websocket::stream::async_accept (3 of 3 overloads)

Start responding to a WebSocket HTTP Upgrade request.

Synopsis

template<
    class Body,
    class Allocator,
    class AcceptHandler>
DEDUCED
async_accept(
    http::request< Body, http::basic_fields< Allocator >> const& req,
    AcceptHandler&& handler);

Description

This function is used to asynchronously send the HTTP response to an HTTP request possibly containing a WebSocket Upgrade request. The function call always returns immediately. The asynchronous operation will continue until one of the following conditions is true:

The response finishes sending.
An error occurs on the stream.

This operation is implemented in terms of one or more calls to the next layer's async_write_some functions, and is known as a composed operation. The program must ensure that the stream performs no other operations until this operation completes.

If the stream receives a valid HTTP WebSocket Upgrade request, an HTTP response is sent back indicating a successful upgrade. When the completion handler is invoked, the stream is then ready to send and receive WebSocket protocol frames and messages. If the HTTP Upgrade request is invalid or cannot be satisfied, an HTTP response is sent indicating the reason and status code (typically 400, "Bad Request"). This counts as a failure, and the completion handler will be invoked with a suitable error code set.

Parameters

Name	Description
`req`	An object containing the HTTP Upgrade request. Ownership is not transferred, the implementation will not access this object from other threads.
`handler`	Invoked when the operation completes. The handler may be moved or copied as needed. 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 `boost::asio::io_context::post`.

Name

Description

req

An object containing the HTTP Upgrade request. Ownership is not transferred, the implementation will not access this object from other threads.

handler

Invoked when the operation completes. The handler may be moved or copied as needed. 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 boost::asio::io_context::post.

Boost C++ Libraries

websocket::stream::async_accept (3 of 3 overloads)