dart_timestamp_provider.cc

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "dart_timestamp_provider.h"
 
#include "dart_tools_api.h"
 
namespace flutter {
 
DartTimestampProvider::DartTimestampProvider() = default;
 
DartTimestampProvider::~DartTimestampProvider() = default;
 
int64_t DartTimestampProvider::ConvertToNanos(int64_t ticks,
                                              int64_t frequency) {
  int64_t nano_seconds = (ticks / frequency) * kNanosPerSecond;
  int64_t leftover_ticks = ticks % frequency;
  int64_t leftover_nanos = (leftover_ticks * kNanosPerSecond) / frequency;
  return nano_seconds + leftover_nanos;
}
 
fml::TimePoint DartTimestampProvider::Now() {
  const int64_t ticks = Dart_TimelineGetTicks();
  const int64_t frequency = Dart_TimelineGetTicksFrequency();
  // optimization for the most common case.
  if (frequency != kNanosPerSecond) {
    return fml::TimePoint::FromTicks(ConvertToNanos(ticks, frequency));
  } else {
    return fml::TimePoint::FromTicks(ticks);
  }
}
 
fml::TimePoint DartTimelineTicksSinceEpoch() {
  return DartTimestampProvider::Instance().Now();
}
 
}  // namespace flutter