Implement Android shared memory data fetcher for Device Motion.

content/browser/device_orientation/data_fetcher_impl_android.cc

Index: content/browser/device_orientation/data_fetcher_impl_android.cc
diff --git a/content/browser/device_orientation/data_fetcher_impl_android.cc b/content/browser/device_orientation/data_fetcher_impl_android.cc
index 069454db1d7faafc243b2bf02287c1148eab600d..8e1c47bd7b2c008713fbe5ed2585aba7e68be75c 100644
--- a/content/browser/device_orientation/data_fetcher_impl_android.cc
+++ b/content/browser/device_orientation/data_fetcher_impl_android.cc
@@ -21,7 +21,9 @@ const int kPeriodInMilliseconds = 100;
 
 }  // namespace
 
-DataFetcherImplAndroid::DataFetcherImplAndroid() {
+DataFetcherImplAndroid::DataFetcherImplAndroid()
+    : device_motion_buffer_(0),

[bulach, 2013/07/04 08:23:36]

nit: s/0/NULL/

[timvolodine, 2013/07/04 12:02:52]

Done.

+      is_buffer_ready_(false) {
   device_orientation_.Reset(
       Java_DeviceMotionAndOrientation_getInstance(AttachCurrentThread()));
 }
@@ -31,14 +33,19 @@ void DataFetcherImplAndroid::Init(JNIEnv* env) {
   DCHECK(result);
 }
 
-// TODO(timvolodine): Modify this method to be able to distinguish
-// device motion from orientation.
+DataFetcherImplAndroid* DataFetcherImplAndroid::instance() {
+  CR_DEFINE_STATIC_LOCAL(DataFetcherImplAndroid, s_data_fetcher, ());
+  return &s_data_fetcher;
+}
+
+// TODO(timvolodine): Remove this method once orientation also switches to
+// shared memory implementation.
 DataFetcher* DataFetcherImplAndroid::Create() {
-  scoped_ptr<DataFetcherImplAndroid> fetcher(new DataFetcherImplAndroid);
+  DataFetcherImplAndroid* fetcher = DataFetcherImplAndroid::instance();
   if (fetcher->Start(DeviceData::kTypeOrientation, kPeriodInMilliseconds))
-    return fetcher.release();
+    return fetcher;
 
-  LOG(ERROR) << "DataFetcherImplAndroid::Start failed!";
+  DVLOG(2) << "DataFetcherImplAndroid::Start failed!";
   return NULL;
 }
 
@@ -46,6 +53,7 @@ DataFetcherImplAndroid::~DataFetcherImplAndroid() {
   // TODO(timvolodine): Support device motion as well. Only stop
   // the active event type(s).

[bulach, 2013/07/04 08:23:36]

the first part of the TODO seem done :)

[timvolodine, 2013/07/04 12:02:52]

Done.

   Stop(DeviceData::kTypeOrientation);
+  Stop(DeviceData::kTypeMotion);
 }
 
 const DeviceData* DataFetcherImplAndroid::GetDeviceData(
@@ -82,17 +90,53 @@ void DataFetcherImplAndroid::GotOrientation(
 
 void DataFetcherImplAndroid::GotAcceleration(
     JNIEnv*, jobject, double x, double y, double z) {
-  NOTIMPLEMENTED();
+  device_motion_buffer_->seqlock.WriteBegin();
+  device_motion_buffer_->data.accelerationX = x;
+  device_motion_buffer_->data.hasAccelerationX = true;
+  device_motion_buffer_->data.accelerationY = y;
+  device_motion_buffer_->data.hasAccelerationY = true;
+  device_motion_buffer_->data.accelerationZ = z;
+  device_motion_buffer_->data.hasAccelerationZ = true;
+  device_motion_buffer_->seqlock.WriteEnd();
+
+  if (!is_buffer_ready_) {
+    receivedMotionData[0] = 1;
+    CheckBufferReadyToRead();
+  }
 }
 
 void DataFetcherImplAndroid::GotAccelerationIncludingGravity(
     JNIEnv*, jobject, double x, double y, double z) {
-  NOTIMPLEMENTED();
+  device_motion_buffer_->seqlock.WriteBegin();
+  device_motion_buffer_->data.accelerationIncludingGravityX = x;
+  device_motion_buffer_->data.hasAccelerationIncludingGravityX = true;
+  device_motion_buffer_->data.accelerationIncludingGravityY = y;
+  device_motion_buffer_->data.hasAccelerationIncludingGravityY = true;
+  device_motion_buffer_->data.accelerationIncludingGravityZ = z;
+  device_motion_buffer_->data.hasAccelerationIncludingGravityZ = true;
+  device_motion_buffer_->seqlock.WriteEnd();
+
+  if (!is_buffer_ready_) {
+    receivedMotionData[1] = 1;
+    CheckBufferReadyToRead();
+  }
 }
 
