IntenseWebs/WordPress
3
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

More performance improvements to metadata lazyloading.

Browse Source 
Comment and term meta lazyloading for `WP_Query` loops, introduced in 4.4,
depended on filter callback methods belonging to `WP_Query` objects. This meant
storing `WP_Query` objects in the `$wp_filter` global (via `add_filter()`),
requiring that PHP retain the objects in memory, even when the local variables
would typically be expunged during normal garbage collection. In cases where a
large number of `WP_Query` objects were instantiated on a single pageload,
and/or where the contents of the `WP_Query` objects were quite large, serious
performance issues could result.

We skirt this problem by moving metadata lazyloading out of `WP_Query`. The
new `WP_Metadata_Lazyloader` class acts as a lazyload queue. Query instances
register items whose metadata should be lazyloaded - such as post terms, or
comments - and a `WP_Metadata_Lazyloader` method will intercept comment and
term meta requests to perform the cache priming. Since `WP_Metadata_Lazyloader`
instances are far smaller than `WP_Query` (containing only object IDs), and
clean up after themselves far better than the previous `WP_Query` methods (bp
only running their callbacks a single time for a given set of queued objects),
the resource use is decreased dramatically.

See [36525] for an earlier step in this direction.

Props lpawlik, stevegrunwell, boonebgorges.
Fixes #35816.
Built from https://develop.svn.wordpress.org/trunk@36566


git-svn-id: http://core.svn.wordpress.org/trunk@36533 1a063a9b-81f0-0310-95a4-ce76da25c4cd
This commit is contained in:
Boone Gorges
2016-02-17 22:58:26 +00:00
parent da5b3a55c4
commit 571e14f897
8 changed files with 263 additions and 96 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
wp-includes/comment-template.php
View File

@@ -1393,9 +1393,6 @@ function comments_template( $file = '/comments.php', $separate_comments = false
*/
$wp_query->comments = apply_filters( 'comments_array', $comments_flat, $post->ID );
// Set up lazy-loading for comment metadata.
add_action( 'get_comment_metadata', array( $wp_query, 'lazyload_comment_meta' ), 10, 2 );
$comments = &$wp_query->comments;
$wp_query->comment_count = count($wp_query->comments);
$wp_query->max_num_comment_pages = $comment_query->max_num_pages;
@@ -2030,6 +2027,8 @@ function wp_list_comments( $args = array(), $comments = null ) {
if ( null === $r['reverse_top_level'] )
$r['reverse_top_level'] = ( 'desc' == get_option('comment_order') );
wp_queue_comments_for_comment_meta_lazyload( $_comments );
if ( empty( $r['walker'] ) ) {
$walker = new Walker_Comment;
} else {