我正在使用 Swift iOS 应用下载大量文件，并对内容使用增量更新。
我的下载代码非常基本，我使用Alamofire将文件下载到临时目录中，解压缩它，检查目标目录中是否存在该文件或文件夹，如果找到则将其删除，然后移动新的文件/文件夹到该目录。
但是在检查现有目录并将其删除后很少出现问题。当我尝试将新的文件/文件夹移动到该目录时，出现错误
"File or directory already exists or contents is not empty."
但是在设备目录中失败后检查一下，它显示一个完全正常的目录，没有可能发生冲突的现有文件，或者有时新内容确实像应该的那样移动到目标目录，即使它说失败。这是我最烦恼的。
有人在目录中保存和移动文件时遇到过这种行为吗？
我差点忘了，我正在应用程序支持目录中工作。
internal func loadArtifact(artifact: Artifact, updateClosure: @escaping ((Bool, Int64, Int64, String?) -> ()))
{
let serverpath = artifact.serverpath
let name = artifact.name
let zipname = artifact.zipname
let root = artifact.artifactSetroot
let hidden = artifact.artifactSet!.hidden
let objectID = artifact.objectID
let baseArtifactSet = artifactSetManager.defaultartifactSetManager.getartifactSetDirectory(artifact.artifactSet!)
if baseArtifactSet == nil
{
errorLog("No target directory for artifactSet")
return
}
if name == nil
{
errorLog("No name for artifact. Can´t save in temp")
return
}
var targetDirectory = baseArtifactSet
targetDirectory?.appendPathComponent("temp")
targetDirectory?.appendPathComponent(zipname!.replacingOccurrences(of: ".zip", with: ""))
let destination: DownloadRequest.DownloadFileDestination = { _, _ in
return (targetDirectory!, [.removePreviousFile, .createIntermediateDirectories])
}
let url = URL(string: serverpath!)
alamofireManager!.download(url!, to: destination).downloadProgress { (progress) in
updateClosure(false, progress.completedUnitCount, progress.completedUnitCount, nil)
}.responseData { (data) in
traceLog("\(data)")
if data.response?.statusCode == 200
{
traceLog("Got an artifact. Will continue to extract itto target position")
self.asyncQueue.async {
var unzipTarget = baseArtifactSet
SSZipArchive.unzipFile(atPath: targetDirectory!.path, toDestination: root ? "\(unzipTarget!.path)/temp/root" : "\(unzipTarget!.path)/temp", progressHandler: { (message, something, progress, max) in
}, completionHandler: { (message, finished, error) in
let tmpPath = root ? "\(unzipTarget!.path)/temp/root" : "\(unzipTarget!.path)/temp/artifacts/\(zipname!.replacingOccurrences(of: ".zip", with: ""))"
let targetPath = root ? unzipTarget!.path : "\(unzipTarget!.path)/artifacts/\(zipname!.replacingOccurrences(of: ".zip", with: ""))"
if error == nil && root == false && FileManager.default.fileExists(atPath: targetPath)
{
do
{
try FileManager.default.removeItem(atPath: targetPath)
traceLog("Deletet old directory at path: \(unzipTarget!.path)")
}catch
{
errorLog("Could not remove directory at path: \(unzipTarget!.path) - \(error)")
updateClosure(true,0,0,"Could not remove directory at path: \(unzipTarget!.path) - \(error)")
}
}
do
{
if FileManager.default.fileExists(atPath: "\(unzipTarget!.path)/artifacts") == false
{
try FileManager.default.createDirectory(atPath: "\(unzipTarget!.path)/artifacts", withIntermediateDirectories: true, attributes: nil)
}
if root
{
do{
let targetDirContent = try FileManager.default.contentsOfDirectory(atPath: targetPath)
for file in targetDirContent
{
if file != "artifacts" && file != "temp"
{
try FileManager.default.removeItem(atPath: "\(targetPath)/\(file)")
}
}
