如果结果限制小于1000，为什么我的CKQueryOperation只返回一个Cursor？

Question

CloudKit has about 2000 records that I am attempting to download. I cannot get all of them to download, I looked at CloudKit CKQueryOperation doesn't get all records to get more than 100 results. Now I can get upto 999 to download, but if I set the results limit to 1000 or more it will fail randomly between 80-500. Will I need to split these entries into different record types?

private func checkForCloudData() {
    let query = CKQuery(recordType: "myRecordType", predicate: .init(value: true))
    let op = CKQueryOperation(query: query)

    op.qualityOfService = .userInitiated
    op.queuePriority = .veryHigh
    op.resultsLimit = 999

    op.recordFetchedBlock = { record in
        // fetched record
    }

    op.queryCompletionBlock =  { cursor, err in

        if cursor != nil {
            print(cursor!)

            self.performOperation(withOperation: CKQueryOperation(cursor: cursor!))
        }

        if err == nil {
            // handle complete download
        } else {
            if (err as! CKError).code == .limitExceeded {
                if cursor != nil {
                    self.performOperation(withOperation: CKQueryOperation(cursor: cursor!))
                    return
                }
                let newOperation = CKQueryOperation(query: query)
                newOperation.resultsLimit = op.resultsLimit
                newOperation.queuePriority = .veryHigh
                newOperation.qualityOfService = .userInitiated
                newOperation.recordFetchedBlock = op.recordFetchedBlock
                newOperation.queryCompletionBlock = op.queryCompletionBlock

                self.performOperation(withOperation: newOperation)
            }
        }

    }

    self.performOperation(withOperation: op)
}

private func performOperation(withOperation operation: CKQueryOperation) {
        publicDB.add(operation)
}

Answer 1

I believe that 400 is the the limit for a single operation, so you need to use cursor to get more records, and keep on doing that while returned cursor is not nil .

See how it is done in RxCloudKit library' RecordFetcher - https://github.com/maxvol/RxCloudKit/blob/master/RxCloudKit/RecordFetcher.swift