From: Rens Groothuijsen Date: Wed, 27 Apr 2022 16:12:41 +0000 (+0200) Subject: Update community statistics after post or comment is deleted by user (#2193) X-Git-Url: http://these/git/readmes/%7B%60https:/%22https:/hacktivis.me/static/%24%7Bsrc%7D?a=commitdiff_plain;h=9c1b9ff3cf198d829630d3d4ab0c03985ecc732f;p=lemmy.git Update community statistics after post or comment is deleted by user (#2193) * Update community statistics after post or comment is deleted by user * Update triggers for site and person aggregates * Restore comment counts when post is restored * Simplify insertion/deletion trigger checks before updating statistics --- diff --git a/migrations/2022-04-04-183652_update_community_aggregates_on_soft_delete/down.sql b/migrations/2022-04-04-183652_update_community_aggregates_on_soft_delete/down.sql new file mode 100644 index 00000000..8a8ea5cb --- /dev/null +++ b/migrations/2022-04-04-183652_update_community_aggregates_on_soft_delete/down.sql @@ -0,0 +1,254 @@ +drop trigger if exists community_aggregates_post_count on post; +drop trigger if exists community_aggregates_comment_count on comment; +drop trigger if exists site_aggregates_comment_insert on comment; +drop trigger if exists site_aggregates_comment_delete on comment; +drop trigger if exists site_aggregates_post_insert on post; +drop trigger if exists site_aggregates_post_delete on post; +drop trigger if exists site_aggregates_community_insert on community; +drop trigger if exists site_aggregates_community_delete on community; +drop trigger if exists person_aggregates_post_count on post; +drop trigger if exists person_aggregates_comment_count on comment; + +drop function was_removed_or_deleted(TG_OP text, OLD record, NEW record); +drop function was_restored_or_created(TG_OP text, OLD record, NEW record); + +-- Community aggregate functions + +create or replace function community_aggregates_post_count() + returns trigger language plpgsql +as $$ +begin + IF (TG_OP = 'INSERT') THEN +update community_aggregates +set posts = posts + 1 where community_id = NEW.community_id; +ELSIF (TG_OP = 'DELETE') THEN +update community_aggregates +set posts = posts - 1 where community_id = OLD.community_id; + +-- Update the counts if the post got deleted +update community_aggregates ca +set posts = coalesce(cd.posts, 0), + comments = coalesce(cd.comments, 0) + from ( + select + c.id, + count(distinct p.id) as posts, + count(distinct ct.id) as comments + from community c + left join post p on c.id = p.community_id + left join comment ct on p.id = ct.post_id + group by c.id + ) cd +where ca.community_id = OLD.community_id; +END IF; +return null; +end $$; + +create or replace function community_aggregates_comment_count() + returns trigger language plpgsql +as $$ +begin + IF (TG_OP = 'INSERT') THEN +update community_aggregates ca +set comments = comments + 1 from comment c, post p +where p.id = c.post_id + and p.id = NEW.post_id + and ca.community_id = p.community_id; +ELSIF (TG_OP = 'DELETE') THEN +update community_aggregates ca +set comments = comments - 1 from comment c, post p +where p.id = c.post_id + and p.id = OLD.post_id + and ca.community_id = p.community_id; + +END IF; +return null; +end $$; + +-- Community aggregate triggers + +create trigger community_aggregates_post_count + after insert or delete on post +for each row +execute procedure community_aggregates_post_count(); + +create trigger community_aggregates_comment_count + after insert or delete on comment +for each row +execute procedure community_aggregates_comment_count(); + +-- Site aggregate functions + +create or replace function site_aggregates_post_insert() + returns trigger language plpgsql +as $$ +begin +update site_aggregates +set posts = posts + 1; +return null; +end $$; + +create or replace function site_aggregates_post_delete() + returns trigger language plpgsql +as $$ +begin +update site_aggregates sa +set posts = posts - 1 + from site s +where sa.site_id = s.id; +return null; +end $$; + +create or replace function site_aggregates_comment_insert() + returns trigger language plpgsql +as $$ +begin +update site_aggregates +set comments = comments + 1; +return null; +end $$; + +create or replace function site_aggregates_comment_delete() + returns trigger language plpgsql +as $$ +begin +update site_aggregates sa +set comments = comments - 1 + from site s +where sa.site_id = s.id; +return null; +end $$; + +create or replace function