WPFC Cache Stats Dashboard

A small WordPress plugin that shows cache statistics from WP Fastest Cache right in the admin dashboard. It answers one question: how much can the server deliver without WordPress having to build a page again?

The plugin's interface is in German. The labels quoted below are the ones you will see in WordPress, with an English explanation.

Features

Dashboard widget

• Cache coverage: share of published posts in the page cache, shown as a bar, plus pages, categories, tags, the front page and paginated archives.

• History: post coverage over the last 30 days as a small chart. It shows how quickly the cache fills up again after it was cleared.

• Most read, but not cached: the most read posts of the last 14 days that are currently not cached. These cause the most load. Requires the view counter of the theme used on linuxundich.de; without it, this section is hidden.

• Throttled warm-up: one click puts these posts in a queue that WP-Cron works through one page at a time. At most 5 pages or 20 seconds per run, and a 5-minute pause as soon as a page takes longer than 15 seconds or fails. The widget shows the queue and the results.

• Warning after full purges: if the whole cache was cleared within the last 24 hours (settings saved, admin bar, button), the widget says so.

• PHP slot errors (optional): counts mod_fcgid: can't apply process slot and aborted PHP processes of the last 24 hours from the Apache error log. This is hosting-specific and only active once the path is set in wp-config.php:

  define('WPFCS_ERROR_LOG', '/path/to/error_log');

• Details (collapsed): number and size of cache files per area, age of the oldest and newest cached page, preload status, and the last cache purges with their trigger (with WPFC Premium).

• Clear cache: with a confirmation prompt, optionally including minified CSS/JS files, through WPFC's own interface.

Post list

• Column "Cache": ✓ with the age of the cache file, or –.
• Row action "Cache leeren" (clear cache): clears only this one URL. WPFC's own function also clears the front page and archives.
• Row action "Vorwärmen" (warm up): adds the post to the warm-up queue.
• With the plugin LUI Admin UI (linuxundich.de) the cache state appears as a pill "Cache ✓/–" in its shared "Status" column instead of a separate column. Other plugins can add to the pill's tooltip through the filter wpfcs_cache_note. After "Cache leeren" the action wpfcs_post_cleared fires with the post ID.

Performance

• The dashboard never waits for the statistics: they load via AJAX and are cached for 15 minutes. A daily cron run extends the history.
• One directory scan per cache area. Mapping cache files to posts, pages and archives uses only the directory structure and four lean slug queries.
• At most the last 2 MB of the error log are read.
• Post list: one file_exists() per row.
• No jQuery. Own options use autoload = off; uninstall.php removes them when the plugin is deleted.

Requirements

• WordPress 6.2 or later, PHP 8.0 or later
• WP Fastest Cache installed and active
• A user role with the manage_options capability
• For warm-up: a working WP-Cron (loopback or external cron)

Mapping cache files to posts requires a permalink structure that ends with %postname%.

Installation

1. Download or clone this repository:

   git clone https://github.com/linuxundich/wpfc-cache-stats-dashboard.git

2. Copy the folder to /wp-content/plugins/wpfc-cache-stats-widget (the plugin slug differs from the repository name) and activate the plugin.

Changelog

See CHANGELOG.md.

License

See LICENSE.