Odd Memory Leak in Ionic & Cordova for iOS
I have an odd memory leak in my ionic and cordova app. The leak is not there in chrome but when I ran the app, it is definitely there. Essentially, I need to loop through a large set of data and set it on $scope .
The data in real life is gathered from a server, but here I just simulated it with a function. Also, in the real app, $scope.vote is called by a button press, not a button press that enacts a for-loop.
That said this is a good simulation for it. The data is smaller but I made the loop run more so you can actually see the leak. The leak is much more significant when using the large datasets I'm gathering from the server.
I am currently running v1.0.0-beta.13 (beta 14 is causing a lot of other issues for me...) The bundle contains angular 1.2.25.
I've boiled this down to a test case below:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no, width=device-width">
<title></title>
<!-- compiled css output -->
<link href="css/ionic.app.css" rel="stylesheet">
<!-- ionic/angularjs js -->
<script src="lib/ionic/js/ionic.bundle.js"></script>
<!-- cordova script (this will be a 404 during development) -->
<script src="cordova.js"></script>
<script>
angular.module('starter', ['ionic'])
.controller("testCtrl", function($scope){
$scope.b = [];
$scope.count = 0;
function getBallots() {
$scope.b.push({
_id: "54d7d680bdd622982e91a45f"
});
$scope.b.push({
_id: "54d7ef2ac659dd302a128924"
});
$scope.b.push({
_id: "54d7ef2ac659dd302a128929"
});
}
getBallots();
$scope.vote = function(){
if($scope.b.length){
$scope.ballot = $scope.b.shift();
$scope.count ++;
}
if($scope.b.length<=0){
getBallots()
}
};
$scope.start = function(){
for(var i = 0; i < 10000; i++){
$scope.vote()
}
}
})
</script>
</head>
<body ng-app="starter" ng-controller="testCtrl">
{{ballot._id}}<br>
{{count}}
<br><br><br>
<button class="button button-large button-royal" ng-click="start()">BUTTON</button>
</body>
</html>
The Instruments tool shows when analyzing the app on my iphone 5S shows this. I know the size of leak is pretty small here in this test case, but in my real app, the data is a lot larger and so this becomes a big problem. Each of the bumps is the result of 5 sequential clicks on the button.
Instruments trace file can be downloaded at: http://s000.tinyupload.com/?file_id=52410311803253693651
I will not select this as an "answer" because it doesn't solve the problem, but I will share what I did to reduce my app's memory problem in case it is helpful for anyone else. Essentially I did this:
This reduced memory leak significantly but did not remove the memory leak completely.
I also experienced similar problems and I spent hours optimising my code to fix it :