chromium/base/metrics/histogram_base.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_METRICS_HISTOGRAM_BASE_H_
#define BASE_METRICS_HISTOGRAM_BASE_H_

#include <limits.h>
#include <stddef.h>
#include <stdint.h>

#include <atomic>
#include <memory>
#include <string>
#include <string_view>

#include "base/atomicops.h"
#include "base/base_export.h"
#include "base/time/time.h"
#include "base/values.h"

namespace base {

class Value;
class HistogramBase;
class HistogramSamples;
class Pickle;
class PickleIterator;

////////////////////////////////////////////////////////////////////////////////
// This enum is used to facilitate deserialization of histograms from other
// processes into the browser. If you create another class that inherits from
// HistogramBase, add new histogram types and names below.

enum HistogramType { … };

// Controls the verbosity of the information when the histogram is serialized to
// a JSON.
// GENERATED_JAVA_ENUM_PACKAGE: org.chromium.base.metrics
enum JSONVerbosityLevel { … };

std::string HistogramTypeToString(HistogramType type);

// This enum is used for reporting how many histograms and of what types and
// variations are being created. It has to be in the main .h file so it is
// visible to files that define the various histogram types.
enum HistogramReport { … };

// Create or find existing histogram that matches the pickled info.
// Returns NULL if the pickled data has problems.
BASE_EXPORT HistogramBase* DeserializeHistogramInfo(base::PickleIterator* iter);

////////////////////////////////////////////////////////////////////////////////

class BASE_EXPORT HistogramBase { … };

}  // namespace base

#endif  // BASE_METRICS_HISTOGRAM_BASE_H_