[sensors] Generic Sensors Framework blink side

third_party/WebKit/Source/modules/sensor/SensorProxy.cpp

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/sensor/SensorProxy.h"
+
+#include "core/frame/LocalFrame.h"
+#include "modules/sensor/SensorProviderProxy.h"
+#include "platform/mojo/MojoHelper.h"
+
+using namespace device::mojom::blink;
+
+namespace blink {
+
+SensorProxy::SensorProxy(SensorType sensorType, SensorProviderProxy* provider)
+    : m_type(sensorType)
+    , m_mode(ReportingMode::CONTINUOUS)
+    , m_provider(provider)
+    , m_clientBinding(this)
+    , m_state(SensorProxy::Uninitialized)
+{
+}
+
+SensorProxy::~SensorProxy()
+{
+}
+
+void SensorProxy::dispose()
+{
+    m_clientBinding.Close();
+}
+
+DEFINE_TRACE(SensorProxy)
+{
+    visitor->trace(m_observers);
+    visitor->trace(m_provider);
+}
+
+void SensorProxy::addObserver(Observer* observer)
+{
+    if (!m_observers.contains(observer))
+        m_observers.add(observer);
+}
+
+void SensorProxy::removeObserver(Observer* observer)
+{
+    if (m_observers.contains(observer))

[timvolodine, 2016/08/25 17:52:33]

no need for contains

[Mikhail, 2016/08/26 16:42:42]

Done.

+        m_observers.remove(observer);
+
+    if (m_observers.isEmpty())
+        m_provider->removeSensor(this);
+}
+
+void SensorProxy::initialize()
+{
+    if (m_state != Uninitialized)
+        return;
+    m_state = Initializing;
+    auto callback = convertToBaseCallback(WTF::bind(&SensorProxy::onSensorCreated, wrapWeakPersistent(this)));
+    m_provider->sensorProvider()->GetSensor(m_type, mojo::GetProxy(&m_sensor), callback);
+}
+
+void SensorProxy::addConfiguration(SensorConfigurationPtr configuration, std::unique_ptr<Function<void(bool)>> callback)
+{
+    DCHECK(isInitialized());
+    m_sensor->AddConfiguration(std::move(configuration), convertToBaseCallback(std::move(callback)));
+}
+
+void SensorProxy::removeConfiguration(SensorConfigurationPtr configuration, std::unique_ptr<Function<void(bool)>> callback)
+{
+    DCHECK(isInitialized());
+    m_sensor->RemoveConfiguration(std::move(configuration), convertToBaseCallback(std::move(callback)));
+}
+
+void SensorProxy::suspend()
+{
+    DCHECK(isInitialized());
+    m_sensor->Suspend();
+}
+
+void SensorProxy::resume()
+{
+    DCHECK(isInitialized());
+    m_sensor->Resume();
+}
+
+void SensorProxy::RaiseError()
+{
+    handleSensorError();
+}
+
+void SensorProxy::SensorReadingChanged()
+{
+    for (Observer* observer : m_observers)
+        observer->onSensorReadingChanged();
+}
+
+void SensorProxy::handleSensorError()
+{
+    m_state = Uninitialized;
+
+    ObserversSet observersCopy(m_observers);
+    for (Observer* observer : observersCopy)
+        observer->onSensorError();
+
+    m_observers.clear();
+    m_provider->removeSensor(this);
+}
+
+void SensorProxy::onSensorCreated(SensorReadBufferPtr buffer, SensorClientRequest clientRequest)
+{
+    if (!buffer) {

[timvolodine, 2016/08/25 17:52:32]

DCHECK?

[Mikhail, 2016/08/26 16:42:42]

(!buffer) just means that platform could not create sensor for us, that might
happen.

[timvolodine, 2016/09/01 19:02:05]

Would it be better to go through handleSensorError (or something like that)
instead of onSensorCreated in that case?

[Mikhail, 2016/09/02 08:23:43]

handleSensorError() is a connection_error_handler for the sensor proxy however
at this point the proxy itself is not initialized so it cannot be invoked from
the mojo framework code.
In the past had had an extra 'result' parameter to show the call result (rather
than null checking of returned parameters), here it was decided to move to the
current semantics https://codereview.chromium.org/2078433002/#msg11.

+        handleSensorError();
+        return;
+    }
+
+    if (buffer->offset % SensorReadBuffer::kReadBufferSize != 0) {

[timvolodine, 2016/08/25 17:52:32]

DCHECK?

[Mikhail, 2016/08/26 16:42:42]

we've NOTREACHED(); below + some exit logic for release code

[timvolodine, 2016/09/01 19:02:06]

still looks DCHECK to me.. in other words if the condition is false looks like
programmatic error (i.e. this could be an invariant when creating buffer and
offset, either true or no buffer at all i.e. buffer==null), this would simplify
code.

[Mikhail, 2016/09/02 08:23:43]

Agreed. Done.

+        NOTREACHED();
+        handleSensorError();
+        return;
+    }
+
+    m_mode = buffer->mode;
+
+    m_clientBinding.Bind(std::move(clientRequest));
+    m_sensor.set_connection_error_handler(convertToBaseCallback(WTF::bind(&SensorProxy::handleSensorError, wrapWeakPersistent(this))));
+
+    m_sharedBufferHandle = std::move(buffer->memory);
+    DCHECK(!m_sharedBuffer);
+    m_sharedBuffer = m_sharedBufferHandle->MapAtOffset(buffer->offset, SensorReadBuffer::kReadBufferSize);
+
+    if (!m_sharedBuffer) {
+        handleSensorError();
+        return;
+    }
+
+    m_state = Initialized;
+
+    for (Observer* observer : m_observers)
+        observer->onSensorInitialized();
+}
+
+} // namespace blink