Pattern Cache using Transient

src/wp-includes/class-wp-theme.php

@@ -1972,14 +1972,17 @@ public function get_block_patterns() {
 	 * Gets block pattern cache.
 	 *
 	 * @since 6.4.0
+	 * @since 6.6.0 Uses transients to cache regardless of site environment.
 	 *
 	 * @return array|false Returns an array of patterns if cache is found, otherwise false.
 	 */
 	private function get_pattern_cache() {
 		if ( ! $this->exists() ) {
 			return false;
 		}
-		$pattern_data = wp_cache_get( 'wp_theme_patterns_' . $this->stylesheet, 'theme_files' );
+
+		$pattern_data = get_site_transient( 'wp_theme_files_patterns-' . $this->cache_hash );
+
 		if ( is_array( $pattern_data ) && $pattern_data['version'] === $this->get( 'Version' ) ) {
 			return $pattern_data['patterns'];
 		}
@@ -1990,6 +1993,7 @@ private function get_pattern_cache() {
 	 * Sets block pattern cache.
 	 *
 	 * @since 6.4.0
+	 * @since 6.6.0 Uses transients to cache regardless of site environment.
 	 *
 	 * @param array $patterns Block patterns data to set in cache.
 	 */
@@ -1998,16 +2002,43 @@ private function set_pattern_cache( array $patterns ) {
 			'version'  => $this->get( 'Version' ),
 			'patterns' => $patterns,
 		);
-		wp_cache_set( 'wp_theme_patterns_' . $this->stylesheet, $pattern_data, 'theme_files' );
+
+		/**
+		 * Filters the cache expiration time for theme files.
+		 *
+		 * @since 6.6.0
+		 *
+		 * @param int    $cache_expiration Cache expiration time in seconds.
+		 * @param string $cache_type       Type of cache being set.
+		 */
+		$cache_expiration = (int) apply_filters( 'wp_theme_files_cache_ttl', self::$cache_expiration, 'theme_block_patterns' );
+
+		// We don't want to cache patterns infinitely.
+		if ( $cache_expiration <= 0 ) {
+			_doing_it_wrong(
+				__METHOD__,
+				sprintf(
+					/* translators: %1$s: The filter name.*/
+					__( 'The %1$s filter must return an integer value greater than 0.' ),
+					'<code>wp_theme_files_cache_ttl</code>'
+				),
+				'6.6.0'
+			);
+
+			$cache_expiration = self::$cache_expiration;
+		}
+
+		set_site_transient( 'wp_theme_files_patterns-' . $this->cache_hash, $pattern_data, $cache_expiration );
 	}
 
 	/**
 	 * Clears block pattern cache.
 	 *
 	 * @since 6.4.0
+	 * @since 6.6.0 Uses transients to cache regardless of site environment.
 	 */
 	public function delete_pattern_cache() {
-		wp_cache_delete( 'wp_theme_patterns_' . $this->stylesheet, 'theme_files' );
+		delete_site_transient( 'wp_theme_files_patterns-' . $this->cache_hash );
 	}
 
 	/**

tests/phpunit/tests/theme/wpThemeGetBlockPatterns.php

@@ -12,6 +12,23 @@
  * @covers WP_Theme::get_block_patterns
  */
 class Tests_Theme_WPThemeGetBlockPatterns extends WP_UnitTestCase {
+	/**
+	 * The initial cache object.
+	 *
+	 * @var object
+	 */
+	private $initial_cache_object;
+
+	public function set_up() {
+		parent::set_up();
+
+		$this->initial_cache_object = wp_using_ext_object_cache();
+	}
+
+	public function tear_down() {
+		wp_using_ext_object_cache( $this->initial_cache_object );
+		parent::tear_down();
+	}
 
 	public static function wpSetUpBeforeClass() {
 		// Ensure development mode is reset before running these tests.
@@ -39,6 +56,20 @@ private function get_pattern_cache( $wp_theme ) {
 		return $pattern_cache;
 	}
 
+	/**
+	 * Test helper to access the private cache_hash propery of a theme.
+	 *
+	 * @param WP_Theme $wp_theme A WP_Theme object.
+	 * @return array|false Returns an array of patterns if cache is found, otherwise false.
+	 */
+	private function get_cache_hash( $wp_theme ) {
+		$reflection = new ReflectionProperty( get_class( $wp_theme ), 'cache_hash' );
+		$reflection->setAccessible( true );
+		$cache_hash = $reflection->getValue( $wp_theme );
+		$reflection->setAccessible( false );
+		return $cache_hash;
+	}
+
 	/**
 	 * @ticket 59490
 	 *
@@ -196,4 +227,72 @@ public function test_should_clear_existing_cache_when_in_development_mode() {
 			'The cache for block theme patterns should have been cleared due to theme development mode.'
 		);
 	}
+
+	/**
+	 * @ticket 59600
+	 *
+	 * @covers WP_Theme::delete_pattern_cache
+	 */
+	public function test_delete_pattern_cache_non_obj_cache() {
+		// Ensure object cache is disabled.
+		wp_using_ext_object_cache( false );
+
+		$theme = wp_get_theme( 'block-theme-patterns' );
+
+		$this->assertTrue( $theme->exists(), 'The test theme could not be found.' );
+
+		$theme->get_block_patterns();
+
+		$this->assertSameSets(
+			array(
+				'cta.php' => array(
+					'title'       => 'Centered Call To Action',
+					'slug'        => 'block-theme-patterns/cta',
+					'description' => '',
+					'categories'  => array( 'call-to-action' ),
+				),
+			),
+			$this->get_pattern_cache( $theme ),
+			'The cache for block theme patterns should match the expected.'
+		);
+		$theme->delete_pattern_cache();
+		$this->assertFalse(
+			$this->get_pattern_cache( $theme ),
+			'The cache for block theme patterns should have been cleared.'
+		);
+	}
+
+	/**
+	 * Check if the pattern cache is stored in transient if object cache is not present.
+	 *
+	 * @ticket 59600
+	 */
+	public function test_pattern_transient_cache_for_non_cache_site() {
+		// Ensure object cache is disabled.
+		wp_using_ext_object_cache( false );
+
+		$theme = wp_get_theme( 'block-theme-patterns' );
+		$theme->get_block_patterns();
+
+		$transient_key   = 'wp_theme_files_patterns-' . $this->get_cache_hash( $theme );
+		$transient_value = get_site_transient( $transient_key );
+
+		$this->assertSameSets(
+			array(
+				'cta.php' => array(
+					'title'       => 'Centered Call To Action',
+					'slug'        => 'block-theme-patterns/cta',
+					'description' => '',
+					'categories'  => array( 'call-to-action' ),
+				),
+			),
+			$transient_value['patterns'],
+			'The transient value should match the expected.'
+		);
+
+		$this->assertNotEmpty(
+			$this->get_pattern_cache( $theme ),
+			'The cache for block theme patterns is empty.'
+		);
+	}
 }