Looking for a good way to write multiple virtual "files" to one system file

Question

I have an application where there are multiple processes. They share the reading and writing of a set of files that grows over time. I'd rather not expose thousands of files to the user's environment, where it would be much easier for them to accidentally modify or delete one of them. Is there an API that will allow reasonably high performant writes and reads to a virtual file system that is ultimately a single file on the hard drive? I would need it in either C# or C++.

Answer 1

I'd use SQLite, or any key-value store with good BLOB values.