> "The Windows Projected File System (ProjFS) allows a user-mode application called a "provider" to project hierarchical data from a backing data store into the file system, making it appear as files and directories in the file system. For example, a simple provider could project the Windows registry into the file system, making registry keys and values appear as files and directories, respectively. An example of a more complex provider is VFS for Git, which is used to virtualize very large git repos." - https://docs.microsoft.com/en-us/windows/win32/projfs/projec...
or this one?
> "Starting in Windows 10, version 1709, Windows provides the cloud files API. This API consists of several native Win32 and WinRT APIs that formalize support for cloud sync engines, and handles tasks such as creating and managing placeholder files and directories." - https://docs.microsoft.com/en-us/windows/win32/cfapi/cloud-f...
Neither is a generic user space vfs API. They are only tailored to some narrow use cases with bunch of limitations.
Last time I checked projfs can't stream files from memory while cloudfs can't stream directories from memory (i.e. you have to pre-create placeholder files in local fs).
