Memory leak in Swift app due to ContiguousArrayStorage - ios

Question

I'm designing an app which has the a feature to let user add their own pin. Recently, I found my app has a memory leak with the title of "ContiguousArrayStorage". I debugged a little and figured out it was a problem with my for loop in my viewdidload, but I am not sure how to fix the leak.
Here is my code:
#IBOutlet weak var AppleMap: MKMapView!
#IBOutlet weak var LogoutOutlet: UIButton!
#IBOutlet weak var OutletforAddPokemon: UIButton!
#IBOutlet weak var FindLocationOutlet: UIButton!
#IBOutlet weak var FilterOutlet: UIButton!
let locationManager = CLLocationManager()
let calendar: NSCalendar! = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
var increment:Int = 0
var currentLoc:CLLocationCoordinate2D?
var centerMap = true
let StoringPin = FIRDatabase.database().reference().child("locations")
var Date = NSDate()
override func viewDidLoad() {
super.viewDidLoad()
AppleMap.delegate = self
StoringPin.observeEventType(.Value, withBlock: {
snapshot in
if snapshot.value is NSNull {
return
}
let val = snapshot.value as! [String : [String : AnyObject]]
for key in val.keys {
let latitudedata = val[key]!["latitude"] as! Double
let longitudedata = val[key]!["longitude"] as! Double
let namedata = val[key]!["name"] as! String
let Username = val[key]!["Username"]
as! String
let DATE = val[key]!["Date"]
as! String
let NumberOflikesforuser = val[key]!["Likes"] as! Int
let NumberOfDislikesforuser = val[key]!["Dislikes"] as! Int
let coord = CLLocationCoordinate2D(latitude: latitudedata, longitude: longitudedata)
let artwork = Capital(title: "\(namedata)", coordinate: coord, info: "HI", username: Username, NumofLikes: NumberOflikesforuser,NumofDisLikes: NumberOfDislikesforuser, UIDSTring: UID, date: DATE, color: MKPinAnnotationColor.Green)
artwork.subtitle = DATE
print("k")
let permastringforemail:String = Username
print(++self.increment)
print(UID)
print(permastringforemail)
stringforemail = permastringforemail
Arrayforpins.append(artwork)
self.AppleMap.addAnnotation(Arrayforpins[Arrayforpins.count - 1])
for Capital in Arrayforpins {
self.AppleMap.addAnnotation(Capital)
}
}
})
print(LogoutOutlet)
LogoutOutlet.layer.cornerRadius = 4
FindLocationOutlet.layer.cornerRadius = 4
OutletforAddPokemon.layer.cornerRadius = 4
//FilterOutlet.layer.cornerRadius = 4
self.locationManager.requestAlwaysAuthorization()
self.locationManager.requestWhenInUseAuthorization()
if CLLocationManager.locationServicesEnabled() {
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
locationManager.startUpdatingLocation()
}
let annotationView = MKAnnotationView()
let detailButton: UIButton = UIButton.init(type: .DetailDisclosure) as UIButton
annotationView.rightCalloutAccessoryView = detailButton
}
let regionRadius: CLLocationDistance = 1000
func centerMapOnLocation(location: CLLocation) {
let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate,
regionRadius * 2.0, regionRadius * 2.0)
AppleMap.setRegion(coordinateRegion, animated: true)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let locValue:CLLocationCoordinate2D = manager.location!.coordinate
if CLLocationManager.authorizationStatus() == .AuthorizedWhenInUse {
AppleMap.showsUserLocation = true
} else {
locationManager.requestWhenInUseAuthorization()
}
print("update")
currentLoc = locValue
if centerMap {
centerMap = false
centerMapOnLocation(CLLocation(latitude: currentLoc!.latitude, longitude: currentLoc!.longitude))
}
}
#IBAction func SendtoSelector(sender: AnyObject) {
self.performSegueWithIdentifier("SeguetoSelector", sender: self)
}
#IBAction func FilterFunc(sender: AnyObject) {
self.performSegueWithIdentifier("SeguetoFilter", sender: self)
}
#IBAction func FindLocation(sender: AnyObject) {
centerMapOnLocation(CLLocation(latitude: currentLoc!.latitude, longitude: currentLoc!.longitude))
}
#IBAction func Logout(sender: AnyObject) {
LO = true
self.performSegueWithIdentifier("BacktoLoginScreen", sender: self)
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
locationManager
if IndexBoolean == true{
//let annotationView = MKPinAnnotationView()
print("Hi")
let artwork = Capital(title: "\(pickerDataSource[chosenindex])", coordinate: CLLocationCoordinate2D(latitude: currentLoc!.latitude, longitude: currentLoc!.longitude), info: "HEY", username: stringforemail, NumofLikes: NumberOfLikes, NumofDisLikes: NumberOfDislike, UIDSTring: UID, date: stringfordate2, color: MKPinAnnotationColor.Green)
//print(now)
print(chosenindex)
artwork.title = "\(pickerDataSource[chosenindex])"
//artwork.subtitle = stringfordate
AppleMap.addAnnotation(artwork)
//annotationView.pinColor = artwork.Green
Arrayforpins.append(artwork)
print(stringforemail)
AppleMap.addAnnotation(Arrayforpins[Arrayforpins.count - 1])
for Capital in Arrayforpins{
AppleMap.addAnnotation(Capital)
}
IndexBoolean = false
var formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss ZZZ"
formatter.timeZone = NSTimeZone(abbreviation: "Central Time")
var utcTimeZoneSTR = formatter.stringFromDate(Date)
stringfordate = "\(utcTimeZoneSTR)"
let uid = NSUUID().UUIDString
UID = uid
StoringPin.child(uid).setValue(["name" : pickerDataSource[chosenindex],
"latitude" : currentLoc!.latitude,
"longitude" : currentLoc!.longitude,"Array Position" : chosenindex,"Username": stringforemail, "Likes": NumberOfLikes2, "Dislikes":
NumberOfDislike, "UID": UID, "Date": stringfordate])
if FilterBoolean == true {
print("b")
if FilterDataSource[Intforfilter] != stringforname {
print("k")
//self.AppleMap.viewForAnnotation(artwork)?.hidden = true
FilterBoolean == false
}
//else {
// print("m")
// self.AppleMap.removeAnnotation(artwork)
//
// }
FilterBoolean == false
}
}
}
func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
let identifier = "Capital"
print(++increment)
if annotation.isKindOfClass(Capital.self) {
print("CAPITAL")
if let annotationView = mapView.dequeueReusableAnnotationViewWithIdentifier(identifier) {
annotationView.annotation = annotation
return annotationView
} else {
let annotationView = MKPinAnnotationView(annotation:annotation, reuseIdentifier:identifier)
annotationView.enabled = true
annotationView.canShowCallout = true
//annotationView.pinColor = MKPinAnnotationColor.Green
let btn = UIButton(type: .DetailDisclosure)
annotationView.rightCalloutAccessoryView = btn
return annotationView
}
}
return nil
}
func mapView(mapView: MKMapView, annotationView view: MKAnnotationView, calloutAccessoryControlTapped control: UIControl) {
let capital = view.annotation as! Capital
let placeName = capital.title
let placeInfo = capital.info
let UserName = capital.username
stringforname = view.annotation!.title!!
coords = view.annotation!.coordinate
stringforemail = capital.username
stringfordate2 = capital.date
NumberOfLikes2 = capital.NumofLikes
UID = capital.UIDSTring
print(stringforname)
print(UID)
self.performSegueWithIdentifier("SegueToInfo", sender: self)
}

Answer 1

I note you're not taking care to specify how to capture self in your closure. When in a disposable object context (a UIViewController) and an async closure you always have to worry about this. You need to capture it as weak or unowned. Are you familiar with closure capture lists?
https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/AutomaticReferenceCounting.html#//apple_ref/doc/uid/TP40014097-CH20-ID56
The pattern I use is to capture self weakly and then bail if self has become nil, e.g. the UIViewController has been dismissed and harvested. If it is still around, I temporarily capture it strongly with a local variable in a guard...let statement.
withBlock: { [weak self] (snapshot) in
guard let s = self else {
print("Callback called after view unloaded")
return
}
// now use 's' instead of 'self'
...
}
Can't say this is the only problem because we don't have the declarations for your helper classes. For example we don't know what mischief Capital is up to.
By the way, just be clear that your for loop does not run at viewDidLoad(). You're merely registering a callback that only reacts if and when the .Value event occurs on the StoringPin object.