Release Notes: WebSocket Implementation Improvements

The previous WS implementation had several limitations that affected the reliability and maintainability of the Pusher client:

1. Didn't handle reconnections and timeouts as robustly as needed.
2. Made it difficult to manage the WebSocket connection lifecycle independently of the main client.

What Changed?

1. Redesigned WS Client Architecture

• We've introduced a dedicated WebSocketClient struct that holds all WS-related functionality.
• The new design makes use of a channel-based approach for sending commands to the WebSocket client

pub struct WebSocketClient {
    url: Url,
    socket: Option<WebSocketStream<MaybeTlsStream<TcpStream>>>,
    state: Arc<RwLock<ConnectionState>>,
    event_tx: mpsc::Sender<Event>,
    command_rx: mpsc::Receiver<WebSocketCommand>,
}

pub enum WebSocketCommand {
    Send(String),
    Close,
}

2. Improved Connection Handling

• The client now attempts to reconnect automatically when the connection is lost, using an exponential backoff strategy.
• Connection State Management: We've implemented a more robust connection state management system, allowing users to accurately track the current state of the WebSocket connection.

3. Ping/Pong Mechanism

• Reliable Keepalive: We've implemented a proper ping/pong mechanism to keep the connection alive and detect disconnections more quickly.
• Configurable Timeouts: Users can now configure ping interval and pong timeout durations to suit their specific needs.

const PING_INTERVAL: Duration = Duration::from_secs(30);
const PONG_TIMEOUT: Duration = Duration::from_secs(10);

4. Async Improvements

• Efficient Event Loop: The new run method in WebSocketClient uses tokio::select! for efficient handling of multiple asynchronous operations.
• Non-blocking Ops: All WebSocket operations are now fully asynchronous, preventing any potential blocking in the event loop.

pub async fn run(&mut self) {
    let mut ping_interval = interval(PING_INTERVAL);
    let mut pong_timeout = Box::pin(sleep(Duration::from_secs(0)));
    let mut waiting_for_pong = false;

    while let Some(socket) = &mut self.socket {
        tokio::select! {
            // ... handle various async events ...
        }
    }
    // ... handle disconnection ...
}

Breaking Changes

• The internal WebSocketClient API has changed significantly. If you were directly interacting with WebSocket internals, you'll need to update your code.
• The PusherClient method signatures related to WebSocket operations have been updated to use the new format.

Changelog

0.1.1 - 2024-09-01

Added

• Implemented batch event triggering capability
  • New BatchEvent struct for representing individual events in a batch
  • Added trigger_batch method to PusherClient for sending multiple events in a single API call
  • Updated documentation and README to reflect new batch triggering functionality

Changed

• Updated PusherClient struct to support batch event operations
• Improved error handling for batch event triggering
• Enhanced test suite to cover batch event scenarios

Fixed

• Minor bug fixes and performance improvements

Documentation

• Added examples for using the new batch event triggering feature
• Updated README with information about batch event support
• Improved inline documentation for new methods and structs

0.1.0 - 2024-08-29

Added

• Initial release of pusher-rs
• Basic Pusher Channels functionality:
  • Connect to Pusher Channels
  • Subscribe to public, private, presence, and private encrypted channels
  • Publish events to channels
  • Handle incoming events
  • Automatic reconnection with exponential backoff
  • Environment-based configuration
  • Flexible channel management