !status.in_reply_to_account_id.nil?
should_filter = blocks_or_mutes?(receiver_id, check_for_blocks, :mentions) # Filter if it's from someone I blocked, in reply to someone I blocked, or mentioning someone I blocked (or muted)
should_filter ||= (status.account.silenced? && !Follow.where(account_id: receiver_id, target_account_id: status.account_id).exists?) # of if the account is silenced and I'm not following them
should_filter
end
def phrase_filtered?(status, receiver_id, context)
active_filters = Rails.cache.fetch("filters:#{receiver_id}") { CustomFilter.where(account_id: receiver_id).active_irreversible.to_a }.to_a
active_filters.select! { |filter| filter.context.include?(context.to_s) && !filter.expired? }
active_filters.map! do |filter|
if filter.whole_word
sb = filter.phrase =~ /\A[[:word:]]/ ? '\b' : ''
eb = filter.phrase =~ /[[:word:]]\z/ ? '\b' : ''
/(?mix:#{sb}#{Regexp.escape(filter.phrase)}#{eb})/
else
/#{Regexp.escape(filter.phrase)}/i
end
end
return false if active_filters.empty?
combined_regex = active_filters.reduce { |memo, obj| Regexp.union(memo, obj) }
status = status.reblog if status.reblog?
combined_text = [
Formatter.instance.plaintext(status),
status.spoiler_text,
status.preloadable_poll ? status.preloadable_poll.options.join("\n\n") : nil,
status.media_attachments.map(&:description).join("\n\n"),
].compact.join("\n\n")
!combined_regex.match(combined_text).nil?
end
# Adds a status to an account's feed, returning true if a status was
# added, and false if it was not added to the feed. Note that this is
# an internal helper: callers must call trim or push updates if
# either action is appropriate.
def add_to_feed(timeline_type, account_id, status, aggregate_reblogs = true)
timeline_key = key(timeline_type, account_id)
reblog_key = key(timeline_type, account_id, 'reblogs')
if status.reblog? && (aggregate_reblogs.nil? || aggregate_reblogs)
# If the original status or a reblog of it is within
# REBLOG_FALLOFF statuses from the top, do not re-insert it into
# the feed
rank = redis.zrevrank(timeline_key, status.reblog_of_id)
return false if !rank.nil? && rank < FeedManager::REBLOG_FALLOFF
reblog_rank = redis.zrevrank(reblog_key, status.reblog_of_id)
if reblog_rank.nil?
# This is not something we've already seen reblogged, so we
# can just add it to the feed (and note that we're
# reblogging it).
redis.zadd(timeline_key, status.id, status.id)
redis.zadd(reblog_key, status.id, status.reblog_of_id)
else
# Another reblog of the same status was already in the
# REBLOG_FALLOFF most recent statuses, so we note that this
# is an "extra" reblog, by storing it in reblog_set_key.
reblog_set_key = key(timeline_type, account_id, "reblogs:#{status.reblog_of_id}")
redis.sadd(reblog_set_key, status.id)
return false
end
else
# A reblog may reach earlier than the original status because of the
# delay of the worker deliverying the original status, the late addition
# by merging timelines, and other reasons.
# If such a reblog already exists, just do not re-insert it into the feed.
rank = redis.zrevrank(reblog_key, status.id)
return false unless rank.nil?
redis.zadd(timeline_key, status.id, status.id)
end
true
end
# Removes an individual status from a feed, correctly handling cases
# with reblogs, and returning true if a status was removed. As with
# `add_to_feed`, this does not trigger push updates, so callers must
# do so if appropriate.
def remove_from_feed(timeline_type, account_id, status, aggregate_reblogs = true)
timeline_key = key(timeline_type, account_id)
reblog_key = key(timeline_type, account_id, 'reblogs')
if status.reblog? && (aggregate_reblogs.nil? || aggregate_reblogs)
# 1. If the reblogging status is not in the feed, stop.
status_rank = redis.zrevrank(timeline_key, status.id)
return false if status_rank.nil?
# 2. Remove reblog from set of this status's reblogs.
reblog_set_key = key(timeline_type, account_id, "reblogs:#{status.reblog_of_id}")
redis.srem(reblog_set_key, status.id)
redis.zrem(reblog_key, status.reblog_of_id)
# 3. Re-insert another reblog or original into the feed if one
# remains in the set. We could pick a random element, but this
# set should generally be small, and it seems ideal to show the
# oldest potential such reblog.
other_reblog = redis.smembers(reblog_set_key).map(&:to_i).min
redis.zadd(timeline_key, other_reblog, other_reblog) if other_reblog
redis.zadd(reblog_key, other_reblog, status.reblog_of_id) if other_reblog
# 4. Remove the reblogging status from the feed (as normal)
# (outside conditional)
else
# If the original is getting deleted, no use for reblog references
redis.del(key(timeline_type, account_id, "reblogs:#{status.id}"))
redis.zrem(reblog_key, status.id)
end
redis.zrem(timeline_key, status.id)
end
def build_crutches(receiver_id, statuses)
crutches = {}
crutches[:active_mentions] = Mention.active.where(status_id: statuses.flat_map { |s| [s.id, s.reblog_of_id] }.compact).pluck(:status_id, :account_id).each_with_object({}) { |(id, account_id), mapping| (mapping[id] ||= []).push(account_id) }
check_for_blocks = statuses.flat_map do |s|
arr = crutches[:active_mentions][s.id] || []
arr.concat([s.account_id])
if s.reblog?
arr.concat([s.reblog.account_id])
arr.concat(crutches[:active_mentions][s.reblog_of_id] || [])
end
arr
end
crutches[:following] = Follow.where(account_id: receiver_id, target_account_id: statuses.map(&:in_reply_to_account_id).compact).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
crutches[:hiding_reblogs] = Follow.where(account_id: receiver_id, target_account_id: statuses.map { |s| s.account_id if s.reblog? }.compact, show_reblogs: false).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
crutches[:blocking] = Block.where(account_id: receiver_id, target_account_id: check_for_blocks).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
crutches[:muting] = Mute.where(account_id: receiver_id, target_account_id: check_for_blocks).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
crutches[:domain_blocking] = AccountDomainBlock.where(account_id: receiver_id, domain: statuses.map { |s| s.reblog&.account&.domain }.compact).pluck(:domain).each_with_object({}) { |domain, mapping| mapping[domain] = true }
crutches[:blocked_by] = Block.where(target_account_id: receiver_id, account_id: statuses.map { |s| s.reblog&.account_id }.compact).pluck(:account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
crutches
end
end