Gets page cache details.

WP_Error|array Page cache detail or else a WP_Error if unable to determine.

• statusstring
  Page cache status. Good, Recommended or Critical.
• advanced_cache_presentbool
  Whether page cache plugin is available or not.
• headersstring[]
  Client caching response headers detected.
• response_timefloat
  Response time of site.

File: wp-admin/includes/class-wp-site-health.php. View all references

private function get_page_cache_detail() {
	$page_cache_detail = $this->check_for_page_caching();
	if ( is_wp_error( $page_cache_detail ) ) {
		return $page_cache_detail;
	}

	// Use the median server response time.
	$response_timings = $page_cache_detail['response_timing'];
	rsort( $response_timings );
	$page_speed = $response_timings[ floor( count( $response_timings ) / 2 ) ];

	// Obtain unique set of all client caching response headers.
	$headers = array();
	foreach ( $page_cache_detail['page_caching_response_headers'] as $page_caching_response_headers ) {
		$headers = array_merge( $headers, array_keys( $page_caching_response_headers ) );
	}
	$headers = array_unique( $headers );

	// Page cache is detected if there are response headers or a page cache plugin is present.
	$has_page_caching = ( count( $headers ) > 0 || $page_cache_detail['advanced_cache_present'] );

	if ( $page_speed && $page_speed < $this->get_good_response_time_threshold() ) {
		$result = $has_page_caching ? 'good' : 'recommended';
	} else {
		$result = 'critical';
	}

	return array(
		'status'                 => $result,
		'advanced_cache_present' => $page_cache_detail['advanced_cache_present'],
		'headers'                => $headers,
		'response_time'          => $page_speed,
	);
}