WordPress · felixarntz · Feb 28, 2022 · Jan 19, 2022 · Jan 20, 2022 · Jan 20, 2022
diff --git a/modules/object-cache/persistent-object-cache-health-check/load.php b/modules/object-cache/persistent-object-cache-health-check/load.php
@@ -0,0 +1,252 @@
+<?php
+/**
+ * Module Name: Persistent Object Cache Health Check
+ * Description: Recommend a persistent object cache for sites with non-trivial amounts of data.
+ * Experimental: No
+ *
+ * @package performance-lab
+ * @since 1.0.0
+ */
+
+/**
+ * Adds a health check testing for and suggesting a persistent object cache backend.
+ *
+ * @since 1.0.0
+ *
+ * @param array $tests An associative array of direct and asynchronous tests.
+ * @return array An associative array of direct and asynchronous tests.
+ */
+function perflab_oc_health_add_tests( $tests ) {
+	if ( wp_get_environment_type() === 'production' ) {
+		$tests['direct']['persistent_object_cache'] = array(
+			'label' => 'persistent_object_cache',
+			'test'  => 'perflab_oc_health_persistent_object_cache',
+		);
+	}
+
+	return $tests;
+}
+add_filter( 'site_status_tests', 'perflab_oc_health_add_tests' );
+
+/**
+ * Callback for `persistent_object_cache` health check.
+ *
+ * @since 1.0.0
+ *
+ * @return array The health check result suggesting persistent object caching.
+ */
+function perflab_oc_health_persistent_object_cache() {
+	/**
+	 * Filter the action URL for the persistent object cache health check.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param string $action_url Learn more link for persistent object cache health check.
+	 */
+	$action_url = apply_filters(
+		'perflab_oc_site_status_persistent_object_cache_url',
+		/* translators: Localized Support reference. */
+		__( 'https://wordpress.org/support/article/optimization/#object-caching', 'performance-lab' )
+	);
+
+	$result = array(
+		'test'        => 'persistent_object_cache',
+		'status'      => 'good',
+		'badge'       => array(
+			'label' => __( 'Performance', 'performance-lab' ),
+			'color' => 'blue',
+		),
+		'description' => sprintf(
+			'<p>%s</p>',
+			__( "WordPress performs at its best when a persistent object cache is used. A persistent object cache helps to reduce load on your SQL server significantly and allows WordPress to retrieve your site's content and settings much faster.", 'performance-lab' )
+		),
+		'actions'     => sprintf(
+			'<p><a href="%s" target="_blank" rel="noopener">%s <span class="screen-reader-text">%s</span><span aria-hidden="true" class="dashicons dashicons-external"></span></a></p>',
+			esc_url( $action_url ),
+			__( 'Learn more about persistent object caching.', 'performance-lab' ),
+			/* translators: Accessibility text. */
+			__( '(opens in a new tab)', 'performance-lab' )
+		),
+	);
+
+	if ( wp_using_ext_object_cache() ) {
+		$result['label'] = __( 'A persistent object cache is being used', 'performance-lab' );
+
+		return $result;
+	}
+
+	/**
+	 * Filter whether to suggest using a persistent object cache.
+	 *
+	 * Plugin and theme authors should NOT use this filter to discourage the use of an object cache.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param bool $suggest Whether to suggest using a persistent object cache.
+	 */
+	if ( ! apply_filters( 'perflab_oc_site_status_suggest_persistent_object_cache', false ) ) {
+		$result['label'] = __( 'A persistent object cache is not required', 'performance-lab' );
+
+		return $result;
+	}
+
+	$available_services = perflab_oc_health_available_object_cache_services();
+
+	$notes = __( 'Speak to your web host about what persistent object caches are available and how to enable them.', 'performance-lab' );
+
+	if ( ! empty( $available_services ) ) {
+		$notes .= sprintf(
+			/* translators: Available object caching services. */
+			__( ' Your host appears to support the following object caching services: %s.', 'performance-lab' ),
+			implode( ', ', $available_services )
+		);
+	}
+
+	/**
+	 * Filter the second paragraph of the health check's description
+	 * when suggesting the use of a persistent object cache.
+	 *
+	 * Hosts may want to replace the notes to recommend their preferred object caching solution.
+	 *
+	 * Plugin authors may want to append notes (not replace) on why object caching is recommended for their plugin.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param string $notes The notes appended to the health check description.
+	 * @param array $available_services The list of available persistent object cache services.
+	 */
+	$notes = apply_filters( 'perflab_oc_site_status_persistent_object_cache_notes', $notes, $available_services );
+
+	$result['status']         = 'recommended';
+	$result['label']          = __( 'You should use a persistent object cache', 'performance-lab' );
+	$result['badge']['color'] = 'orange';
+	$result['description']   .= sprintf(
+		'<p>%s</p>',
+		wp_kses(
+			$notes,
+			array(
+				'a'      => array( 'href' => true ),
+				'code'   => true,
+				'em'     => true,
+				'strong' => true,
+			)
+		)
+	);
+
+	return $result;
+}
+
+/**
+ * Callback for `site_status_persistent_object_cache` filter.
+ *
+ * Determines whether to suggest using a persistent object cache.
+ *
+ * @since 1.0.0
+ *
+ * @param mixed $should_suggest Whether to suggest using a persistent object cache.
+ * @return bool Whether to suggest using a persistent object cache.
+ */
+function perflab_oc_health_should_persistent_object_cache( $should_suggest ) {
+	global $wpdb;
+
+	// Bypass expensive calls if `$should_suggest` was already set truthy.
