GNUe Traffic #117 For 22 May 

Editor: Peter Sullivan

By Peter Sullivan

"nah, I think the definition of "programmer" is pretty loose these days - after all, jamest claims to be one"

Table Of Contents

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• Introduction
• Threads Covered

  1.	16 May  - 18 May		Performance tuning of Application Server
  2.	22 May		Layout in GNUe Forms with wx 2.6 driver
  3.	22 May		Allowable typecast attributes for GNUe Forms

Introduction

1. Performance tuning of Application Server

16 May  - 18 May  Archive Link: "[IRC] 16 May 2006"

Summary By Peter Sullivan

Topics: Application Server

People: Malek Hadj-Ali, Reinhard Müller, Malik Hadj-Ali, Jason Cater

Further to Issue #116, Section #2  (10 May : Performance issues with Application Server and XML-RPC) , Malek Hadj-Ali (lekma) reported "the script that use to take 4min+ is now" under 2. There were still some "strange bugs in http 1.1 with hessian" and "the request still eats 300Meg of memory" . But, as Reinhard Müller (reinhard) noted "at least for speed we're not magnitudes away any more" . Malek did further testing, and noted that a hessian dump run independantly took a fraction of a second - the same hessian dump via the GNUe Application Server took 26 seconds. Reinhard noted that it was not unusual to see odd results like this when profiling python code - "I suspect all the hidden python magic like garbage collection and the like has a big impact on performance - and the decision when exactly python runs the garbage collection might depend on conditions that we as humans would regard as "random"" . Jason Cater (jcater) wondered if using unicode, or the presence of the python psyco module was making a difference, but neither of these proved to be the case. Both Jason and Reinhard volunteered to have a look at Malek's code to see if they could spot anything.

The next day, Malek reported that he had "figured it out - a bug in hessianlib that shown itself when dumping instances" . He did some more tests with various different combinations (using XML-RPC, hessian and direct database access, both with and without GNUe Application Server) and found that hessian was still somewhat faster than the original XML-RPC protocol that GNUe had been using previously, but felt a bit frustrated that it should be significantly faster - as "pure dumps/loads is around 3 times faster in hessian than xmlrpc" .

The next day, Reinhard said he would apply Malik's patch "so others can have a look and a try" . Malek explained that his patch fixed "a bug withe the hessian lib - but that don't solve all performance issue" . Jason noted that his profiling tests conmfirmed this - "I wrapped the calls into the hotshot profiler the other day - and noticed that most of the wait was inside of the networking code of hessianlib.py" . Malek pointed out that "appserver adds a non negligeabable overhead in ClientAdapter and ServerAdapter" , regardless of whether hessian or XML-RPC was used, "but it tries hard to balance this overhead with agressive http 1.1 connections - so all in all it's not that bad." .

2. Layout in GNUe Forms with wx 2.6 driver

22 May  Archive Link: "[IRC] 22 May 2006"

Summary By Peter Sullivan

Topics: Forms

People: James Thompson, Reinhard Müller, Johanes Vetter, Johannes Vetter

James Thompson (jamest) asked "how stable is forms head? and the wx driver in particular - 2.6" as "the dropdowns in the old wx driver have started causing us lots of issues" . Reinhard Müller (reinhard) replied "head should be perfectly usable, and wx26 should be possibly the most stable driver of all" (as previously discussed in Issue #108, Section #8  (16 Mar : Reducing the number of user interface drivers for GNUe) and similar threads). But he cautioned that this did not mean "that you *won't* hit bugs..." . James tried it, and noted "2.6 computes spacing a bit different than 2.4 did doesn't it" ? Johannes Vetter (johannesV) explained "spacing depends on the biggest control possible - depending on the platform used" . Reinhard clarified "it just takes standard entry size, standard button size, standard dropdown size - and takes the biggest of them - so no control will get chopped" . James was concerned that this "really increases the horizontal space usage though - like on a rows=10 - it looking like whitespace is doubled" .

Reinhard wondered "whether widgetWidth and widgetHeight point sizes could be a configuration option - and if set override the auto dectected widget sizes" . Johannes said that this "should be handled quite well if there are layoutmanagers ..." . But James noted that this would also need to take account of what X themes the user was running - "as for whatever reason themes effect forms here - a form that fits on user A's screen doesn't on User B's" . Reinhard agreed "that the only real solution is layout management - a button simply *isn't* of the same size as an entry" for example.

3. Allowable typecast attributes for GNUe Forms

22 May  Archive Link: "[IRC] 22 May 2006"

Summary By Peter Sullivan

Topics: Forms

People: James Thompson, Reinhard Müller

James Thompson (jamest) noted that "the two biggest things stopping me from opening forms are" lack of support for integer and boolean typecasts - the typecast-attribute only seemed to support date, text and number as of time of writing. He asked "is there a reason we don't don't support typecast= boolean or integer in" GNUe Form Definitions? Reinhard Müller (reinhard) replied "I have no idea, the set of possible values was defined ages ago - but it was never checked. I am not opposed at all to add any other values to the list as you see fit" .

Sharon And Joy