我需要从大约6000个网页中提取数据。在做了一些研究之后,我决定给WinHTTP一个镜头。我能够做到这一点,但是我在同步做事,所以需要一段时间才能完成。我现在试图异步使用WinHTTP,但我遇到了障碍。我搜索了很多教程和示例,但我只能找到MSDN文档,这对我所做的事情来说似乎过于复杂。如前所述,我无法找到很多资源,所以我继续给它一个镜头:WinHTTP多个异步请求
std::string theSource = "";
char * httpBuffer;
DWORD dwSize = 1;
DWORD dwRecv = 1;
HINTERNET hOpen =
WinHttpOpen
(
L"Example Agent",
WINHTTP_ACCESS_TYPE_NO_PROXY,
NULL,
NULL,
WINHTTP_FLAG_ASYNC
);
WINHTTP_STATUS_CALLBACK theCallback =
WinHttpSetStatusCallback
(
hOpen,
(WINHTTP_STATUS_CALLBACK) HttpCallback,
WINHTTP_CALLBACK_FLAG_ALL_NOTIFICATIONS,
NULL
);
HINTERNET hConnect =
WinHttpConnect
(
hOpen,
L"example.org",
INTERNET_DEFAULT_HTTPS_PORT,
0
);
HINTERNET hRequest = NULL;
BOOL allComplete = false;
int theRequest = 1;
while (!allComplete)
{
if (theRequest == 1)
{
hRequest = WinHttpOpenRequest
(
hConnect,
L"GET",
L"example.html",
0,
WINHTTP_NO_REFERER,
WINHTTP_DEFAULT_ACCEPT_TYPES,
WINHTTP_FLAG_SECURE
);
WinHttpSendRequest
(
hRequest,
WINHTTP_NO_ADDITIONAL_HEADERS,
0,
WINHTTP_NO_REQUEST_DATA,
0,
0,
0
);
}
else if (theRequest == 2)
{
WinHttpReceiveResponse(hRequest, NULL);
}
else if (theRequest == 3)
{
WinHttpQueryHeaders
(
hRequest,
WINHTTP_QUERY_RAW_HEADERS_CRLF,
WINHTTP_HEADER_NAME_BY_INDEX,
NULL,
&dwSize,
WINHTTP_NO_HEADER_INDEX
);
WCHAR * headerBuffer = new WCHAR[dwSize/sizeof(WCHAR)];
WinHttpQueryHeaders
(
hRequest,
WINHTTP_QUERY_RAW_HEADERS_CRLF,
WINHTTP_HEADER_NAME_BY_INDEX,
headerBuffer,
&dwSize,
WINHTTP_NO_HEADER_INDEX
);
delete [] headerBuffer;
dwSize = 1;
while (dwSize > 0)
{
if (!WinHttpQueryDataAvailable(hRequest, &dwSize))
{
break;
}
httpBuffer = new char[dwSize + 1];
ZeroMemory(httpBuffer, dwSize + 1);
if (!WinHttpReadData(hRequest, httpBuffer, dwSize, &dwRecv))
{
std::cout << "WinHttpReadData() - Error Code: " << GetLastError() << "\n";
}
else
{
theSource = theSource + httpBuffer;
}
delete [] httpBuffer;
// Parse the source for the data I'm looking for.
break;
}
}
下面是我的回调函数:
void CALLBACK HttpCallback(HINTERNET hInternet, DWORD * dwContext, DWORD dwInternetStatus, void * lpvStatusInfo, DWORD dwStatusInfoLength)
{
switch (dwInternetStatus)
{
default:
std::cout << dwInternetStatus << "\n";
break;
case WINHTTP_CALLBACK_STATUS_HANDLE_CREATED:
std::cout << "Handle created.\n";
theRequest = 1;
break;
case WINHTTP_CALLBACK_STATUS_REQUEST_SENT:
std::cout << "Request sent.\n";
theRequest = 2;
break;
case WINHTTP_CALLBACK_STATUS_RESPONSE_RECEIVED:
std::cout << "Response received.\n";
theRequest = 3;
break;
}
}
注:我只提供这部分我的代码,因为它是涉及我的问题/问题的部分。我很抱歉如果一个变量声明丢失。
上面的代码对我的作品和做实际上让我在寻找所需的信息,但只有一个页面。在完成这一步之后,我意识到当用这种方法发出多个请求时,我不知道该怎么做。同样,除了MSDN文章之外,搜索功能还没有出现,据我所知,这些文章不是一次就发出多个请求的示例。另外,我用来打开/发送/ etc的while循环。基于请求的价值的请求似乎是这样做的一个可怕的方式。我会很感激任何其他建议,以改善我的代码。
在一般情况下,这里是我的问题的总结:我需要使用异步的WinHTTP约6000 GET请求。我并不完全相信如何做到这一点,因为我是WinHTTP的新手,所以我正在寻找处理多个异步请求的最基本的(或可能有效的)方法。
你看到这个MSDN文章:异步的WinHTTP(http://msdn.microsoft.com/en-us/magazine/cc716528.aspx)?也许这个单线程,多套接字和易于理解的[Perl API'HTTP :: Async'](https://metacpan.org/module/HTTP::Async)可以为您提供一些启发,让您了解如何继续。 – Lumi