为什么在CloudKit中CKModifyRecordsOperation要批量删除记录而不是删除记录？

Question

我有从CloudKit的私有数据库中批量删除记录的代码，但它不起作用。(我还注意到我保存的记录没有保留。)我使用的是一台实际的iPhone 8，有一个我个人使用的实际苹果ID，而不是一个开发人员账户。我用iPhone 8模拟器得到了同样的结果。使用iPhone 8模拟器使用与我的开发人员帐户相同的苹果ID登录iCloud时，我不会遇到此问题。

在这篇文章的答案没有给我一个解决方案之后，我认为这个问题最重要的事情是，当我使用一个不是我的开发人员账户的Apple ID时，它就会发生。我在两个不同的苹果it上尝试了它，这两个it不是我的开发人员帐户。会不会是我忽略了某个场景？

stackoverflow上的类似帖子都没有解决这个问题。

看起来代码应该删除的一些记录实际上被删除了，但有些却没有删除。当我再次运行代码时，仍然存在记录，但与以前一样减少了一个记录。

下面是我的代码：

class AppDelegate: UIResponder, UIApplicationDelegate, UISplitViewControllerDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        let splitViewController = window!.rootViewController as! UISplitViewController
        let navigationController = splitViewController.viewControllers[splitViewController.viewControllers.count-1] as! UINavigationController
        navigationController.topViewController!.navigationItem.leftBarButtonItem = splitViewController.displayModeButtonItem
        splitViewController.delegate = self

        deleteRecords()
        return true
    }

}

let privateDatabase = CKContainer.default().privateCloudDatabase

func deleteRecords() {

    print("deleteRecords()")

    let predicate = NSPredicate(value: true)
    let query = CKQuery(recordType: DatabaseNameStrings.recordTypeAffirmation, predicate: predicate)

    privateDatabase.perform(query, inZoneWith: nil) {

        (records: [CKRecord]?, error: Error?) in

        if error != nil {

            print(error as Any)

        } else {

            if let records = records {

                print("records.count=", records.count)

                let recordIDsToDelete = records.map { $0.recordID }
                print("recordIDsToDelete:")
                print(recordIDsToDelete)
                let operation = CKModifyRecordsOperation(recordsToSave: nil, recordIDsToDelete: recordIDsToDelete)
                operation.modifyRecordsCompletionBlock = { savedRecords, deletedRecordIDs, error in
                    if error == nil {
                        print("Batch delete records!")
                        print("number of records deleted:", deletedRecordIDs?.count as Any)
                        printNumberOfRecords()
                    } else {
                        print(error as Any)
                    }
                }
                privateDatabase.add(operation)

            }

        }

    }
}

func printNumberOfRecords() {

    let predicate = NSPredicate(value: true)
    let query = CKQuery(recordType: DatabaseNameStrings.recordTypeAffirmation, predicate: predicate)

    privateDatabase.perform(query, inZoneWith: nil) {

        (records: [CKRecord]?, error: Error?) in

        if error != nil {

            print(error as Any)

        } else {

            if let records = records {

                print("Number of records in CloudKit=", records.count)

            }

        }

    }

}

以下是第一次运行代码时在调试窗口中的输出：

deleteRecords()
records.count= 93
recordIDsToDelete:
[<CKRecordID: 0x280bbcb00; recordName=B33A3F23-23D3-44C6-AEBC-86DD718DBB62, zoneID=...>, ... ]
Batch delete records!
number of records deleted: Optional(93)
Number of records in CloudKit= 67

下面是第二次运行代码时在调试窗口中的输出：

deleteRecords()
records.count= 92
recordIDsToDelete:
[<CKRecordID: 0x280080d00; recordName=BBA5B236-A036-4AC9-82E1-165D3B003E23, zoneID=...>, ... ]
Batch delete records!
number of records deleted: Optional(92)
Number of records in CloudKit= 52

当我使用此代码而不是deleteRecords()时...

func deleteRecordsOneAtATime() {

    print("deleteRecordsOneAtATime()")

    let predicate = NSPredicate(value: true)
    let query = CKQuery(recordType: DatabaseNameStrings.recordTypeAffirmation, predicate: predicate)

    privateDatabase.perform(query, inZoneWith: nil) {

        (records: [CKRecord]?, error: Error?) in

        if error != nil {

            print(error as Any)

        } else {

            if let records = records {

                print("records.count=", records.count)

                let recordIDsToDelete = records.map { $0.recordID }
                print("recordIDsToDelete:")
                print(recordIDsToDelete)

                for recordID in recordIDsToDelete {

                    privateDatabase.delete(withRecordID: recordID) {
                        (localRecordID: CKRecord.ID?, error: Error?) in
                        if error != nil {
                            print("error:\n", error as Any)
                        } else {
                            if localRecordID != nil {
                                print("localRecordID:", localRecordID as Any)
                            }
                        }
                    }

                printNumberOfRecords()

