naiveproxy/base/metrics/histogram_delta_serialization.cc
2018-02-02 05:49:39 -05:00

82 lines
2.7 KiB
C++

// 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 "base/metrics/histogram_delta_serialization.h"
#include "base/logging.h"
#include "base/metrics/histogram_base.h"
#include "base/metrics/histogram_snapshot_manager.h"
#include "base/metrics/statistics_recorder.h"
#include "base/numerics/safe_conversions.h"
#include "base/pickle.h"
#include "base/values.h"
namespace base {
namespace {
// Create or find existing histogram and add the samples from pickle.
// Silently returns when seeing any data problem in the pickle.
void DeserializeHistogramAndAddSamples(PickleIterator* iter) {
HistogramBase* histogram = DeserializeHistogramInfo(iter);
if (!histogram)
return;
if (histogram->flags() & HistogramBase::kIPCSerializationSourceFlag) {
DVLOG(1) << "Single process mode, histogram observed and not copied: "
<< histogram->histogram_name();
return;
}
histogram->AddSamplesFromPickle(iter);
}
} // namespace
HistogramDeltaSerialization::HistogramDeltaSerialization(
const std::string& caller_name)
: histogram_snapshot_manager_(this), serialized_deltas_(nullptr) {}
HistogramDeltaSerialization::~HistogramDeltaSerialization() = default;
void HistogramDeltaSerialization::PrepareAndSerializeDeltas(
std::vector<std::string>* serialized_deltas,
bool include_persistent) {
DCHECK(thread_checker_.CalledOnValidThread());
serialized_deltas_ = serialized_deltas;
// Note: Before serializing, we set the kIPCSerializationSourceFlag for all
// the histograms, so that the receiving process can distinguish them from the
// local histograms.
StatisticsRecorder::PrepareDeltas(
include_persistent, Histogram::kIPCSerializationSourceFlag,
Histogram::kNoFlags, &histogram_snapshot_manager_);
serialized_deltas_ = nullptr;
}
// static
void HistogramDeltaSerialization::DeserializeAndAddSamples(
const std::vector<std::string>& serialized_deltas) {
for (std::vector<std::string>::const_iterator it = serialized_deltas.begin();
it != serialized_deltas.end(); ++it) {
Pickle pickle(it->data(), checked_cast<int>(it->size()));
PickleIterator iter(pickle);
DeserializeHistogramAndAddSamples(&iter);
}
}
void HistogramDeltaSerialization::RecordDelta(
const HistogramBase& histogram,
const HistogramSamples& snapshot) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_NE(0, snapshot.TotalCount());
Pickle pickle;
histogram.SerializeInfo(&pickle);
snapshot.Serialize(&pickle);
serialized_deltas_->push_back(
std::string(static_cast<const char*>(pickle.data()), pickle.size()));
}
} // namespace base