// Copyright (c) 2008 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 NET_DISK_CACHE_STATS_HISTOGRAM_H_
#define NET_DISK_CACHE_STATS_HISTOGRAM_H_

#include "base/histogram.h"

namespace disk_cache {

class Stats;

// This class provides support for sending the disk cache size stats as a UMA
// histogram. We'll provide our own storage and management for the data, and a
// SampleSet with a copy of our data.
class StatsHistogram : public Histogram {
 public:
  class StatsSamples : public SampleSet {
   public:
    Counts* GetCounts() {
      return &counts_;
    }
  };

  explicit StatsHistogram(const wchar_t* name)
      : Histogram(name, 1, 1, 2), init_(false) {}
  ~StatsHistogram();

  // We'll be reporting data from the given set of cache stats.
  bool Init(const Stats* stats);

  virtual Sample ranges(size_t i) const;
  virtual size_t bucket_count() const;
  virtual void SnapshotSample(SampleSet* sample) const;

 private:
  bool init_;
  static const Stats* stats_;
  DISALLOW_COPY_AND_ASSIGN(StatsHistogram);
};

}  // namespace disk_cache

#endif  // NET_DISK_CACHE_STATS_HISTOGRAM_H_