// Copyright (c) 2012 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 CHROME_BROWSER_UI_WEBUI_PERFORMANCE_MONITOR_PERFORMANCE_MONITOR_UI_UTIL_H_
#define CHROME_BROWSER_UI_WEBUI_PERFORMANCE_MONITOR_PERFORMANCE_MONITOR_UI_UTIL_H_
#include "chrome/browser/performance_monitor/database.h"
#include "chrome/browser/ui/webui/performance_monitor/performance_monitor_ui_constants.h"
namespace performance_monitor {
typedef std::vector<Database::MetricVector> VectorOfMetricVectors;
class PerformanceMonitorUtilTest;
// This is an interface for the various aggregation functions. The base class
// will handle the separation of the metrics vector into the various intervals,
// and each derived class represents a different method of aggregation.
class Aggregator {
public:
Aggregator();
virtual ~Aggregator();
// Aggregate a full metric vector into a vector of metric vectors, with each
// metric vector representing the aggregation for an active interval. |start|
// is the start time of the metrics to aggregate, |intervals| is the vector
// of all intervals for which the database was active for the span to
// aggregate, and |resolution| is the time distance between aggregated points.
scoped_ptr<VectorOfMetricVectors> AggregateMetrics(
MetricType metric_type,
const Database::MetricVector* metrics,
const base::Time& start,
const std::vector<TimeRange>& intervals,
const base::TimeDelta& resolution);
protected:
friend class PerformanceMonitorUtilTest;
// Aggregate only a single interval, advancing the |metric| iterator to the
// end of the active interval (or the end of the vector). |metric| points to
// the start of the section to be aggregated, |metric_end| is the hard-limit
// for the end of the vector (so we don't advance past it), |time_start| and
// |time_end| represent the interval to aggregate, and |resolution| is the
// time distance between aggregated points.
virtual scoped_ptr<Database::MetricVector> AggregateInterval(
MetricType metric_type,
Database::MetricVector::const_iterator* metric,
const Database::MetricVector::const_iterator& metric_end,
const base::Time& time_start,
const base::Time& time_end,
const base::TimeDelta& resolution) = 0;
};
// Aggregation method classes.
class NoAggregation : public Aggregator {
private:
virtual scoped_ptr<Database::MetricVector> AggregateInterval(
MetricType metric_type,
Database::MetricVector::const_iterator* metric,
const Database::MetricVector::const_iterator& metric_end,
const base::Time& time_start,
const base::Time& time_end,
const base::TimeDelta& resolution) OVERRIDE;
};
class MedianAggregation : public Aggregator {
private:
virtual scoped_ptr<Database::MetricVector> AggregateInterval(
MetricType metric_type,
Database::MetricVector::const_iterator* metric,
const Database::MetricVector::const_iterator& metric_end,
const base::Time& time_start,
const base::Time& time_end,
const base::TimeDelta& resolution) OVERRIDE;
};
class MeanAggregation : public Aggregator {
private:
virtual scoped_ptr<Database::MetricVector> AggregateInterval(
MetricType metric_type,
Database::MetricVector::const_iterator* metric,
const Database::MetricVector::const_iterator& metric_end,
const base::Time& time_start,
const base::Time& time_end,
const base::TimeDelta& resolution) OVERRIDE;
};
// Return the factor by which all metrics should be multiplied in order to be in
// the preferred unit (e.g., memory usage is in bytes, but we display it in
// megabytes, so we return 1/1024^2).
double GetConversionFactor(UnitDetails from, UnitDetails to);
// Metric data can be either dense or sporadic, so AggregateMetric() normalizes
// the metric data in time. |metrics| must be sorted in increasing time.
// AggregateMetrics() will perform the aggregation according to the |strategy|
// provided.
//
// Median: Use the median of sample values from the window, ignoring
// irregularity in sample timings.
// Mean: Use the mean value within the window.
// None: Return all samples from the window.
//
// In the methods which do aggregation, sampling windows start and end at an
// integer multiple of |resolution| away from |start| and data points are
// omitted if there are no points to resample. The time associated with each
// slice is the time at the end of the slice. This aggregation is performed for
// each interval within |intervals|.
//
// Returns a pointer to a vector of MetricVectors, with one MetricVector per
// interval given, NULL if |metrics| is empty.
scoped_ptr<std::vector<Database::MetricVector> > AggregateMetric(
MetricType type,
const Database::MetricVector* metrics,
const base::Time& start,
const std::vector<TimeRange>& intervals,
const base::TimeDelta& resolution,
AggregationMethod method);
} // namespace performance_monitor
#endif // CHROME_BROWSER_UI_WEBUI_PERFORMANCE_MONITOR_PERFORMANCE_MONITOR_UI_UTIL_H_