feat: Display total size of current directory

[krivahtoo]

Add the option to display lazily loaded directory sizes.

The displayed size is not accurate, to get the actual size of a directory one has to navigate recursively to all its child directories.

[display]
# ...
# Options include:
# - count (use the number of items in the directory)
# - size (use the total size of items in a directory)
size_mode = "count"
# ...

Screenshot

closes #229

[DLFW]

Hi!

When I have not visited all sub-dirs, does Joshuto show the wrong directory size?

If yes, is there some way to know which sub-dirs I have visited and which are not included in the total size yet?

[krivahtoo]

When I have not visited all sub-dirs, does Joshuto show the wrong directory size?

Yes. Without visiting sub-dirs, it will only calculate the total size of files in the directory.

If yes, is there some way to know which sub-dirs I have visited and which are not included in the total size yet?

No.

Having such a feature would be great though I am not sure how it would be implemented without traversing the directory.

[DLFW]

Hm, I just have a concern that this behavior breaks user-expectations, because people either check the sizes of files or a directory fully recursive (maybe except of other file-system mounted in the sub-tree and alike). I have never seen such a “partial dir-size” calculation, and I would certainly not expect this. @fritzrehde was also asking for a du -hs equivalent in #229, and that will always include the complete sub-tree. I'm not sure if this PR would suit his use-case.

Furthermore, users would not have a chance to see that their expectation is wrong unless they realize that “something with the size does not look right”. That's a dangerous combination in terms of usability, and in this case even more as a directory size might be considered in decisions about deleting, coping, or moving files.

I also don't see a use-case for this “partial dir-size” where I have to remember what sub-dirs I have visited before, but maybe I'm missing something.

Sorry, I don't want to interfere in your MR, and I'm really a fan of all your Joshuto contributions, but I have some serious concerns about this one.

[krivahtoo]

Okay, I see what you mean. Yeah, this will probably break user expectations.

Thanks for your feedback.

I think the solution would be to calculate but only show the size when all the files/dirs have been calculated and/or add a command to traverse the directory. This way the users would see the directory size only when it has been fully calculated.