LONGPOLLING.md

Vix WebSocket - Long Polling (Offline First)

Long Polling is used when WebSockets cannot connect or the network is unstable.

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1. Server Poll Endpoint

auto pending = store.dequeue(session_id, max);
return pending;

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2. Browser Poll Loop

async function poll() {
  try {
    const res = await fetch("/ws/poll?session_id=123");
    const arr = await res.json();
    for (const msg of arr) handle(msg);
  } catch (e) {
    console.log("Offline:", e);
  }
  poll();
}

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3. Sending messages (LP mode)

await fetch("/ws/send", {
  method: "POST",
  body: JSON.stringify({
    session_id: sid,
    type: "chat.message",
    payload: { text: "Hello" }
  })
});

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4. Queue Behavior

• Messages stored in SQLite
• Incrementing IDs
• Poll returns only new messages
• Queue expires older entries

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5. Combined WS + LP Logic

1. Try WS
2. If WS closes -> LP
3. When WS reconnects -> stop LP
4. If offline -> queue messages
5. Replay queue on reconnect