1// Copyright 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/metrics/histogram_delta_serialization.h"
6
7#include <vector>
8
9#include "base/metrics/histogram.h"
10#include "base/metrics/histogram_base.h"
11#include "base/metrics/statistics_recorder.h"
12#include "testing/gtest/include/gtest/gtest.h"
13
14namespace base {
15
16TEST(HistogramDeltaSerializationTest, DeserializeHistogramAndAddSamples) {
17  StatisticsRecorder statistic_recorder;
18  HistogramDeltaSerialization serializer("HistogramDeltaSerializationTest");
19  std::vector<std::string> deltas;
20  // Nothing was changed yet.
21  serializer.PrepareAndSerializeDeltas(&deltas);
22  EXPECT_TRUE(deltas.empty());
23
24  HistogramBase* histogram = Histogram::FactoryGet(
25      "TestHistogram", 1, 1000, 10, HistogramBase::kIPCSerializationSourceFlag);
26  histogram->Add(1);
27  histogram->Add(10);
28  histogram->Add(100);
29  histogram->Add(1000);
30
31  serializer.PrepareAndSerializeDeltas(&deltas);
32  EXPECT_FALSE(deltas.empty());
33
34  HistogramDeltaSerialization::DeserializeAndAddSamples(deltas);
35
36  // The histogram has kIPCSerializationSourceFlag. So samples will be ignored.
37  scoped_ptr<HistogramSamples> snapshot(histogram->SnapshotSamples());
38  EXPECT_EQ(1, snapshot->GetCount(1));
39  EXPECT_EQ(1, snapshot->GetCount(10));
40  EXPECT_EQ(1, snapshot->GetCount(100));
41  EXPECT_EQ(1, snapshot->GetCount(1000));
42
43  // Clear kIPCSerializationSourceFlag to emulate multi-process usage.
44  histogram->ClearFlags(HistogramBase::kIPCSerializationSourceFlag);
45  HistogramDeltaSerialization::DeserializeAndAddSamples(deltas);
46
47  scoped_ptr<HistogramSamples> snapshot2(histogram->SnapshotSamples());
48  EXPECT_EQ(2, snapshot2->GetCount(1));
49  EXPECT_EQ(2, snapshot2->GetCount(10));
50  EXPECT_EQ(2, snapshot2->GetCount(100));
51  EXPECT_EQ(2, snapshot2->GetCount(1000));
52}
53
54}  // namespace base
55