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 "base/logging.h"
8 #include "base/metrics/histogram_base.h"
9 #include "base/metrics/histogram_snapshot_manager.h"
10 #include "base/pickle.h"
11 #include "base/safe_numerics.h"
12 #include "base/values.h"
13
14 namespace base {
15
16 namespace {
17
18 // Create or find existing histogram and add the samples from pickle.
19 // Silently returns when seeing any data problem in the pickle.
DeserializeHistogramAndAddSamples(PickleIterator * iter)20 void DeserializeHistogramAndAddSamples(PickleIterator* iter) {
21 HistogramBase* histogram = DeserializeHistogramInfo(iter);
22 if (!histogram)
23 return;
24
25 if (histogram->flags() & HistogramBase::kIPCSerializationSourceFlag) {
26 DVLOG(1) << "Single process mode, histogram observed and not copied: "
27 << histogram->histogram_name();
28 return;
29 }
30 histogram->AddSamplesFromPickle(iter);
31 }
32
33 } // namespace
34
HistogramDeltaSerialization(const std::string & caller_name)35 HistogramDeltaSerialization::HistogramDeltaSerialization(
36 const std::string& caller_name)
37 : histogram_snapshot_manager_(this),
38 serialized_deltas_(NULL) {
39 inconsistencies_histogram_ =
40 LinearHistogram::FactoryGet(
41 "Histogram.Inconsistencies" + caller_name, 1,
42 HistogramBase::NEVER_EXCEEDED_VALUE,
43 HistogramBase::NEVER_EXCEEDED_VALUE + 1,
44 HistogramBase::kUmaTargetedHistogramFlag);
45
46 inconsistencies_unique_histogram_ =
47 LinearHistogram::FactoryGet(
48 "Histogram.Inconsistencies" + caller_name + "Unique", 1,
49 HistogramBase::NEVER_EXCEEDED_VALUE,
50 HistogramBase::NEVER_EXCEEDED_VALUE + 1,
51 HistogramBase::kUmaTargetedHistogramFlag);
52
53 inconsistent_snapshot_histogram_ =
54 Histogram::FactoryGet(
55 "Histogram.InconsistentSnapshot" + caller_name, 1, 1000000, 50,
56 HistogramBase::kUmaTargetedHistogramFlag);
57 }
58
~HistogramDeltaSerialization()59 HistogramDeltaSerialization::~HistogramDeltaSerialization() {
60 }
61
PrepareAndSerializeDeltas(std::vector<std::string> * serialized_deltas)62 void HistogramDeltaSerialization::PrepareAndSerializeDeltas(
63 std::vector<std::string>* serialized_deltas) {
64 serialized_deltas_ = serialized_deltas;
65 // Note: Before serializing, we set the kIPCSerializationSourceFlag for all
66 // the histograms, so that the receiving process can distinguish them from the
67 // local histograms.
68 histogram_snapshot_manager_.PrepareDeltas(
69 Histogram::kIPCSerializationSourceFlag, false);
70 serialized_deltas_ = NULL;
71 }
72
73 // static
DeserializeAndAddSamples(const std::vector<std::string> & serialized_deltas)74 void HistogramDeltaSerialization::DeserializeAndAddSamples(
75 const std::vector<std::string>& serialized_deltas) {
76 for (std::vector<std::string>::const_iterator it = serialized_deltas.begin();
77 it != serialized_deltas.end(); ++it) {
78 Pickle pickle(it->data(), checked_numeric_cast<int>(it->size()));
79 PickleIterator iter(pickle);
80 DeserializeHistogramAndAddSamples(&iter);
81 }
82 }
83
RecordDelta(const HistogramBase & histogram,const HistogramSamples & snapshot)84 void HistogramDeltaSerialization::RecordDelta(
85 const HistogramBase& histogram,
86 const HistogramSamples& snapshot) {
87 DCHECK_NE(0, snapshot.TotalCount());
88
89 Pickle pickle;
90 histogram.SerializeInfo(&pickle);
91 snapshot.Serialize(&pickle);
92 serialized_deltas_->push_back(
93 std::string(static_cast<const char*>(pickle.data()), pickle.size()));
94 }
95
InconsistencyDetected(HistogramBase::Inconsistency problem)96 void HistogramDeltaSerialization::InconsistencyDetected(
97 HistogramBase::Inconsistency problem) {
98 inconsistencies_histogram_->Add(problem);
99 }
100
UniqueInconsistencyDetected(HistogramBase::Inconsistency problem)101 void HistogramDeltaSerialization::UniqueInconsistencyDetected(
102 HistogramBase::Inconsistency problem) {
103 inconsistencies_unique_histogram_->Add(problem);
104 }
105
InconsistencyDetectedInLoggedCount(int amount)106 void HistogramDeltaSerialization::InconsistencyDetectedInLoggedCount(
107 int amount) {
108 inconsistent_snapshot_histogram_->Add(std::abs(amount));
109 }
110
111 } // namespace base
112