在iOS10上恢复NSUrlSession [英] Resume NSUrlSession on iOS10
问题描述
iOS 10即将发布，因此测试应用程序是否与其兼容是值得的。在此类测试期间，我们发现我们的应用程序无法在iOS10上恢复后台下载。在以前版本上运行良好的代码在模拟器和设备上都不适用于新版本。
iOS 10 is going to be released soon so it worth to test applications for compatibility with it. During such test we've discovered that our app can't resume background downloads on iOS10. Code that worked well on previous versions does not work on new one, both on an emulator and on a device.
而不是将我们的代码减少到最小的工作测试用例I'我们在互联网上搜索了NSUrlSession教程并测试了它们。行为是相同的：恢复工作在iOS的previos版本，但在10日休息。
Instead of reducing our code to minimal working test case I've searched internet for NSUrlSession tutorials and tested them. Behaviour is the same: resuming works on previos versions of iOS but breaks on 10th.
- 下载项目表单NSUrlSession教程
https ：//www.raywenderlich.com/110458/nsurlsession-tutorial-getting-started - 直接链接：
http://www.raywenderlich.com/wp-content/uploads/2016/01/HalfTunes-Final .zip - 构建并在iOS 10下启动。搜索一些内容，例如
swift。开始下载，然后点击暂停然后恢复
预期结果：
下载恢复。您可以查看iOS10之前版本的工作原理。
Expected Results:
Download is resumed. You can check how it works with versions prior to iOS10.
下载失败。在xcode控制台中，您可以看到：
Download fails. In xcode console you can see:
2016-09-02 16:11:24.913 HalfTunes[35205:2279228] *** -[NSKeyedUnarchiver initForReadingWithData:]: data is NULL
2016-09-02 16:11:24.913 HalfTunes[35205:2279228] *** -[NSKeyedUnarchiver initForReadingWithData:]: data is NULL
2016-09-02 16:11:24.913 HalfTunes[35205:2279228] Invalid resume data for background download. Background downloads must use http or https and must download to an accessible file.
更多场景：
如果激活离线模式，当文件被下载时，你得到
More scenarios:
If you activate offline mode while a file is beeng downloaded you get
Url session completed with error: Error Domain=NSURLErrorDomain Code=-1002 "unsupported URL" UserInfo={NSLocalizedDescription=unsupported URL} {
NSLocalizedDescription = "unsupported URL";
}
当网络关闭时，下载永远不会在网络再次启动时恢复。暂停的其他用例（例如重启）也不起作用。
when network is shut down and download never recovers when network is up again. Other use cases with pause, such as reboot, do not work either.
我'我试图使用
如何检查NSData blob是否有效作为NSURLSessionDownloadTask的resumeData？
但目标文件已到位。虽然resumeData格式已经改变，现在文件名存储在NSURLSessionResumeInfoTempFileName中，你必须将NSTemporaryDirectory（）附加到它。
but the target file is in place. Though resumeData format has changed and now file name is stored in NSURLSessionResumeInfoTempFileName and you have to append NSTemporaryDirectory() to it.
除此之外，我已经向苹果填写了一个错误报告，但他们还没有回复。
Beside that I've filled a bug report to apple, but they haven't replied yet.
在所有其他应用中，NSUrlSession的恢复是否已被破坏？是否可以在应用程序端修复？
Is resuming of NSUrlSession broken in all other apps? Can it be fixed on application side?
推荐答案
此问题源于currentRequest和originalRequest NSKeyArchived编码的异常根NSKeyedArchiveRootObjectKey而不是NSKeyedArchiveRootObjectKey常量，它是字面上的root和NSURL（Mutable）请求的编码过程中的一些其他行为异常。
This problem arose from currentRequest and originalRequest NSKeyArchived encoded with an unusual root of "NSKeyedArchiveRootObjectKey" instead of NSKeyedArchiveRootObjectKey constant which is "root" literally and some other misbehaves in encoding process of NSURL(Mutable)Request.