site_aggregates_community_insert() + returns trigger language plpgsql +as $$ +begin +update site_aggregates +set communities = communities + 1; +return null; +end $$; + +create or replace function site_aggregates_community_delete() + returns trigger language plpgsql +as $$ +begin +update site_aggregates sa +set communities = communities - 1 + from site s +where sa.site_id = s.id; +return null; +end $$; + + +-- Site update triggers + +create trigger site_aggregates_post_insert + after insert on post + for each row + when (NEW.local = true) + execute procedure site_aggregates_post_insert(); + +create trigger site_aggregates_post_delete + after delete on post + for each row + when (OLD.local = true) + execute procedure site_aggregates_post_delete(); + +create trigger site_aggregates_comment_insert + after insert on comment + for each row + when (NEW.local = true) + execute procedure site_aggregates_comment_insert(); + +create trigger site_aggregates_comment_delete + after delete on comment + for each row + when (OLD.local = true) + execute procedure site_aggregates_comment_delete(); + +create trigger site_aggregates_community_insert + after insert on community + for each row + when (NEW.local = true) + execute procedure site_aggregates_community_insert(); + +create trigger site_aggregates_community_delete + after delete on community + for each row + when (OLD.local = true) + execute procedure site_aggregates_community_delete(); + +-- Person aggregate functions + +create or replace function person_aggregates_post_count() + returns trigger language plpgsql +as $$ +begin + IF (TG_OP = 'INSERT') THEN +update person_aggregates +set post_count = post_count + 1 where person_id = NEW.creator_id; + +ELSIF (TG_OP = 'DELETE') THEN +update person_aggregates +set post_count = post_count - 1 where person_id = OLD.creator_id; + +-- If the post gets deleted, the score calculation trigger won't fire, +-- so you need to re-calculate +update person_aggregates ua +set post_score = pd.score + from ( + select u.id, + coalesce(0, sum(pl.score)) as score + -- User join because posts could be empty + from person u + left join post p on u.id = p.creator_id + left join post_like pl on p.id = pl.post_id + group by u.id + ) pd +where ua.person_id = OLD.creator_id; + +END IF; +return null; +end $$; + +create or replace function person_aggregates_comment_count() + returns trigger language plpgsql +as $$ +begin + IF (TG_OP = 'INSERT') THEN +update person_aggregates +set comment_count = comment_count + 1 where person_id = NEW.creator_id; +ELSIF (TG_OP = 'DELETE') THEN +update person_aggregates +set comment_count = comment_count - 1 where person_id = OLD.creator_id; + +-- If the comment gets deleted, the score calculation trigger won't fire, +-- so you need to re-calculate +update person_aggregates ua +set comment_score = cd.score + from ( + select u.id, + coalesce(0, sum(cl.score)) as score + -- User join because comments could be empty + from person u + left join comment c on u.id = c.creator_id + left join comment_like cl on c.id = cl.comment_id + group by u.id + ) cd +where ua.person_id = OLD.creator_id; +END IF; +return null; +end $$; + + +-- Person aggregate triggers + +create trigger person_aggregates_post_count + after insert or delete on post + for each row +execute procedure person_aggregates_post_count(); + +create trigger person_aggregates_comment_count + after insert or delete on comment + for each row +execute procedure person_aggregates_comment_count(); \ No newline at end of file diff --git a/migrations/2022-04-04-183652_update_community_aggregates_on_soft_delete/up.sql b/migrations/2022-04-04-183652_update_community_aggregates_on_soft_delete/up.sql new file mode 100644 index 00000000..472be541 --- /dev/null +++ b/migrations/2022-04-04-183652_update_community_aggregates_on_soft_delete/up.sql @@ -0,0 +1,327 @@ +drop trigger if exists community_aggregates_post_count on post; +drop trigger if exists community_aggregates_comment_count on comment; +drop trigger if exists site_aggregates_comment_insert on comment; +drop trigger if exists site_aggregates_comment_delete on comment; +drop trigger if exists site_aggregates_post_insert on post; +drop trigger if exists site_aggregates_post_delete on post; +drop trigger if exists site_aggregates_community_insert on community; +drop trigger if exists site_aggregates_community_delete on community; +drop trigger if exists person_aggregates_post_count on post; +drop