diff options
Diffstat (limited to 'app/models/trends/links.rb')
-rw-r--r-- | app/models/trends/links.rb | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/app/models/trends/links.rb b/app/models/trends/links.rb new file mode 100644 index 000000000..a7cd9e29d --- /dev/null +++ b/app/models/trends/links.rb @@ -0,0 +1,122 @@ +# frozen_string_literal: true + +class Trends::Links < Trends::Base + PREFIX = 'trending_links' + + # Minimum amount of uses by unique accounts to begin calculating the score + THRESHOLD = 15 + + # Minimum rank (lower = better) before requesting a review + REVIEW_THRESHOLD = 10 + + # For this amount of time, the peak score (if bigger than current score) is decayed-from + MAX_SCORE_COOLDOWN = 2.days.freeze + + # How quickly a peak score decays + MAX_SCORE_HALFLIFE = 8.hours.freeze + + def register(status, at_time = Time.now.utc) + original_status = status.reblog? ? status.reblog : status + + return unless original_status.public_visibility? && status.public_visibility? && + !original_status.account.silenced? && !status.account.silenced? && + !original_status.spoiler_text? + + 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 get(allowed, limit) + preview_card_ids = currently_trending_ids(allowed, limit) + preview_cards = PreviewCard.where(id: preview_card_ids).index_by(&:id) + preview_card_ids.map { |id| preview_cards[id] }.compact + 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) + trim_older_items + end + + def request_review + preview_cards = PreviewCard.where(id: currently_trending_ids(false, -1)) + + preview_cards_requiring_review = 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 + + return if preview_cards_requiring_review.empty? + + User.staff.includes(:account).find_each do |user| + AdminMailer.new_trending_links(user.account, preview_cards_requiring_review).deliver_later! if user.allows_trending_tag_emails? + end + end + + protected + + def key_prefix + PREFIX + end + + private + + def calculate_scores(preview_cards, at_time) + 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 - MAX_SCORE_COOLDOWN) + + score = begin + if expected > observed || observed < 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) / MAX_SCORE_HALFLIFE.to_f)) + + if decaying_score.zero? + redis.zrem("#{PREFIX}:all", preview_card.id) + redis.zrem("#{PREFIX}:allowed", preview_card.id) + else + redis.zadd("#{PREFIX}:all", decaying_score, preview_card.id) + + if preview_card.trendable? + redis.zadd("#{PREFIX}:allowed", decaying_score, preview_card.id) + else + redis.zrem("#{PREFIX}:allowed", preview_card.id) + end + end + end + end + + def would_be_trending?(id) + score(id) > score_at_rank(REVIEW_THRESHOLD - 1) + end +end |