blob: ccadb12894fc57ab57439b00e08560dc2cf02d63 [file] [log] [blame]
// Copyright 2013 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 <string>
#include <vector>
#include "base/base_export.h"
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "base/metrics/histogram_flattener.h"
#include "base/metrics/histogram_snapshot_manager.h"
namespace base {
class HistogramBase;
// Serializes and restores histograms deltas.
class BASE_EXPORT HistogramDeltaSerialization : public HistogramFlattener {
// |caller_name| is string used in histograms for counting inconsistencies.
explicit HistogramDeltaSerialization(const std::string& caller_name);
virtual ~HistogramDeltaSerialization();
// Computes deltas in histogram bucket counts relative to the previous call to
// this method. Stores the deltas in serialized form into |serialized_deltas|.
// If |serialized_deltas| is NULL, no data is serialized, though the next call
// will compute the deltas relative to this one.
void PrepareAndSerializeDeltas(std::vector<std::string>* serialized_deltas);
// Deserialize deltas and add samples to corresponding histograms, creating
// them if necessary. Silently ignores errors in |serialized_deltas|.
static void DeserializeAndAddSamples(
const std::vector<std::string>& serialized_deltas);
// HistogramFlattener implementation.
virtual void RecordDelta(const HistogramBase& histogram,
const HistogramSamples& snapshot) OVERRIDE;
virtual void InconsistencyDetected(
HistogramBase::Inconsistency problem) OVERRIDE;
virtual void UniqueInconsistencyDetected(
HistogramBase::Inconsistency problem) OVERRIDE;
virtual void InconsistencyDetectedInLoggedCount(int amount) OVERRIDE;
// Calculates deltas in histogram counters.
HistogramSnapshotManager histogram_snapshot_manager_;
// Output buffer for serialized deltas.
std::vector<std::string>* serialized_deltas_;
// Histograms to count inconsistencies in snapshots.
HistogramBase* inconsistencies_histogram_;
HistogramBase* inconsistencies_unique_histogram_;
HistogramBase* inconsistent_snapshot_histogram_;
} // namespace base