trigger if exists person_aggregates_comment_count on comment; + +create or replace function was_removed_or_deleted(TG_OP text, OLD record, NEW record) +RETURNS boolean +LANGUAGE plpgsql +as $$ + begin + IF (TG_OP = 'INSERT') THEN + return false; + end if; + + IF (TG_OP = 'DELETE') THEN + return true; + end if; + + return TG_OP = 'UPDATE' AND ( + (OLD.deleted = 'f' AND NEW.deleted = 't') OR + (OLD.removed = 'f' AND NEW.removed = 't') + ); +END $$; + +create or replace function was_restored_or_created(TG_OP text, OLD record, NEW record) + RETURNS boolean + LANGUAGE plpgsql +as $$ +begin + IF (TG_OP = 'DELETE') THEN + return false; + end if; + + IF (TG_OP = 'INSERT') THEN + return true; + end if; + + return TG_OP = 'UPDATE' AND ( + (OLD.deleted = 't' AND NEW.deleted = 'f') OR + (OLD.removed = 't' AND NEW.removed = 'f') + ); +END $$; + +-- Community aggregate functions + +create or replace function community_aggregates_post_count() + returns trigger language plpgsql +as $$ +begin + IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN +update community_aggregates +set posts = posts + 1 where community_id = NEW.community_id; + +IF (TG_OP = 'UPDATE') THEN + -- Post was restored, so restore comment counts as well + update community_aggregates ca + set posts = coalesce(cd.posts, 0), + comments = coalesce(cd.comments, 0) + from ( + select + c.id, + count(distinct p.id) as posts, + count(distinct ct.id) as comments + from community c + left join post p on c.id = p.community_id and p.deleted = 'f' and p.removed = 'f' + left join comment ct on p.id = ct.post_id and ct.deleted = 'f' and ct.removed = 'f' + where c.id = NEW.community_id + group by c.id + ) cd + where ca.community_id = NEW.community_id; +END IF; + +ELSIF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN +update community_aggregates +set posts = posts - 1 where community_id = OLD.community_id; + +-- Update the counts if the post got deleted +update community_aggregates ca +set posts = coalesce(cd.posts, 0), + comments = coalesce(cd.comments, 0) + from ( + select + c.id, + count(distinct p.id) as posts, + count(distinct ct.id) as comments + from community c + left join post p on c.id = p.community_id and p.deleted = 'f' and p.removed = 'f' + left join comment ct on p.id = ct.post_id and ct.deleted = 'f' and ct.removed = 'f' + where c.id = OLD.community_id + group by c.id + ) cd +where ca.community_id = OLD.community_id; +END IF; +return null; +end $$; + +-- comment count +create or replace function community_aggregates_comment_count() + returns trigger language plpgsql +as $$ +begin + IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN +update community_aggregates ca +set comments = comments + 1 from comment c, post p +where p.id = c.post_id + and p.id = NEW.post_id + and ca.community_id = p.community_id; +ELSIF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN +update community_aggregates ca +set comments = comments - 1 from comment c, post p +where p.id = c.post_id + and p.id = OLD.post_id + and ca.community_id = p.community_id; + +END IF; +return null; +end $$; + +-- Community aggregate triggers + +create trigger community_aggregates_post_count + after insert or delete or update of removed, deleted on post + for each row +execute procedure community_aggregates_post_count(); + +create trigger community_aggregates_comment_count + after insert or delete or update of removed, deleted on comment +for each row +execute procedure community_aggregates_comment_count(); + +-- Site aggregate functions + +create or replace function site_aggregates_post_insert() + returns trigger language plpgsql +as $$ +begin + IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN + update site_aggregates sa + set posts = posts + 1 + from site s + where sa.site_id = s.id; + END IF; + return null; +end $$; + +create or replace function site_aggregates_post_delete() + returns trigger language plpgsql +as $$ +begin + IF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN + update site_aggregates sa + set posts = posts - 1 + from site s + where sa.site_id = s.id; + END IF; + return null; +end $$; + +create or replace function site_aggregates_comment_insert() + returns trigger language plpgsql +as $$ +begin + IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN + update site_aggregates sa + set comments = comments + 1 + from site s + where sa.site_id = s.id; + END IF; + return null; +end $$; + +create or replace function