Re: [Boost-users] Serialization Archive IncompatibilitybetweenBoostVersions

Subject: Re: [Boost-users] Serialization Archive IncompatibilitybetweenBoostVersions
From: Robert Ramey (ramey_at_[hidden])
Date: 2009-05-18 12:52:45

This looks useful.

May we presume that you're trying to read this with boost 1.37 and the 
exception is thrown?

Note that the the 1.35 version has archive library version #4 while 1.37 has 
archive library version #5 in the top row. The archive library version is 
changed every time we make a change which might mean that older archive have 
to be handled differently.  A example where this has happened is where we 
change the type of the integer which indicates how may items there are in a 
collection.

In this case, 1.37 (library version # 5)  is expecting data which 1.35 
(library version #4) didn't put there. That is, 1.37 is missing some code 
which looks like:

if(library_version >4)
    ar >> i
...

Of course the rub is to figure out where that is.  The key line differs in 
that:

1.35 1 12 ...
1.37 1 0 12 ... // extr 0
With your test case I would do the following:

Generate the same two files with the xml_archive.  This should reveal what 
the extra "0" corresponds to.
With the debugger, trap the program where the exception is thrown.  This 
might reveal the part of code which is throwing this extra "0".  This is 
where the mistake might lie.

Robert Ramey

David Graf wrote:
>> Hello Robert
>>
>> Attached, please find two text archive outputs. The first is
>> generated using boost version 1.35. The second is generated using
>> boost version
>> 1.37. Additionally, I attached the diff between these archives.
>>
>> In this diff, you can safely ignore the second and the last
>> difference. Those are due to random generated data. We assume that
>> the exception (see attached stacktrace.txt) is caused by the third
>> difference.
>>
>> Do you have any idea why this exception is thrown?
>>
>> David
>>
>>
>>
>>
>
>
>
>>
>>
>>
>>
>> On Apr 9, 2009, at 6:38 PM, Robert Ramey wrote:
>>
>>> This version is declared at the beginning of a serialized archive.
>>> E.g.:
>>>
>>>
>>> The following beginning of a text archive is serialized with boost
>>> 1.37:
>>> 22 serialization::archive 5 0 35 ...
>>>
>>>
>>> Serialized with boost 1.35 it looks like this:
>>> 22 serialization::archive 4 0 35 ...
>>>
>>>
>>> Otherwise, the archives are in my case completely identical.
>>>
>>>
>>> Somehow, if this version number does not match to the serialized or
>>> archive
>>> version of the used boost library, boost throws an exception.
>>>
>>> **** where does this exception get thrown?
>>>
>>>
>>> Robert Ramey
>>>
>>>
>>>
>>> _______________________________________________
>>> Boost-users mailing list
>>> Boost-users_at_[hidden]
>>> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>>
>
>
>
>> _______________________________________________
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