关于序列化：把某个对象序列化成字节流

Posted 2020-09-18

在网络编程中。一个常常的操作是将本地的数据块转换成字符流并将其发送到远端。远端将这个字符串流恢复成数据库。如果有例如以下一个类CObject。编写两个函数，分别将CObject中的成员变量转换为一个字符流（convert2Stream()函数）。并将字符流的数据又一次恢复到一个CObject对象中（convert2Object()函数）：

char* convert2Stream(const CObject* vObject);

CObject* convert2Object(const char* vStream);

class CObject { private: int m_NumSample; std::vector<int> m_Data; bool m_IsDirty; }

#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <boost/assign/list_of.hpp>
#include <boost/archive/text_iarchive.hpp>
#include <boost/archive/text_oarchive.hpp>
#include <boost/serialization/access.hpp>
#include <boost/serialization/vector.hpp>  

class CObject
{
public:
	CObject() {}
	~CObject() {}

	void printMember() const
	{
		std::cout << "Number " << m_NumSample << "\n";
		std::cout << "vector: ";
		for (int i=0; i<m_Data.size(); ++i)
		{
			std::cout << m_Data[i] << " ";
		}std::cout << std::endl;
		std::cout << "bool " << m_IsDirty << std::endl;
	}

	void setValue(int vNumber, const std::vector<int>& vData, bool vB)
	{
		m_NumSample = vNumber;
		m_Data = vData;
		m_IsDirty = vB;
	}

private:
	friend boost::serialization::access;
	template<typename Archive>
	void serialize(Archive& ar, const unsigned int)
	{
		ar & m_NumSample;
		ar & m_Data;
		ar & m_IsDirty;
	}
private:
	int m_NumSample;
	std::vector<int> m_Data;
	bool m_IsDirty;
};

//*********************************************************************************
//FUNCTION:
char* convert2Stream(const CObject* vObject)
{
	//没有推断vObject的合法性
	std::ostringstream OutStream;
	boost::archive::text_oarchive OArchive(OutStream);
	OArchive << vObject;
	std::string TempString = OutStream.str();
	char *pBuffer = new char[TempString.size()+1];
	memcpy(pBuffer, TempString.c_str(), TempString.size());
	pBuffer[TempString.size()] = ‘\0‘;
	return pBuffer;
}

//*********************************************************************************
//FUNCTION: 要求vStream是以‘\0‘结束
CObject* convert2Object(const char* vStream)
{
	int Length = 0;
	const char *pTemp = vStream;
	while (*pTemp != ‘\0‘)
	{
		++pTemp;
		++Length;
	}
	if (Length == 0) return NULL;
	std::string TempString(vStream, Length);
	std::istringstream InStream(TempString);
	boost::archive::text_iarchive InArchive(InStream);
	CObject* pObject = NULL;//这里要传一个空指针，序列化时会申请内存
	InArchive >> pObject;
	return pObject;
}

int main()
{
	std::vector<int>  TempData = boost::assign::list_of(1)(11)(111)(1111)(11111);
	CObject Obj;
	Obj.setValue(2, TempData, false);
	char *pBuf = convert2Stream(&Obj);
	CObject* pObject = convert2Object(pBuf);
	assert(pObject != NULL);
	pObject->printMember();
	delete[] pBuf;
	delete pObject;//注意内存泄露

	getchar();
	return 0;
}