gecko-dev/xpcom/threads/InputEventStatistics.cpp

80 строки
2.4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "InputEventStatistics.h"
#include "nsRefreshDriver.h"
namespace mozilla {
/*static*/ InputEventStatistics&
InputEventStatistics::Get()
{
static UniquePtr<InputEventStatistics> sInstance;
if (!sInstance) {
sInstance = MakeUnique<InputEventStatistics>(ConstructorCookie());
ClearOnShutdown(&sInstance);
}
return *sInstance;
}
TimeDuration
InputEventStatistics::TimeDurationCircularBuffer::GetMean()
{
return mTotal / (int64_t)mSize;
}
InputEventStatistics::InputEventStatistics(ConstructorCookie&&)
: mEnable(false)
{
MOZ_ASSERT(Preferences::IsServiceAvailable());
uint32_t inputDuration =
Preferences::GetUint("input_event_queue.default_duration_per_event",
sDefaultInputDuration);
TimeDuration defaultDuration = TimeDuration::FromMilliseconds(inputDuration);
uint32_t count =
Preferences::GetUint("input_event_queue.count_for_prediction",
sInputCountForPrediction);
mLastInputDurations =
MakeUnique<TimeDurationCircularBuffer>(count, defaultDuration);
uint32_t maxDuration =
Preferences::GetUint("input_event_queue.duration.max",
sMaxReservedTimeForHandlingInput);
uint32_t minDuration =
Preferences::GetUint("input_event_queue.duration.min",
sMinReservedTimeForHandlingInput);
mMaxInputDuration = TimeDuration::FromMilliseconds(maxDuration);
mMinInputDuration = TimeDuration::FromMilliseconds(minDuration);
}
TimeStamp
InputEventStatistics::GetInputHandlingStartTime(uint32_t aInputCount)
{
MOZ_ASSERT(mEnable);
Maybe<TimeStamp> nextTickHint = nsRefreshDriver::GetNextTickHint();
if (nextTickHint.isNothing()) {
// Return a past time to process input events immediately.
return TimeStamp::Now() - TimeDuration::FromMilliseconds(1);
}
TimeDuration inputCost = mLastInputDurations->GetMean() * aInputCount;
inputCost = inputCost > mMaxInputDuration
? mMaxInputDuration
: inputCost < mMinInputDuration
? mMinInputDuration
: inputCost;
return nextTickHint.value() - inputCost;
}
} // namespace mozilla