Re: [Boost-users] [Serialization, XML] - how to get info "where am i?" in serialization helper (encoding is not recursive)?

From: Frank Bergemann (FBergemann_at_[hidden])
Date: 2007-04-23 02:25:14

Hi Robert,

> -----Ursprüngliche Nachricht-----
> Von: boost-users_at_[hidden]
> Gesendet: 23.04.07 01:37:58
> An: boost-users_at_[hidden]
> Betreff: Re: [Boost-users] [Serialization, XML] - how to get info "where am i?" in serialization helper (encoding is not recursive)?

> 
> Frank Bergemann wrote:
> > i use an external XML format for configuration of CORBA (MICO) data
> > and managed to align that with boost::serialization
> > (To not write my own encoder/decoder and to minimize efforts for my
> > module, in case the customer wants more CORBA objects/methods in
> > future. Actually i think it would be a good options to let generate
> > the boost::serialitzation helper file directly by MICO idl compiler.)
> 
> What is the boost::serialitzation helper file? Oh maybe its what i called a 
> wrapper

i meant the serialize(...) functions.
The ones, which are related to the CORBA data types are plain simple now, directly related to the IDL file - e.g.

                 template<class Archive>                         
                 void serialize(Archive & ar,                               
                     ::EmiHLRINData::HLRINData_V4::DCsiList_s &pInstance,
                      const unsigned int version)
                {
                ar & make_nvp_wrapper( "d_csi_opt", pInstance.d_csi_opt );               
                ar & make_nvp_wrapper( "neg_ph_vlr", pInstance.neg_ph_vlr );               
                ar & make_nvp_wrapper( "cap", pInstance.cap );               
                ar & make_nvp_wrapper( "d_csi", pInstance.d_csi );               
                ar & make_nvp_wrapper( "lowph", pInstance.lowph );               
                ar & make_nvp_wrapper( "lowac", pInstance.lowac );               
                }

I saved it in a file.cc.template and let it be expanded for the Archives i use (e.g. file_xml_oarchive.cc).
So i can pre-compile the whole stuff in a library. And only re-compile, if the IDL files change.
( Using templates it took ages to compile my module :-) )

> 
> > OK, for this now i have to check, that the (external, non by
> > boost::serialization generated) XML image is _actually_ compliant with
> > C/C++ data structures - especially for dynamic sized data. That is
> > also covered now, the checks do fine.
> 
> How much time/effort did it take to do this?
> 

Was not that much.
I have a XML "catalogue" of CORBA commands, for each cmd referring to CORBA object, method of object & related root data objects (holding event/subscriber variables inside, to be expanded).
Then I use boost::serialization save(xml_oarchive,...) to create a *dummy* reference object. 
I traverse this one with some XML lib. And while traversing, i lookup corresponding positions in my XML formatted configuration file (for data to fill-into the boost::serialization image) and update the value in boost::serialization XML image.
Then i use load(xml_oarchive, ...) to create the C/C++ object, populated with my "real" data now.
I save all the objects needed for a command in a boost::any container (for invoking a generic CORBA-object/method dispatcher).
All this alignment stuff will be shifted to process startup phase.
In the end it's better than writing my own XML decoder for each CORBA data object.
It is much more generic using your boost::serialization lib :-)

> > But what i didn't manage is to get the _location_ of error in the XML
> > file - in case there is an error.
> 
> Hmmm - location as ? point to the line/character? current name? or ?

location in XML data structure (XML-path).

> 
> > opsc_hlr    :2204 084723:D:### invoked for <value>
> > opsc_hlr    :2204 084723:D:### c'tor
> > opsc_hlr    :2204 084723:D:### done for <value>
> > opsc_hlr    :2204 084723:D:### d'tor
> 
> > So there is no recursion(???).
> 
> > Is there another way to get a "where am i" information within a
> > serialize (load/save) helper?
> 
> make_...wrapper is not recurssive, save/load are.
> 
> I would derive from xml_?archive and override the save(NVP(T)..) and/or
> load(NVP...) to capture/whatever the tags as they are read/writting.  Don't
> forget to call the original save/load.

Could you pls refer to short example for deriving from xml_?archive ?

> Robert Ramey
> 

\Frank

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