On 29/07/2013 21:33, Sven Van Caekenberghe wrote:
Chris,
On 29 Jul 2013, at 20:52, Chris <cpmbai...@btinternet.com> wrote:
I've been getting a little concerned with certain aspects of performance
recently. Just a couple of examples off the top of my head were trying to do a
printString on 200000 floats which takes over 3 seconds. If I do the same in
Python it is only 0.25 seconds. Similarly reading 65000 points from a database
with the PostgresV2 driver was about 800m/s and only 40 with psycopg. I'd have
to try it again but am pretty sure going native was faster than OpenDBX as
well. I appreciate Pharo is never going to be able to compete with the
static-typed heavyweight languages but would hope we can get performance at
least comparable to other dynamic languages :) Is it just that some method
implementations are in need of some TLC; more things moved on top of C
libraries and primitives and so forth rather than anything with the VM itself?
Cheers
Chris
You could try:
| floats |
floats := (1 to: 200000) collect: #asFloat.
[ FloatPrintPolicy
value: InexactFloatPrintPolicy new
during: [
String new: 1500000 streamContents: [ :stream |
floats do: [ :each | each printOn: stream ] ] ] ] timeToRun
=> 796 ms
I haven't looked at the Postgresql driver in detail, but I would guess that
PostgresV2 reads from a String somewhere, which is slow unless care is taken,
while psycopg probably does a binary read. That last thing can be done in Pharo
as well, but not if the driver is text based somehow.
You are right: Pharo should definitively be in the same range as other
dynamically typed languages. But dynamic languages are dangerous: user become
lazy / ignorant about performance.
Thanks for pushing this.
Sven
--
Sven Van Caekenberghe
http://stfx.eu
Smalltalk is the Red Pill
Thanks for the float tip :) I think I need to investigate the Postgres
thing a bit further. I thought it was a fairly native driver but the
double array type may well be using a string
