class ScoreCalculator def self.default_score_weights { reply_count: 5, like_score: 15, incoming_link_count: 5, bookmark_count: 2, avg_time: 0.05, reads: 0.2 } end def initialize(weightings = nil) @weightings = weightings || ScoreCalculator.default_score_weights end # Calculate the score for all posts based on the weightings def calculate(opts = nil) update_posts_score(opts) update_posts_rank(opts) update_topics_rank(opts) end private def update_posts_score(opts) limit = 20000 components = [] @weightings.each_key { |k| components << "COALESCE(posts.#{k}, 0) * :#{k}" } components = components.join(" + ") builder = DB.build < #{components}", @weightings) filter_topics(builder, opts) while builder.exec == limit end end def update_posts_rank(opts) limit = 20000 builder = DB.build <<~SQL UPDATE posts SET percent_rank = X.percent_rank FROM ( SELECT posts.id, Y.percent_rank FROM posts JOIN ( SELECT id, percent_rank() OVER (PARTITION BY topic_id ORDER BY SCORE DESC) as percent_rank FROM posts ) Y ON Y.id = posts.id JOIN topics ON posts.topic_id = topics.id /*where*/ LIMIT #{limit} ) AS X WHERE posts.id = X.id SQL builder.where("posts.percent_rank IS NULL OR Y.percent_rank <> posts.percent_rank") filter_topics(builder, opts) while builder.exec == limit end end def update_topics_rank(opts) builder = DB.build <<~SQL UPDATE topics AS topics SET has_summary = (topics.like_count >= :likes_required AND topics.posts_count >= :posts_required AND x.max_score >= :score_required), score = x.avg_score FROM (SELECT p.topic_id, MAX(p.score) AS max_score, AVG(p.score) AS avg_score FROM posts AS p GROUP BY p.topic_id) AS x /*where*/ SQL defaults = { likes_required: SiteSetting.summary_likes_required, posts_required: SiteSetting.summary_posts_required, score_required: SiteSetting.summary_score_threshold } builder.where(<<~SQL, defaults) x.topic_id = topics.id AND ( (topics.score <> x.avg_score OR topics.score IS NULL) OR (topics.has_summary IS NULL OR topics.has_summary <> ( topics.like_count >= :likes_required AND topics.posts_count >= :posts_required AND x.max_score >= :score_required )) ) SQL filter_topics(builder, opts) builder.exec end def filter_topics(builder, opts) return builder unless opts if min_topic_age = opts[:min_topic_age] builder.where("topics.bumped_at > :bumped_at ", bumped_at: min_topic_age) end if max_topic_length = opts[:max_topic_length] builder.where("topics.posts_count < :max_topic_length", max_topic_length: max_topic_length) end builder end end