[squeak-dev] Re: etoys performance problems

Bert Freudenberg bert at freudenbergs.de
Wed Mar 26 10:07:16 UTC 2008

On Mar 26, 2008, at 9:37 , Hans-Martin Mosner wrote:
> Hilaire Fernandes schrieb:
>> As a concrete simple example, how can I examine the content of this
>> project file http://swiki.ofset.org:8000/super/36 (produced with a  
>> 3.8
>> image)?
>> It use 3 graphics and I am really curious to know what inside  
>> the .pr file.
>> The info I got from the .pr is:
>> hilaire at tice:/tmp$ file ENGRENAGE4.001.pr
>> ENGRENAGE4.001.pr: gzip compressed data, from FAT filesystem (MS- 
>> DOS, OS/2, NT)
>> Once gunzipped, I can't examine the content...
> Probably the file command is confused about this file.
> .pr files are just ZIP files, so you should be able to unzip the  
> file to
> see its contents.

The format for .pr files changed over time.

Hilaire's ENGRENAGE4.001.pr is indeed just a gzip-compressed object  
file, after decompressing it begins thus:

'From Squeak3.8 of ''5 May 2005'' [latest update: #6665] on 26  
September 2005 at 4:44:57 pm'!
!ObjectScanner new initialize!
!self smartRefStream!

... followed by the data.

Newer .pr files are zipped, and contain yet another .pr file which is  
a raw image segment.

And then there is the new project file format that we are switching to  
now, it's a high-level text-based project description rather than a  
direct object serialization.

The project loading code is pretty flexible and accepts many  
combinations of plain/zipped/gzipped refstreams or image segments or s- 

- Bert -

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