                }

            }

        }

    }

}

我进入调试窗口：

deleteRecordsOneAtATime()
Number of records in CloudKit= 97
records.count= 97
recordIDsToDelete:
[<CKRecordID: 0x283622ec0; recordName=600B7BFE-04FE-4F63-BC4C-5AD1AE08908D, zoneID=...>, ... ]
localRecordID: Optional(<CKRecordID: 0x2821ff320; recordName=8E8CD0F0-FDF5-4CB9-B16C-5CF91C3503A2, zoneID=_defaultZone:__defaultOwner__>)
localRecordID: Optional(<CKRecordID: 0x2821ff320; recordName=8E0A0816-1B05-4707-A4E7-C40762E68663, zoneID=_defaultZone:__defaultOwner__>)
localRecordID: Optional(<CKRecordID: 0x28210b200; recordName=8E127624-F1D3-401E-ADF2-BB97354FCA98, zoneID=_defaultZone:__defaultOwner__>)
...
Number of records in CloudKit= 87
localRecordID: Optional(<CKRecordID: 0x282108660; recordName=962639D1-83E6-40D2-A57D-F70ADCEBED08, zoneID=_defaultZone:__defaultOwner__>)
localRecordID: Optional(<CKRecordID: 0x28210ff20; recordName=968D62AB-523E-464B-94B8-3C90E0382AB6, zoneID=_defaultZone:__defaultOwner__>)
localRecordID: Optional(<CKRecordID: 0x28210faa0; recordName=96C92DD2-ED27-4FED-8320-44D03981B04F, zoneID=_defaultZone:__defaultOwner__>)
localRecordID: Optional(<CKRecordID: 0x2821085a0; recordName=96A2D515-D3E7-475E-B609-8389DE4B88D1, zoneID=_defaultZone:__defaultOwner__>)

下面是我的最新代码，它仍然不能工作：

func removeRecords() {

    print("removeRecords()")

    let predicate = NSPredicate(value: true)
    let query = CKQuery(recordType: DatabaseNameStrings.recordTypeAffirmation, predicate: predicate)

    privateDatabase.perform(query, inZoneWith: nil) {

        (records: [CKRecord]?, error: Error?) in

        if error != nil {

            print(error as Any)

        } else {

            if let records = records {

                print("records.count=", records.count)

                let recordIDsToDelete = records.map { $0.recordID }
                print("recordIDsToDelete:")
                print(recordIDsToDelete)

                DispatchQueue.main.async {

                    if recordIDsToDelete.count > 50 {
                        let slice = Array(recordIDsToDelete[0 ..< 50])
                        let leftOver = Array(recordIDsToDelete[50 ... recordIDsToDelete.count-1])

                        privateDatabase.remove(recordsWith: slice) {
                            (result: Result<Void, Error>) in
                            print("result:", result)
                            switch result {
                            case .failure(let err):
                                print("failure")
                                print(err)
                            case .success(()):
                                print("success")
                                DispatchQueue.main.async {
                                    privateDatabase.remove(recordsWith: leftOver) {
                                        (result: Result<Void, Error>) in
                                        print("result:", result)
                                        switch result {
                                        case .failure(let err):
                                            print("failure")
                                            print(err)
                                        case .success(()):
                                            print("success")
                                        }
                                        print("type of result:", type(of: result))
                                    }
                                }
                            }
                            print("type of result:", type(of: result))
                        }

                    } else {

                        privateDatabase.remove(recordsWith: recordIDsToDelete) {
                            (result: Result<Void, Error>) in
                            print("result:", result)
                            switch result {
                            case .failure(let err):
                                print("failure")
                                print(err)
                            case .success(()):
                                print("success")
                            }
                            print("type of result:", type(of: result))
                        }

                    }





                    privateDatabase.remove(recordsWith: recordIDsToDelete) {
                        (result: Result<Void, Error>) in
                        print("result:", result)
                        switch result {
                        case .failure(let err):
                            print("failure")
                            print(err)
                        case .success(()):
                            print("success")
                        }
                        print("type of result:", type(of: result))
                    }

                }

            }

        }

    }

}

extension CKDatabase {
    func remove(
        recordsWith ids: [CKRecord.ID], completion: @escaping CompletionHandler<Void>) {
        let operation = CKModifyRecordsOperation(recordIDsToDelete: ids)
        operation.qualityOfService = .userInitiated
        operation.modifyRecordsCompletionBlock = { _, _, error in
            if let error = error {
                print("error:")
                print(error)
                if let err = error as? CKError, let time = err.retryAfterSeconds {
                    DispatchQueue.main.asyncAfter(deadline: .now() + time) {
                        self.remove(recordsWith: ids, completion: completion)
                    }
                } else {
                    completion(.failure(error))
                    print("CKDatabase.remove(_:_:) failed.")
                }
            } else {
                completion(.success(()))
                print("CKDatabase.remove(_:_:) succeeded.")
            }
        }
        self.add(operation)
    }
}

Answer 1

我认为代码正在删除它从执行查询方法中获得的内容。只是执行查询方法没有从所有现有记录中返回记录ids。

Answer 2

有时CloudKit会抛出不同的错误，所以你必须确保你能处理它们，如果error包含retryAfterSeconds，就再次触发调用。在这里，使用CKDatabase的这个包装器方法可以很轻松地处理中的错误。在调用任何CloudKit应用程序接口时，请确保将请求批处理为较小的块(例如，每个100个项目)。

extension CKDatabase {
    func remove(
        recordsWith ids: [CKRecord.ID], 
        completion: @escaping (Result<Void, Error>) -> Void
    ) {
        let operation = CKModifyRecordsOperation(recordIDsToDelete: ids)
        operation.qualityOfService = .userInitiated
        operation.modifyRecordsCompletionBlock = { _, _, error in
            if let error = error {
                if let err = error as? CKError, let time = err.retryAfterSeconds {
                    DispatchQueue.main.asyncAfter(deadline: .now() + time) {
                        self.remove(recordsWith: ids, completion: completion)
                    }
                } else {
                    completion(.failure(error))
                }
            } else {
                completion(.success(()))
            }
        }
        self.add(operation)
    }
}

Answer 3

尝试这些改变；

之后

  let operation = CKModifyRecordsOperation(recordsToSave: nil, recordIDsToDelete: recordIDsToDelete)

添加

  operation.database = privateDatabase
  operation.queuePriority = .veryHigh
  operation.configuration =  CKOperation.Configuration()
  operation.configuration.qualityOfService = .userInteractive

然后使用以下命令开始操作：

  operation.start()    

而不是

  privateDatabase.add(operation)