DateTime's and LargeIntegers

Doug Way dway at
Tue Jun 29 03:11:08 UTC 2004

On Monday, June 28, 2004, at 09:10 PM, Ross Boylan wrote:

> I'm looking for ways to speed up my application, which has gotten
> intolerably slow.  It spends a lot of its time doing operations on
> DateAndTime objects, which are basically Brent Pinkney's
> implementation of the ANSI standard for squeak.  However, I see he has
> made some changes since the version I got.  See
> I notice that this class doesn't seem to have made it into the
> mainline image (3.6), though there is a TimeStamp class there.  Aside
> from the fact that it  has a different vocabulary, it doesn't have any
> associated concept of durations (e.g., a week), which I also need.
> There is at least one obvious functional difference: DateAndTime knows
> its offset from UTC, while TimeStamp doesn't.  Not a must have feature
> for me.
> (However, I see some Mar 2004 messages with fixes, that sort of give
> the impression it is in the main update stream...?)

Yes, the ANSI DateAndTime (Chronology) changes are in the current 
update stream (3.7beta).  The current stable release (3.6) on was released last fall, so it's not going to contain 
anything from this year.  3.7 final should be coming out within the 
next month or so.

- Doug

> My first question is if anyone could fill me in on the history of
> Date/Times and Durations in the image.  I recall a couple of years ago
> there was some discussion of this, but I don't know how it turned out.
> In particular, there are issues of functionality, ANSI compatibility,
> and, as I've just discovered, speed.  (DateAndTime generally converts
> stuff to a large integer and then operates; TimeStamp does not, at
> least in the < operator, which is eating a lot of my time).
> I also recall there was another change set being bandied about that
> introduced ANSI compatibility into the image.  That had a different
> Date/Time implementation. Details at
> Second, I see some discussion of LargeInteger plugins.  That might
> make my operations go much faster.  Are those builtin by default?  I
> don't see anything in /usr/lib/squeak, even for the 3.6 Debianized vm
> that I got, I think, from Ned Konz.  Would such a plugin help?  How do
> I get or build it?  How do I know if I'm already using it?
> To give you a sense of why I care, here are some timings in the
> profiler as I add a single task to my tasklist:
> The first column is time in seconds (not ms)
> 43 LargeNegativeInteger>>quo:
> 21 SmallInteger>>*
> 18 LargePositiveInteger>>asFloat
> 14 LargePositiveInteger>>+
> That's a total of 68% of total execution time right there.
> Overall, the operations spends
> 64% of its time in the main morphic loop, within which
>   19% operations on DateAndTime or Durations
> 36% evaluating a sort block, within which
>   35% (i.e., almost all) operations on DateAndTime
> Obviously, waiting over a minute to add a task is far from user
> friendly!  (Athlon 800Mhz).
> There is also the possibility of making it do fewer of these
> operations to begin with, but if there's a quick way to get a speed up
> that would be great.

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