...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Perform the WebSocket handshake asynchronously in the server role.
template< class ConstBufferSequence, class AcceptHandler = net::default_completion_token_t<executor_type>> DEDUCED async_accept( ConstBufferSequence const& buffers, AcceptHandler&& handler = net::default_completion_token_t< executor_type >{});
This initiating function is used to asynchronously begin performing the WebSocket handshake, required before messages can be sent and received. During the handshake, the client sends the Websocket Upgrade HTTP request, and the server replies with an HTTP response indicating the result of the handshake. This call always returns immediately. The asynchronous operation will continue until one of the following conditions is true:
The algorithm, known as a composed asynchronous operation,
is implemented in terms of calls to the next layer's async_read_some
and async_write_some
functions. No other operation may be performed on the stream until this
operation completes. If a valid upgrade request is received, an HTTP
response with a status-code
of beast::http::status::switching_protocols
is sent
to the peer, otherwise a non-successful error is associated with the
operation. If the request size exceeds the capacity of the stream's internal
buffer, the error error::buffer_overflow
will be indicated.
To handle larger requests, an application should read the HTTP request
directly using
http::async_read
and then pass the
request to the appropriate overload of accept
or async_accept
Name |
Description |
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|
Caller provided data that has already been received on the stream. This may be used for implementations allowing multiple protocols on the same stream. The buffered data will first be applied to the handshake, and then to received WebSocket frames. The implementation will copy the caller provided data before the function returns. |
|
The completion handler to invoke when the operation completes. The implementation takes ownership of the handler by performing a decay-copy. The equivalent function signature of the handler must be: void handler( error_code const& ec // Result of operation );
Regardless of whether the asynchronous operation completes
immediately or not, the handler will not be invoked from within
this function. Invocation of the handler will be performed
in a manner equivalent to using |