CLGeocoder reverseGeocodeLocation with timeout swift 2.0

CLGeocoder+Timeout.swift

//
//  CLGeocoder+Timeout.swift
//
//  Created by Bertrand Souriau on 17/06/2016.
//  Thanks to Mathias Amnell (https://github.com/apping/APFoundation/blob/master/Pod/Classes/CLGeocoder%2BTimeout.m)

import Foundation
import MobileCoreServices
import CoreLocation

// https://github.com/apple/swift-evolution/blob/master/proposals/0088-libdispatch-for-swift3.md

extension CLGeocoder {
    
    public func reverseGeocodeLocation(location: CLLocation, timeout: NSTimeInterval, completionHandler: CLGeocodeCompletionHandler) {
        
        if( timeout <= 0 ) {
            reverseGeocodeLocation(location, completionHandler: completionHandler)
            return
        }
        
        var handled = false
        
        reverseGeocodeLocation(location) { (placemarks:[CLPlacemark]?, error:NSError?) in
            
            if( handled ) {
                return
            }
            
            handled = true
            
            completionHandler(placemarks, error)
            
        }
        
        let delay = dispatch_time(DISPATCH_TIME_NOW, Int64(timeout * Double(NSEC_PER_SEC)))
        dispatch_after(delay, dispatch_get_main_queue()) {
            
            if( handled ) {
                return
            }
            
            handled = true
            
            self.cancelGeocode()
            completionHandler(nil, NSError(domain: kCLErrorDomain, code: CLError.GeocodeFoundNoResult.rawValue, userInfo: nil))
        }
        
        
    }
    
}