Sharkey/packages/backend/src/server/api/RateLimiterService.ts

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2022-09-17 21:27:08 +03:00
import { Inject, Injectable } from '@nestjs/common';
import Limiter from 'ratelimiter';
import Redis from 'ioredis';
import { DI } from '@/di-symbols.js';
import Logger from '@/logger.js';
import type { IEndpointMeta } from './endpoints.js';
const logger = new Logger('limiter');
@Injectable()
export class RateLimiterService {
constructor(
@Inject(DI.redis)
private redisClient: Redis.Redis,
) {
}
public limit(limitation: IEndpointMeta['limit'] & { key: NonNullable<string> }, actor: string) {
return new Promise<void>((ok, reject) => {
if (process.env.NODE_ENV === 'test') ok();
// Short-term limit
const min = (): void => {
const minIntervalLimiter = new Limiter({
id: `${actor}:${limitation.key}:min`,
duration: limitation.minInterval,
max: 1,
db: this.redisClient,
});
minIntervalLimiter.get((err, info) => {
if (err) {
return reject('ERR');
}
logger.debug(`${actor} ${limitation.key} min remaining: ${info.remaining}`);
if (info.remaining === 0) {
reject('BRIEF_REQUEST_INTERVAL');
} else {
if (hasLongTermLimit) {
max();
} else {
ok();
}
}
});
};
// Long term limit
const max = (): void => {
const limiter = new Limiter({
id: `${actor}:${limitation.key}`,
duration: limitation.duration,
max: limitation.max,
db: this.redisClient,
});
limiter.get((err, info) => {
if (err) {
return reject('ERR');
}
logger.debug(`${actor} ${limitation.key} max remaining: ${info.remaining}`);
if (info.remaining === 0) {
reject('RATE_LIMIT_EXCEEDED');
} else {
ok();
}
});
};
const hasShortTermLimit = typeof limitation.minInterval === 'number';
const hasLongTermLimit =
typeof limitation.duration === 'number' &&
typeof limitation.max === 'number';
if (hasShortTermLimit) {
min();
} else if (hasLongTermLimit) {
max();
} else {
ok();
}
});
}
}