Handling InternetCloseHandle failure - c++

Question

INTRODUCTION AND RELEVANT INFORMATION:
I am learning WinInet on my own. I have written (in my humble opinion) "typical" piece of code, that needs to perform cleanup in the end:
DWORD CSomeClass::MVCE4StackOverflow()
{
DWORD errorCode = ERROR_SUCCESS;
URL_COMPONENTS urlComp;
::ZeroMemory(&urlComp, sizeof(URL_COMPONENTS));
urlComp.dwStructSize = sizeof(URL_COMPONENTS);
urlComp.dwHostNameLength = -1;
urlComp.dwSchemeLength = -1;
urlComp.dwUrlPathLength = -1;
if (!::InternetCrackUrl(m_URL.c_str(), m_URL.length(), 0, &urlComp))
{
errorCode = ::GetLastError();
return errorCode;
}
HINTERNET hInternetSession = ::InternetOpen("WinInet",
INTERNET_OPEN_TYPE_DIRECT,
NULL, NULL, 0);
if (NULL == hInternetSession)
{
errorCode = ::GetLastError();
return errorCode;
}
std::string hostname(urlComp.dwHostNameLength, 0);
::memcpy(&hostname[0], urlComp.lpszHostName, urlComp.dwHostNameLength);
HINTERNET hHttpSession = ::InternetConnect(hInternetSession,
hostname.c_str(),
INTERNET_DEFAULT_HTTP_PORT, 0, 0,
INTERNET_SERVICE_HTTP, 0, NULL);
if (NULL == hHttpSession)
{
errorCode = ::GetLastError();
return errorCode;
}
HINTERNET hHttpRequest = ::HttpOpenRequest(hHttpSession, "POST",
urlComp.lpszUrlPath, 0, 0, 0,
INTERNET_FLAG_RELOAD, 0);
if (NULL == hHttpRequest)
{
errorCode = ::GetLastError();
return errorCode;
}
const char header[] = "Content-Type: application/x-www-form-urlencoded";
std::string data = "input=1234";
if (!::HttpSendRequest(hHttpRequest, header, strlen(header),
&data[0], data.length()))
{
errorCode = ::GetLastError();
return errorCode;
}
DWORD dwBytesRead = 0;
BOOL result = false;
char szBuffer[1025] = "";
char *temp = szBuffer;
const DWORD dwBytes2Read = sizeof(szBuffer) - 1;
do{
result = ::InternetReadFile(hHttpRequest, szBuffer, dwBytes2Read, &dwBytesRead);
if (FALSE == result)
{
errorCode = ::GetLastError();
}
temp += dwBytesRead;
} while (result && dwBytesRead > 0);
// need error handling for below 3
result = ::InternetCloseHandle(hHttpRequest);
result = ::InternetCloseHandle(hHttpSession);
result = ::InternetCloseHandle(hInternetSession);
return errorCode;
}
PROBLEM:
In the provided code example, I need to call InternetCloseHandle 3 times consecutively.
I do not know how to structure that part of code to perform proper error handling.
My idea would be to do do the following:
result = ::InternetCloseHandle(hHttpRequest);
if(result)
{
result = ::InternetCloseHandle(hHttpSession);
if (result)
{
result = ::InternetCloseHandle(hInternetSession);
if(!result) return ::GetLastError();
}
else return ::GetLastError();
}
else return ::GetLastError();
However, being new to WinInet, I am not sure if my solution is correct.
QUESTION:
Can you please instruct me on how to handle the scenario in the provided code example?
I understand that my question might be confusing, but please take into consideration that English is not my native. Please leave a comment seeking further clarifications.
UPDATE #1:
I have tried to apply RAII:
#include <Windows.h>
#include <iostream>
#include <WinInet.h>
#pragma comment(lib, "Wininet.lib")
class CInternetOpenRAII
{
HINTERNET hIntSession;
public:
CInternetOpenRAII(){}
HINTERNET get() const { return hIntSession; }
DWORD init()
{
hIntSession = ::InternetOpen("WinInet", INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
return hIntSession ? ERROR_SUCCESS : ::GetLastError();
}
~CInternetOpenRAII()
{
if(hIntSession)
{
if(!::InternetCloseHandle(hIntSession))
{
std::cerr << "InternetOpen failed with GetLastErrorCode: " << ::GetLastError();
}
}
}
};
class CInternetConnectRAII
{
HINTERNET hHttpSession;
public:
CInternetConnectRAII() {}
HINTERNET get() const { return hHttpSession; }
DWORD init(const HINTERNET &hIntSession, const char *url)
{
hHttpSession = ::InternetConnect(hIntSession, url, INTERNET_DEFAULT_HTTP_PORT, 0, 0, INTERNET_SERVICE_HTTP, 0, NULL);
return hHttpSession ? ERROR_SUCCESS : ::GetLastError();
}
~CInternetConnectRAII()
{
if(hHttpSession)
{
if(!::InternetCloseHandle(hHttpSession))
{
std::cerr << "InternetConnect failed with GetLastErrorCode: " << ::GetLastError();
}
}
}
};
class CHttpOpenRequestRAII
{
HINTERNET hHttpRequest;
public:
CHttpOpenRequestRAII() {}
HINTERNET get() const { return hHttpRequest; }
DWORD init(const HINTERNET &hHttpSession, const char *request)
{
hHttpRequest = ::HttpOpenRequest(hHttpSession, "POST", request, 0, 0, 0, INTERNET_FLAG_RELOAD, 0);
return hHttpRequest ? ERROR_SUCCESS : ::GetLastError();
}
DWORD doRequest(const char *data, size_t dataLength, const char *header, size_t headerLength)
{
if (!::HttpSendRequest(hHttpRequest, header, headerLength, (void *)data, dataLength))
return ::GetLastError();
CHAR szBuffer[10] = "";
DWORD dwRead = 0;
const int dwBytes2Read = sizeof(szBuffer) - 1;
while (::InternetReadFile(hHttpRequest, szBuffer, dwBytes2Read, &dwRead) && dwRead)
{
std::cout << szBuffer;
}
return ERROR_SUCCESS;
}
~CHttpOpenRequestRAII()
{
if(hHttpRequest)
{
if(!::InternetCloseHandle(hHttpRequest))
{
std::cerr << "HttpOpenRequest failed with GetLastErrorCode: " << ::GetLastError();
}
}
}
};
int main()
{
DWORD error = ERROR_SUCCESS;
CInternetOpenRAII session;
error = session.init();
if(error) return error;
CInternetConnectRAII conn;
error = conn.init(session.get(), "www.test.com");
if(error) return error;
CHttpOpenRequestRAII req;
error = req.init(conn.get(), "/home/something");
if(error) return error;
error = req.doRequest("parameter=1234", strlen("parameter=1234"),
"Content-Type: application/x-www-form-urlencoded", strlen("Content-Type: application/x-www-form-urlencoded"));
if(error) return error;
return 0;
}
Now I do not know how to handle error in destructor. Can somebody please look at the code and provide some advice on that?