perf: avoid N+1 query in recent topics and news

This commit is contained in:
Lephe 2022-05-12 21:53:26 +01:00
parent 8393cf1933
commit 13ce27b682
Signed by: Lephenixnoir
GPG Key ID: 1BBA026E13FC0495
1 changed files with 13 additions and 7 deletions

View File

@ -16,13 +16,17 @@ def menu_processor():
main_forum = Forum.query.filter_by(parent=None).first()
# Constructing last active topics
raw = db.session.execute( """SELECT topic.id FROM topic
rows = db.session.execute( """SELECT topic.id FROM topic
INNER JOIN comment ON topic.thread_id = comment.thread_id
INNER JOIN post ON post.id = comment.id
GROUP BY topic.id
ORDER BY MAX(post.date_created) DESC
LIMIT 20;""")
last_active_topics = [Topic.query.get(id) for id in raw]
ids = [row[0] for row in rows]
# Somewhat inelegant, but much better than loading individually
recent_topics = db.session.query(Topic).filter(Topic.id.in_(ids)).all()
recent_topics = sorted(recent_topics, key=lambda t: ids.index(t.id))
# Filter the topics the user can view and limit to 10
if current_user.is_authenticated:
@ -30,10 +34,10 @@ def menu_processor():
else:
f = lambda t: t.forum.is_default_accessible()
last_active_topics = list(filter(f, last_active_topics))[:10]
recent_topics = list(filter(f, recent_topics))[:10]
# Constructing last news
raw = db.session.execute( """SELECT topic.id FROM topic
rows = db.session.execute( """SELECT topic.id FROM topic
INNER JOIN forum ON topic.forum_id = forum.id
INNER JOIN comment ON topic.thread_id = comment.thread_id
INNER JOIN post ON post.id = comment.id
@ -42,8 +46,10 @@ def menu_processor():
ORDER BY MIN(post.date_created) DESC
LIMIT 10;
""")
last_news = [Topic.query.get(id) for id in raw]
ids = [row[0] for row in rows]
recent_news = db.session.query(Topic).filter(Topic.id.in_(ids)).all()
recent_news = sorted(recent_news, key=lambda t: ids.index(t.id))
return dict(login_form=login_form, search_form=search_form,
main_forum=main_forum, last_active_topics=last_active_topics,
last_news=last_news)
main_forum=main_forum, last_active_topics=recent_topics,
last_news=recent_news)