我在beta 1中检测到并提交了一个错误（号码27144153，万一你想复制）。甚至我发送了一封电子邮件给Quinn the Eskimo（eskimo1 at apple dot com），他是NSURLSession团队的支持者，确认他们收到了这封邮件，他说他们得到了这个并且知道问题。
I detected that in beta 1 and filed a bug (no. 27144153 in case you want duplicate). Even I sent an email to "Quinn the Eskimo" (eskimo1 at apple dot com) whom is support guy of NSURLSession team, to confirm they received it and he said they got that and are aware of issue.
更新：我终于找到了解决此问题的方法。将数据提供给correctResumeData（）函数，它将返回可用的恢复数据
UPDATE: I finally figured out how to resolve this issue. Give data to correctResumeData() function and it will return usable resume data
更新2：您可以使用NSURLSession.correctedDownloadTaskWithResumeData（）/ URLSession。 correctDownloadTask（withResumeData :)函数用于获取具有正确originalRequest和currentRequest变量的任务
UPDATE 2: You can use NSURLSession.correctedDownloadTaskWithResumeData() / URLSession.correctedDownloadTask(withResumeData:) function to get a task with a correct originalRequest and currentRequest variables
更新3： Quinn说此问题已在iOS中解决10.2，您可以继续使用此代码与iOS 10.0和10.1兼容，它可以在没有任何问题的情况下使用新版本。
UPDATE 3: Quinn says This issue is resolved in iOS 10.2, you can keep using this code to have compatibility with iOS 10.0 and 10.1 and it will work with new version without any issue.
（对于Swift 3代码，请在下面滚动，对于Objective C，请参阅 leavesstar帖子，但我没有对其进行测试）
(For Swift 3 code, scroll below, for Objective C see leavesstar post but I didn't tested it)
Swift 2.3：
func correctRequestData(data: NSData?) -> NSData? {
guard let data = data else {
return nil
}
// return the same data if it's correct
if NSKeyedUnarchiver.unarchiveObjectWithData(data) != nil {
return data
}
guard let archive = (try? NSPropertyListSerialization.propertyListWithData(data, options: [.MutableContainersAndLeaves], format: nil)) as? NSMutableDictionary else {
return nil
}
// Rectify weird __nsurlrequest_proto_props objects to $number pattern
var k = 0
while archive["$objects"]?[1].objectForKey("$\(k)") != nil {
k += 1
}
var i = 0
while archive["$objects"]?[1].objectForKey("__nsurlrequest_proto_prop_obj_\(i)") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_prop_obj_\(i)"] {
dic.setObject(obj, forKey: "$\(i + k)")
dic.removeObjectForKey("__nsurlrequest_proto_prop_obj_\(i)")
arr?[1] = dic
archive["$objects"] = arr
}
i += 1
}
if archive["$objects"]?[1].objectForKey("__nsurlrequest_proto_props") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_props"] {
dic.setObject(obj, forKey: "$\(i + k)")
dic.removeObjectForKey("__nsurlrequest_proto_props")
arr?[1] = dic
archive["$objects"] = arr
}
}
// Rectify weird "NSKeyedArchiveRootObjectKey" top key to NSKeyedArchiveRootObjectKey = "root"
if archive["$top"]?.objectForKey("NSKeyedArchiveRootObjectKey") != nil {
archive["$top"]?.setObject(archive["$top"]?["NSKeyedArchiveRootObjectKey"], forKey: NSKeyedArchiveRootObjectKey)
archive["$top"]?.removeObjectForKey("NSKeyedArchiveRootObjectKey")
}
// Reencode archived object
let result = try? NSPropertyListSerialization.dataWithPropertyList(archive, format: NSPropertyListFormat.BinaryFormat_v1_0, options: NSPropertyListWriteOptions())
return result
}
func getResumeDictionary(data: NSData) -> NSMutableDictionary? {
var iresumeDictionary: NSMutableDictionary? = nil
// In beta versions, resumeData is NSKeyedArchive encoded instead of plist
if #available(iOS 10.0, OSX 10.12, *) {
var root : AnyObject? = nil
let keyedUnarchiver = NSKeyedUnarchiver(forReadingWithData: data)
do {
root = try keyedUnarchiver.decodeTopLevelObjectForKey("NSKeyedArchiveRootObjectKey") ?? nil
