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..65d3dd58dc4c5e92c2b162e9134a506582bc4677 100644
--- a/content/browser/device_orientation/data_fetcher_impl_android.cc
+++ b/content/browser/device_orientation/data_fetcher_impl_android.cc
@@ -4,8 +4,10 @@
 
 #include "content/browser/device_orientation/data_fetcher_impl_android.h"
 
+#include <string.h>
+
 #include "base/android/jni_android.h"
-#include "base/logging.h"
+#include "base/memory/singleton.h"
 #include "content/browser/device_orientation/orientation.h"
 #include "jni/DeviceMotionAndOrientation_jni.h"
 
@@ -21,31 +23,26 @@ const int kPeriodInMilliseconds = 100;
 
 }  // namespace
 
-DataFetcherImplAndroid::DataFetcherImplAndroid() {
+DataFetcherImplAndroid::DataFetcherImplAndroid()
+    : number_active_device_motion_sensors_(0),
+      device_motion_buffer_(NULL),
+      is_buffer_ready_(false) {
+  memset(received_motion_data_, 0, sizeof(received_motion_data_));
   device_orientation_.Reset(
       Java_DeviceMotionAndOrientation_getInstance(AttachCurrentThread()));
 }
 
+DataFetcherImplAndroid::~DataFetcherImplAndroid() {
+}
+
 void DataFetcherImplAndroid::Init(JNIEnv* env) {
   bool result = RegisterNativesImpl(env);
   DCHECK(result);
 }
 
-// TODO(timvolodine): Modify this method to be able to distinguish
-// device motion from orientation.
-DataFetcher* DataFetcherImplAndroid::Create() {
-  scoped_ptr<DataFetcherImplAndroid> fetcher(new DataFetcherImplAndroid);
-  if (fetcher->Start(DeviceData::kTypeOrientation, kPeriodInMilliseconds))
-    return fetcher.release();
-
-  LOG(ERROR) << "DataFetcherImplAndroid::Start failed!";
-  return NULL;
-}
-
-DataFetcherImplAndroid::~DataFetcherImplAndroid() {
-  // TODO(timvolodine): Support device motion as well. Only stop
-  // the active event type(s).
-  Stop(DeviceData::kTypeOrientation);
+DataFetcherImplAndroid* DataFetcherImplAndroid::GetInstance() {
+  return Singleton<DataFetcherImplAndroid,
+                   LeakySingletonTraits<DataFetcherImplAndroid> >::get();
 }
 
 const DeviceData* DataFetcherImplAndroid::GetDeviceData(
@@ -82,26 +79,61 @@ 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_) {
+    received_motion_data_[RECEIVED_MOTION_DATA_ACCELERATION] = 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_) {
+    received_motion_data_[RECEIVED_MOTION_DATA_ACCELERATION_INCL_GRAVITY] = 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_) {
+    received_motion_data_[RECEIVED_MOTION_DATA_ROTATION_RATE] = 1;
+    CheckBufferReadyToRead();
+  }
 }
 
-bool DataFetcherImplAndroid::Start(
-    DeviceData::Type event_type, int rate_in_milliseconds) {
+bool DataFetcherImplAndroid::Start(DeviceData::Type event_type) {
   DCHECK(!device_orientation_.is_null());
   return Java_DeviceMotionAndOrientation_start(
       AttachCurrentThread(), device_orientation_.obj(),
       reinterpret_cast<jint>(this), static_cast<jint>(event_type),
-      rate_in_milliseconds);
+      kPeriodInMilliseconds);
 }
 
 void DataFetcherImplAndroid::Stop(DeviceData::Type event_type) {
@@ -117,4 +149,48 @@ int DataFetcherImplAndroid::GetNumberActiveDeviceMotionSensors() {
       AttachCurrentThread(), device_orientation_.obj());
 }
 
+
+// ----- Shared memory API methods
+
+bool DataFetcherImplAndroid::StartFetchingDeviceMotionData(
+    DeviceMotionHardwareBuffer* buffer) {
+  device_motion_buffer_ = buffer;
+  ClearInternalBuffers();
+  bool success = Start(DeviceData::kTypeMotion);
+
+  // 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);
+  ClearInternalBuffers();
+}
+
+void DataFetcherImplAndroid::CheckBufferReadyToRead() {
+  if (received_motion_data_[RECEIVED_MOTION_DATA_ACCELERATION] +
+      received_motion_data_[RECEIVED_MOTION_DATA_ACCELERATION_INCL_GRAVITY] +
+      received_motion_data_[RECEIVED_MOTION_DATA_ROTATION_RATE] ==
+      number_active_device_motion_sensors_) {
+    SetBufferReadyStatus(true);
+  }
+}
+
+void DataFetcherImplAndroid::SetBufferReadyStatus(bool ready) {
+  device_motion_buffer_->seqlock.WriteBegin();
+  device_motion_buffer_->data.allAvailableSensorsAreActive = ready;
+  device_motion_buffer_->seqlock.WriteEnd();
+  is_buffer_ready_ = ready;
+}
+
+void DataFetcherImplAndroid::ClearInternalBuffers() {
+  memset(received_motion_data_, 0, sizeof(received_motion_data_));
+  number_active_device_motion_sensors_ = 0;
+  SetBufferReadyStatus(false);
+}
+
 }  // namespace content