88 lines
2.1 KiB
TypeScript
88 lines
2.1 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/>
|
|
*/
|
|
|
|
interface MemoEntry<T> {
|
|
p: Promise<T>;
|
|
t: number;
|
|
n: number;
|
|
}
|
|
|
|
export class AsyncOpMemoMap<T> {
|
|
private n = 0;
|
|
private memoMap: { [k: string]: MemoEntry<T> } = {};
|
|
|
|
private cleanUp(key: string, n: number): void {
|
|
const r = this.memoMap[key];
|
|
if (r && r.n === n) {
|
|
delete this.memoMap[key];
|
|
}
|
|
}
|
|
|
|
memo(key: string, pg: () => Promise<T>): Promise<T> {
|
|
const res = this.memoMap[key];
|
|
if (res) {
|
|
return res.p;
|
|
}
|
|
const n = this.n++;
|
|
// Wrap the operation in case it immediately throws
|
|
const p = Promise.resolve().then(() => pg());
|
|
this.memoMap[key] = {
|
|
p,
|
|
n,
|
|
t: new Date().getTime(),
|
|
};
|
|
return p.finally(() => {
|
|
this.cleanUp(key, n);
|
|
});
|
|
}
|
|
clear(): void {
|
|
this.memoMap = {};
|
|
}
|
|
}
|
|
|
|
export class AsyncOpMemoSingle<T> {
|
|
private n = 0;
|
|
private memoEntry: MemoEntry<T> | undefined;
|
|
|
|
private cleanUp(n: number): void {
|
|
if (this.memoEntry && this.memoEntry.n === n) {
|
|
this.memoEntry = undefined;
|
|
}
|
|
}
|
|
|
|
memo(pg: () => Promise<T>): Promise<T> {
|
|
const res = this.memoEntry;
|
|
if (res) {
|
|
return res.p;
|
|
}
|
|
const n = this.n++;
|
|
// Wrap the operation in case it immediately throws
|
|
const p = Promise.resolve().then(() => pg());
|
|
p.finally(() => {
|
|
this.cleanUp(n);
|
|
});
|
|
this.memoEntry = {
|
|
p,
|
|
n,
|
|
t: new Date().getTime(),
|
|
};
|
|
return p;
|
|
}
|
|
clear(): void {
|
|
this.memoEntry = undefined;
|
|
}
|
|
}
|