[Zope-dev] ConflictError shouldn't subclass Exception

[Chris Withers]

Hi All,

Chris McDonough wrote:
> Is this the number of log messages that indicate a conflict error  
> occurred (e.g. "x conflict errors since DATE" messages in the event  
> log) or the number of conflict errors that are retried more than  three 
> times and thus make it "out" to the app user?  I'm guessing the  former.

I'm interested to see that this causes everyone the same level of 
confusion ;-) I'll reply to the other message about this though...

> The real reason they're called "errors" is only because they're  
> implemented as Python exceptions.  They are implemented as exceptions  
> because it was the easiest mechanism to use (exceptions are already  
> built into Python).

Interestingly, you can raise things that don't subclass Exception in 
python. This was discussed before, and I firmly agree with, that zodb 
conflicts should _not_ sublcass exception. That way, there's less chance 
of them being caught by inexperienced programmers putting in try: except 
Exception: 's.

How would we go about making this change?

> The Zope conflict exception catching code is written in such a  
> complicated way (and without the benefit of any automated tests) that  
> tracking that down could take an entire day which I don't have to  burn 
> ATM.  So I'm afraid the status quo will prevail until someone  gets so 
> indignant about it that they either pay for it to be fixed or  fix it 
> themselves.  Apologies for that. :-(

Okay, I'll bite, I might well be able to stump up the paid time on this 
if you guys can help me justify it as a performance improvement :-)

I hope I can count on a bit of moral and intellectual support if I 
manage to make this happen!

cheers,

Chris

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