pi-mono/packages/durable/test/examples/35-durable-on-the-store.ts

// Durable on the store: a session's worker keeps everything in one store. Durable's Session (a Harness) opens
// `StoreStorage` over the host's store under its object's type name, next to a Chord object's own table and documents;
// both commit through the store's one commit queue (one seq each), one id allocator numbers them all, and one export
// carries both.
// Run from packages/durable:
//   node --conditions=source --experimental-strip-types test/examples/35-durable-on-the-store.ts
import { mkdtemp, rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { BACKGROUND_CONTEXT } from "@earendil-works/chord/context";
import {
	createHost,
	defineFacet,
	defineTable,
	local,
	method,
	openStore,
	sqliteBackend,
	str,
} from "@earendil-works/chord/next";
import { openNodeSqliteDatabase } from "@earendil-works/chord/sqlite/node";
import { createModels } from "@earendil-works/pi-ai";
import { createRegistry, Harness, ROOT_CONVERSATION_ID } from "../../src/index.ts";
import { StoreStorage } from "../../src/storage/store/index.ts";

const context = BACKGROUND_CONTEXT;

const Notes = defineTable("notes", { version: 1, columns: { id: str(), text: str() }, key: ["id"] });

// The harness object: local with empty params, so it lives as long as the host and may persist (P3).
const Chat = local("example.chat", {
	version: 1,
	params: {},
	members: { note: method(str()), say: method(str()) },
});

const facet = defineFacet((host) => {
	host.serve(Chat, (_, self) => {
		// Its own table, under its type name ...
		const notes = self.table(Notes);
		// ... and Durable's records under the same owner name: claims per table and per document namespace.
		const harness = self.open(
			async (open) => {
				const opened = await Harness.open(
					await StoreStorage.open(store, Chat.name, open),
					{ models: createModels(), registry: createRegistry() },
					open,
				);
				await opened.root(open);
				return opened;
			},
			(h, _reason, close) => h.close(close),
		);
		return {
			note: async (text, ctx) => {
				await self.tx(async (tx) => tx.put(notes, { id: `n${text.length}`, text }), ctx);
				return null;
			},
			say: async (text, ctx) => {
				const root = await harness.value.conversation(ROOT_CONVERSATION_ID, ctx);
				await root!.submit({ type: "write", entry: { kind: "example.said", data: { text } } }, ctx);
				return null;
			},
		};
	});
});

const directory = await mkdtemp(join(tmpdir(), "chord-example-26-"));
const path = join(directory, "session.sqlite");
// 1. The worker's start code opens the store and gives it to its host.
const store = await openStore(sqliteBackend(await openNodeSqliteDatabase(path)), context);
const host = createHost({ store, onError: (error) => console.log("onError", error.kind) });
await host.load([{ name: "@example/core", facet }], context);
const chat = await host.get(Chat, {}, context);

// 2. Chord's commit and Durable's commit, each one seq of the same store.
const before = store.lastSeq;
await chat.note("hello", context);
await chat.say("hello, Durable", context);
console.log("seqs taken:", store.lastSeq - before);

// 3. One archive holds both: Chord's table, Durable's tables and documents, all under the owner name.
const owners = new Map<string, number>();
for await (const part of store.export(context)) {
	const owner =
		part.kind === "table" || part.kind === "put"
			? part.table.split(":")[0]
			: part.kind === "document.create"
				? part.record.owner
				: undefined;
	if (owner !== undefined) owners.set(`${owner} ${part.kind}`, (owners.get(`${owner} ${part.kind}`) ?? 0) + 1);
	if (part.kind === "manifest") console.log("manifest:", { lastSeq: part.lastSeq, nextId: part.nextId });
}
console.log("parts by owner and kind:", Object.fromEntries(owners));

// 4. The app closes the host, then the store; a reopen finds both.
await host.close(context);
await store.close(context);
const reopened = await openStore(sqliteBackend(await openNodeSqliteDatabase(path)), context);
const storage = await StoreStorage.open(reopened, Chat.name, context);
const page = await storage.scanEntries({ conversationId: ROOT_CONVERSATION_ID }, 10, undefined, context);
console.log(
	"Durable entries after reopen:",
	page.items.map((entry) => entry.kind),
);
await storage.close(context);
await reopened.close(context);
await rm(directory, { recursive: true, force: true });