How to read from and write to files under the same directory?

[yanshay]

I want to read content from a file in the root folder and write content from there to files in the same volume at different levels of the folder hierartchy (so under the same root directory).

For that if I get it right, I need to open the root folder, open the file, then change directory and open file for write and write.

However, once the file is open (and I don't close it since I'm processing it), I can't change_dir (can't borrow the dir as mutable because it's borrowed for the open file).

So how can this be done?

Should I open a second instance of the root folder and change from there?
What if I close the root folder of the second instance? will it close also the first? Or are these just two instances of the same folder that work separately? But then what happens if in one I add files? Will the other reflect that?

[thejpster]

You can only open each folder once - it checks to see if a directory has already been opened.

It should be fine to open multiple files and dirs at the same time with the latest version as it uses RefCells to allow the handlers to hold shared references to the volume.

[yanshay]

So if I don’t know in advance which folders will be opened I need to manage my own list of folders and in case I want to open a file in an already opened folder to reuse the already opened folder? And make sure to close only after the last use of folder is closed?

What is considered the last version? Only the latest one released? And before that accessing files simultaneously is not possible?

[thejpster]

I would do what the hexdump() function does in the examples. It takes a path, opens the folders one at a time to walk the path, and returns the file handle. You can then do what you want with the file, and close it again.

[thejpster]

Previous versions had File and RawFile, and File would mutably borrow the Volume Manager so you could only open one File at once (but you could have many RawFiles open, they just needed to be passed back to methods on the Volume Manager to use them).

[yanshay]

Previous versions had File and RawFile, and File would mutably borrow the Volume Manager so you could only open one File at once (but you could have many RawFiles open, they just needed to be passed back to methods on the Volume Manager to use them).

Got it, that’s what I’m struggling with among other things.
Unfortunately I’m using the async PR and these changes aren’t there so sounds like I can’t perform what I’m trying to do 😕