The Tor Browser: hal/windows/WindowsSensor.cpp@97036ab72558 (annotated)

hal/windows/WindowsSensor.cpp@97036ab72558 (annotated)

hal/windows/WindowsSensor.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "Hal.h"
 #include <sensorsapi.h>
 #include <sensors.h>
 #include <portabledevicetypes.h>
 #define MEAN_GRAVITY 9.80665
 #define DEFAULT_SENSOR_POLL 100
 using namespace mozilla::hal;
 namespace mozilla {
 namespace hal_impl {
 static nsRefPtr<ISensor> sAccelerometer;
 class SensorEvent MOZ_FINAL : public ISensorEvents {
 public:
   SensorEvent() : mCount(0) {
   }
   // IUnknown interface
   STDMETHODIMP_(ULONG) AddRef() {
     return InterlockedIncrement(&mCount);
   }
   STDMETHODIMP_(ULONG) Release() {
     ULONG count = InterlockedDecrement(&mCount);
     if (!count) {
       delete this;
       return 0;
     }
     return count;
   }
   STDMETHODIMP QueryInterface(REFIID iid, void** ppv) {
     if (iid == IID_IUnknown) {
       *ppv = static_cast<IUnknown*>(this);
     } else if (iid == IID_ISensorEvents) {
       *ppv = static_cast<ISensorEvents*>(this);
     } else {
       return E_NOINTERFACE;
     }
     AddRef();
     return S_OK;
   }
   // ISensorEvents interface
   STDMETHODIMP OnEvent(ISensor *aSensor, REFGUID aId, IPortableDeviceValues *aData) {
     return S_OK;
   }
   STDMETHODIMP OnLeave(REFSENSOR_ID aId) {
     return S_OK;
   }
   STDMETHODIMP OnStateChanged(ISensor *aSensor, SensorState state) {
     return S_OK;
   }
   STDMETHODIMP OnDataUpdated(ISensor *aSensor, ISensorDataReport *aReport) {
     PROPVARIANT v;
     HRESULT hr;
     InfallibleTArray<float> values;
     // X-axis acceleration in g's
     hr = aReport->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_X_G, &v);
     if (FAILED(hr)) {
       return hr;
     }
     values.AppendElement(float(-v.dblVal * MEAN_GRAVITY));
     // Y-axis acceleration in g's
     hr = aReport->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_Y_G, &v);
     if (FAILED(hr)) {
       return hr;
     }
     values.AppendElement(float(-v.dblVal * MEAN_GRAVITY));
     // Z-axis acceleration in g's
     hr = aReport->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_Z_G, &v);
     if (FAILED(hr)) {
       return hr;
     }
     values.AppendElement(float(-v.dblVal * MEAN_GRAVITY));
     hal::SensorData sdata(hal::SENSOR_ACCELERATION,
                           PR_Now(),
                           values,
                           hal::SENSOR_ACCURACY_UNKNOWN);
     hal::NotifySensorChange(sdata);
     return S_OK;
   }
 private:
   ULONG mCount;
 };
 void
 EnableSensorNotifications(SensorType aSensor)
 {
   if (aSensor != SENSOR_ACCELERATION) {
     return;
   }
   if (sAccelerometer) {
     return;
   }
   nsRefPtr<ISensorManager> manager;
   if (FAILED(CoCreateInstance(CLSID_SensorManager, nullptr,
                               CLSCTX_INPROC_SERVER,
                               IID_ISensorManager,
                               getter_AddRefs(manager)))) {
     return;
   }
   // accelerometer event
   nsRefPtr<ISensorCollection> collection;
   if (FAILED(manager->GetSensorsByType(SENSOR_TYPE_ACCELEROMETER_3D,
                                        getter_AddRefs(collection)))) {
     return;
   }
   ULONG count = 0;
   collection->GetCount(&count);
   if (!count) {
     return;
   }
   nsRefPtr<ISensor> sensor;
   collection->GetAt(0, getter_AddRefs(sensor));
   if (!sensor) {
     return;
   }
   // Set report interval to 100ms if possible.
   // Default value depends on drivers.
   nsRefPtr<IPortableDeviceValues> values;
   if (SUCCEEDED(CoCreateInstance(CLSID_PortableDeviceValues, nullptr,
                                  CLSCTX_INPROC_SERVER,
                                  IID_IPortableDeviceValues,
                                  getter_AddRefs(values)))) {
     if (SUCCEEDED(values->SetUnsignedIntegerValue(
                     SENSOR_PROPERTY_CURRENT_REPORT_INTERVAL,
                     DEFAULT_SENSOR_POLL))) {
       nsRefPtr<IPortableDeviceValues> returns;
       sensor->SetProperties(values, getter_AddRefs(returns));
     }
   }
   nsRefPtr<SensorEvent> event = new SensorEvent();
   nsRefPtr<ISensorEvents> sensorEvents;
   if (FAILED(event->QueryInterface(IID_ISensorEvents,
                                    getter_AddRefs(sensorEvents)))) {
     return;
   }
   if (FAILED(sensor->SetEventSink(sensorEvents))) {
     return;
   }
   sAccelerometer = sensor;
 }
 void
 DisableSensorNotifications(SensorType aSensor)
 {
   if (aSensor == SENSOR_ACCELERATION && sAccelerometer) {
     sAccelerometer->SetEventSink(nullptr);
     sAccelerometer = nullptr;
   }
 }
 } // hal_impl
 } // mozilla

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hal/windows/WindowsSensor.cpp@97036ab72558 (annotated)

hal/windows/WindowsSensor.cpp