识别坏ReparsePoints与GetDirectories（）在.NET 3.5中？ [英] Identifying bad ReparsePoints with GetDirectories() in .Net 3.5?

问题描述

我使用 Directory.GetDirectories（）通过一个文件夹中所没有的系统文件夹中的所有目录中的LINQ的声明中循环，但是我发现了一堆坏 ReparsePoints 的文件夹，这是造成该方法需要很长的时间，因为它在超时每个坏的重新分析点。

I am using Directory.GetDirectories() with a Linq statement to loop through all directories in a folder that aren't system folders, however I am discovering a bunch of bad ReparsePoints in the folder, which is causing the method to take a long time as it times out on each bad reparse point.

在code我目前使用看起来像这样：

The code I am currently using looks like this:

subdirectories = directory.GetDirectories("*", SearchOption.TopDirectoryOnly)
    .Where(d => ((d.Attributes & FileAttributes.Hidden) != FileAttributes.Hidden)
         && ((d.Attributes & FileAttributes.System) != FileAttributes.System));

我也尝试过使用code这样的测试，但它也挂起了一分钟左右就坏了文件夹：

I have also tried using code like this for testing, but it also hangs for a full minute or so on the bad folders:

foreach (var item in dir.GetDirectories("*", SearchOption.TopDirectoryOnly))
{
    Console.WriteLine(item.Name);
    Console.WriteLine(item.Attributes);
}

应当指出的是，code以上位工作正常，在.NET 4.0中，但在3.5，将挂起对每个坏重新分析点一分钟。

It should be noted that the above bit of code works fine in .Net 4.0, but in 3.5 it will hang for a minute on each bad reparse point.

试图在Windows资源管理器导致手动打开这些文件夹找不到网络路径错误。

Trying to open these folders manually in Windows Explorer results in a "Network Path Not Found" error.

有另一种方式，通过一个文件夹内良好的子文件夹，不使用属性财产循环，或绕过坏的重分析点？

Is there another way to loop through good subfolders inside a folder that doesn't use the Attributes property, or that bypasses the bad reparse points?

我已经尝试过使用 Directory.Exists（），这同样是缓慢的。

I have already tried using Directory.Exists(), and that is equally slow.

推荐答案

根据这样的回答：<一href="http://stackoverflow.com/questions/3582823/fastest-directory-listing/8827241#8827241">*FASTEST*目录列表

为了获得最佳性能，有可能的P / Invoke NtQueryDirectoryFile ，记录为 ZwQueryDirectoryFile

For the best performance, it is possible to P/Invoke NtQueryDirectoryFile, documented as ZwQueryDirectoryFile

从MSDN： FILE_REPARSE_POINT_INFORMATION 结构

From MSDN: FILE_REPARSE_POINT_INFORMATION structure

这信息可通过以下任一方式进行查询：

This information can be queried in either of the following ways:

呼叫 ZwQueryDirectoryFile ，通过 FileReparsePointInformation 作为FileInformationClass的价值，并通过调用者分配， FILE_REPARSE_POINT_INFORMATION -structured缓冲区 FileInformation 的价值。

Call ZwQueryDirectoryFile, passing FileReparsePointInformation as the value of FileInformationClass and passing a caller-allocated, FILE_REPARSE_POINT_INFORMATION-structured buffer as the value of FileInformation.

创建与主要功能code的 IRP_MJ_DIRECTORY_CONTROL 和次要功能code IRP_MN_QUERY_DIRECTORY 。

Create an IRP with major function code IRP_MJ_DIRECTORY_CONTROL and minor function code IRP_MN_QUERY_DIRECTORY.

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