vector-im-hydrogen-web/src/matrix/storage/idb/transaction.js

import {txnAsPromise} from "./utils.js";
import {StorageError} from "../common.js";
import Store from "./store.js";
import SessionStore from "./stores/SessionStore.js";
import RoomSummaryStore from "./stores/RoomSummaryStore.js";
import TimelineEventStore from "./stores/TimelineEventStore.js";
import RoomStateStore from "./stores/RoomStateStore.js";
import TimelineFragmentStore from "./stores/TimelineFragmentStore.js";

export default class Transaction {
	constructor(txn, allowedStoreNames) {
		this._txn = txn;
		this._allowedStoreNames = allowedStoreNames;
		this._stores = {
			session: null,
			roomSummary: null,
			roomTimeline: null,
			roomState: null,
		};
	}

	_idbStore(name) {
		if (!this._allowedStoreNames.includes(name)) {
			// more specific error? this is a bug, so maybe not ...
			throw new StorageError(`Invalid store for transaction: ${name}, only ${this._allowedStoreNames.join(", ")} are allowed.`);
		}
		return new Store(this._txn.objectStore(name));
	}

	_store(name, mapStore) {
		if (!this._stores[name]) {
			const idbStore = this._idbStore(name);
			this._stores[name] = mapStore(idbStore);
		}
		return this._stores[name];
	}

	get session() {
		return this._store("session", idbStore => new SessionStore(idbStore));
	}

	get roomSummary() {
		return this._store("roomSummary", idbStore => new RoomSummaryStore(idbStore));
	}

    get timelineFragments() {
        return this._store("timelineFragments", idbStore => new TimelineFragmentStore(idbStore));
    }

	get timelineEvents() {
		return this._store("timelineEvents", idbStore => new TimelineEventStore(idbStore));
	}

	get roomState() {
		return this._store("roomState", idbStore => new RoomStateStore(idbStore));
	}

	complete() {
		return txnAsPromise(this._txn);
	}

	abort() {
		this._txn.abort();
	}
}