 void DataFetcherImplAndroid::GotRotationRate(
     JNIEnv*, jobject, double alpha, double beta, double gamma) {
-  NOTIMPLEMENTED();
+  device_motion_buffer_->seqlock.WriteBegin();
+  device_motion_buffer_->data.rotationRateAlpha = alpha;
+  device_motion_buffer_->data.hasRotationRateAlpha = true;
+  device_motion_buffer_->data.rotationRateBeta = beta;
+  device_motion_buffer_->data.hasRotationRateBeta = true;
+  device_motion_buffer_->data.rotationRateGamma = gamma;
+  device_motion_buffer_->data.hasRotationRateGamma = true;
+  device_motion_buffer_->seqlock.WriteEnd();
+
+  if (!is_buffer_ready_) {
+    receivedMotionData[2] = 1;
+    CheckBufferReadyToRead();
+  }
 }
 
 bool DataFetcherImplAndroid::Start(
@@ -117,4 +161,46 @@ int DataFetcherImplAndroid::GetNumberActiveDeviceMotionSensors() {
       AttachCurrentThread(), device_orientation_.obj());
 }
 
+
+// ----- New shared memory API methods
+
+bool DataFetcherImplAndroid::FetchDeviceMotionDataIntoBuffer() {
+  // This method should not be called because it is a push based fetcher.
+  DCHECK(NeedsPolling());
+  return false;
+}
+
+void DataFetcherImplAndroid::CheckBufferReadyToRead() {
+  if (receivedMotionData[0] + receivedMotionData[1] + receivedMotionData[2] ==
+      number_active_device_motion_sensors_) {
+    device_motion_buffer_->seqlock.WriteBegin();
+    device_motion_buffer_->data.allAvailableSensorsAreActive = true;

[bulach, 2013/07/04 08:23:36]

just checking:
once it has all three datatypes, the buffer will be ready.
then, if it updates only one of them, the "other side" would still consider the
whole set "fresh" ? or should this flag be per sensor?

[timvolodine, 2013/07/04 12:02:52]

This flag is actually intended for the cases where some of the sensors are not
available (i.e. it is possible for allAvailableSensorsAreActive to be true while
no motion data can be provided in which case Blink would eventually receive an
event with null values). So this flag is not related to freshness rather that
the data is in a sense complete and good to read for the other side.

+    device_motion_buffer_->seqlock.WriteEnd();
+    is_buffer_ready_ = true;
+  }
+}
+
+bool DataFetcherImplAndroid::StartFetchingDeviceMotionData(
+    DeviceMotionHardwareBuffer* buffer) {
+  device_motion_buffer_ = buffer;
+  receivedMotionData[0] = receivedMotionData[1] = receivedMotionData[2] = 0;

[bulach, 2013/07/04 08:23:36]

nit:
memset(received_motion_data, 0, sizeof(received_motion_data));

[timvolodine, 2013/07/04 12:02:52]

Done.

+  number_active_device_motion_sensors_ = 0;
+  is_buffer_ready_ = false;
+  bool success = Start(DeviceData::kTypeMotion, kPeriodInMilliseconds);
+
+  // If no motion data can ever be provided, the number of active device motion
+  // sensors will be zero. In that case flag the shared memory buffer
+  // as ready to read, as it will not change anyway.
+  number_active_device_motion_sensors_ = GetNumberActiveDeviceMotionSensors();
+  CheckBufferReadyToRead();
+  return success;
+}
+
+void DataFetcherImplAndroid::StopFetchingDeviceMotionData() {
+  Stop(DeviceData::kTypeMotion);
+  number_active_device_motion_sensors_ = 0;
+  receivedMotionData[0] = receivedMotionData[1] = receivedMotionData[2] = 0;

[bulach, 2013/07/04 08:23:36]

nit: memset

[timvolodine, 2013/07/04 12:02:52]

Done.

+  is_buffer_ready_ = false;
+}
+
 }  // namespace content