5 Performance Improvements for Core Data in iOS Apps
Reach for quality!
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My favourite way of persisting data is with Core Data.
It’s an integrated Apple Framework — so don’t worry about your third-party stuff here. I like to write a Core Data Manager that is testable and can even be mocked.
However, where are the performance improvements that can make your App, well, usable?
They’re right below!
Difficulty: Beginner | Easy | Normal | Challenging
Terminology
Core Data: A framework that allows you to manage the model layer objects in your application. Core Data does this by being an object graph management and persistence framework.
Prerequisites:
- You will be expected to be aware how to make a Single View Application in Swift
- You’ll need to know about the basics of Core Data
- This article uses my method of having a Core Data Manager
- Knowing something about concurrency and threading would be useful
Stop using the viewContext!
That sounds a little bit strong. However, in my example Core Data Manager I have hard-baked the viewContext. Now you should only read on the viewContext from the main thread, and you should write using persistentContainer.newBackgroundContext().
This prevents saving on the main thread, while stops the user having to wait around for the background thread (but if you are only shifting a small amount of data this will not be a concern).
Only save if the managedObjectContext.hasChanges
You can check if your managed Object context actually has any changes before engaging in the heavyweight action.
if self.managedObjectContext.hasChanges {
// save your work
}This is surely the least you can do?
Test with NSInMemoryStoreType
If not you can inject a managedObjectContext with an NSInMemoryStoreType with something like the following:
