Windows（共享）上检查多个文件的最快方法

Question

I've a huge list of file paths to a remote share that I need to check for existence. example input:

\\server\\folder1\\file1
\\server\\folder1\\file2
\\server\\folder2\\file3
etc.

We currently simply do File.Exists (which basically uses the FindFirstFile WinAPI) per file but it's pretty slow. Is there any more efficient way of doing it? is there a way to parallelize is somehow?

Answer 1

Using I/O operations is usually slow and expensive.
I suggest using a different approach all together:

Get the list of files once, when the program is initialized, and store it in a database.

Use a FileSystemWatcher to monitor creation of files within the path (if you have different parent directories or different remote computers you might need to use a FileSystemWatcher for each one), and then update the database on each created, deleted and renamed event for the relevant files.

Then all you have to do to get the files that exists is a simple sql query, that will be lightning fast comparing to iterating on a large list and test for File.Exist