提升 C++ 序列化开销

2021-12-21 00:00:00 serialization c++ boost

我正在尝试使用以下代码测量序列化开销

I'm trying to measure serialization overhead with following code

const int message_size=1000; std::vector<short> message(message_size); std::string s((char*)(&message[0]), message_size * sizeof(short)); double size= 1000*sizeof(short); double size2= s.size(); double overhead = size2 - size; //is zero

正确吗?(这是从矢量序列化)

如何衡量序列化开销?- 主要问题是测量序列化向量.我可以使用 Boost 进行序列化.

How can I measure serialization overhead? - main problem is to measure serialized vector. I can use Boost for serialization.

推荐答案

这个通用的测试平台应该能让你做出决定:看它生活在 Coliru 上

This generic test bed should enable you to decide: see it Live On Coliru

#include <boost/archive/binary_oarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/fusion/adapted/boost_tuple.hpp> #include <boost/make_shared.hpp> #include <boost/phoenix.hpp> #include <boost/serialization/array.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/vector.hpp> #include <boost/tuple/tuple.hpp> #include <iostream> #include <sstream> namespace detail { struct add_to_archive_f { template <typename, typename> struct result { typedef void type; }; template <typename Archive, typename T> void operator()(Archive& ar, T const& t) const { ar << BOOST_SERIALIZATION_NVP(t); } }; static const boost::phoenix::function<add_to_archive_f> add_to_archive { }; } template <typename Archive = boost::archive::binary_oarchive, typename... Data> size_t archive_size(Data const&... data) { std::ostringstream oss; Archive oa(oss); boost::fusion::for_each(boost::make_tuple(data...), detail::add_to_archive( boost::phoenix::ref(oa), boost::phoenix::arg_names::arg1 )); return oss.str().size(); } template <typename Archive = boost::archive::binary_oarchive, typename... Data> void benchmark(Data const&... data) { std::cout << __PRETTY_FUNCTION__ << ": " << archive_size<Archive>(data...) << " "; } struct Base { boost::array<double, 1000> data; virtual ~Base() {} private: friend class boost::serialization::access; template <typename Archive> void serialize(Archive& ar, unsigned /*version*/) { ar & BOOST_SERIALIZATION_NVP(data); } }; struct Derived : Base { std::string x; Derived() : x(1000, '') { } private: friend class boost::serialization::access; template <typename Archive> void serialize(Archive& ar, unsigned /*version*/) { ar & boost::serialization::make_nvp("base", boost::serialization::base_object<Base>(*this)); ar & BOOST_SERIALIZATION_NVP(x); } };

测试驱动程序:

template <typename Archive> void some_scenarios() { benchmark<Archive>(std::vector<char>(1000)); benchmark<Archive>(boost::make_shared<std::vector<char>>(1000)); benchmark<Archive>(3.14f, 42, 42ull, "hello world"); benchmark<Archive>(boost::make_shared<Base>()); benchmark<Archive>(boost::make_shared<Derived>()); } int main() { some_scenarios<boost::archive::binary_oarchive>(); some_scenarios<boost::archive::text_oarchive>(); some_scenarios<boost::archive::xml_oarchive>(); }

我的 64 位 Ubuntu 和 Boost 1.55 的输出:

The output on my 64-bit Ubuntu with Boost 1.55:

void benchmark(const Data& ...) [with Archive = boost::archive::binary_oarchive; Data = {std::vector<char, std::allocator<char> >}]: 1052 void benchmark(const Data& ...) [with Archive = boost::archive::binary_oarchive; Data = {boost::shared_ptr<std::vector<char, std::allocator<char> > >}]: 1059 void benchmark(const Data& ...) [with Archive = boost::archive::binary_oarchive; Data = {float, int, long long unsigned int, char [12]}]: 76 void benchmark(const Data& ...) [with Archive = boost::archive::binary_oarchive; Data = {boost::shared_ptr<Base>}]: 8069 void benchmark(const Data& ...) [with Archive = boost::archive::binary_oarchive; Data = {boost::shared_ptr<Derived>}]: 9086 void benchmark(const Data& ...) [with Archive = boost::archive::text_oarchive; Data = {std::vector<char, std::allocator<char> >}]: 2037 void benchmark(const Data& ...) [with Archive = boost::archive::text_oarchive; Data = {boost::shared_ptr<std::vector<char, std::allocator<char> > >}]: 2043 void benchmark(const Data& ...) [with Archive = boost::archive::text_oarchive; Data = {float, int, long long unsigned int, char [12]}]: 92 void benchmark(const Data& ...) [with Archive = boost::archive::text_oarchive; Data = {boost::shared_ptr<Base>}]: 2049 void benchmark(const Data& ...) [with Archive = boost::archive::text_oarchive; Data = {boost::shared_ptr<Derived>}]: 3083 void benchmark(const Data& ...) [with Archive = boost::archive::xml_oarchive; Data = {std::vector<char, std::allocator<char> >}]: 16235 void benchmark(const Data& ...) [with Archive = boost::archive::xml_oarchive; Data = {boost::shared_ptr<std::vector<char, std::allocator<char> > >}]: 17307 void benchmark(const Data& ...) [with Archive = boost::archive::xml_oarchive; Data = {float, int, long long unsigned int, char [12]}]: 436 void benchmark(const Data& ...) [with Archive = boost::archive::xml_oarchive; Data = {boost::shared_ptr<Base>}]: 19393 void benchmark(const Data& ...) [with Archive = boost::archive::xml_oarchive; Data = {boost::shared_ptr<Derived>}]: 21508

如你所见，

XML 的开销相当大
对于二进制文件，对于许多不同(例如多态)小类型元素的小档案来说，开销变得很大

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