question(s) from a newcomer Squeak-fan about changes and images

Hello all,

I've been playing with Squeak (and smalltalk) for a bit now, and i just LOVE
it.

Being an old school programmer im still a bit overwhelmed by the concept
(and all consequences of that) ... ;).

One of the things i'm having a hard time with to 'grasp' is the relation
between the image and the changes file.

What i think to understand is:
- the changes file keeps all changes done to the image. I Never have to
explicitly save the (current) changes file...
- image file is saved when i ask for it... and keeps all contents (data) of
the current world.
- then there is also a sources file which is like changes but "readonly" ?

What i dont get is, do these files just grow forever ?.
Or do i (at a certain point in development) incorparate all changes in the
image and then start a new changes file ?

I've also seen the SqueakLight image, how is a thing like this made ?

I have seen and looked at the diff manager, and i understand its meaning (in
a cvs kind of understanding), but im
unsure of the whole concept of it.

I hope this makes any sense ...

Keep up the good work!

from a new admirer,

 - Jeroen

Jeroen van Hilst puso en su mail :

> I've also seen the SqueakLight image, how is a thing like this made ?
With giants before me breaking the rocks.
And a long work.

All what I do is rearranging all and trying to have a modular system what
could go from about 3.6 mb (a minimal start morphic and no much more, to
current 3.4.5 (yes , today I deliver a fix of all Alexander complaints and a
couple of requested "I want that into ").

And when all refactoring and packages going out of 3.9 end and Spoon
continue his way, you could go from nothing to all ( or I hope so).

Thanks for interest !!

Edgar



       

       
               
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Jeroen van Hilst puso en su mail :

> - image file is saved when i ask for it... and keeps all contents (data) of
> the current world.
The image contains all living object, from ancient 30 years old as nil to
whose you just create , this is not amazing ?

> What i dont get is, do these files just grow forever ?.
> Or do i (at a certain point in development) incorparate all changes in the
> image and then start a new changes file ?

You could do Smalltalk condenseChanges and keep only what matters.

And when 4.0 arrives, a new .sources for all classes in the system and a new
empty .changes

Edgar




       

       
               
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From: "Jeroen van Hilst" <[hidden email]> wrote:



> Hello all,
>

>
> What i dont get is, do these files just grow forever ?.
> Or do i (at a certain point in development) incorparate all changes in the
> image and then start a new changes file ?
>

These files grow, but they cannot grow forever - they are limited
to 32 MBytes.

You have these options:

1.
You can 'cleanup the changes file. That clean-up is done with

   Smalltalk condenseChanges.

This clean-up removes all 'historical'definitions from the changes
file and keeps only the most recent ones. Condensation of
the changes destroys the changes history which is sometimes felt
as a disadvantage. It reduces the size of the changes file
which is sometimes a necessity.
Condensation of the changes does not affect the sources file.

2.
You can merge the currently valid definitions from the changes file
with the sources file. This empties the changes file and it also
removes the changes history (that you see when you read the
versions of a method.)  Outdated definitions are removed
from both the changes file and the sources file.
When you merge the changes into the sources file, that file
grows.

To do that, you evaluate

  Smalltalk condenseSources

The messages  condenseSources, condenseChanges

are part of the instance protocol of class SystemDictionary.


It is good practise to backup a Smalltalk system before you
do changes condensation or sources condensation. The
backup should include these files:
 * the image
 * the changes
 * the sources

I should also mention that the images file contains pointers
into both the sources file and the changes file. It is therefore
necessary to keep these three files together. (The image
contains compiled versions of all methods, the changes file
and the sources file are only needed for code development
and for code examination. The debugger also fetches method
definitions from these files.)

Gretings.
Boris

Thank you very much for the explanation! Its perfectly clear now.

About SqueakLight,
when playing with it i have come across some things (minor glitches...).
Ive tried to solve some things (as an excercise). Do you want to know about
these? If so, How?

Thanks for your time.

    - Jeroen

Jeroen van Hilst puso en su mail :
Email me all problems , questions, wishes.

Also here have a beginners oriented group what starts Spanish speakers only
but have some non Spanish speakers now.
And people are friendly, several understand English, others pro in.

Could orient and guide you via Internet if you wish.
Having a "SummerTeam" of students with a couple of games, a server how to
set for doing what (Socket - Service - Komanche - HttpView - Seaside )
misteries setup and simple exercises.
And a final user super ppt or upcoming Sophie, involving all kinds of files
(audio, video, etc) what you could use with Squeak for doing something.
Using normal 3.9 and what you loose on using SqueakLight.

Edgar



       

       
               
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