discourse/lib/score_calculator.rb

137 lines
3.4 KiB
Ruby

class ScoreCalculator
def self.default_score_weights
{
reply_count: 5,
like_score: 15,
incoming_link_count: 5,
bookmark_count: 2,
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 <<SQL
UPDATE posts p
SET score = x.score
FROM (
SELECT posts.id, #{components} as score FROM posts
join topics on posts.topic_id = topics.id
/*where*/
limit #{limit}
) AS x
WHERE x.id = p.id
SQL
builder.where("posts.score IS NULL OR posts.score <> #{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