Class WsConnection

packages/server/src/ws/connection.ts:130–733

const DEFAULT_MAX_EVENT_BUFFER = 1000;

export class WsConnection {
  public readonly id: string;

  public readonly subscriptions = new Set<string>();

  /** Last cursor each subscribed session was synced from (client-claimed). */
  public readonly cursorsBySession = new Map<string, SessionCursor>();

  /** ISO 8601 UTC timestamp the socket was accepted at. */
  public readonly connectedAt: string;

  /** Peer address from the upgrade socket. Null when unavailable. */
  public readonly remoteAddress: string | null;

  /** `User-Agent` header from the upgrade request. Null when absent. */
  public readonly userAgent: string | null;

  private readonly socket: WebSocket;
  private readonly logger: ILogService;
  private readonly sessionClients: ISessionClientsService;
  private readonly wsBroadcast: BufferReplaySource;
  private readonly abortHandler: AbortHandler | undefined;
  private readonly fsWatchHandler: FsWatchHandler | undefined;
  private readonly terminalHandler: TerminalHandler | undefined;
  private readonly pingIntervalMs: number;
  private readonly pongTimeoutMs: number;
  private readonly maxEventBufferSize: number;

  private pingTimer?: NodeJS.Timeout;
  private pongTimer?: NodeJS.Timeout;
  private closed = false;
  private gotClientHello = false;

  constructor(opts: WsConnectionOptions) {
    this.id = `conn_${ulid()}`;
    this.connectedAt = new Date().toISOString();
    this.remoteAddress = opts.remoteAddress ?? null;
    this.userAgent = opts.userAgent ?? null;
    this.socket = opts.socket;
    this.logger = opts.logger.child({ connId: this.id });
    this.sessionClients = opts.sessionClients;
    this.wsBroadcast = opts.wsBroadcast;
    this.abortHandler = opts.abortHandler;
    this.fsWatchHandler = opts.fsWatchHandler;
    this.terminalHandler = opts.terminalHandler;
    this.pingIntervalMs = opts.pingIntervalMs ?? DEFAULT_PING_INTERVAL_MS;
    this.pongTimeoutMs = opts.pongTimeoutMs ?? DEFAULT_PONG_TIMEOUT_MS;
    this.maxEventBufferSize = opts.maxEventBufferSize ?? DEFAULT_MAX_EVENT_BUFFER;

    this.send(
      buildServerHello({
        ws_connection_id: this.id,
        protocol_version: WS_PROTOCOL_VERSION,
        heartbeat_ms: this.pingIntervalMs,
        max_event_buffer_size: this.maxEventBufferSize,
        capabilities: { event_batching: false, compression: false },
      }),
    );