Re: [Boost-users] [Boost.Serialization] Documentation about the archivefile formats

Subject: Re: [Boost-users] [Boost.Serialization] Documentation about the archivefile formats
From: Júlio Hoffimann (julio.hoffimann_at_[hidden])
Date: 2012-03-26 20:01:58

Robert,

Could you please take a look at the following simplified scenario?

Suppose i have a base class B for which the serialization is just the
dimension (2) and the associated probability distributions (uniform 0 1,
uniform 0 1). A derived class D: B for which the serialization just adds
the number of samples for each dimension (5, 5).

//// Somewhere in the code...//
D obj;std::vector<boost::optional<double>> v;
while (in a loop) {

    if (is time to save) {

        boost::fylesystem::remove( archive_filename );
        boost::ofstream file( archive_filename );
        boost::archive::text_oarchive oa( file );
        oa << obj << v;
    }}

The archive contents for this case:

22 serialization::archive 9 0 7 UQ::PCM 1 0
0 0 0 2 0 0 2 0 0 0 7 uniform 2 0 0 1 7 uniform 2 0 0 1 2 0 5 5 0 0 25 0 0
0 1 0 0.002200555327023207 1 0 0.010825220107479879 1 0
0.023455038515334009 1 0 0.036084856923188136 1 0 0.044709521703644811 1 0
0.010825220107479879 1 0 0.053252644428581027 1 0 0.11538267247357922 1 0
0.1775127005185774 1 0 0.21994012483967856 1 0 0.023455038515334009 1 0
0.11538267247357922 1 0 0.25 1 0 0.38461732752642075 1 0
0.47654496148466596 1 0 0.036084856923188136 1 0 0.1775127005185774 1 0
0.38461732752642075 1 0 0.59172195453426402 1 0 0.73314979812965331 1 0
0.044709521703644811 1 0 0.21994012483967856 1 0 0.47654496148466596 1 0
0.73314979812965331 1 0 0.90838040126568709

Could you very generally explain what each section is about? I'm trying
hard to fix the bug in my code, but all the approaches i had so far were
not successful. :-(

Even the v.size() being constant during the entire run (just the
boost::optionals<> change), seems the archive overwrite operation above is
putting different amount of words in the file as the simulation goes on.
Maybe is something related to object tracking? How is v tracked?

I really appreciate any help,
Júlio.

2012/3/25 Júlio Hoffimann <julio.hoffimann_at_[hidden]>

> Thank you for your reply Robert, i'll take a better look at what is
> happening. I rewrote my application to use text_archives for debug
> purposes, and just now realized there is no defined format.
>
> If i find something that can help solve the problem, i'll share. ;-)
>
> Regards,
> Júlio.
>
>
> 2012/3/25 Robert Ramey <ramey_at_[hidden]>
>
>> Júlio Hoffimann wrote:
>> > Dear all,
>> >
>> >
>> > I'm trying to debug an application and would be helpful to know how
>> > the contents of the archives should look like. I read the entire
>> > Boost.S11n documentation, but can't find any explanation about the
>> > archive file formats.
>>
>> This is because the file formats are undefined.  More accurately, the file
>> format is defined by (and reflects) the structure of the achive data.
>>  This
>> easy to see my using the serialization library on your own classes and
>> and generating an XML archive.  This is nicely indented and you'll
>> be able to see the one-to-one correspondence from your C++ classes
>> to the archive text.
>>
>> That is, C++ data structures => archive format.
>>
>> Note that is the opposite from other approaches such as google
>> protocol buffers which do something like:
>>
>> protocol buffers description => C++ code to read/write the file.
>>
>> If one thinks about it, you can see that these are not really comparable
>> as they really do different things.
>>
>> >
>> > Do you have some technical material?
>> >
>> >
>> > I'm having an annoying (and famous) "input stream error":
>> >
>> http://stackoverflow.com/questions/5178321/boost-serialization-problem-in-windows-vs2005-input-stream-error
>> .
>> > The link describes exactly the same problem, the "author's solution"
>> > isn't satisfactory at all.
>>
>> This doesn't ring a bell with me.  Check the Trac system to see if it's
>> already described in there.  If it's not, feel free to include you're own
>> description of the problem and optionally suggestions and/or you're own
>> patch. I'll be happy to look at it.
>>
>> Robert Ramey
>>
>> >
>> >
>> > Best regards,
>> > Júlio.
>> >
>> >
>> >
>> > _______________________________________________
>> > Boost-users mailing list
>> > Boost-users_at_[hidden]
>> > http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>>
>>
>>
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