Re: [boost] [filesystem] revised function to determine available file system space

From: Thomas Matelich (matelich_at_[hidden])
Date: 2005-09-12 21:14:45

On 9/12/05, Beman Dawes <bdawes_at_[hidden]> wrote:
> 
> I'm planning to add a filesystem function to determine available disk 
> space.
> Perhaps something like:
> 
> struct space
> {
> boost::uintmax_t available; // bytes available to user
> boost::uintmax_t total; // total bytes on volume
> };
> 
> space filesystem_space( const path & p );
> 
> Comments?

Seems like a perfectly usable API. 

How safe is the assumption that uintmax_t is large enough nowadays for any
> modern compiler on a system supporting large disks.

Well, you need 50 bits for a petabyte, I don't think people are 
using/exceeding that much these days, so platforms supporting long long 
should keep you in space for few years. I'd think you'll find the answer to 
that as you write platform specific versions. As long as uintmax_t is larger 
than the parameter to the function, you'll be sitting pretty.

I suppose a platform supporting insane amounts of diskspace could report 
with a low-longlong and hi-longlong, but I'm sure we'll be able to ifdef 
apm_unsigned by then.

> Better suggestions for the names?

I think filesystem::filesystem_space is a bit redundant. If we want to be 
forward looking we should avoid the word disk since flash HD's are becoming 
a reality. This information will return free space on the partition path 
lives on. Unix often calls partitions volumes. I'm not really brainstorming 
myself into any great names. 

space usage(path const&); //kinda like it
drive_space drive_usage(path const&); //bad - not info for the whole drive
volume_info stats(path const&); //bad - too confusing with stat

Oh well, whatever the name, it'll be a good addition.

Tom