|
- # frozen_string_literal: true
-
- class TrendingTags
- KEY = 'trending_tags'
- EXPIRE_HISTORY_AFTER = 7.days.seconds
- EXPIRE_TRENDS_AFTER = 1.day.seconds
- THRESHOLD = 5
- LIMIT = 10
-
- class << self
- include Redisable
-
- def record_use!(tag, account, at_time = Time.now.utc)
- return if account.silenced? || account.bot? || !tag.usable? || !(tag.trendable? || tag.requires_review?)
-
- increment_historical_use!(tag.id, at_time)
- increment_unique_use!(tag.id, account.id, at_time)
- increment_vote!(tag, at_time)
- end
-
- def get(limit, filtered: true)
- tag_ids = redis.zrevrange("#{KEY}:#{Time.now.utc.beginning_of_day.to_i}", 0, LIMIT - 1).map(&:to_i)
-
- tags = Tag.where(id: tag_ids)
- tags = tags.where(trendable: true) if filtered
- tags = tags.each_with_object({}) { |tag, h| h[tag.id] = tag }
-
- tag_ids.map { |tag_id| tags[tag_id] }.compact.take(limit)
- end
-
- def trending?(tag)
- rank = redis.zrevrank("#{KEY}:#{Time.now.utc.beginning_of_day.to_i}", tag.id)
- rank.present? && rank <= LIMIT
- end
-
- private
-
- def increment_historical_use!(tag_id, at_time)
- key = "activity:tags:#{tag_id}:#{at_time.beginning_of_day.to_i}"
- redis.incrby(key, 1)
- redis.expire(key, EXPIRE_HISTORY_AFTER)
- end
-
- def increment_unique_use!(tag_id, account_id, at_time)
- key = "activity:tags:#{tag_id}:#{at_time.beginning_of_day.to_i}:accounts"
- redis.pfadd(key, account_id)
- redis.expire(key, EXPIRE_HISTORY_AFTER)
- end
-
- def increment_vote!(tag, at_time)
- key = "#{KEY}:#{at_time.beginning_of_day.to_i}"
- expected = redis.pfcount("activity:tags:#{tag.id}:#{(at_time - 1.day).beginning_of_day.to_i}:accounts").to_f
- expected = 1.0 if expected.zero?
- observed = redis.pfcount("activity:tags:#{tag.id}:#{at_time.beginning_of_day.to_i}:accounts").to_f
-
- if expected > observed || observed < THRESHOLD
- redis.zrem(key, tag.id)
- else
- score = ((observed - expected)**2) / expected
- old_rank = redis.zrevrank(key, tag.id)
-
- redis.zadd(key, score, tag.id)
- request_review!(tag) if (old_rank.nil? || old_rank > LIMIT) && redis.zrevrank(key, tag.id) <= LIMIT && !tag.trendable? && tag.requires_review? && !tag.requested_review?
- end
-
- redis.expire(key, EXPIRE_TRENDS_AFTER)
- end
-
- def request_review!(tag)
- return unless Setting.trends
-
- tag.touch(:requested_review_at)
-
- User.staff.includes(:account).find_each { |u| AdminMailer.new_trending_tag(u.account, tag).deliver_later! if u.allows_trending_tag_emails? }
- end
- end
- end
|