是否可以在不序列化类型信息的情况下序列化数据?我问,因为我正在使用Cereal将数据序列化为数据包并通过网络发送,并希望尽可能减少数据包大小,因此不包括类型信息会有所帮助。
我认为这是可能的唯一原因是由于在发送端和接收端,应用程序已经知道类型信息以及序列化的顺序。
我更容易理解我是如何从实际实现中序列化和反序列化数据的:
NetPacket.h
#pragma once
#include <cereal\archives\portable_binary.hpp>
#include <cereal\types\polymorphic.hpp>
#include <cereal\types\memory.hpp>
#include <cereal\types\vector.hpp>
#include <cereal\types\string.hpp>
#include <sstream>
class NetVar_ {
protected:
virtual void MakeMePolymorphic() {}
public:
template <class Archive> void serialize(Archive & archive) {}
};
class NetPacket;
template <class VARTYPE> class NetVar : public NetVar_
{
public:
NetVar(void) {}
NetVar(VARTYPE Value)
{
Var = Value;
}
template <class Archive> void serialize(Archive & archive)
{
archive(Var);
}
private:
friend class NetPacket;
VARTYPE Var;
};
class NetPacket
{
private:
ENetHost* Host;
enet_uint8 ChannelNumber;
unsigned int ThisMessageID;
std::vector<std::shared_ptr<NetVar_>> PacketData;
std::string SerializePacket();
public:
NetPacket(ENetHost* iHost, const unsigned int MessageID, enet_uint8 ChannelNum);
NetPacket(const char* Data, size_t Size);
template <class DATATYPE> void WriteData(DATATYPE AddData)
{
PacketData.push_back(std::make_shared<NetVar<DATATYPE>>(AddData));
}
template <class DATATYPE> DATATYPE ReadData(const unsigned int VarNum) const
{
std::shared_ptr<NetVar_> Content = PacketData[VarNum];
std::shared_ptr<NetVar<DATATYPE>> Temp = std::static_pointer_cast<NetVar<DATATYPE>>(Content);
return Temp->Var;
}
void Send(const bool Reliable);
void Send(NetClient* Client, const bool Reliable);
unsigned int GetMessageID(void) const;
enet_uint8 GetChannelNumber(void) const;
};
NetPacket.cpp
#include <enet\enet.h>
#include "NetClient.h"
#include "NetPacket.h"
// Register Types here that you want to
// read and write to packets
CEREAL_REGISTER_TYPE(NetVar<bool>);
CEREAL_REGISTER_TYPE(NetVar<unsigned int>);
CEREAL_REGISTER_TYPE(NetVar<int>);
CEREAL_REGISTER_TYPE(NetVar<float>);
CEREAL_REGISTER_TYPE(NetVar<std::string>);
std::string NetPacket::SerializePacket()
{
std::ostringstream SData;
{
cereal::PortableBinaryOutputArchive Archive(SData);
Archive(ThisMessageID, PacketData);
}
return SData.str();
}
NetPacket::NetPacket(ENetHost* iHost, const unsigned int MessageID, enet_uint8 ChannelNum)
{
Host = iHost;
ThisMessageID = MessageID;
ChannelNumber = ChannelNum;
}
NetPacket::NetPacket(const char* Data, size_t Size)
{
std::istringstream SData(std::string(Data, Size));
{
cereal::PortableBinaryInputArchive Archive(SData);
Archive(ThisMessageID, PacketData);
}
}
void NetPacket::Send(const bool Reliable)
{
auto Out = SerializePacket();
ENetPacket* Packet;
if (Reliable)
{
Packet = enet_packet_create(Out.data(), Out.size(), ENET_PACKET_FLAG_RELIABLE);
}
else {
Packet = enet_packet_create(Out.data(), Out.size(), ENET_PACKET_FLAG_UNRELIABLE_FRAGMENT);
}
enet_host_broadcast(Host, ChannelNumber, Packet);
}
void NetPacket::Send(NetClient* Client, const bool Reliable)
{
auto Out = SerializePacket();
ENetPacket* Packet;
if (Reliable)
{
Packet = enet_packet_create(Out.data(), Out.size(), ENET_PACKET_FLAG_RELIABLE);
}
else {
Packet = enet_packet_create(Out.data(), Out.size(), ENET_PACKET_FLAG_UNRELIABLE_FRAGMENT);
}
enet_peer_send(Client->GetPeer(), ChannelNumber, Packet);
}
unsigned int NetPacket::GetMessageID(void) const
{
return ThisMessageID;
}
enet_uint8 NetPacket::GetChannelNumber(void) const
{
return ChannelNumber;
}
从NetPacket.h中定义的ReadData和WriteData可以看出,要读取和写入数据,您需要在模板函数中指定类型信息。由于这个要求,读者和作者的类型信息已知,并且编写的顺序。在序列化数据时有没有办法省略类型信息?
我为这个大问题道歉,我非常感谢你在这件事上的时间。