Dactyloidae iOS initial commit

mobile/ios/Shared/SystemUtils.swift

@@ -0,0 +1,69 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import Foundation
+
+/**
+ *  System helper methods written in Swift.
+ */
+public struct SystemUtils {
+
+    /**
+     Returns an accurate version of the system uptime even while the device is asleep.
+     http://stackoverflow.com/questions/12488481/getting-ios-system-uptime-that-doesnt-pause-when-asleep
+
+     - returns: Time interval since last reboot.
+     */
+    public static func systemUptime() -> TimeInterval {
+        var boottime = timeval()
+        var mib = [CTL_KERN, KERN_BOOTTIME]
+        var size = MemoryLayout<timeval>.stride
+        var now = time_t()
+        time(&now)
+
+        sysctl(&mib, u_int(mib.count), &boottime, &size, nil, 0)
+        let tv_sec: time_t = withUnsafePointer(to: &boottime.tv_sec) { $0.pointee }
+        return TimeInterval(now - tv_sec)
+    }
+}
+
+extension SystemUtils {
+    // This should be run on first run of the application. 
+    // It shouldn't be run from an extension.
+    // Its function is to write a lock file that is only accessible from the application, 
+    // and not accessible from extension when the device is locked. Thus, we can tell if an extension is being run
+    // when the device is locked.
+    public static func onFirstRun() {
+        guard let lockFileURL = lockedDeviceURL else {
+            return
+        }
+        
+        let lockFile = lockFileURL.path
+        let fm = FileManager.default
+        if fm.fileExists(atPath: lockFile) {
+            return
+        }
+        let contents = "Device is unlocked".data(using: String.Encoding.utf8)
+        fm.createFile(atPath: lockFile, contents: contents, attributes: [FileAttributeKey.protectionKey.rawValue: FileProtectionType.complete])
+    }
+
+    private static var lockedDeviceURL: URL? {
+        let directoryURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: AppInfo.sharedContainerIdentifier)
+        return directoryURL?.appendingPathComponent("security.dummy")
+    }
+
+    public static func isDeviceLocked() -> Bool {
+        guard let lockFileURL = lockedDeviceURL else {
+            return true
+        }
+        do {
+            _ = try Data(contentsOf: lockFileURL, options: .mappedIfSafe)
+            return false
+        } catch let err as NSError {
+            return err.code == 257
+        } catch _ {
+            return true
+        }
+    }
+}