feat(backend): RpcClient (spawn/send/request/event) over JSONL

2026-06-27 20:52:22 +02:00
parent de56694433
commit df5d2c36ac
2 changed files with 64 additions and 0 deletions
@@ -0,0 +1,38 @@
+import type { ChildProcessWithoutNullStreams } from "node:child_process";
+import { attachJsonlReader } from "./line-splitter.js";
+
+type Listener = (evt: any) => void;
+
+export class RpcClient {
+  private seq = 0;
+  private pending = new Map<string, (resp: any) => void>();
+  private listeners = new Set<Listener>();
+
+  constructor(private child: ChildProcessWithoutNullStreams) {
+    attachJsonlReader(child.stdout, (line) => {
+      if (!line) return;
+      let msg: any;
+      try { msg = JSON.parse(line); } catch { return; }
+      if (msg.type === "response" && msg.id && this.pending.has(msg.id)) {
+        this.pending.get(msg.id)!(msg);
+        this.pending.delete(msg.id);
+        return;
+      }
+      for (const l of this.listeners) l(msg);
+    });
+  }
+
+  nextId(): string { return `c${++this.seq}`; }
+
+  send(cmd: object): void { this.child.stdin.write(JSON.stringify(cmd) + "\n"); }
+
+  request(cmd: object & { type: string }): Promise<any> {
+    const id = this.nextId();
+    return new Promise((resolve) => {
+      this.pending.set(id, resolve);
+      this.send({ ...cmd, id });
+    });
+  }
+
+  on(_event: "event", cb: Listener): void { this.listeners.add(cb); }
+}