Re: RFC 163 (v2) Objects: Autoaccessors for object data structures

On Mon, Sep 18, 2000 at 01:02:31PM -0700, Glenn Linderman wrote:
> OK, thanks for the info.  I'm not an internals guy, but I guess I
> should have written the benchmark.  It just _seemed_ they should be
> slower, because there is more work to do the hashing.  The actual
> lookup, I agree, should be the same.

Similar mistaken logic leads to "globals are faster than lexicals".


> Now while it is _totally_ true from your numbers that the lookup
> (read reference) costs are the same, it would seem that the
> variability in write references could still make this pay off.  The
> set_const is about 40% slower for hash, and set_var is about 166%
> slower.

Accessor overhead swamps all.


> N.B.  I wonder if the hash accessor is faster because the array
> accessor is referencing past the end of the array?  (not apples to
> apples here, you use index 0 everywhere else, and index 1 in the
> accessor.)

Its just benchmarking flutter.  I reran it with 1 everywhere else and
the same results.  Besides, because $aobj is global, the first call
would extend the array and the following 899_999 wouldn't worrry about
it.


> > I know, lets call it a pseudo-hash!
> >
> > Been there, done that, worn the scars proudly.
> 
> Is _that_ what a pseudo-hash is?  Then it sounds like a good idea.
> But maybe there are some differences between today's pseudo-hash and
> my proposal, even though they might be similar.  I think mine is
> pretty general, and the discussion on this list made it sound like
> pseudo-hash has some other restrictions?

Read RFC 241 for a brief overview of pseudo-hash problems.


-- 

Michael G Schwern      http://www.pobox.com/~schwern/      [email protected]
Just Another Stupid Consultant                      Perl6 Kwalitee Ashuranse
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