blob: 913762c95df490b9c6000b1fb01db13dcf233f8a [file] [log] [blame]
// 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.
#include <stddef.h>
#include <stdint.h>
#include <map>
#include <memory>
#include <string>
#include "base/base_export.h"
#include "base/macros.h"
#include "base/metrics/histogram_base.h"
#include "base/metrics/histogram_samples.h"
#include "base/synchronization/lock.h"
namespace base {
class HistogramSamples;
class PersistentHistogramAllocator;
class Pickle;
class PickleIterator;
class BASE_EXPORT SparseHistogram : public HistogramBase {
// If there's one with same name, return the existing one. If not, create a
// new one.
static HistogramBase* FactoryGet(const std::string& name, int32_t flags);
// Create a histogram using data in persistent storage. The allocator must
// live longer than the created sparse histogram.
static std::unique_ptr<HistogramBase> PersistentCreate(
PersistentHistogramAllocator* allocator,
const char* name,
HistogramSamples::Metadata* meta,
HistogramSamples::Metadata* logged_meta);
~SparseHistogram() override;
// HistogramBase implementation:
uint64_t name_hash() const override;
HistogramType GetHistogramType() const override;
bool HasConstructionArguments(Sample expected_minimum,
Sample expected_maximum,
uint32_t expected_bucket_count) const override;
void Add(Sample value) override;
void AddCount(Sample value, int count) override;
void AddSamples(const HistogramSamples& samples) override;
bool AddSamplesFromPickle(base::PickleIterator* iter) override;
std::unique_ptr<HistogramSamples> SnapshotSamples() const override;
std::unique_ptr<HistogramSamples> SnapshotDelta() override;
std::unique_ptr<HistogramSamples> SnapshotFinalDelta() const override;
void WriteHTMLGraph(std::string* output) const override;
void WriteAscii(std::string* output) const override;
// HistogramBase implementation:
void SerializeInfoImpl(base::Pickle* pickle) const override;
// Clients should always use FactoryGet to create SparseHistogram.
explicit SparseHistogram(const char* name);
SparseHistogram(PersistentHistogramAllocator* allocator,
const char* name,
HistogramSamples::Metadata* meta,
HistogramSamples::Metadata* logged_meta);
friend BASE_EXPORT HistogramBase* DeserializeHistogramInfo(
base::PickleIterator* iter);
static HistogramBase* DeserializeInfoImpl(base::PickleIterator* iter);
void GetParameters(DictionaryValue* params) const override;
void GetCountAndBucketData(Count* count,
int64_t* sum,
ListValue* buckets) const override;
// Helpers for emitting Ascii graphic. Each method appends data to output.
void WriteAsciiImpl(bool graph_it,
const std::string& newline,
std::string* output) const;
// Write a common header message describing this histogram.
void WriteAsciiHeader(const Count total_count,
std::string* output) const;
// For constuctor calling.
friend class SparseHistogramTest;
// Protects access to |samples_|.
mutable base::Lock lock_;
// Flag to indicate if PrepareFinalDelta has been previously called.
mutable bool final_delta_created_ = false;
std::unique_ptr<HistogramSamples> unlogged_samples_;
std::unique_ptr<HistogramSamples> logged_samples_;
} // namespace base