Re: [Boost-users] [serialization] load/save seem to different headerformat

Subject: Re: [Boost-users] [serialization] load/save seem to different headerformat
From: Robert Ramey (ramey_at_[hidden])
Date: 2009-01-02 13:41:17

Tweak your code to use the xml_archive.  Then examine this.  This
will reveal what is out of sync.

Robert Ramey

Ewald Peiszer wrote:
> 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;
> }
>
> ----------------------------------
> (end of post)