wallet-core/packages/taler-wallet-core/src/operations/state.ts
2021-01-18 23:35:41 +01:00

122 lines
4.1 KiB
TypeScript

/*
This file is part of GNU Taler
(C) 2019 GNUnet e.V.
GNU Taler is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
import { HttpRequestLibrary } from "../util/http";
import { BalancesResponse } from "../types/walletTypes";
import { CryptoApi, CryptoWorkerFactory } from "../crypto/workers/cryptoApi";
import { AsyncOpMemoMap, AsyncOpMemoSingle } from "../util/asyncMemo";
import { Logger } from "../util/logging";
import { PendingOperationsResponse } from "../types/pendingTypes";
import { WalletNotification } from "../types/notifications";
import { Database } from "../util/query";
import { openPromise, OpenedPromise } from "../util/promiseUtils";
import { Stores } from "../types/dbTypes";
type NotificationListener = (n: WalletNotification) => void;
const logger = new Logger("state.ts");
export const EXCHANGE_COINS_LOCK = "exchange-coins-lock";
export const EXCHANGE_RESERVES_LOCK = "exchange-reserves-lock";
export class InternalWalletState {
memoProcessReserve: AsyncOpMemoMap<void> = new AsyncOpMemoMap();
memoMakePlanchet: AsyncOpMemoMap<void> = new AsyncOpMemoMap();
memoGetPending: AsyncOpMemoSingle<
PendingOperationsResponse
> = new AsyncOpMemoSingle();
memoGetBalance: AsyncOpMemoSingle<BalancesResponse> = new AsyncOpMemoSingle();
memoProcessRefresh: AsyncOpMemoMap<void> = new AsyncOpMemoMap();
memoProcessRecoup: AsyncOpMemoMap<void> = new AsyncOpMemoMap();
memoProcessDeposit: AsyncOpMemoMap<void> = new AsyncOpMemoMap();
cryptoApi: CryptoApi;
listeners: NotificationListener[] = [];
/**
* Promises that are waiting for a particular resource.
*/
private resourceWaiters: Record<string, OpenedPromise<void>[]> = {};
/**
* Resources that are currently locked.
*/
private resourceLocks: Set<string> = new Set();
constructor(
// FIXME: Make this a getter and make
// the actual value nullable.
// Check if we are in a DB migration / garbage collection
// and throw an error in that case.
public db: Database<typeof Stores>,
public http: HttpRequestLibrary,
cryptoWorkerFactory: CryptoWorkerFactory,
) {
this.cryptoApi = new CryptoApi(cryptoWorkerFactory);
}
notify(n: WalletNotification): void {
logger.trace("Notification", n);
for (const l of this.listeners) {
const nc = JSON.parse(JSON.stringify(n));
setTimeout(() => {
l(nc);
}, 0);
}
}
addNotificationListener(f: (n: WalletNotification) => void): void {
this.listeners.push(f);
}
/**
* Run an async function after acquiring a list of locks, identified
* by string tokens.
*/
async runSequentialized<T>(tokens: string[], f: () => Promise<T>) {
// Make sure locks are always acquired in the same order
tokens = [...tokens].sort();
for (const token of tokens) {
if (this.resourceLocks.has(token)) {
const p = openPromise<void>();
let waitList = this.resourceWaiters[token];
if (!waitList) {
waitList = this.resourceWaiters[token] = [];
}
waitList.push(p);
await p.promise;
}
this.resourceLocks.add(token);
}
try {
logger.trace(`begin exclusive execution on ${JSON.stringify(tokens)}`);
const result = await f();
logger.trace(`end exclusive execution on ${JSON.stringify(tokens)}`);
return result;
} finally {
for (const token of tokens) {
this.resourceLocks.delete(token);
let waiter = (this.resourceWaiters[token] ?? []).shift();
if (waiter) {
waiter.resolve();
}
}
}
}
}