ui/latency/latency_histogram_macros.h

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_LATENCY_LATENCY_HISTOGRAM_MACROS_H_
#define UI_LATENCY_LATENCY_HISTOGRAM_MACROS_H_

#include "base/metrics/histogram_functions.h"

// Check valid timing for start and end latency components.
#define CONFIRM_VALID_TIMING(start, end)     \
  DCHECK(!start.first_event_time.is_null()); \
  DCHECK(!end.last_event_time.is_null());    \
  DCHECK_GE(end.last_event_time, start.first_event_time);

// Event latency that is mostly under 1 second. We should only use 100 buckets
// when needed.
#define UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(name, start, \
                                                                 end)         \
  CONFIRM_VALID_TIMING(start, end)                                            \
  base::UmaHistogramCustomCounts(                                             \
      name, (end.last_event_time - start.first_event_time).InMicroseconds(),  \
      1, 1000000, 100);

#define UMA_HISTOGRAM_INPUT_LATENCY_MILLISECONDS(name, start, end)           \
  CONFIRM_VALID_TIMING(start, end)                                           \
  base::UmaHistogramCustomCounts(                                            \
      name, (end.last_event_time - start.first_event_time).InMilliseconds(), \
      1, 1000, 50);

// Long touch/wheel scroll latency component that is mostly under 200ms.
#define UMA_HISTOGRAM_SCROLL_LATENCY_LONG_2(name, start, end)                 \
  CONFIRM_VALID_TIMING(start, end)                                            \
  base::Histogram::FactoryGet(name, 1000, 200000, 50,                         \
                              base::HistogramBase::kUmaTargetedHistogramFlag) \
      ->Add((end.last_event_time - start.first_event_time).InMicroseconds());

// Short touch/wheel scroll latency component that is mostly under 50ms.
#define UMA_HISTOGRAM_SCROLL_LATENCY_SHORT_2(name, start, end)                \
  CONFIRM_VALID_TIMING(start, end)                                            \
  base::Histogram::FactoryGet(name, 1, 50000, 50,                             \
                              base::HistogramBase::kUmaTargetedHistogramFlag) \
      ->Add((end.last_event_time - start.first_event_time).InMicroseconds());

#endif  // UI_LATENCY_LATENCY_HISTOGRAM_MACROS_H_