[Boost-users] [serialization] load/save seem to different header format

Subject: [Boost-users] [serialization] load/save seem to different header format
From: Ewald Peiszer (ewald.peiszer_at_[hidden])
Date: 2009-01-02 10:29:52

Hi

I am using the boost s11n lib, version 1.35.0,  in combination with a 
text archive, Windows platform, MSVC++ 2005 compiler.

I have split serialize into load and save members, as indicated in the 
tutorial.

However, it seems as if save expects a different header format (ie text 
stream like stringstream etc) as the corresponding load method outputs.

Output of my load method:
22 serialization::archive 4 0 0 10(...)

Everything before 10 is s11n housekeeping stuff, 10 is the beginning of 
the "real" data.

Now, if a string like this is used as input for save, then the first 
variable that is extracted is not the 10 (what it should be) but rather 
a 0 (or something else which is equally wrong); instead, the 10 shows up 
as the value of the const unsigned int version which is one of the two 
parameters of load/save/serialize members. Actually, version is supposed 
to be 0, I do not set a version number deliberatly anywhere.

Playing around, I added a third 0 to the header, resulting in

22 serialization::archive 4 0 0 0 10

and, guess what, this time save(...) correctly managed to de-serialize 
the data congtained in the string.

I tried it also with a single seralize() member (and not splitting into 
save/load). Save behaviour.

The relevant code is below (class code and code to (de)serialize class 
instance.

Has anybody experienced the same or similar problems? Any help is 
greatly appreciated. If you need more information please ask.

Regards
Ewald

-------------------------------------
Excerpt of class code:

class Foo {

(...)

private:
        int buflen;

        // s11n stuff
        friend class boost::serialization::access;
        
template<class Archive>
void save(Archive & ar, const unsigned int version) const
  {
        // store length of buffer
        ar & buflen;
        // store data itself
        for (int j = 0; j < buflen; j++)
                ar &  buffer[j];
}

template<class Archive>
void load(Archive & ar, const unsigned int version) {
        // get length of buffer
        ar & buflen;

        // create buffer with appropriate length
        deleteBuffer();
        init(buflen);

        // reat data into buffer
        for (int j = 0; j < buflen; j++)
                ar & buffer[j];
}

     BOOST_SERIALIZATION_SPLIT_MEMBER()

        
        
        
/*
        // just to try it with serialize alone:
        template<class Archive>
     void serialize(Archive &ar, const unsigned int version)
     {
                ar & buflen;
     }
*/

(...)
};
-------------------------------------

// check the save operation
std::stringstream ssq (std::stringstream::in | std::stringstream::out);
                {
                const Foo rp(10);
                boost::archive::text_oarchive oa(ssq);
                oa << rp;
                }

-----------------------------------

// load
{
stringstream ss (stringstream::in| std::stringstream::out);
                        ss << s11nbuf << endl;

                        boost::archive::text_iarchive ia(ss);

                        // restore  from the archive
                        ia >> rp;
                }

----------------------------------
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