[M3devel] pickle bug..solved?.. not supposed to work?

[Jay K]

I assume there is a need to keep the code around for compatibility?

You know -- to read existing files?

And to keep testing that?

  And write them at least so the tests can read them back?

 

 

But maybe we should take a read-only attitude?

 

 

And switch the quake netobj=netobj1 to netobj=netobj2?

 

 

It's tough..if you convert-upon-write, and people are

running old programs, you'll break their files.

 

 

It's also tough, you know, I think this stuff is too automatic.

I'm pretty sure we should change the Text internal representation,

but I'm also pretty sure the persistance (disk) representation

is automatically derived from the transient (memory)

representation and changing the second breaks the first.

 

 

You know, I suspect it is like those systems

that do:

 

 

struct foo a;

fwrite(&a, sizeof(a));

 

 

but just with endian/wordsize conversions and

hashes/typeid to do checks upon read, so it

won't crash if you change things, but it also won't

read back successfully.

 

 

Maybe the v1 limitations are good as well, in that maybe

it is faster, and sometimes the limitations don't matter???

 

 

 - Jay

 


Date: Sun, 13 Dec 2009 00:52:53 -0500
From: rcoleburn at scires.com
To: m3devel at elegosoft.com
Subject: Re: [M3devel] pickle bug..solved?.. not supposed to work?


Jay:
 
I've done a lot with Pickles and with NetObj.
 
I switched to the v2 version a long time ago and never looked back.
 
IMO, we should switch over to v2 exclusively and consider v1 obsolete.  Perhaps some others should comment on this to see if they share my opinion.
 
Regards,
Randy

>>> Jay K <jay.krell at cornell.edu> 12/13/2009 12:34 AM >>>

https://projects.elego.de/cm3/ticket/1068





I've only spent a few minutes here.

Trying to find the relative code and such.





The code is here:





C:\dev2\cm3.2\m3-comm\netobj\tests\perf\src



I found it by looking near the top of the stack in

the bug report -- NetObjTest.m3 -- and

then dir /s/b NetObjTest.m3.



or find . | grep NetObjTest.m3$ on Unix.





It appears that Pickle v1 and v2 are both

available in the same library.

There is INTERFACE Pickle and INTERFACE Pickle2.





It appears netobj can use either.



If you look at the stack in the bug, there is a lot of "v1" stuff.





We provide Quake functions:



readonly proc netobjv1(intf, type) is
...

end



readonly proc Netobjv1(intf, type) is
...

end



readonly proc netobjv2(intf, type) is
...

end



readonly proc netobj(intf, type) is
  netobjv1(intf, type)
end






v1 pickles cannot cross endian/wordsize boundaries.





I think the bug is not so much in the pickle code, nor in the netobj code,

but in the test code, or the running of it.



Tests involving v1 won't work crossing endian/wordsize boundaries.

V1 tests probably should still run, and maybe detect the mismatch

and just claim success?



And then v2 should get better coverage?





Any more bugs then?

I was procrastinating on this because I've never done anything with pickles 		 	   		  
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