+	if ( $should_suggest ) {
+		return true;
+	}
+
+	/**
+	 * Filter the thresholds used to determine whether to suggest the use of a persistent object cache.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param array $thresholds The list of threshold names and numbers.
+	 */
+	$thresholds = apply_filters(
+		'perflab_oc_site_status_persistent_object_cache_thresholds',
+		array(
+			'alloptions_count' => 500,
+			'alloptions_bytes' => 100000,
+			'comments_count'   => 1000,
+			'options_count'    => 1000,
+			'posts_count'      => 1000,
+			'terms_count'      => 1000,
+			'users_count'      => 1000,
+		)
+	);
+
+	$alloptions = wp_load_alloptions();
+
+	if ( $thresholds['alloptions_count'] < count( $alloptions ) ) {
+		return true;
+	}
+
+	if ( $thresholds['alloptions_bytes'] < strlen( serialize( $alloptions ) ) ) {
+		return true;
+	}
+
+	$table_names = implode( "','", array( $wpdb->comments, $wpdb->options, $wpdb->posts, $wpdb->terms, $wpdb->users ) );
+
+	// With InnoDB the `TABLE_ROWS` are estimates, which are accurate enough and faster to retrieve than individual `COUNT()` queries.
+	$results = $wpdb->get_results(
+		$wpdb->prepare(
+			// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+			"SELECT TABLE_NAME AS 'table', TABLE_ROWS AS 'rows', SUM(data_length + index_length) as 'bytes'
+			FROM information_schema.TABLES
+			WHERE TABLE_SCHEMA = %s
+			AND TABLE_NAME IN ('$table_names')
+			GROUP BY TABLE_NAME;",
+			// phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+			DB_NAME
+		),
+		OBJECT_K
+	);
+
+	$threshold_map = array(
+		'comments_count' => $wpdb->comments,
+		'options_count'  => $wpdb->options,
+		'posts_count'    => $wpdb->posts,
+		'terms_count'    => $wpdb->terms,
+		'users_count'    => $wpdb->users,
+	);
+
+	foreach ( $threshold_map as $threshold => $table ) {
+		if ( $thresholds[ $threshold ] <= $results[ $table ]->rows ) {
+			return true;
+		}
+	}
+
+	return false;
+}
+add_filter( 'perflab_oc_site_status_suggest_persistent_object_cache', 'perflab_oc_health_should_persistent_object_cache', 20 );
+
+/**
+ * Returns a list of available persistent object cache services.
+ *
+ * @since 1.0.0
+ *
+ * @return array The list of available persistent object cache services.
+ */
+function perflab_oc_health_available_object_cache_services() {
+	$extensions = array_map(
+		'extension_loaded',
+		array(
+			'APCu'      => 'apcu',
+			'Redis'     => 'redis',
+			'Relay'     => 'relay',
+			'Memcached' => 'memcache', // The `memcached` extension seems unmaintained.
+		)
+	);
+
+	$services = array_keys( array_filter( $extensions ) );
+
+	/**
+	 * Filter the persistent object cache services available to the user.
+	 *
+	 * This can be useful to hide or add services not included in the defaults.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param array $services The list of available persistent object cache services.
+	 */
+	return apply_filters( 'perflab_oc_site_status_available_object_cache_services', $services );
+}
diff --git a/tests/modules/object-cache/persistent-object-cache-health-check/health-check-test.php b/tests/modules/object-cache/persistent-object-cache-health-check/health-check-test.php
@@ -0,0 +1,142 @@
+<?php
+/**
+ * Tests for persistent-object-cache-health-check module.
+ *
+ * @package performance-lab
+ * @group persistent-object-cache-health-check
+ */
+
+class Object_Cache_Health_Check_Tests extends WP_UnitTestCase {
+
+	function test_object_cache_thresholds_check_is_bypassed() {
+		$bypassed = true;
+
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) use ( $bypassed ) {
+				$bypassed = false;
+
+				return $thresholds;
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( true );
+
+		$this->assertTrue( $result );
+		$this->assertTrue( $bypassed );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+	function test_object_cache_default_thresholds() {
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertFalse( $result );
+	}
+
+	function test_object_cache_comments_threshold() {
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) {
+				return array_merge( $thresholds, array( 'comments_count' => 0 ) );
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertTrue( $result );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+	function test_object_cache_posts_threshold() {
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) {
+				return array_merge( $thresholds, array( 'posts_count' => 0 ) );
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertTrue( $result );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+	function test_object_cache_terms_threshold() {
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) {
+				return array_merge( $thresholds, array( 'terms_count' => 1 ) );
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertTrue( $result );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+	function test_object_cache_options_threshold() {
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) {
+				return array_merge( $thresholds, array( 'options_count' => 100 ) );
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertTrue( $result );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+	function test_object_cache_users_threshold() {
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) {
+				return array_merge( $thresholds, array( 'users_count' => 0 ) );
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertTrue( $result );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+	function test_object_cache_alloptions_count_threshold() {
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) {
+				return array_merge( $thresholds, array( 'alloptions_count' => 100 ) );
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertTrue( $result );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+	function test_object_cache_alloptions_bytes_threshold() {
+		add_filter(
+			'perflab_oc_site_status_persistent_object_cache_thresholds',
+			function ( $thresholds ) {
+				return array_merge( $thresholds, array( 'alloptions_bytes' => 1000 ) );
+			}
+		);
+
+		$result = perflab_oc_health_should_persistent_object_cache( false );
+
+		$this->assertTrue( $result );
+
+		remove_all_filters( 'perflab_oc_site_status_persistent_object_cache_thresholds' );
+	}
+
+}