Re: [boost] [filesystem] temp_directory_path() behavior on Windows

Subject: Re: [boost] [filesystem] temp_directory_path() behavior on Windows
From: Beman Dawes (bdawes_at_[hidden])
Date: 2015-02-04 17:39:22

On Wed, Feb 4, 2015 at 7:56 AM, Niall Douglas <s_sourceforge_at_[hidden]> wrote:
> On 4 Feb 2015 at 7:37, Rob Stewart wrote:
>
>> > I had
>> > thought you were recommending an ACL lookup for path viability.
>>
>> I was thinking that would be useful while we were at it, but I recognize that's easily overreaching.
>
> Also, Windows can only open 30k file handles per second even across
> eight CPU cores. It's an enormous performance bottleneck. And you
> can't check ACLs without opening the file.
>
>> > No I meant that temp_directory_path() basically needs to iterate
>> > those options I listed. If the given environment variable does not
>> > expand to a valid path (note no FS operations needed here), we move
>> > to the next option. We don't check for feasibility.
>>
>> How would you judge that the expansion is a valid path? A regex or something else?
>
> Perhaps even simpler. Does the environment variable exist, and does
> it have contents.

That's the obvious rule, and what I coded up originally. I may well
revert to that.

Thanks,

--Beman