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// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/modules/compute_pressure/change_rate_monitor.h"
#include "base/rand_util.h"
#include "third_party/blink/renderer/modules/compute_pressure/pressure_source_index.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
namespace blink {
// |observation_window_time| boundaries in seconds.
constexpr uint64_t kMinObservationWindowInSeconds = 300;
constexpr uint64_t kMaxObservationWindowInSeconds = 600;
// |change_count_threshold| boundaries in changes.
constexpr uint64_t kMinChangesThreshold = 50;
constexpr uint64_t kMaxChangesThreshold = 100;
// |penalty_duration| boundaries in seconds.
constexpr uint64_t kMinPenaltyDurationInSeconds = 5;
constexpr uint64_t kMaxPenaltyDurationInSeconds = 10;
ChangeRateMonitor::ChangeRateMonitor() {
Reset();
}
ChangeRateMonitor::~ChangeRateMonitor() = default;
void ChangeRateMonitor::Reset() {
observation_window_time_ = base::Seconds(base::RandInt(
kMinObservationWindowInSeconds, kMaxObservationWindowInSeconds));
change_count_threshold_ =
base::RandInt(kMinChangesThreshold, kMaxChangesThreshold);
penalty_duration_ = base::Seconds(base::RandInt(
kMinPenaltyDurationInSeconds, kMaxPenaltyDurationInSeconds));
start_time_ = base::TimeTicks::Now();
change_count_.fill(0);
}
void ChangeRateMonitor::ResetIfNeeded() {
const base::TimeDelta time_diff = base::TimeTicks::Now() - start_time_;
CHECK(time_diff.is_positive());
if (time_diff > observation_window_time_) {
Reset();
}
}
void ChangeRateMonitor::ResetChangeCount(V8PressureSource::Enum source) {
change_count_[ToSourceIndex(source)] = 0;
}
void ChangeRateMonitor::IncreaseChangeCount(V8PressureSource::Enum source) {
change_count_[ToSourceIndex(source)]++;
}
bool ChangeRateMonitor::ChangeCountExceedsLimit(
V8PressureSource::Enum source) const {
return change_count_[ToSourceIndex(source)] >= change_count_threshold_;
}
} // namespace blink
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