site_aggregates_comment_delete() + returns trigger language plpgsql +as $$ +begin + IF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN + update site_aggregates sa + set comments = comments - 1 + from site s + where sa.site_id = s.id; + END IF; + return null; +end $$; + +create or replace function site_aggregates_community_insert() + returns trigger language plpgsql +as $$ +begin + IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN + update site_aggregates sa + set communities = communities + 1 + from site s + where sa.site_id = s.id; + END IF; + return null; +end $$; + +create or replace function site_aggregates_community_delete() + returns trigger language plpgsql +as $$ +begin + IF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN + update site_aggregates sa + set communities = communities - 1 + from site s + where sa.site_id = s.id; + END IF; + return null; +end $$; + +-- Site aggregate triggers + +create trigger site_aggregates_post_insert + after insert or update of removed, deleted on post + for each row + when (NEW.local = true) +execute procedure site_aggregates_post_insert(); + +create trigger site_aggregates_post_delete + after delete or update of removed, deleted on post + for each row + when (OLD.local = true) +execute procedure site_aggregates_post_delete(); + +create trigger site_aggregates_comment_insert + after insert or update of removed, deleted on comment + for each row + when (NEW.local = true) +execute procedure site_aggregates_comment_insert(); + +create trigger site_aggregates_comment_delete + after delete or update of removed, deleted on comment + for each row + when (OLD.local = true) +execute procedure site_aggregates_comment_delete(); + +create trigger site_aggregates_community_insert + after insert or update of removed, deleted on community + for each row + when (NEW.local = true) +execute procedure site_aggregates_community_insert(); + +create trigger site_aggregates_community_delete + after delete or update of removed, deleted on community + for each row + when (OLD.local = true) +execute procedure site_aggregates_community_delete(); + +-- Person aggregate functions + +create or replace function person_aggregates_post_count() + returns trigger language plpgsql +as $$ +begin + IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN + update person_aggregates + set post_count = post_count + 1 where person_id = NEW.creator_id; + + ELSIF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN + update person_aggregates + set post_count = post_count - 1 where person_id = OLD.creator_id; + + -- If the post gets deleted, the score calculation trigger won't fire, + -- so you need to re-calculate + update person_aggregates ua + set post_score = pd.score + from ( + select u.id, + coalesce(0, sum(pl.score)) as score + -- User join because posts could be empty + from person u + left join post p on u.id = p.creator_id and p.deleted = 'f' and p.removed = 'f' + left join post_like pl on p.id = pl.post_id + group by u.id + ) pd + where ua.person_id = OLD.creator_id; + + END IF; + return null; +end $$; + +create or replace function person_aggregates_comment_count() + returns trigger language plpgsql +as $$ +begin + IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN + update person_aggregates + set comment_count = comment_count + 1 where person_id = NEW.creator_id; + ELSIF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN + update person_aggregates + set comment_count = comment_count - 1 where person_id = OLD.creator_id; + + -- If the comment gets deleted, the score calculation trigger won't fire, + -- so you need to re-calculate + update person_aggregates ua + set comment_score = cd.score + from ( + select u.id, + coalesce(0, sum(cl.score)) as score + -- User join because comments could be empty + from person u + left join comment c on u.id = c.creator_id and c.deleted = 'f' and c.removed = 'f' + left join comment_like cl on c.id = cl.comment_id + group by u.id + ) cd + where ua.person_id = OLD.creator_id; + END IF; + return null; +end $$; + +-- Person aggregate triggers + +create trigger person_aggregates_post_count + after insert or delete or update of removed, deleted on post + for each row +execute procedure person_aggregates_post_count(); + +create trigger person_aggregates_comment_count + after insert or delete or update of removed, deleted on comment + for each row +execute procedure person_aggregates_comment_count();