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mastodon/app/models/trends/links.rb
Eugen Rochko 6476f7e4da
Change trending statuses to only show one status from each account (#18181)
Calculate trends in temporary sets to avoid having to manage items
that go below the decay threshold while not having any moments
where a half-processed set is accessible to end-users
2022-04-29 22:42:42 +02:00

115 lines
3.4 KiB
Ruby

# frozen_string_literal: true
class Trends::Links < Trends::Base
PREFIX = 'trending_links'
self.default_options = {
threshold: 5,
review_threshold: 3,
max_score_cooldown: 2.days.freeze,
max_score_halflife: 8.hours.freeze,
decay_threshold: 1,
}
def register(status, at_time = Time.now.utc)
original_status = status.proper
return unless (original_status.public_visibility? && status.public_visibility?) &&
!(original_status.account.silenced? || status.account.silenced?) &&
!(original_status.spoiler_text? || original_status.sensitive?)
original_status.preview_cards.each do |preview_card|
add(preview_card, status.account_id, at_time) if preview_card.appropriate_for_trends?
end
end
def add(preview_card, account_id, at_time = Time.now.utc)
preview_card.history.add(account_id, at_time)
record_used_id(preview_card.id, at_time)
end
def refresh(at_time = Time.now.utc)
preview_cards = PreviewCard.where(id: (recently_used_ids(at_time) + currently_trending_ids(false, -1)).uniq)
calculate_scores(preview_cards, at_time)
end
def request_review
preview_cards = PreviewCard.where(id: currently_trending_ids(false, -1))
preview_cards.filter_map do |preview_card|
next unless would_be_trending?(preview_card.id) && !preview_card.trendable? && preview_card.requires_review_notification?
if preview_card.provider.nil?
preview_card.provider = PreviewCardProvider.create(domain: preview_card.domain, requested_review_at: Time.now.utc)
else
preview_card.provider.touch(:requested_review_at)
end
preview_card
end
end
protected
def key_prefix
PREFIX
end
def klass
PreviewCard
end
private
def calculate_scores(preview_cards, at_time)
global_items = []
locale_items = Hash.new { |h, key| h[key] = [] }
preview_cards.each do |preview_card|
expected = preview_card.history.get(at_time - 1.day).accounts.to_f
expected = 1.0 if expected.zero?
observed = preview_card.history.get(at_time).accounts.to_f
max_time = preview_card.max_score_at
max_score = preview_card.max_score
max_score = 0 if max_time.nil? || max_time < (at_time - options[:max_score_cooldown])
score = begin
if expected > observed || observed < options[:threshold]
0
else
((observed - expected)**2) / expected
end
end
if score > max_score
max_score = score
max_time = at_time
# Not interested in triggering any callbacks for this
preview_card.update_columns(max_score: max_score, max_score_at: max_time)
end
decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / options[:max_score_halflife].to_f))
next unless decaying_score >= options[:decay_threshold]
global_items << { score: decaying_score, item: preview_card }
locale_items[preview_card.language] << { score: decaying_score, item: preview_card } if valid_locale?(preview_card.language)
end
replace_items('', global_items)
Trends.available_locales.each do |locale|
replace_items(":#{locale}", locale_items[locale])
end
end
def filter_for_allowed_items(items)
items.select { |item| item[:item].trendable? }
end
def would_be_trending?(id)
score(id) > score_at_rank(options[:review_threshold] - 1)
end
end