Struct WebSocketStream 

pub struct WebSocketStream<S> { /* private fields */ }

A WebSocket stream over an async transport

This type implements both Stream<Item = Result<Message>> for receiving and Sink<Message> for sending messages.

Backpressure

The stream supports backpressure monitoring through is_backpressured() and write_buffer_len() methods. When the write buffer exceeds the high water mark, producers should pause sending until the buffer drains below the low water mark.

Example

use futures_util::{SinkExt, StreamExt};
use sockudo_ws::WebSocketStream;

async fn handle(mut ws: WebSocketStream<TcpStream>) {
    while let Some(msg) = ws.next().await {
        match msg {
            Ok(Message::Text(text)) => {
                // Check backpressure before sending
                if ws.is_backpressured() {
                    ws.flush().await?;
                }
                ws.send(Message::Text(text)).await?;
            }
            Ok(Message::Close(_)) => break,
            _ => {}
        }
    }
}

Implementations

impl<S> WebSocketStream<S>

where S: AsyncRead + AsyncWrite + Unpin,

pub fn from_raw(inner: S, role: Role, config: Config) -> Self

Create a new WebSocket stream from an already-upgraded connection

pub fn server(inner: S, config: Config) -> Self

Create a server-side WebSocket stream

pub fn client(inner: S, config: Config) -> Self

Create a client-side WebSocket stream

pub fn get_ref(&self) -> &S

Get a reference to the underlying stream

pub fn get_mut(&mut self) -> &mut S

Get a mutable reference to the underlying stream

pub fn into_inner(self) -> S

Consume the WebSocket stream and return the underlying stream

pub fn is_closed(&self) -> bool

Check if the connection is closed

pub fn is_backpressured(&self) -> bool

Check if the write buffer is backpressured

Returns true when the write buffer has exceeded the high water mark. Producers should pause sending new messages until is_write_buffer_low() returns true or until the buffer is flushed.

Example

if ws.is_backpressured() {
    // Wait for buffer to drain before sending more
    ws.flush().await?;
}

pub fn is_write_buffer_low(&self) -> bool

Check if the write buffer is below the low water mark

Returns true when the write buffer has drained below the low water mark. This can be used to resume sending after backpressure was detected.

pub fn write_buffer_len(&self) -> usize

Get the current write buffer size in bytes

Useful for monitoring and debugging backpressure issues.

pub fn read_buffer_len(&self) -> usize

Get the current read buffer size in bytes

Useful for monitoring memory usage and debugging.

pub fn set_high_water_mark(&mut self, size: usize)

Set the high water mark for backpressure

When the write buffer exceeds this threshold, is_backpressured() returns true. Default is 64KB.

pub fn set_low_water_mark(&mut self, size: usize)

Set the low water mark for backpressure

When the write buffer drops below this threshold, is_write_buffer_low() returns true. Default is 16KB.

pub fn high_water_mark(&self) -> usize

Get the current high water mark

pub fn low_water_mark(&self) -> usize

Get the current low water mark

pub async fn close(&mut self, code: u16, reason: &str) -> Result<()>

Send a close frame

impl<S> WebSocketStream<S>

where S: AsyncRead + AsyncWrite + Unpin,

pub fn split(self) -> (SplitReader<S>, SplitWriter<S>)

Split the WebSocket stream into separate read and write halves

This allows TRUE concurrent reading and writing from different tasks with ZERO lock contention. The underlying TCP stream is split at the OS level for maximum performance.

Example

let (mut reader, mut writer) = ws.split();

// Read in one task - NEVER blocks writer
tokio::spawn(async move {
    while let Some(msg) = reader.next().await {
        println!("Got: {:?}", msg);
    }
});

// Write in another - NEVER blocks reader
writer.send(Message::Text("Hello".into())).await?;

Trait Implementations

impl<S> Sink<Message> for WebSocketStream<S>

where S: AsyncRead + AsyncWrite + Unpin,

type Error = Error

The type of value produced by the sink when an error occurs.

fn poll_ready(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<()>>

Attempts to prepare the Sink to receive a value.

fn start_send(self: Pin<&mut Self>, item: Message) -> Result<()>

Begin the process of sending a value to the sink. Each call to this function must be preceded by a successful call to poll_ready which returned Poll::Ready(Ok(())).

fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Flush any remaining output from this sink.

fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Flush any remaining output and close this sink, if necessary.

impl<S> Stream for WebSocketStream<S>

where S: AsyncRead + AsyncWrite + Unpin,

type Item = Result<Message, Error>

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.

impl<'__pin, S> Unpin for WebSocketStream<S>

where PinnedFieldsOf<__Origin<'__pin, S>>: Unpin,