components/metrics/single_sample_metrics.cc

   1 // Copyright 2017 The Chromium Authors
   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 "components/metrics/single_sample_metrics.h"
   6
   7 #include <memory>
   8 #include <utility>
   9
  10 #include "base/metrics/single_sample_metrics.h"
  11 #include "base/threading/thread_checker.h"
  12 #include "components/metrics/single_sample_metrics_factory_impl.h"
  13 #include "mojo/public/cpp/bindings/pending_receiver.h"
  14 #include "mojo/public/cpp/bindings/self_owned_receiver.h"
  15
  16 namespace metrics {
  17 namespace {
  18
  19 class MojoSingleSampleMetric : public mojom::SingleSampleMetric {
  20  public:
  21   MojoSingleSampleMetric(const std::string& histogram_name,
  22                          base::HistogramBase::Sample min,
  23                          base::HistogramBase::Sample max,
  24                          uint32_t bucket_count,
  25                          int32_t flags)
  26       : metric_(histogram_name, min, max, bucket_count, flags) {}
  27
  28   MojoSingleSampleMetric(const MojoSingleSampleMetric&) = delete;
  29   MojoSingleSampleMetric& operator=(const MojoSingleSampleMetric&) = delete;
  30
  31   ~MojoSingleSampleMetric() override {}
  32
  33  private:
  34   // mojom::SingleSampleMetric:
  35   void SetSample(base::HistogramBase::Sample sample) override {
  36     metric_.SetSample(sample);
  37   }
  38
  39   base::DefaultSingleSampleMetric metric_;
  40 };
  41
  42 class MojoSingleSampleMetricsProvider
  43     : public mojom::SingleSampleMetricsProvider {
  44  public:
  45   MojoSingleSampleMetricsProvider() {}
  46
  47   MojoSingleSampleMetricsProvider(const MojoSingleSampleMetricsProvider&) =
  48       delete;
  49   MojoSingleSampleMetricsProvider& operator=(
  50       const MojoSingleSampleMetricsProvider&) = delete;
  51
  52   ~MojoSingleSampleMetricsProvider() override {
  53     DCHECK(thread_checker_.CalledOnValidThread());
  54   }
  55
  56  private:
  57   // mojom::SingleSampleMetricsProvider:
  58   void AcquireSingleSampleMetric(
  59       const std::string& histogram_name,
  60       base::HistogramBase::Sample min,
  61       base::HistogramBase::Sample max,
  62       uint32_t bucket_count,
  63       int32_t flags,
  64       mojo::PendingReceiver<mojom::SingleSampleMetric> receiver) override {
  65     DCHECK(thread_checker_.CalledOnValidThread());
  66     mojo::MakeSelfOwnedReceiver(
  67         std::make_unique<MojoSingleSampleMetric>(histogram_name, min, max,
  68                                                  bucket_count, flags),
  69         std::move(receiver));
  70   }
  71
  72   // Providers must be created, used on, and destroyed on the same thread.
  73   base::ThreadChecker thread_checker_;
  74 };
  75
  76 }  // namespace
  77
  78 // static
  79 void InitializeSingleSampleMetricsFactory(CreateProviderCB create_provider_cb) {
  80   base::SingleSampleMetricsFactory::SetFactory(
  81       std::make_unique<SingleSampleMetricsFactoryImpl>(
  82           std::move(create_provider_cb)));
  83 }
  84
  85 // static
  86 void CreateSingleSampleMetricsProvider(
  87     mojo::PendingReceiver<mojom::SingleSampleMetricsProvider> receiver) {
  88   mojo::MakeSelfOwnedReceiver(
  89       std::make_unique<MojoSingleSampleMetricsProvider>(), std::move(receiver));
  90 }
  91
  92 }  // namespace metrics