websocket-demo

WebSocket echo

This example shows the useful integration point between HyperServe’s HTTP server and its dependency-free WebSocket package:

• the route remains an ordinary HTTP handler;
• same-origin browser upgrades are allowed by default;
• srv.WebSocketUpgrader() records successful upgrades in server telemetry;
• aggregate message memory is bounded, including fragmented messages;
• reads and writes use the request context.

The core setup is intentionally small:

upgrader := srv.WebSocketUpgrader()
upgrader.MaxMessageSize = 512 << 10 // 512 KiB across all fragments

srv.GET("/ws/echo", func(w http.ResponseWriter, r *http.Request) {
    conn, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        return
    }
    defer conn.Close()

    messageType, payload, err := conn.Read(r.Context())
    if err == nil {
        err = conn.Write(r.Context(), messageType, payload)
    }
})

Run from the repository root:

go run ./examples/websocket-demo

Then open http://localhost:8080. The embedded page connects to the same origin, sends text, and displays the echoed response.

For a cross-origin browser client, set AllowedOrigins to an explicit allowlist. Reconnect policy, authentication, and application messages remain application concerns. See the WebSocket guide for outbound dialing, proxy behavior, close semantics, and deployment details.