if root == nil {
root = try keyedUnarchiver.decodeTopLevelObjectForKey(NSKeyedArchiveRootObjectKey)
}
} catch {}
keyedUnarchiver.finishDecoding()
iresumeDictionary = root as? NSMutableDictionary
}
if iresumeDictionary == nil {
do {
iresumeDictionary = try NSPropertyListSerialization.propertyListWithData(data, options: [.MutableContainersAndLeaves], format: nil) as? NSMutableDictionary;
} catch {}
}
return iresumeDictionary
}
func correctResumeData(data: NSData?) -> NSData? {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
guard let data = data, let resumeDictionary = getResumeDictionary(data) else {
return nil
}
resumeDictionary[kResumeCurrentRequest] = correctRequestData(resumeDictionary[kResumeCurrentRequest] as? NSData)
resumeDictionary[kResumeOriginalRequest] = correctRequestData(resumeDictionary[kResumeOriginalRequest] as? NSData)
let result = try? NSPropertyListSerialization.dataWithPropertyList(resumeDictionary, format: NSPropertyListFormat.XMLFormat_v1_0, options: NSPropertyListWriteOptions())
return result
}
extension NSURLSession {
func correctedDownloadTaskWithResumeData(resumeData: NSData) -> NSURLSessionDownloadTask {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
let cData = correctResumeData(resumeData) ?? resumeData
let task = self.downloadTaskWithResumeData(cData)
// a compensation for inability to set task requests in CFNetwork.
// While you still get -[NSKeyedUnarchiver initForReadingWithData:]: data is NULL error,
// this section will set them to real objects
if let resumeDic = getResumeDictionary(cData) {
if task.originalRequest == nil, let originalReqData = resumeDic[kResumeOriginalRequest] as? NSData, let originalRequest = NSKeyedUnarchiver.unarchiveObjectWithData(originalReqData) as? NSURLRequest {
task.setValue(originalRequest, forKey: "originalRequest")
}
if task.currentRequest == nil, let currentReqData = resumeDic[kResumeCurrentRequest] as? NSData, let currentRequest = NSKeyedUnarchiver.unarchiveObjectWithData(currentReqData) as? NSURLRequest {
task.setValue(currentRequest, forKey: "currentRequest")
}
}
return task
}
}
Swift 3：
func correct(requestData data: Data?) -> Data? {
guard let data = data else {
return nil
}
if NSKeyedUnarchiver.unarchiveObject(with: data) != nil {
return data
}
guard let archive = (try? PropertyListSerialization.propertyList(from: data, options: [.mutableContainersAndLeaves], format: nil)) as? NSMutableDictionary else {
return nil
}
// Rectify weird __nsurlrequest_proto_props objects to $number pattern
var k = 0
while ((archive["$objects"] as? NSArray)?[1] as? NSDictionary)?.object(forKey: "$\(k)") != nil {
k += 1
}
var i = 0
while ((archive["$objects"] as? NSArray)?[1] as? NSDictionary)?.object(forKey: "__nsurlrequest_proto_prop_obj_\(i)") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_prop_obj_\(i)"] {
dic.setObject(obj, forKey: "$\(i + k)" as NSString)
dic.removeObject(forKey: "__nsurlrequest_proto_prop_obj_\(i)")
arr?[1] = dic
archive["$objects"] = arr
}
i += 1
}
if ((archive["$objects"] as? NSArray)?[1] as? NSDictionary)?.object(forKey: "__nsurlrequest_proto_props") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_props"] {
dic.setObject(obj, forKey: "$\(i + k)" as NSString)
dic.removeObject(forKey: "__nsurlrequest_proto_props")
arr?[1] = dic
archive["$objects"] = arr
}
}
/* I think we have no reason to keep this section in effect
for item in (archive["$objects"] as? NSMutableArray) ?? [] {
