websocket::stream::async_write

Write a complete message asynchronously.

Synopsis

template<
    class ConstBufferSequence,
    class WriteHandler = net::default_completion_token_t<                executor_type>>
DEDUCED
async_write(
    ConstBufferSequence const& buffers,
    WriteHandler&& handler = net::default_completion_token_t< executor_type >{});

Description

This function is used to asynchronously write a complete message.

This call always returns immediately. The asynchronous operation will continue until one of the following conditions is true:

The complete message is written.
An error occurs.

The algorithm, known as a composed asynchronous operation, is implemented in terms of calls to the next layer's async_write_some function. The program must ensure that no other calls to write, write_some, async_write, or async_write_some are performed until this operation completes.

The current setting of the binary option controls whether the message opcode is set to text or binary. If the auto_fragment option is set, the message will be split into one or more frames as necessary. The actual payload contents sent may be transformed as per the WebSocket protocol settings.

Parameters

Name	Description
`buffers`	A buffer sequence containing the entire message payload. The implementation will make copies of this object as needed, but ownership of the underlying memory is not transferred. The caller is responsible for ensuring that the memory locations pointed to by buffers remains valid until the completion handler is called.
`handler`	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 std::size_t bytes_transferred // Number of bytes sent from the // buffers. If an error occurred, // this will be less than the buffer_size. ); If the handler has an associated immediate executor, an immediate completion will be dispatched to it. Otherwise, the handler will not be invoked from within this function. Invocation of the handler will be performed by dispatching to the immediate executor. If no immediate executor is specified, this is equivalent to using `net::post`.

Name

Description

buffers

A buffer sequence containing the entire message payload. The implementation will make copies of this object as needed, but ownership of the underlying memory is not transferred. The caller is responsible for ensuring that the memory locations pointed to by buffers remains valid until the completion handler is called.

handler

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
    std::size_t bytes_transferred   // Number of bytes sent from the
                                    // buffers. If an error occurred,
                                    // this will be less than the buffer_size.
);

If the handler has an associated immediate executor, an immediate completion will be dispatched to it. Otherwise, the handler will not be invoked from within this function. Invocation of the handler will be performed by dispatching to the immediate executor. If no immediate executor is specified, this is equivalent to using net::post.

Per-Operation Cancellation

This asynchronous operation supports cancellation for the following net::cancellation_type values:

net::cancellation_type::terminal
net::cancellation_type::total

totalcancellation succeeds if the operation is suspended due to ongoing control operations such as a ping/pong.

terminal cancellation succeeds when supported by the underlying stream.

terminal cancellation leaves the stream in an undefined state, so that only closing it is guaranteed to succeed.

Boost C++ Libraries

websocket::stream::async_write

Synopsis

Description

Parameters

Per-Operation Cancellation