POC: deleted files

[tatref]

Hi,

This is a quick and dirty POC for #444

Here are the changes

• I used procfs to walk the processes under /proc/, but we can do this manually if you don't want to add a new dependency. The function to list files is get_deleted_files
• I added a function to modify the node tree: insert_deleted_file_in_node, maybe it could be merged with build_node
• The handling of the deleted files is done in walk_it
• I also made InodeAndDevice pub(crate) and used it to replace a few (u64, u64)

The drawbacks:

• There is an edge case with multiple deleted hardlinks with different paths: in this case, only the 1st file will be listed
• I only handle the file size for now (no filecount, filetime...), also WalkData is not used (no regex, ignore_dir...)
• I hardcoded the flag to handle the deleted files
• No cfg(windows), unix, linux... yet

On the bright side, there is no change (performance or inner working) if we set handle_deleted_files to false

Let me know what you think about it

[bootandy]

thanks, that's an interesting demonstration.

[bootandy]

Thanks, I'll dig into this next week