histogram_samples.h | Explore in Territory

// 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_SAMPLES_H_
#define BASE_METRICS_HISTOGRAM_SAMPLES_H_

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

#include <limits>
#include <memory>
#include <string>
#include <string_view>

#include "base/atomicops.h"
#include "base/base_export.h"
#include "base/gtest_prod_util.h"
#include "base/memory/raw_ptr.h"
#include "base/metrics/histogram_base.h"

namespace base {

class Pickle;
class PickleIterator;
class SampleCountIterator;

// HistogramSamples is a container storing all samples of a histogram. All
// elements must be of a fixed width to ensure 32/64-bit interoperability.
// If this structure changes, bump the version number for kTypeIdHistogram
// in persistent_histogram_allocator.cc.
//
// Note that though these samples are individually consistent (through the use
// of atomic operations on the counts), there is only "eventual consistency"
// overall when multiple threads are accessing this data. That means that the
// sum, redundant-count, etc. could be momentarily out-of-sync with the stored
// counts but will settle to a consistent "steady state" once all threads have
// exited this code.
class BASE_EXPORT HistogramSamples { … };

class BASE_EXPORT SampleCountIterator { … };

class BASE_EXPORT SingleSampleIterator : public SampleCountIterator { … };

}  // namespace base

#endif  // BASE_METRICS_HISTOGRAM_SAMPLES_H_
chromium/base/metrics/histogram_samples.h