if let cls = item as? NSMutableDictionary, cls["$classname"] as? NSString == "NSURLRequest" {
cls["$classname"] = NSString(string: "NSMutableURLRequest")
(cls["$classes"] as? NSMutableArray)?.insert(NSString(string: "NSMutableURLRequest"), at: 0)
}
}*/
// Rectify weird "NSKeyedArchiveRootObjectKey" top key to NSKeyedArchiveRootObjectKey = "root"
if let obj = (archive["$top"] as? NSMutableDictionary)?.object(forKey: "NSKeyedArchiveRootObjectKey") as AnyObject? {
(archive["$top"] as? NSMutableDictionary)?.setObject(obj, forKey: NSKeyedArchiveRootObjectKey as NSString)
(archive["$top"] as? NSMutableDictionary)?.removeObject(forKey: "NSKeyedArchiveRootObjectKey")
}
// Reencode archived object
let result = try? PropertyListSerialization.data(fromPropertyList: archive, format: PropertyListSerialization.PropertyListFormat.binary, options: PropertyListSerialization.WriteOptions())
return result
}
func getResumeDictionary(_ data: Data) -> NSMutableDictionary? {
// In beta versions, resumeData is NSKeyedArchive encoded instead of plist
var iresumeDictionary: NSMutableDictionary? = nil
if #available(iOS 10.0, OSX 10.12, *) {
var root : AnyObject? = nil
let keyedUnarchiver = NSKeyedUnarchiver(forReadingWith: data)
do {
root = try keyedUnarchiver.decodeTopLevelObject(forKey: "NSKeyedArchiveRootObjectKey") ?? nil
if root == nil {
root = try keyedUnarchiver.decodeTopLevelObject(forKey: NSKeyedArchiveRootObjectKey)
}
} catch {}
keyedUnarchiver.finishDecoding()
iresumeDictionary = root as? NSMutableDictionary
}
if iresumeDictionary == nil {
do {
iresumeDictionary = try PropertyListSerialization.propertyList(from: data, options: PropertyListSerialization.ReadOptions(), format: nil) as? NSMutableDictionary;
} catch {}
}
return iresumeDictionary
}
func correctResumeData(_ data: Data?) -> Data? {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
guard let data = data, let resumeDictionary = getResumeDictionary(data) else {
return nil
}
resumeDictionary[kResumeCurrentRequest] = correct(requestData: resumeDictionary[kResumeCurrentRequest] as? Data)
resumeDictionary[kResumeOriginalRequest] = correct(requestData: resumeDictionary[kResumeOriginalRequest] as? Data)
let result = try? PropertyListSerialization.data(fromPropertyList: resumeDictionary, format: PropertyListSerialization.PropertyListFormat.xml, options: PropertyListSerialization.WriteOptions())
return result
}
extension URLSession {
func correctedDownloadTask(withResumeData resumeData: Data) -> URLSessionDownloadTask {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
let cData = correctResumeData(resumeData) ?? resumeData
let task = self.downloadTask(withResumeData: cData)
// a compensation for inability to set task requests in CFNetwork.
// While you still get -[NSKeyedUnarchiver initForReadingWithData:]: data is NULL error,
// this section will set them to real objects
if let resumeDic = getResumeDictionary(cData) {
if task.originalRequest == nil, let originalReqData = resumeDic[kResumeOriginalRequest] as? Data, let originalRequest = NSKeyedUnarchiver.unarchiveObject(with: originalReqData) as? NSURLRequest {
task.setValue(originalRequest, forKey: "originalRequest")
}
if task.currentRequest == nil, let currentReqData = resumeDic[kResumeCurrentRequest] as? Data, let currentRequest = NSKeyedUnarchiver.unarchiveObject(with: currentReqData) as? NSURLRequest {
task.setValue(currentRequest, forKey: "currentRequest")
}
}
return task
}
}
这篇关于在iOS10上恢复NSUrlSession的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
