blob: 7e4fe0200ac576a604dd18bd1c19a5263e2a6e8e [file] [log] [blame]
/*
* 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.
*/
#include "webrtc/modules/pacing/interval_budget.h"
#include <algorithm>
namespace webrtc {
namespace {
constexpr int kWindowMs = 500;
constexpr int kDeltaTimeMs = 2000;
}
IntervalBudget::IntervalBudget(int initial_target_rate_kbps)
: IntervalBudget(initial_target_rate_kbps, false) {}
IntervalBudget::IntervalBudget(int initial_target_rate_kbps,
bool can_build_up_underuse)
: bytes_remaining_(0), can_build_up_underuse_(can_build_up_underuse) {
set_target_rate_kbps(initial_target_rate_kbps);
}
void IntervalBudget::set_target_rate_kbps(int target_rate_kbps) {
target_rate_kbps_ = target_rate_kbps;
max_bytes_in_budget_ = (kWindowMs * target_rate_kbps_) / 8;
bytes_remaining_ = std::min(std::max(-max_bytes_in_budget_, bytes_remaining_),
max_bytes_in_budget_);
}
void IntervalBudget::IncreaseBudget(int64_t delta_time_ms) {
RTC_DCHECK_LT(delta_time_ms, kDeltaTimeMs);
int bytes = target_rate_kbps_ * delta_time_ms / 8;
if (bytes_remaining_ < 0 || can_build_up_underuse_) {
// We overused last interval, compensate this interval.
bytes_remaining_ = std::min(bytes_remaining_ + bytes, max_bytes_in_budget_);
} else {
// If we underused last interval we can't use it this interval.
bytes_remaining_ = std::min(bytes, max_bytes_in_budget_);
}
}
void IntervalBudget::UseBudget(size_t bytes) {
bytes_remaining_ = std::max(bytes_remaining_ - static_cast<int>(bytes),
-max_bytes_in_budget_);
}
size_t IntervalBudget::bytes_remaining() const {
return static_cast<size_t>(std::max(0, bytes_remaining_));
}
int IntervalBudget::budget_level_percent() const {
return bytes_remaining_ * 100 / max_bytes_in_budget_;
}
int IntervalBudget::target_rate_kbps() const {
return target_rate_kbps_;
}
} // namespace webrtc