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

import Transaction from "./transaction.js";
import { STORE_NAMES, StorageError } from "../common.js";

export default class Storage {
	constructor(idbDatabase) {
		this._db = idbDatabase;
		const nameMap = STORE_NAMES.reduce((nameMap, name) => {
			nameMap[name] = name;
			return nameMap;
		}, {});
		this.storeNames = Object.freeze(nameMap);
	}

	_validateStoreNames(storeNames) {
		const idx = storeNames.findIndex(name => !STORE_NAMES.includes(name));
		if (idx !== -1) {
			throw new StorageError(`Tried top, a transaction unknown store ${storeNames[idx]}`);
		}
	}

	async readTxn(storeNames) {
		this._validateStoreNames(storeNames);
		try {
			const txn = this._db.transaction(storeNames, "readonly");
			return new Transaction(txn, storeNames);
		} catch(err) {
			throw new StorageError("readTxn failed", err);
		}
	}

	async readWriteTxn(storeNames) {
		this._validateStoreNames(storeNames);
		try {
			const txn = this._db.transaction(storeNames, "readwrite");
			return new Transaction(txn, storeNames);
		} catch(err) {
			throw new StorageError("readWriteTxn failed", err);
		}
	}
}