class FanOutOnWriteService < BaseService MAX_FEED_SIZE = 800 # Push a status into home and mentions feeds # @param [Status] status def call(status) replied_to_user = status.reply? ? status.thread.account : nil # Deliver to local self push(:home, status.account.id, status) if status.account.local? # Deliver to local followers status.account.followers.each do |follower| next if (status.reply? && !follower.following?(replied_to_user)) || !follower.local? push(:home, follower.id, status) end # Deliver to local mentioned status.mentions.each do |mentioned_account| next unless mentioned_account.local? push(:mentions, mentioned_account.id, status) end end private def push(type, receiver_id, status) redis.zadd(key(type, receiver_id), status.created_at.to_i, status.id) trim(type, receiver_id) end def trim(type, receiver_id) return unless redis.zcard(key(type, receiver_id)) > MAX_FEED_SIZE last = redis.zrevrange(key(type, receiver_id), MAX_FEED_SIZE - 1, MAX_FEED_SIZE - 1) redis.zremrangebyscore(key(type, receiver_id), '-inf', "(#{last.last}") end def key(type, id) "feed:#{type}:#{id}" end def redis $redis end end