[Python-Dev] doc for new restricted execution design for Python
andreas.raab at gmx.de
Wed Jun 28 21:02:05 CEST 2006
Guido van Rossum wrote:
> On 6/28/06, Brett Cannon <brett at python.org> wrote:
>> On 6/28/06, Guido van Rossum <guido at python.org> wrote:
>>> - File size should be rounded up to some block size (512 if you don't
>>> have filesystem specific information) before adding to the total.
> Because that's how filesystems work. Allocations are in terms of block
> sizes. 1000 files of 1 byte take up the same space as 1000 files of
> 512 bytes (in most common filesystems anyway -- I think Reiserfs may
> be different).
Forgive me if I'm missing the obvious but shouldn't block size be taken
into consideration when setting the cap rather than for testing the file
size? E.g., what happens if you specify a cap of 100 bytes, your block
size is 512 and the user tries to write a single byte? Fail, because
it's logically allocation 512 and the cap is at 100? That seems
backwards to me since it would require that the app first determine the
block size of the OS it's running on before it can even set a "working"
And if the interpreter implicitly rounds the cap up to block size, then
there isn't much of a point in specifying the number of bytes to begin
with - perhaps use number of blocks instead?
In any case, I'd argue that if you allow the cap to be set at any
specific number of bytes, the interpreter should honor *exactly* that
number of bytes, blocks or not.
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