text: //
  // Copyright 2015 The ANGLE 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.
  //
  // histogram_macros.h:
  //   Helpers for making histograms, to keep consistency with Chromium's
  //   histogram_macros.h.
  
  #ifndef LIBANGLE_HISTOGRAM_MACROS_H_
  #define LIBANGLE_HISTOGRAM_MACROS_H_
  
  #include <platform/Platform.h>
  
  #define ANGLE_HISTOGRAM_TIMES(name, sample) ANGLE_HISTOGRAM_CUSTOM_TIMES( \
      name, sample, 1, 10000, 50)
  
  #define ANGLE_HISTOGRAM_MEDIUM_TIMES(name, sample) ANGLE_HISTOGRAM_CUSTOM_TIMES( \
      name, sample, 10, 180000, 50)
  
  // Use this macro when times can routinely be much longer than 10 seconds.
  #define ANGLE_HISTOGRAM_LONG_TIMES(name, sample) ANGLE_HISTOGRAM_CUSTOM_TIMES( \
      name, sample, 1, 3600000, 50)
  
  // Use this macro when times can routinely be much longer than 10 seconds and
  // you want 100 buckets.
  #define ANGLE_HISTOGRAM_LONG_TIMES_100(name, sample) ANGLE_HISTOGRAM_CUSTOM_TIMES( \
      name, sample, 1, 3600000, 100)
  
  // For folks that need real specific times, use this to select a precise range
  // of times you want plotted, and the number of buckets you want used.
  #define ANGLE_HISTOGRAM_CUSTOM_TIMES(name, sample, min, max, bucket_count) \
      ANGLE_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, bucket_count)
  
  #define ANGLE_HISTOGRAM_COUNTS(name, sample) ANGLE_HISTOGRAM_CUSTOM_COUNTS( \
      name, sample, 1, 1000000, 50)
  
  #define ANGLE_HISTOGRAM_COUNTS_100(name, sample) \
      ANGLE_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1, 100, 50)
  
  #define ANGLE_HISTOGRAM_COUNTS_10000(name, sample) \
      ANGLE_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1, 10000, 50)
  
  #define ANGLE_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, bucket_count) \
      ANGLEPlatformCurrent()->histogramCustomCounts(\
        name, sample, min, max, bucket_count)
  
  #define ANGLE_HISTOGRAM_PERCENTAGE(name, under_one_hundred) \
      ANGLE_HISTOGRAM_ENUMERATION(name, under_one_hundred, 101)
  
  #define ANGLE_HISTOGRAM_BOOLEAN(name, sample) \
      ANGLEPlatformCurrent()->histogramBoolean(name, sample)
  
  #define ANGLE_HISTOGRAM_ENUMERATION(name, sample, boundary_value) \
      ANGLEPlatformCurrent()->histogramEnumeration(name, sample, boundary_value)
  
  #define ANGLE_HISTOGRAM_MEMORY_KB(name, sample) ANGLE_HISTOGRAM_CUSTOM_COUNTS( \
      name, sample, 1000, 500000, 50)
  
  #define ANGLE_HISTOGRAM_MEMORY_MB(name, sample) ANGLE_HISTOGRAM_CUSTOM_COUNTS( \
      name, sample, 1, 1000, 50)
  
  #define ANGLE_HISTOGRAM_SPARSE_SLOWLY(name, sample) \
      ANGLEPlatformCurrent()->histogramSparse(name, sample)
  
  // Scoped class which logs its time on this earth as a UMA statistic. This is
  // recommended for when you want a histogram which measures the time it takes
  // for a method to execute. This measures up to 10 seconds.
  #define SCOPED_ANGLE_HISTOGRAM_TIMER(name) \
      SCOPED_ANGLE_HISTOGRAM_TIMER_EXPANDER(name, false, __COUNTER__)
  
  // Similar scoped histogram timer, but this uses ANGLE_HISTOGRAM_LONG_TIMES_100,
  // which measures up to an hour, and uses 100 buckets. This is more expensive
  // to store, so only use if this often takes >10 seconds.
  #define SCOPED_ANGLE_HISTOGRAM_LONG_TIMER(name) \
      SCOPED_ANGLE_HISTOGRAM_TIMER_EXPANDER(name, true, __COUNTER__)
  
  // This nested macro is necessary to expand __COUNTER__ to an actual value.
  #define SCOPED_ANGLE_HISTOGRAM_TIMER_EXPANDER(name, is_long, key) \
      SCOPED_ANGLE_HISTOGRAM_TIMER_UNIQUE(name, is_long, key)
  
  #define SCOPED_ANGLE_HISTOGRAM_TIMER_UNIQUE(name, is_long, key)                              \
      class ScopedHistogramTimer##key                                                          \
      {                                                                                        \
        public:                                                                                \
          ScopedHistogramTimer##key() : constructed_(ANGLEPlatformCurrent()->currentTime()) {} \
          ~ScopedHistogramTimer##key()                                                         \
          {                                                                                    \
              if (constructed_ == 0)                                                           \
                  return;                                                                      \
              double elapsed = ANGLEPlatformCurrent()->currentTime() - constructed_;           \
              int elapsedMS = static_cast<int>(elapsed * 1000.0);                              \
              if (is_long)                                                                     \
              {                                                                                \
                  ANGLE_HISTOGRAM_LONG_TIMES_100(name, elapsedMS);                             \
              }                                                                                \
              else                                                                             \
              {                                                                                \
                  ANGLE_HISTOGRAM_TIMES(name, elapsedMS);                                      \
              }                                                                                \
          }                                                                                    \
                                                                                               \
        private:                                                                               \
          double constructed_;                                                                 \
      } scoped_histogram_timer_##key
  
  #endif  // BASE_METRICS_HISTOGRAM_MACROS_H_
  