Tiny cache

Cache post content, translations and nav menu output in persistent object cache.

WordPress performance

How to achieve high performance in WordPress?

Item	Tool	Speedup
Infrastructure	CPU, disk, web server, PHP (OPcache) and DNS	Overall performance
In-memory object cache	Redis, Memcached, APCu	options, post, post meta etc.
Server-side functionality plugins (backup, db cleanup)	Use WP-CLI instead	Degrades performance
Theme and plugins	Cache-aware ones using object cache or transients
Translations	tiny-translation-cache	.mo file parsing
Navigation menus	tiny-nav-menu-cache	wp_nav_menu()
Post content	tiny-cache	the_content()
Widgets	widget-output-cache plugin	dynamic_sidebar()

This list concentrates on WordPress core generating HTML code. Frontend loading is another topic.

Usage

Of course you need persistent object cache. Consider Redis server and wp-redis plugin.

Replace the_content(); instances in your theme.

NOTICE Replace only argument-less calls! $more_link_text and $strip_teaser are not supported.

find -type f -name "*.php" | xargs -r -L 1 sed -i -e 's|\bthe_content();|the_content_cached();|g'

No-cache situations

• wp_suspend_cache_addition( true );
• define( 'DONOTCACHEPAGE', true );

Missing plugin

Protection against plugin deactivation.

Copy these to your theme's functions.php.

    if ( ! function_exists( 'the_content_cached' ) ) {
        function the_content_cached( $more_link_text = null, $strip_teaser = false ) {
            the_content( $more_link_text, $strip_teaser );
        }
    }
    if ( ! function_exists( 'get_the_content_cached' ) ) {
        function get_the_content_cached( $more_link_text = null, $strip_teaser = false ) {
            return get_the_content( $more_link_text, $strip_teaser );
        }
    }

Little sisters

1. Tiny navigation menu cache
2. Tiny translation cache

@TODO

1. Document mu-cache-flush-button mu-cache-flush-on-maintenance mu-cache-flush-post-button
2. Support groups: wp_cache_add_global_groups( 'the_content' ); and WP_REDIS_USE_CACHE_GROUPS
3. Add $more_link_text and $strip_teaser hash to cache key

Alternative

https://github.com/Rarst/fragment-cache