Commit

Carthage/Checkouts/TrueTime.swift/Sources/TimedOperation.swift

@@ -0,0 +1,38 @@
+//
+//  TimedOperation.swift
+//  TrueTime
+//
+//  Created by Michael Sanders on 7/18/16.
+//  Copyright © 2016 Instacart. All rights reserved.
+//
+
+import Foundation
+
+protocol TimedOperation: class {
+    var started: Bool { get }
+    var timeout: TimeInterval { get }
+    var timer: DispatchSourceTimer? { get set }
+    var timerQueue: DispatchQueue { get }
+
+    func debugLog(_ message: @autoclosure () -> String)
+    func timeoutError(_ error: NSError)
+}
+
+extension TimedOperation {
+    func startTimer() {
+        cancelTimer()
+        timer = DispatchSource.makeTimerSource(flags: [], queue: timerQueue)
+        timer?.schedule(deadline: .now() + timeout)
+        timer?.setEventHandler {
+            guard self.started else { return }
+            self.debugLog("Got timeout for \(self)")
+            self.timeoutError(NSError(trueTimeError: .timedOut))
+        }
+        timer?.resume()
+    }
+
+    func cancelTimer() {
+        timer?.cancel()
+        timer = nil
+    }
+}