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
14 namespace base {
15
TEST(HistogramDeltaSerializationTest,DeserializeHistogramAndAddSamples)16 TEST(HistogramDeltaSerializationTest, DeserializeHistogramAndAddSamples) {
17 std::unique_ptr<StatisticsRecorder> statistic_recorder(
18 StatisticsRecorder::CreateTemporaryForTesting());
19 HistogramDeltaSerialization serializer("HistogramDeltaSerializationTest");
20 std::vector<std::string> deltas;
21 // Nothing was changed yet.
22 serializer.PrepareAndSerializeDeltas(&deltas, true);
23 EXPECT_TRUE(deltas.empty());
24
25 HistogramBase* histogram = Histogram::FactoryGet(
26 "TestHistogram", 1, 1000, 10, HistogramBase::kIPCSerializationSourceFlag);
27 histogram->Add(1);
28 histogram->Add(10);
29 histogram->Add(100);
30 histogram->Add(1000);
31
32 serializer.PrepareAndSerializeDeltas(&deltas, true);
33 EXPECT_FALSE(deltas.empty());
34
35 HistogramDeltaSerialization::DeserializeAndAddSamples(deltas);
36
37 // The histogram has kIPCSerializationSourceFlag. So samples will be ignored.
38 std::unique_ptr<HistogramSamples> snapshot(histogram->SnapshotSamples());
39 EXPECT_EQ(1, snapshot->GetCount(1));
40 EXPECT_EQ(1, snapshot->GetCount(10));
41 EXPECT_EQ(1, snapshot->GetCount(100));
42 EXPECT_EQ(1, snapshot->GetCount(1000));
43
44 // Clear kIPCSerializationSourceFlag to emulate multi-process usage.
45 histogram->ClearFlags(HistogramBase::kIPCSerializationSourceFlag);
46 HistogramDeltaSerialization::DeserializeAndAddSamples(deltas);
47
48 std::unique_ptr<HistogramSamples> snapshot2(histogram->SnapshotSamples());
49 EXPECT_EQ(2, snapshot2->GetCount(1));
50 EXPECT_EQ(2, snapshot2->GetCount(10));
51 EXPECT_EQ(2, snapshot2->GetCount(100));
52 EXPECT_EQ(2, snapshot2->GetCount(1000));
53 }
54
55 } // namespace base
56