let files = try FileManager.default.contentsOfDirectory(atPath: tmpPath)
for file in files
{
let fileURL = URL(fileURLWithPath: "\(tmpPath)/\(file)")
if fileURL != nil
{
try FileManager.default.moveItem(atPath: fileURL.path, toPath: "\(targetPath)/\(file)")
}
}
if root && hidden
{
let deviceInfoString = "var deviceInfo={'platform':'iOS'}"
if FileManager.default.fileExists(atPath: "\(targetPath)/deviceInfo.js")
{
try FileManager.default.removeItem(atPath: "\(targetPath)/deviceInfo.js")
}
}
}
catch{
errorLog("Error while enumerating files in temp root directory: \(error)")
updateClosure(true,0,0,"Error while enumerating files in temp root directory: \(error)")
}
}else
{
if FileManager.default.fileExists(atPath: targetPath)
{
debugLog("Deleting: \(targetPath)")
try FileManager.default.removeItem(atPath: targetPath)
}else
{
debugLog("Creating: \(targetPath)")
}
debugLog("Trying to move")
try FileManager.default.moveItem(atPath: tmpPath, toPath: targetPath)
}
}catch
{
errorLog("Could not move directory for artifact: \(unzipTarget!.path) - \(error)")
updateClosure(true,0,0,"Could not move directory for artifact: \(unzipTarget!.path) - \(error)")
}
try FileManager.default.removeItem(atPath: targetDirectory!.path)
self.asyncQueue.async (flags: .barrier) {
let ownContext = MyStorageClient.defaultManager.newBackgroundWorkerMOC()
let ownArtifact = ownContext.object(with: objectID) as! Artifact
ownArtifact.state = ArtifactState.Ready.rawValue
ownArtifact.updateAvaiable = false
if root == true && ownArtifact.artifactSet?.state == artifactSetState.Initialised.rawValue
{
ownArtifact.artifactSet?.state = artifactSetState.Created.rawValue
}
do{
try ownContext.save()
updateClosure(true, 0,0,nil)
}catch{
errorLog("Error while saving artifact context")
updateClosure(true, 0,0, "Error while saving context after artifact Update. \(error)")
}
}
})
}
}else
{
errorLog("Something went wrong downloading an artifact: \(data.response)")
updateClosure(true,0,0,"Something went wrong downloading an artifact: \(data.response)")
}
}
}
那么，谁能告诉我，为什么它失败了？ 我在大多数 try 行周围添加了 do-try-catch，当它失败时，它基本上是在这个 block 上失败的:
if FileManager.default.fileExists(atPath: targetPath)
{
debugLog("Deleting: \(targetPath)")
try FileManager.default.removeItem(atPath: targetPath)
}else
{
debugLog("Creating: \(targetPath)")
}
debugLog("Trying to move")
try FileManager.default.moveItem(atPath: tmpPath, toPath: targetPath)
目标路径是: 文件:///var/mobile/Containers/Data/Application/applicationIdAndStuff/Library/Application%20Support/environment/workspace/customers/customer/temp/downloadFileOrFolder
另一个更新: 我更改了代码，因此旧文件将被移动到备份文件夹而不是立即删除，因为我认为更改地址应该比完全删除文件更快。错误的。现在，该错误比以前更频繁地发生。
所以对我来说问题是文件管理器，它需要很长时间才能完成程序。我真的不想让我的 block 永远处于 sleep 状态，您对如何处理这个问题还有其他想法吗？
最佳答案
我解决了这个问题，只需将代码排序为所需的仅一次任务<和每个工件的任务<，以减轻文件管理器的压力。
因此，此代码处理每个工件的下载、解档和移动过程，并且它总是检查更高级别的目录(如果存在)，如果不存在则添加它们。对于每一件神器。 因此，当多个下载和解档几乎同时完成并开始执行目录操作时，这已经有可能发生冲突。
然后，准备用于移动文件的文件夹会带来更多麻烦而不是帮助。 尽管它在大多数情况下都有效，但有时会扰乱移动文件的系统检查，并导致错误告诉我目录或文件已经存在。
因此，在访问文件的每个 loadArtifact 之前，我重置了所需的目录并创建更高级别的目录，以防止在循环中重复检查。
因为一切都按预期进行。
关于ios - Swift - 移动或更新文件失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47637616/