而不是使用NSTimer
,請使用dispatch_after
。
print("Network failure!!")
if let retryAfterValue = error.userInfo[CKErrorRetryAfterKey] as? NSTimeInterval {
let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(retryAfterValue * Double(NSEC_PER_SEC)))
dispatch_after(delayTime, dispatch_get_main_queue()) {
saveHandler(saveRecord: saveRecord, error: error)
}
}
這是一個輔助方法(在Objective-C中),我用它來記錄所有的修改和刪除操作。它處理常見錯誤和重試。
- (void)modifyRecords:(NSArray<CKRecord *> *)records andDeleteRecords:(NSArray<CKRecordID *> *)deleteIds completion:(void (^)(NSArray<CKRecord *> *savedRecords, NSArray<CKRecordID *> *deletedRecordIDs, NSError *error))completion {
CKModifyRecordsOperation *op = [[CKModifyRecordsOperation alloc] initWithRecordsToSave:records recordIDsToDelete:deleteIds];
op.savePolicy = CKRecordSaveAllKeys;
op.modifyRecordsCompletionBlock = ^(NSArray *savedRecords, NSArray *deletedRecordIDs, NSError *operationError) {
NSError *returnError = operationError;
if (operationError) {
switch (operationError.code) {
case CKErrorRequestRateLimited:
case CKErrorServiceUnavailable:
case CKErrorZoneBusy:
{
double delay = 3.0;
NSNumber *delayVal = operationError.userInfo[CKErrorRetryAfterKey];
if (delayVal) {
delay = delayVal.doubleValue;
}
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delay * NSEC_PER_SEC)), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
[self modifyRecords:records andDeleteRecords:deleteIds completion:completion];
});
}
return;
case CKErrorPartialFailure:
{
if (savedRecords.count || deletedRecordIDs.count) {
returnError = nil;
}
break;
}
default:
{
NSLog(@"Unhandled error in modify/deleteRecords: %@", operationError);
}
break;
}
}
if (completion) {
completion(savedRecords, deletedRecordIDs, returnError);
}
};
[someCloudKitDatabase addOperation:op];
}
如果你只是想添加/修改記錄,通過nil
到deleteIds
參數。
這裏是Swift 3中的相同幫助方法(這個方法還沒有經過測試,但是除了最後一行外,它的確可以編譯)。
func modifyRecords(_ records: [CKRecord]?, andDelete deleteIds: [CKRecordID]?, completionHandler: @escaping ([CKRecord]?, [CKRecordID]?, Error?) -> Void) {
let op = CKModifyRecordsOperation(recordsToSave: records, recordIDsToDelete: deleteIds)
op.savePolicy = .allKeys
op.modifyRecordsCompletionBlock = { (_ savedRecords: [CKRecord]?, _ deletedRecordIds: [CKRecordID]?, _ operationError: Error?) -> Void in
var returnError = operationError
if let ckerror = operationError as? CKError {
switch ckerror {
case CKError.requestRateLimited, CKError.serviceUnavailable, CKError.zoneBusy:
let retry = ckerror.retryAfterSeconds ?? 3.0
DispatchQueue.global().asyncAfter(deadline: DispatchTime.now() + retry, execute: {
modifyRecords(records, andDelete: deleteIds, completionHandler: completionHandler)
})
return
case CKError.partialFailure:
if (savedRecords != nil && savedRecords!.count > 0) || (deletedRecordIds != nil && deletedRecordIds!.count > 0) {
returnError = nil
}
default:
break
}
}
completionHandler(savedRecords, deletedRecordIds, returnError)
}
someCloudKitDatabase.add(op)
}
感謝dispatch_after提示。我的問題是在失敗期間saveRecord爲零。當我運行代碼並關閉WiFi以生成錯誤代碼時。這是我的問題。 – Coder1224
我會使用'CKModifyRecordsOperation'而不是'CKDatabase'的基本'saveRecord'方法。你有更多的控制權,並且使得使用這種「重試」邏輯變得更簡單。 – rmaddy
你能指點我一個'CKModifyRecordsOperation'使重試邏輯更簡單的例子嗎? – Coder1224