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

From: Beman Dawes (bdawes_at_[hidden])
Date: 2005-09-13 06:42:58

"Thomas Matelich" <matelich_at_[hidden]> wrote in message 
news:3944d458050912191464699fcb_at_mail.gmail.com...
> 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.

I've now looked at the config_info results for every compiler reported in 
the Boost regression tests. All support a 64-bit type, so we are home free 
with uintmax_t.

>> 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.

Or maybe:

space_info space((path const&);

Thanks for the feedback; I'll go ahead and implement something.

--Beman