signal-desktop/ts/textsecure/cds/CDSBase.ts
2024-03-20 11:05:10 -07:00

68 lines
1.7 KiB
TypeScript

// Copyright 2022 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import type {
CDSAuthType,
CDSRequestOptionsType,
CDSResponseType,
} from './Types.d';
import type { LoggerType } from '../../types/Logging';
import { isOlderThan } from '../../util/timestamp';
import { HOUR } from '../../util/durations';
import { createProxyAgent } from '../../util/createProxyAgent';
import type { ProxyAgent } from '../../util/createProxyAgent';
// 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 proxyAgent?: ProxyAgent;
protected cachedAuth?: CachedAuthType;
constructor(protected readonly options: Options) {
this.logger = options.logger;
}
public abstract request(
options: CDSRequestOptionsType
): Promise<CDSResponseType>;
protected async getAuth(): Promise<CDSAuthType> {
// Lazily create proxy agent
if (!this.proxyAgent && this.options.proxyUrl) {
this.proxyAgent = await createProxyAgent(this.options.proxyUrl);
}
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;
}
}