我试图通过修改Boost ASIO example来编写一个简单的HTTPS服务器。它可以工作，但问题是它为来自客户端的每个请求建立了安全连接，这极大地减慢了通信速度。
我知道HTTPS服务器应该使用Keep-Alive连接。但我不知道如何扩展提到的例子来做到这一点。在我的情况下情况非常简单，因为我总是有1：1的连接，所以不需要会话管理，总是只有一个有效的会话。
我使用两种HTTP响应：
std::string HTTPS::createResponse(status_type status)
{
std::stringstream response;
response<<statusCodeToString(status);
response<<"Content-Length: "<<statusToContentString(status).size()<<"\r\n";
response<<"Content-Type: text/html\r\n\r\n";
response<<statusToContentString(status);
return response.str();
}
std::string HTTPS::createResponse(status_type status, const std::string &data)
{
std::stringstream response;
response<<"HTTP/1.1 200 OK\r\n";
response<<"Content-Length: "<<data.size()<<"\r\n";
response<<"Content-Type: text/plain\r\n\r\n";
response<<data;
return response.str();
}
std::string HLSProxyServerSSL::statusCodeToString(status_type status)
{
static const char ok_s[] =
"HTTP/1.1 200 OK\r\n";
static const char created_s[] =
"HTTP/1.1 201 Created\r\n";
static const char accepted_s[] =
"HTTP/1.1 202 Accepted\r\n";
static const char no_content_s[] =
"HTTP/1.1 204 No Content\r\n";
static const char multiple_choices_s[] =
"HTTP/1.1 300 Multiple Choices\r\n";
static const char moved_permanently_s[] =
"HTTP/1.1 301 Moved Permanently\r\n";
static const char moved_temporarily_s[] =
"HTTP/1.1 302 Moved Temporarily\r\n";
static const char not_modified_s[] =
"HTTP/1.1 304 Not Modified\r\n";
static const char bad_request_s[] =
"HTTP/1.1 400 Bad Request\r\n";
static const char unauthorized_s[] =
"HTTP/1.1 401 Unauthorized\r\n";
static const char forbidden_s[] =
"HTTP/1.1 403 Forbidden\r\n";
static const char not_found_s[] =
"HTTP/1.1 404 Not Found\r\n";
static const char not_supported_s[] =
"HTTP/1.1 405 Method Not Supported\r\n";
static const char not_acceptable_s[] =
"HTTP/1.1 406 Method Not Acceptable\r\n";
static const char internal_server_error_s[] =
"HTTP/1.1 500 Internal Server Error\r\n";
static const char not_implemented_s[] =
"HTTP/1.1 501 Not Implemented\r\n";
static const char bad_gateway_s[] =
"HTTP/1.1 502 Bad Gateway\r\n";
static const char service_unavailable_s[] =
"HTTP/1.1 503 Service Unavailable\r\n";
switch (status)
{
case ok:
return ok_s;
case created:
return created_s;
case accepted:
return accepted_s;
case no_content:
return no_content_s;
case multiple_choices:
return multiple_choices_s;
case moved_permanently:
return moved_permanently_s;
case moved_temporarily:
return moved_temporarily_s;
case not_modified:
return not_modified_s;
case bad_request:
return bad_request_s;
case unauthorized:
return unauthorized_s;
case forbidden:
return forbidden_s;
case not_found:
return not_found_s;
case not_supported:
return not_supported_s;
case not_acceptable:
return not_acceptable_s;
case internal_server_error:
return internal_server_error_s;
case not_implemented:
return not_implemented_s;
case bad_gateway:
return bad_gateway_s;
case service_unavailable:
return service_unavailable_s;
default:
return internal_server_error_s;
}
}
std::string HLSProxyServerSSL::statusToContentString(status_type status)
{
static const char ok_s[] = "";
static const char created_s[] =
"<html>"
"<head><title>Created</title></head>"
"<body><h1>201 Created</h1></body>"
"</html>";
static const char accepted_s[] =
"<html>"
"<head><title>Accepted</title></head>"
"<body><h1>202 Accepted</h1></body>"
"</html>";
static const char no_content_s[] =
"<html>"
"<head><title>No Content</title></head>"
"<body><h1>204 Content</h1></body>"
"</html>";
static const char multiple_choices_s[] =
"<html>"
"<head><title>Multiple Choices</title></head>"
"<body><h1>300 Multiple Choices</h1></body>"
"</html>";
static const char moved_permanently_s[] =
"<html>"
"<head><title>Moved Permanently</title></head>"
"<body><h1>301 Moved Permanently</h1></body>"
"</html>";
static const char moved_temporarily_s[] =
"<html>"
"<head><title>Moved Temporarily</title></head>"
"<body><h1>302 Moved Temporarily</h1></body>"
"</html>";
static const char not_modified_s[] =
"<html>"
"<head><title>Not Modified</title></head>"
"<body><h1>304 Not Modified</h1></body>"
"</html>";
static const char bad_request_s[] =
"<html>"
"<head><title>Bad Request</title></head>"
"<body><h1>400 Bad Request</h1></body>"
