signal-desktop/ts/textsecure/cds/CDSBase.ts
2022-06-14 18:15:33 -07:00

67 lines
1.6 KiB
TypeScript

// Copyright 2022 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import ProxyAgent from 'proxy-agent';
import type {
CDSAuthType,
CDSRequestOptionsType,
CDSResponseType,
} from './Types.d';
import type { LoggerType } from '../../types/Logging';
import { isOlderThan } from '../../util/timestamp';
import { HOUR } from '../../util/durations';
// It is 24 hours, but we don't want latency between server and client to be
// count.
const CACHED_AUTH_TTL = 23 * HOUR;
export type CDSBaseOptionsType = Readonly<{
logger: LoggerType;
proxyUrl?: string;
getAuth(): Promise<CDSAuthType>;
}>;
export type CachedAuthType = Readonly<{
timestamp: number;
auth: CDSAuthType;
}>;
export abstract class CDSBase<
Options extends CDSBaseOptionsType = CDSBaseOptionsType
> {
protected readonly logger: LoggerType;
protected readonly proxyAgent?: ReturnType<typeof ProxyAgent>;
protected cachedAuth?: CachedAuthType;
constructor(protected readonly options: Options) {
this.logger = options.logger;
if (options.proxyUrl) {
this.proxyAgent = new ProxyAgent(options.proxyUrl);
}
}
public abstract request(
options: CDSRequestOptionsType
): Promise<CDSResponseType>;
protected async getAuth(): Promise<CDSAuthType> {
if (this.cachedAuth) {
if (isOlderThan(this.cachedAuth.timestamp, CACHED_AUTH_TTL)) {
this.cachedAuth = undefined;
} else {
return this.cachedAuth.auth;
}
}
const auth = await this.options.getAuth();
this.cachedAuth = {
auth,
timestamp: Date.now(),
};
return auth;
}
}