const settings = require('settings-sharelatex') const Metrics = require('metrics-sharelatex') const RedisWrapper = require('./RedisWrapper') const rclient = RedisWrapper.client('ratelimiter') const RollingRateLimiter = require('rolling-rate-limiter') const { promisifyAll } = require('../util/promises') const RateLimiter = { addCount(opts, callback) { if (settings.disableRateLimits) { return callback(null, true) } if (callback == null) { callback = function() {} } const namespace = `RateLimit:${opts.endpointName}:` const k = `{${opts.subjectName}}` const limiter = RollingRateLimiter({ redis: rclient, namespace, interval: opts.timeInterval * 1000, maxInInterval: opts.throttle }) limiter(k, function(err, timeLeft, actionsLeft) { if (err) { return callback(err) } const allowed = timeLeft === 0 if (!allowed) { Metrics.inc(`rate-limit-hit.${opts.endpointName}`, 1, { path: opts.endpointName }) } return callback(null, allowed) }) }, clearRateLimit(endpointName, subject, callback) { // same as the key which will be built by RollingRateLimiter (namespace+k) const keyName = `RateLimit:${endpointName}:{${subject}}` rclient.del(keyName, callback) } } RateLimiter.promises = promisifyAll(RateLimiter) module.exports = RateLimiter