"</html>";
static const char unauthorized_s[] =
"<html>"
"<head><title>Unauthorized</title></head>"
"<body><h1>401 Unauthorized</h1></body>"
"</html>";
static const char forbidden_s[] =
"<html>"
"<head><title>Forbidden</title></head>"
"<body><h1>403 Forbidden</h1></body>"
"</html>";
static const char not_found_s[] =
"<html>"
"<head><title>Not Found</title></head>"
"<body><h1>404 Not Found</h1></body>"
"</html>";
static const char not_supported_s[] =
"<html>"
"<head><title>Method Not Supported</title></head>"
"<body><h1>Method Not Supported</h1></body>"
"</html>";
static const char not_acceptable_s[] =
"<html>"
"<head><title>Request Not Acceptable</title></head>"
"<body><h1>Request Not Acceptable</h1></body>"
"</html>";
static const char internal_server_error_s[] =
"<html>"
"<head><title>Internal Server Error</title></head>"
"<body><h1>500 Internal Server Error</h1></body>"
"</html>";
static const char not_implemented_s[] =
"<html>"
"<head><title>Not Implemented</title></head>"
"<body><h1>501 Not Implemented</h1></body>"
"</html>";
static const char bad_gateway_s[] =
"<html>"
"<head><title>Bad Gateway</title></head>"
"<body><h1>502 Bad Gateway</h1></body>"
"</html>";
static const char service_unavailable_s[] =
"<html>"
"<head><title>Service Unavailable</title></head>"
"<body><h1>503 Service Unavailable</h1></body>"
"</html>";
switch (status)
{
case ok:
return ok_s;
case created:
return created_s;
case accepted:
return accepted_s;
case no_content:
return no_content_s;
case multiple_choices:
return multiple_choices_s;
case moved_permanently:
return moved_permanently_s;
case moved_temporarily:
return moved_temporarily_s;
case not_modified:
return not_modified_s;
case bad_request:
return bad_request_s;
case unauthorized:
return unauthorized_s;
case forbidden:
return forbidden_s;
case not_found:
return not_found_s;
case not_supported:
return not_supported_s;
case not_acceptable:
return not_acceptable_s;
case internal_server_error:
return internal_server_error_s;
case not_implemented:
return not_implemented_s;
case bad_gateway:
return bad_gateway_s;
case service_unavailable:
return service_unavailable_s;
default:
return internal_server_error_s;
}
}
我相信答案还可以，但请检查一下 - 这不是我的专业领域。
现在通信流程如下：
1，服务器开始接受新连接 - 创建会话，绑定等待传入握手请求的异步接收器。
2，如果发生传入握手，则服务器在第1点创建的会话上开始握手。
3，一旦握手完成，它就会处理传入的消息
会话握手句柄如下。它读取一个HTTP命令并对其进行处理。我故意不关心标题的其余部分，因为从服务器端只有GET命令有效 - 服务器就像一个简单的重发件。
void SSLSession::handleHandshake(const boost::system::error_code& error)
{
__log_print(LOG_INFO, "SSLSession", "handleHandshake");
if (!error)
{
boost::asio::async_read_until(_socket, _data, "\r\n", boost::bind(&SSLSession::handleHttpRequestLine, this, _1));
}
else
{
delete this;
}
}
void SSLSession::handleHttpRequestLine(boost::system::error_code ec)
{
std::string method, uri, version;
if (!ec)
{
char sp1, sp2, cr, lf;
std::istream is(&_data);
is.unsetf(std::ios_base::skipws);
is >> method >> sp1 >> uri >> sp2 >> version >> cr >> lf;
}
handleHttpRequest(method, uri);
}
所以我的问题是，我该如何修改方法：
void SSLSession::handleHandshake(const boost::system::error_code& error)
开始不仅要监听一个命令，还要继续监听对此会话有效的连续传入GET命令？我试过添加另一个
boost::asio::async_read_until(_socket, _data, "\r\n", boost::bind(&SSLSession::handleHttpRequestLine, this, _1));
调用handleHttpRequest(method, uri);方法结束，但我遇到了僵局......我认为它必须是微不足道的，但我迷失在所有这些异步接受器和处理程序中......
答案 0 :(得分：3)
要持续侦听传入的GET命令，最简单的解决方案是从处理async_read_until的链中启动async_read_until操作。在示例代码中，将其置于handleHttpRequest听起来像是一个可行的选项。
如果您迷失在异步调用链中，请考虑说明它们：
void SSLSession::handleHandshake(...)
{
if (!error)
{
boost::asio::async_read_until(...); ----.
} |
} .-----------------------------'
| .--------------------------.
v v |
void SSLSession::handleHttpRequestLine(...) |
{ |
handleHttpRequest(...); --. |
} | |
.------------' |
v |
void SSLSession::handleHttpRequest(...) |
{ |
boost::asio::async_read_until(...); ------'
}
对于Boost.Asio 1.47+，调试链的另一个很好的选择是启用handle tracking。只需定义BOOST_ASIO_ENABLE_HANDLER_TRACKING和Boost.Asio就会将调试输出（包括时间戳）写入标准错误流。 This回答有关调试处理程序的详细信息。
如果您遇到死锁，那么很可能是在应用程序代码中。对于大多数Boost.Asio类型，在对象上挂起多个异步操作是安全的。它只是指定对象的并发调用是不安全的。然而，它通常不会在某些类型上出现问题，例如ip::tcp::socket。但是，ssl::stream强调了：
应用程序还必须确保所有异步操作都在同一个隐式或显式链中执行。
可能会发生未定义的行为，这可能会导致死锁，如this问题中所示。如果多个线程正在处理io_service事件循环，那么考虑在boost::asio::strand中运行异步操作。