about summary refs log tree commit diff
path: root/app/lib/feed_manager.rb
blob: 28e7127049783e9f3733357e578e7eaa566ea77f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
# frozen_string_literal: true

require 'singleton'

class FeedManager
  include Singleton

  MAX_ITEMS = 400

  def key(type, id)
    "feed:#{type}:#{id}"
  end

  def filter?(timeline_type, status, receiver_id)
    if timeline_type == :home
      filter_from_home?(status, receiver_id)
    elsif timeline_type == :mentions
      filter_from_mentions?(status, receiver_id)
    else
      false
    end
  end

  def push(timeline_type, account, status)
    timeline_key = key(timeline_type, account.id)

    if status.reblog?
      # If the original status is within 40 statuses from top, do not re-insert it into the feed
      rank = redis.zrevrank(timeline_key, status.reblog_of_id)
      return if !rank.nil? && rank < 40
      redis.zadd(timeline_key, status.id, status.reblog_of_id)
    else
      redis.zadd(timeline_key, status.id, status.id)
      trim(timeline_type, account.id)
    end

    broadcast(account.id, event: 'update', payload: inline_render(account, 'api/v1/statuses/show', status))
  end

  def broadcast(timeline_id, options = {})
    options[:queued_at] = (Time.now.to_f * 1000.0).to_i
    ActionCable.server.broadcast("timeline:#{timeline_id}", options)
  end

  def trim(type, account_id)
    return unless redis.zcard(key(type, account_id)) > FeedManager::MAX_ITEMS
    last = redis.zrevrange(key(type, account_id), FeedManager::MAX_ITEMS - 1, FeedManager::MAX_ITEMS - 1)
    redis.zremrangebyscore(key(type, account_id), '-inf', "(#{last.last}")
  end

  def merge_into_timeline(from_account, into_account)
    timeline_key = key(:home, into_account.id)
    query        = from_account.statuses.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 || 0
      query = query.where('id > ?', oldest_home_score)
    end

    redis.pipelined do
      query.each do |status|
        next if status.direct_visibility? || filter?(:home, status, into_account)
        redis.zadd(timeline_key, status.id, status.id)
      end
    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').where('id > ?', oldest_home_score).find_in_batches do |statuses|
      redis.pipelined do
        statuses.each do |status|
          redis.zrem(timeline_key, status.id)
          redis.zremrangebyscore(timeline_key, status.id, status.id)
        end
      end
    end
  end

  def inline_render(target_account, template, object)
    Rabl::Renderer.new(template, object, view_path: 'app/views', format: :json, scope: InlineRablScope.new(target_account)).render
  end

  private

  def redis
    Redis.current
  end

  def filter_from_home?(status, receiver_id)
    return true if status.reply? && status.in_reply_to_id.nil?

    check_for_mutes = [status.account_id]
    check_for_mutes.concat([status.reblog.account_id]) if status.reblog?

    return true if Mute.where(account_id: receiver_id, target_account_id: check_for_mutes).any?

    check_for_blocks = status.mentions.map(&:account_id)
    check_for_blocks.concat([status.reblog.account_id]) if status.reblog?

    return true if Block.where(account_id: receiver_id, target_account_id: check_for_blocks).any?

    if status.reply? && !status.in_reply_to_account_id.nil?                                                              # Filter out if it's a reply
      should_filter   = !Follow.where(account_id: receiver_id, target_account_id: status.in_reply_to_account_id).exists? # 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
      return Block.where(account_id: status.reblog.account_id, target_account_id: receiver_id).exists?                   # or if the author of the reblogged status is blocking me
    end

    false
  end

  def filter_from_mentions?(status, receiver_id)
    check_for_blocks = [status.account_id]
    check_for_blocks.concat(status.mentions.select('account_id').map(&:account_id))
    check_for_blocks.concat([status.in_reply_to_account]) if status.reply? && !status.in_reply_to_account_id.nil?

    should_filter   = receiver_id == status.account_id                                                                                   # Filter if I'm mentioning myself
    should_filter ||= Block.where(account_id: receiver_id, target_account_id: check_for_blocks).any?                                     # or it's from someone I blocked, in reply to someone I blocked, or mentioning someone I blocked
    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
end