mirror of
https://github.com/facebookincubator/mvfst.git
synced 2025-11-10 21:22:20 +03:00
99e5aedc21
Summary: Without this the math doesn't really make sense, since it's done in whole intervals of seconds. Reviewed By: sharmafb Differential Revision: D21614903 fbshipit-source-id: 1bd9fddb9c667de1ae509340feedc0058befd50c
37 lines
1.2 KiB
C++
37 lines
1.2 KiB
C++
// Copyright 2004-present Facebook. All Rights Reserved.
|
|
|
|
#pragma once
|
|
|
|
#include <quic/server/RateLimiter.h>
|
|
|
|
namespace quic {
|
|
|
|
/*
|
|
* Simple "sliding window" rate limiter. This enforces a rate limit of count
|
|
* events per window. The window "slides" by multiplying the average rate of
|
|
* the previous full window by the amount of time that the current sliding
|
|
* window occurred in the previous window.
|
|
* E.g.
|
|
* Limit of 100 events per 10s. The previous window had 50 events. The current
|
|
* window has had 5 events. We check an event 3 seconds into our current
|
|
* window. The sliding window has 3 seconds in our current window, and 7
|
|
* seconds in the previous window. We psuedo-count for the current sliding
|
|
* window is: 50/10 * 7 + 5 + 1 = 41.
|
|
*/
|
|
class SlidingWindowRateLimiter : public RateLimiter {
|
|
public:
|
|
SlidingWindowRateLimiter(uint64_t count, std::chrono::seconds window)
|
|
: count_(count), window_(window) {}
|
|
|
|
bool check(TimePoint time) override;
|
|
|
|
private:
|
|
const uint64_t count_;
|
|
const std::chrono::microseconds window_;
|
|
folly::Optional<TimePoint> currentWindowStartPoint_{folly::none};
|
|
uint64_t countInPrevWindow_{0};
|
|
uint64_t countInCurWindow_{0};
|
|
};
|
|
|
|
} // namespace quic
|