Improve is_multi_author() performance

[alexvorn2]

I have 100k posts.

If I delete the function twentythirteen_body_class() - the home page loads in 1 second,
with this function the page loads in 4.4 seconds!

I use this for page load time:

add_action( 'wp_footer',             'footer_timer_stop', 1000               );

// Footer timer to show page load speed
function footer_timer_stop() {
	echo '<!-- stats: ' . get_num_queries() . ' queries. ' . timer_stop( 0 ) . ' seconds. -->';
}

This function is not so important and I think it should be removed.

[alexvorn2]

inside this function we have is_multi_author() that cause the page to load so slow...

[nacin]

Care to tell us how long the query in is_multi_author() is taking? How many rows in your posts table?

This function is not new. It was used similarly in Twenty Eleven and Twenty Twelve as well.

I was thinking about an optimization the other day to is_multi_author(), but it would only help for multi-author blogs. Basically:

$is_multi_author = ( count( array_unique( wp_list_pluck( 'post_author', $wp_query->posts ) ) ) > 1 );

If that returns false, we'd have to do the query either way. That said, I find it hard to believe that query is taking a particularly long time.

[alexvorn2]

Replying to nacin:

Care to tell us how long the query in is_multi_author() is taking? How many rows in your posts table?

I take 3.4 seconds to load.
100000 rows in the wp_posts table.

[lancewillett]

I think we could get rid of custom-font, won't speed things up a ton, but it's not used anywhere in the theme.

[lancewillett]

In 24390:

Twenty Thirteen: remove unused custom-font body class value. See #24445.

[alexvorn2]

the problem is in the is_multi_author() function, so I think the patch is not entirely resolving the problem.

[markjaquith]

We could use a transient for storing this value instead of raw cache get/set. That way people without persistent object caching would still benefit from the caching of that value.

[markjaquith]

Untested patch that converts to use transients API.

[lancewillett]

Moving out of Bundle Theme component as it's a core template improvement.

[alexvorn2]

I tested the patch, works nice.

[alex-ye]

Nice improvement, for me the is_multi_author() doesn't take a lot time, but maybe it's related with the posts count.

In addition to the above patch I will love to see a new filter 'pre_is_multi_author' to set a predefined value so the function doesn't need to run the database query.

[nacin]

Replying to markjaquith:

We could use a transient for storing this value instead of raw cache get/set. That way people without persistent object caching would still benefit from the caching of that value.

Transients came up when we originally did this, see #14405. Reading back through the ticket, what tipped the scales was an assumption that:

• This query was fast
• Transients require more queries

However, an unexpiring transient is autoloaded. And this is the perfect use case for one, because we know when it needs to be cleared.

[nacin]

westi, objections?

[nacin]

In 24628:

Switch to a transient for is_multi_author(). props markjaquith, fixes #24445.

[westi]

Replying to nacin:

westi, objections?

Nope, seems sane and sensible to me.