clean_dirsize_cache() WordPress Function

function clean_dirsize_cache( $path ) {
	if ( ! is_string( $path ) || empty( $path ) ) {
		trigger_error(
			sprintf(
				/* translators: 1: Function name, 2: A variable type, like "boolean" or "integer". */
				__( '%1$s only accepts a non-empty path string, received %2$s.' ),
				'<code>clean_dirsize_cache()</code>',
				'<code>' . gettype( $path ) . '</code>'
			)
		);
		return;
	}

	$directory_cache = get_transient( 'dirsize_cache' );

	if ( empty( $directory_cache ) ) {
		return;
	}

	if (
		strpos( $path, '/' ) === false &&
		strpos( $path, '\\' ) === false
	) {
		unset( $directory_cache[ $path ] );
		set_transient( 'dirsize_cache', $directory_cache );
		return;
	}

	$last_path = null;
	$path      = untrailingslashit( $path );
	unset( $directory_cache[ $path ] );

	while (
		$last_path !== $path &&
		DIRECTORY_SEPARATOR !== $path &&
		'.' !== $path &&
		'..' !== $path
	) {
		$last_path = $path;
		$path      = dirname( $path );
		unset( $directory_cache[ $path ] );
	}

	set_transient( 'dirsize_cache', $directory_cache );
}