import Foundation enum RDEPUBBackgroundTrace { static func log(_ scope: String, _ message: String) { let threadRole = Thread.isMainThread ? "main" : "bg" let queueLabel = String(validatingUTF8: __dispatch_queue_get_label(nil)) ?? "unknown" print("[EPUB][\(scope)][\(threadRole)][queue=\(queueLabel)] \(message)") } }