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/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef RTC_BASE_RATE_LIMITER_H_
#define RTC_BASE_RATE_LIMITER_H_
#include <stddef.h>
#include <stdint.h>
#include "rtc_base/rate_statistics.h"
#include "rtc_base/synchronization/mutex.h"
#include "rtc_base/thread_annotations.h"
namespace webrtc {
class Clock;
// Class used to limit a bitrate, making sure the average does not exceed a
// maximum as measured over a sliding window. This class is thread safe; all
// methods will acquire (the same) lock befeore executing.
class RateLimiter {
public:
RateLimiter(Clock* clock, int64_t max_window_ms);
RateLimiter() = delete;
RateLimiter(const RateLimiter&) = delete;
RateLimiter& operator=(const RateLimiter&) = delete;
~RateLimiter();
// Try to use rate to send bytes. Returns true on success and if so updates
// current rate.
bool TryUseRate(size_t packet_size_bytes);
// Set the maximum bitrate, in bps, that this limiter allows to send.
void SetMaxRate(uint32_t max_rate_bps);
// Set the window size over which to measure the current bitrate.
// For example, irt retransmissions, this is typically the RTT.
// Returns true on success and false if window_size_ms is out of range.
bool SetWindowSize(int64_t window_size_ms);
private:
Clock* const clock_;
Mutex lock_;
RateStatistics current_rate_ RTC_GUARDED_BY(lock_);
int64_t window_size_ms_ RTC_GUARDED_BY(lock_);
uint32_t max_rate_bps_ RTC_GUARDED_BY(lock_);
};
} // namespace webrtc
#endif // RTC_BASE_RATE_LIMITER_H_