base/metrics/histogram_delta_serialization.cc

   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/numerics/safe_conversions.h"
  11 #include "base/pickle.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.
  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
  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
  59 HistogramDeltaSerialization::~HistogramDeltaSerialization() {
  60 }
  61
  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, Histogram::kNoFlags);
  70   serialized_deltas_ = NULL;
  71 }
  72
  73 // static
  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_cast<int>(it->size()));
  79     PickleIterator iter(pickle);
  80     DeserializeHistogramAndAddSamples(&iter);
  81   }
  82 }
  83
  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
  96 void HistogramDeltaSerialization::InconsistencyDetected(
  97     HistogramBase::Inconsistency problem) {
  98   inconsistencies_histogram_->Add(problem);
  99 }
 100
 101 void HistogramDeltaSerialization::UniqueInconsistencyDetected(
 102     HistogramBase::Inconsistency problem) {
 103   inconsistencies_unique_histogram_->Add(problem);
 104 }
 105
 106 void HistogramDeltaSerialization::InconsistencyDetectedInLoggedCount(
 107     int amount) {
 108   inconsistent_snapshot_histogram_->Add(std::abs(amount));
 109 }
 110
 111 }  // namespace base