message: Adding some fb303 timeseries abstractions
  Summary: As in title.
diff: @@ -94,6 +94,21 @@ class MultiLevelTimeSeries : public folly::MultiLevelTimeSeries<T> {
  }
  };
  +const int kMinuteDurations[] = {60, 0};
  +
  +template <class T>
  +class MinuteTimeSeries : public MultiLevelTimeSeries<T> {
  + public:
  + enum Levels {
  + MINUTE,
  + ALLTIME,
  + NUM_LEVELS,
  + };
  +
  + MinuteTimeSeries()
  + : MultiLevelTimeSeries<T>(NUM_LEVELS, 60, kMinuteDurations) {}
  +};
  +
  const int kMinuteHourDurations[] = {60, 3600, 0};
  template <class T>
  @@ -176,6 +191,20 @@ class TenMinuteHourTimeSeries : public MultiLevelTimeSeries<T> {
  : MultiLevelTimeSeries<T>(NUM_LEVELS, 60, kTenMinuteHourDurations) {}
  };
  +const int kQuarterMinuteOnlyDurations[] = {15};
  +
  +template <class T>
  +class QuarterMinuteOnlyTimeSeries : public MultiLevelTimeSeries<T> {
  + public:
  + enum Levels {
  + QUARTER_MINUTE,
  + NUM_LEVELS,
  + };
  +
  + QuarterMinuteOnlyTimeSeries()
  + : MultiLevelTimeSeries<T>(NUM_LEVELS, 15, kQuarterMinuteOnlyDurations) {}
  +};
  +
  const int kMinuteOnlyDurations[] = {60};
  template <class T>
  