blob: df4cc343b20cf846125ffe3bc77491e209bfaa79 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
/*
This file is part of GNU Taler
(C) 2019 GNUnet e.V.
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.
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
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* An opened promise.
*
* @see {@link openPromise}
*/
export interface OpenedPromise<T> {
promise: Promise<T>;
resolve: (val: T) => void;
reject: (err: any) => void;
}
/**
* Get an unresolved promise together with its extracted resolve / reject
* function.
*
* Recent ECMAScript proposals also call this a promise capability.
*/
export function openPromise<T>(): OpenedPromise<T> {
let resolve: ((x?: any) => void) | null = null;
let reject: ((reason?: any) => void) | null = null;
const promise = new Promise<T>((res, rej) => {
resolve = res;
reject = rej;
});
if (!(resolve && reject)) {
// Never happens, unless JS implementation is broken
throw Error();
}
return { resolve, reject, promise };
}
export class AsyncCondition {
private promCap?: OpenedPromise<void> = undefined;
constructor() {}
wait(): Promise<void> {
if (!this.promCap) {
this.promCap = openPromise<void>();
}
return this.promCap.promise;
}
trigger(): void {
if (this.promCap) {
this.promCap.resolve();
}
this.promCap = undefined;
}
}
|