通过大数组过滤会导致冻结-Swift [英] Filtering through large array causes freezing - Swift

问题描述

我正在尝试过滤具有字符串数组的大型对象数据库，在这种情况下为kids.

I'm trying to filter through a large database of objects with arrays of strings, in this case, kids.

class Thing: Object, Decodable {
  @objc dynamic var id: String?
  let kids = List<String>
}

由于Realm不支持查询数组中的原始数据(根据Realm，您尚不能使用谓词和过滤器来执行此操作)，因此我正在使用它来对它们进行过滤:

Since Realm does not support querying primitive data in arrays (According to Realm, you can't use a predicate & filter to do this yet), I'm using this to filter through them:

let things = realm.objects(Thing.self)
for thing in things {
    if thing.kids.contains("Momo") {
        // Success
    }
}

我也尝试过:

realm.objects(Thing.self).filter(NSPredicate("%@ IN kids", "Momo"))

但是它不起作用.我还尝试在谓词中使用SUBQUERY，但它也不适用于原始数据类型.

But it does not work. I also tried to use SUBQUERY inside the predicate but it also does not work for primitive data types.

因为我有成千上万个Thing对象，所以这非常慢，并且冻结了我的应用程序.有没有一种方法可以加快速度，或者至少不冻结我的应用程序?我无法为字符串创建新的自定义类，因为必须完全更改存储所有内容的JSON.

Because I have thousands of Thing objects, this is very slow and it freezes my app. Is there a way to speed this up or make it not freeze my app at least? I can't make a new custom class for strings because I would have to completely change my JSON, which is where everything is stored.

推荐答案

基于注释，您可以尝试在后台线程中执行任务.不过，对UI的更新必须使用主线程.

Based on comments, you can try executing the task in a background thread. Updates to the UI must use the main thread though.

DispatchQueue.global(qos: .background).async

在下面的块中移动冻结UI的代码，以使其异步执行.

Move the code that freezes your UI in the below block to get it executed asynchronously.

DispatchQueue.main.async(execute: {
    // Place code that freezes UI or takes time to execute here. 
    let things = realm.objects(Thing.self)
    for thing in things {
        if thing.kids.contains("Momo") {
            // Success
        }
    }
}

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