blob: 7af431cacb8a76cb8b003e3ccf097268e23a51a5 [file] [log] [blame]
// Copyright 2014 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 <stdint.h>
#include <memory>
#include <string>
#include <vector>
#include "base/lazy_instance.h"
#include "base/macros.h"
#include "base/metrics/histogram_flattener.h"
#include "base/metrics/histogram_snapshot_manager.h"
#include "base/synchronization/lock.h"
#include "third_party/metrics_proto/chrome_user_metrics_extension.pb.h"
namespace cronet {
// A HistogramManager instance is created by the app. It is the central
// controller for the acquisition of log data, and recording deltas for
// transmission to an external server. Public APIs are all thread-safe.
class HistogramManager : public base::HistogramFlattener {
~HistogramManager() override;
// Snapshot all histograms to record the delta into |uma_proto_| and then
// returns the serialized protobuf representation of the record in |data|.
// Returns true if it was successfully serialized.
bool GetDeltas(std::vector<uint8_t>* data);
// TODO(mef): Hang Histogram Manager off java object instead of singleton.
static HistogramManager* GetInstance();
friend struct base::LazyInstanceTraitsBase<HistogramManager>;
// base::HistogramFlattener:
void RecordDelta(const base::HistogramBase& histogram,
const base::HistogramSamples& snapshot) override;
base::HistogramSnapshotManager histogram_snapshot_manager_;
// Stores the protocol buffer representation for this log.
metrics::ChromeUserMetricsExtension uma_proto_;
// Should be acquired whenever GetDeltas() is executing to maintain
// thread-safety.
base::Lock get_deltas_lock_;
} // namespace cronet