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libs/serialization/test/test_diamond.cpp

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// test_diamond.cpp

// (C) Copyright 2002-2009 Vladimir Prus and Robert Ramey. 
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

// test of serialization library for diamond inheritence situations

#include <cstddef> // NULL
#include <fstream>
#include <iostream>

#include <boost/config.hpp>
#include <cstdio> // remove
#if defined(BOOST_NO_STDC_NAMESPACE)
namespace std{ 
    using ::remove;
}
#endif

#include "test_tools.hpp"

#include <boost/serialization/map.hpp>
#include <boost/serialization/utility.hpp>
#include <boost/serialization/split_member.hpp>
#include <boost/serialization/tracking.hpp>
#include <boost/serialization/base_object.hpp>
#include <boost/serialization/nvp.hpp>
#include <boost/serialization/export.hpp>

int save_count = 0; // used to detect when base class is saved multiple times
int load_count = 0; // used to detect when base class is loaded multiple times

class base {
public:
    base() : i(0) {}
    base(int i) : i(i)
    {
        m[i] = "text";
    }

    template<class Archive>
    void save(Archive &ar, const unsigned int /* file_version */) const
    {
        std::cout << "Saving base\n";
        ar << BOOST_SERIALIZATION_NVP(i);
        ar << BOOST_SERIALIZATION_NVP(m);
        ++save_count;
    }

    template<class Archive>
    void load(Archive & ar, const unsigned int /* file_version */)
    {
        std::cout << "Restoring base\n";
        ar >> BOOST_SERIALIZATION_NVP(i);
        ar >> BOOST_SERIALIZATION_NVP(m);
        ++load_count;
    }

    BOOST_SERIALIZATION_SPLIT_MEMBER()

    bool operator==(const base& another) const 
    {
        return i == another.i && m == another.m;
    }
    // make polymorphic by marking at least one function virtual
    virtual ~base() {};
private:
    int i;
    std::map<int, std::string> m;    
};

// note: the default is for object tracking to be performed if and only
// if and object of the corresponding class is anywhere serialized
// through a pointer.  In this example, that doesn't occur so 
// by default, the shared base object wouldn't normally be tracked.
// This would leave to multiple save/load operation of the data in
// this shared base class.  This wouldn't cause an error, but it would
// be a waste of time.  So set the tracking behavior trait of the base
// class to always track serialized objects of that class.  This permits
// the system to detect and elminate redundent save/load operations.
// (It is concievable that this might someday be detected automatically
// but for now, this is not done so we have to rely on the programmer
// to specify this trait)
BOOST_CLASS_TRACKING(base, track_always)

class derived1 : virtual public base {
public:
    template<class Archive>
    void save(Archive &ar, const unsigned int /* file_version */) const
    {
        std::cout << "Saving derived1\n";
        ar << BOOST_SERIALIZATION_BASE_OBJECT_NVP(base);
    }

    template<class Archive>
    void load(Archive & ar, const unsigned int /* file_version */)
    {
        std::cout << "Restoring derived1\n";
        ar >> BOOST_SERIALIZATION_BASE_OBJECT_NVP(base);
    }

    BOOST_SERIALIZATION_SPLIT_MEMBER()
};

class derived2 : virtual public base {
public:    
    template<class Archive>
    void save(Archive &ar, const unsigned int /* file_version */) const
    {
        std::cout << "Saving derived2\n";
        ar << BOOST_SERIALIZATION_BASE_OBJECT_NVP(base);
    }

    template<class Archive>
    void load(Archive & ar, const unsigned int /* file_version */)
    {
        std::cout << "Restoring derived2\n";
        ar >> BOOST_SERIALIZATION_BASE_OBJECT_NVP(base);
    }

    BOOST_SERIALIZATION_SPLIT_MEMBER()
};

class final : public derived1, public derived2 {
public:
    final() {}
    final(int i) : base(i) {}

    template<class Archive>
    void save(Archive &ar, const unsigned int /* file_version */) const
    {
        std::cout << "Saving final\n";
        ar << BOOST_SERIALIZATION_BASE_OBJECT_NVP(derived1);    
        ar << BOOST_SERIALIZATION_BASE_OBJECT_NVP(derived2);
    }

    template<class Archive>
    void load(Archive & ar, const unsigned int /* file_version */)
    {
        std::cout << "Restoring final\n";
        ar >> BOOST_SERIALIZATION_BASE_OBJECT_NVP(derived1);  
        ar >> BOOST_SERIALIZATION_BASE_OBJECT_NVP(derived2);
    }

    BOOST_SERIALIZATION_SPLIT_MEMBER()
};

BOOST_CLASS_EXPORT(final)

int
test_main( int /* argc */, char* /* argv */[] )
{
    const char * testfile = boost::archive::tmpnam(NULL);
    BOOST_REQUIRE(NULL != testfile);
    
    const final b(3);   
    {
        test_ostream ofs(testfile, TEST_STREAM_FLAGS);
        test_oarchive oa(ofs);
        oa << boost::serialization::make_nvp("b", b);
    }

    final b2;
    {
        test_istream ifs(testfile, TEST_STREAM_FLAGS);
        test_iarchive ia(ifs);
        ia >> boost::serialization::make_nvp("b2", b2);
    }
    BOOST_CHECK(1 == save_count);
    BOOST_CHECK(1 == load_count);
    BOOST_CHECK(b2 == b);
    std::remove(testfile);

    // do the same test with pointers
    testfile = boost::archive::tmpnam(NULL);
    BOOST_REQUIRE(NULL != testfile);

    save_count = 0;
    load_count = 0;

    const base* bp = new final( 3 );
    {
        test_ostream ofs(testfile);    
        test_oarchive oa(ofs);
        oa << BOOST_SERIALIZATION_NVP(bp);
    }

    base* bp2;
    {
        test_istream ifs(testfile);
        test_iarchive ia(ifs);
        ia >> BOOST_SERIALIZATION_NVP(bp2);
    }

    BOOST_CHECK(1 == save_count);
    BOOST_CHECK(1 == load_count);
    BOOST_CHECK(*bp2 == *bp);
    std::remove(testfile);

    return EXIT_SUCCESS;
}