如何获取Stream的底层文件句柄？
我有一个使用物理内存快照（例如，VMware VMEM 文件）的应用程序。除此之外，它可以通过虚拟地址而不是物理地址从快照中读取进程/模块。这涉及通过页表一次重建 4KB 的模块，这又意味着对 Stream 的 Seek() 方法的大量调用。
由于我不确定的原因，这些对 Seek() 的调用使事情急剧恶化。因此，我正在寻找一种绕过它们的方法——或者至少是一种绕过托管 Seek() 实现的方法。我最好的猜测是 PInvoke SetFilePointer 并直接使用它，但为了做到这一点，我需要获取流的 IntPtr/SafeFileHandle 。我有一些限制：
我正在使用的 API 仅限于 .NET 3.5，因此不幸的是 MemoryMappedFile 不是一个选项。
我无法使用 FileStream（它已经有一个可以通过反射访问的私有 SafeFileHandle 字段）或 PInvoke CreateFile() 来以另一种方式获取快照 - 该 API 包含一个具有独占锁的 BinaryReader
当然，与 FileStream 不同，BinaryReader 及其底层 Stream 都没有对文件句柄的引用。但肯定存在一个吗？在这种情况下，我该如何获取它？
I have an application that works with physical memory snapshots (for example, VMware VMEM files). Among other things, it can read processes/modules out of the snapshot by virtual rather than physical address. This involves reconstructing the module 4KB at a time through the page table, which, in turn, means a lot of calls to the Stream's Seek() method.
For reasons I'm not sure of, these calls to Seek() bog things down dramatically. As a result, I'm looking for a way around them -- or at least, a way around the managed Seek() implementation. My best guess is to PInvoke SetFilePointer and work with that directly, but in order to do that I need to get the IntPtr/SafeFileHandle for the Stream. I have a few restrictions:
The API I'm working with is limited to .NET 3.5, so unfortunately MemoryMappedFile isn't an option.
I can't use a FileStream (which already has a private SafeFileHandle field that can be accessed with reflection) or PInvoke CreateFile() to get at the snapshot another way -- the API includes a BinaryReader that has an exclusive lock on the snapshot.
Of course, unlike FileStream, neither BinaryReader nor its underlying Stream have a reference to the file handle. But certainly one must exist? In which case, how do I go about acquiring it?
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Stream没有文件句柄，因为它是一个抽象类。实现 Stream 的类可能会也可能不会使用文件句柄——FileStream会使用文件句柄，因为它从文件中读取数据，但MemoryStream会从文件中读取数据。例如，没有。要获取
BinaryReader的底层文件句柄（在本例中为SafeFileHandle），其Stream是FileStream，使用反射来访问private SafeFileHandle _handle，如下所示：旁注：直接调用
SetFilePointer()和MemoryMappedFile都对此没有帮助 案件。似乎没有快速的方法来处理我正在使用的卷的随机磁盘访问（数百万个连续调用）。There's no file handle for
Streambecause it's an abstract class. A class implementingStreammay or may not use a file handle --FileStreamdoes, since it reads data from a file, butMemoryStream, for example, does not.To get the underlying file handle (in this case a
SafeFileHandle) of aBinaryReaderwhoseStreamis aFileStream, use reflection to accessprivate SafeFileHandle _handle, like so:On a side note: neither direct calls to
SetFilePointer()norMemoryMappedFilehelped in this case. It seems there's no fast way to handle random disk access at the volume I'm using it (millions of consecutive calls).由于您在
FileStream上有BinaryReader，因此您可以访问阅读器的BaseStream，将其转换为FileStream，然后使用其公共SafeFileHandle属性来访问句柄。像这样的东西：Since you have
BinaryReaderoverFileStreamyou can access theBaseStreamof the reader, cast that toFileStreamand then use its publicSafeFileHandleproperty to access the handle. Something like this: