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Read a complete message asynchronously.

    class DynamicBuffer,
    class ReadHandler>
    DynamicBuffer& buffer,
    ReadHandler&& handler);

This function is used to asynchronously read a complete message. 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. The program must ensure that no other calls to websocket::stream::read, websocket::stream::read_some, websocket::stream::async_read, or websocket::stream::async_read_some are performed until this operation completes. Received message data is appended to the buffer. The functions websocket::stream::got_binary and websocket::stream::got_text may be used to query the stream and determine the type of the last received message. Until the operation completes, the implementation will read incoming control frames and handle them automatically as follows:

Pong frames and close frames sent by the implementation while the read operation is outstanding do not prevent the application from also writing message data, sending pings, sending pongs, or sending close frames.





A dynamic buffer to append message data to.


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_written   // Number of bytes appended to buffer

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 net::post.