chromium/base/metrics/persistent_sample_map.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// PersistentSampleMap implements HistogramSamples interface. It is used
// by the SparseHistogram class to store samples in persistent memory which
// allows it to be shared between processes or live across restarts.

#ifndef BASE_METRICS_PERSISTENT_SAMPLE_MAP_H_
#define BASE_METRICS_PERSISTENT_SAMPLE_MAP_H_

#include <stdint.h>

#include <map>
#include <memory>
#include <optional>

#include "base/base_export.h"
#include "base/compiler_specific.h"
#include "base/memory/raw_ptr.h"
#include "base/metrics/histogram_base.h"
#include "base/metrics/histogram_samples.h"
#include "base/metrics/persistent_memory_allocator.h"

namespace base {

class PersistentHistogramAllocator;
class PersistentSampleMapRecords;

// The logic here is similar to that of SampleMap but with different data
// structures. Changes here likely need to be duplicated there.
class BASE_EXPORT PersistentSampleMap : public HistogramSamples { … };

}  // namespace base

#endif  // BASE_METRICS_PERSISTENT_SAMPLE_MAP_H_