我正在使用boost beast websocket通过发送订阅消息来订阅消息,并且应该先获得订阅回复,然后再获取订阅的消息。收到订阅回复,但是ioc.run()返回并且没有接收到其他消息。请问如何使它工作?
从助力野兽中使用的示例,而无需调用close。 https://www.boost.org/doc/libs/1_70_0/libs/beast/example/websocket/client/async-ssl/websocket_client_async_ssl.cpp
// Report a failure
void
fail(beast::error_code ec, char const* what)
{
std::cerr << what << ": " << ec.message() << "\n";
}
// Sends a WebSocket message and prints the response
class session : public std::enable_shared_from_this<session>
{
tcp::resolver resolver_;
websocket::stream<
beast::ssl_stream<beast::tcp_stream>> ws_;
beast::flat_buffer buffer_;
std::string host_;
std::string text_;
public:
// Resolver and socket require an io_context
explicit
session(net::io_context& ioc, ssl::context& ctx)
: resolver_(net::make_strand(ioc))
, ws_(net::make_strand(ioc), ctx)
{
}
// Start the asynchronous operation
void
run(
char const* host,
char const* port,
char const* text)
{
// Save these for later
host_ = host;
text_ = text;
// Look up the domain name
resolver_.async_resolve(
host,
port,
beast::bind_front_handler(
&session::on_resolve,
shared_from_this()));
}
void
on_resolve(
beast::error_code ec,
tcp::resolver::results_type results)
{
if(ec)
return fail(ec, "resolve");
// Set a timeout on the operation
beast::get_lowest_layer(ws_).expires_after(std::chrono::seconds(30));
// Make the connection on the IP address we get from a lookup
beast::get_lowest_layer(ws_).async_connect(
results,
beast::bind_front_handler(
&session::on_connect,
shared_from_this()));
}
void
on_connect(beast::error_code ec, tcp::resolver::results_type::endpoint_type)
{
if(ec)
return fail(ec, "connect");
// Set a timeout on the operation
beast::get_lowest_layer(ws_).expires_after(std::chrono::seconds(30));
// Perform the SSL handshake
ws_.next_layer().async_handshake(
ssl::stream_base::client,
beast::bind_front_handler(
&session::on_ssl_handshake,
shared_from_this()));
}
void
on_ssl_handshake(beast::error_code ec)
{
if(ec)
return fail(ec, "ssl_handshake");
// Turn off the timeout on the tcp_stream, because
// the websocket stream has its own timeout system.
beast::get_lowest_layer(ws_).expires_never();
// Set suggested timeout settings for the websocket
ws_.set_option(
websocket::stream_base::timeout::suggested(
beast::role_type::client));
// Set a decorator to change the User-Agent of the handshake
ws_.set_option(websocket::stream_base::decorator(
[](websocket::request_type& req)
{
req.set(http::field::user_agent,
std::string(BOOST_BEAST_VERSION_STRING) +
" websocket-client-async-ssl");
}));
// Perform the websocket handshake
ws_.async_handshake(host_, "/ws",
beast::bind_front_handler(
&session::on_handshake,
shared_from_this()));
}
void
on_handshake(beast::error_code ec)
{
if(ec)
return fail(ec, "handshake");
// Send the message
ws_.async_write(
net::buffer(text_),
beast::bind_front_handler(
&session::on_write,
shared_from_this()));
}
void
on_write(
beast::error_code ec,
std::size_t bytes_transferred)
{
boost::ignore_unused(bytes_transferred);
if(ec)
return fail(ec, "write");
// Read a message into our buffer
ws_.async_read(
buffer_,
beast::bind_front_handler(
&session::on_read,
shared_from_this()));
}
void
on_read(
beast::error_code ec,
std::size_t bytes_transferred)
{
boost::ignore_unused(bytes_transferred);
if(ec)
return fail(ec, "read");
std::cout << beast::make_printable(buffer_.data()) << std::endl;
}
void
on_close(beast::error_code ec)
{
if(ec)
return fail(ec, "close");
}
};
//------------------------------------------------------------------------------
int main(int argc, char** argv)
{
auto const host = "";
auto const port = "";
auto const text = "";
net::io_context ioc;
ssl::context ctx{ssl::context::tlsv12_client};
std::make_shared<session>(ioc, ctx)->run(host, port, text.c_str());
ioc.run();
return EXIT_SUCCESS;
}