[Swift4] メソッドの動作確認用クロージャ

methodMonitoring.swift

/*
// example:
func getAuthToken() -> String {
  return methodMonitoring {
    return apiService.requestToken()
  }
}

MONITORING: ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
MONITORING: ┃ Thread: <NSThread: 0x6000036ef280>{number = 1, name = main}
MONITORING: ┃   Time: 0.5726439952850342
MONITORING: ┠----------------------------------------------------------------------------------------------------
MONITORING: ┃   0   ExampleApp          ...
MONITORING: ┃   1   ExampleApp          ...
MONITORING: ┃   2   ExampleApp          ...
MONITORING: ┃   ...
MONITORING: ┠----------------------------------------------------------------------------------------------------
MONITORING: ┃   Function: getAuthToken
MONITORING: ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
*/

func methodMonitoring<T>(function: String = #function, _ closure: (() -> T)) -> T {
    let start = Date()
    let ret = closure()
    let elapsed = Date().timeIntervalSince(start)

    let traceMaxNum = 8
    let traceNum = traceMaxNum < Thread.callStackSymbols.count ? traceMaxNum : Thread.callStackSymbols.count
    let separateNum = 100
    let tag = "MONITORING: "
    var log: [String] = []
    log.append("\(tag)┏" + String(repeating: "━", count: separateNum))
    log.append("\(tag)┃ Thread: \(Thread.current)")
    log.append("\(tag)┃   Time: \(elapsed)")
    log.append("\(tag)┠" + String(repeating: "-", count: separateNum))
    Thread.callStackSymbols[0 ... traceNum].forEach { trace in
        log.append("\(tag)┃   \(trace)")
    }
    log.append("\(tag)┠" + String(repeating: "-", count: separateNum))
    log.append("\(tag)┃   Function: \(function)")
    log.append("\(tag)┗" + String(repeating: "━", count: separateNum))
    log.forEach { print($0) }
    return ret
}

メソッドの処理時間、コールスタック、スレッド　の情報を出します