Run the desktop's model layer in the browser (#557)

2026-08-23 03:44:08 +02:00 · 2026-08-16 07:34:48 -07:00
parent 32e92d484b
commit 6f91f76064
36 changed files with 3266 additions and 24 deletions
@@ -0,0 +1,47 @@
+/**
+ * The messages that cross between a tab and the worker that owns the database.
+ *
+ * Declared once and imported from both sides, so a change to the shape is a
+ * type error in whichever side forgot. Kept deliberately small: commands in,
+ * results or errors out, and events pushed the other way — the same envelope
+ * the desktop's IPC uses, because that is what the frontend is written against.
+ */
+
+/** Tab → worker */
+export type ToWorker =
+  | { type: "rpc"; id: number; cmd: string; payload: unknown; label: string }
+  | { type: "blob_get"; id: number; blobId: string }
+  | { type: "blob_put"; id: number; blobId: string; bytes: ArrayBuffer }
+  | { type: "blob_delete"; id: number; blobId: string }
+  /** The tab is going away; the worker can forget its port. */
+  | { type: "goodbye" };
+
+/** Worker → tab */
+export type FromWorker =
+  /**
+   * Sent synchronously the moment a port connects, before anything else. Its
+   * only job is to prove the worker is alive: a tab that connects during a
+   * shared worker's teardown gets a port that is accepted and then never
+   * serviced, and this is how it tells that apart from a slow boot.
+   */
+  | { type: "hello" }
+  /** The database is open. Sent to each port once boot has finished. */
+  | { type: "ready" }
+  /** The database could not be opened; every command will fail with this. */
+  | { type: "boot_error"; message: string }
+  | { type: "result"; id: number; result: unknown }
+  | { type: "error"; id: number; message: string }
+  /** A backend event for the app — today only `model_writes`. Sent to every port. */
+  | { type: "event"; event: string; payload: unknown };
+
+/** What the worker registers itself under. Tabs on one origin share it. */
+export const WORKER_NAME = "yaak-db";
+
+/**
+ * The Web Lock the worker takes before opening the database.
+ *
+ * The browser already guarantees one SharedWorker per origin for this name.
+ * The lock covers the one overlap it doesn't rule out: a tab reloading itself,
+ * whose old worker may still be letting go while the new one comes up.
+ */
+export const DB_LOCK_NAME = "yaak-db";