yumechi-no-kuni/src/api/limitter.ts

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2016-12-28 16:49:51 -06:00
import * as Limiter from 'ratelimiter';
import limiterDB from '../db/redis';
import { IEndpoint } from './endpoints';
import { IAuthContext } from './authenticate';
export default (endpoint: IEndpoint, ctx: IAuthContext) => new Promise((ok, reject) => {
const limitKey = endpoint.hasOwnProperty('limitKey')
? endpoint.limitKey
: endpoint.name;
const hasMinInterval =
endpoint.hasOwnProperty('minInterval');
const hasRateLimit =
endpoint.hasOwnProperty('limitDuration') &&
endpoint.hasOwnProperty('limitMax');
if (hasMinInterval) {
min();
} else if (hasRateLimit) {
max();
} else {
ok();
}
// Short-term limit
function min(): void {
const minIntervalLimiter = new Limiter({
id: `${ctx.user._id}:${limitKey}:min`,
duration: endpoint.minInterval,
max: 1,
db: limiterDB
});
minIntervalLimiter.get((limitErr, limit) => {
if (limitErr) {
reject('ERR');
} else if (limit.remaining === 0) {
reject('BRIEF_REQUEST_INTERVAL');
} else {
if (hasRateLimit) {
max();
} else {
ok();
}
}
});
}
// Long term limit
function max(): void {
const limiter = new Limiter({
id: `${ctx.user._id}:${limitKey}`,
duration: endpoint.limitDuration,
max: endpoint.limitMax,
db: limiterDB
});
limiter.get((limitErr, limit) => {
if (limitErr) {
reject('ERR');
} else if (limit.remaining === 0) {
reject('RATE_LIMIT_EXCEEDED');
} else {
ok();
}
});
}
});