DBus changes for implementing local GATT attributes.

device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.cc

Index: device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.cc
diff --git a/device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.cc b/device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.cc
index e69a52e222111e6eb7b5bc8008797c8fd637fdc7..79fcc0248a52de96f15e26705ce45cdf6b084d5d 100644
--- a/device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.cc
+++ b/device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.cc
@@ -6,17 +6,14 @@
 
 #include <stddef.h>
 
-#include <memory>
-#include <utility>
-
 #include "base/bind.h"
+#include "base/callback.h"
 #include "base/logging.h"
-#include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string_util.h"
 #include "base/threading/platform_thread.h"
 #include "dbus/exported_object.h"
-#include "dbus/message.h"
 #include "device/bluetooth/dbus/bluez_dbus_manager.h"
 #include "device/bluetooth/dbus/fake_bluetooth_gatt_characteristic_service_provider.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
@@ -37,7 +34,7 @@ class BluetoothGattCharacteristicServiceProviderImpl
   BluetoothGattCharacteristicServiceProviderImpl(
       dbus::Bus* bus,
       const dbus::ObjectPath& object_path,
-      Delegate* delegate,
+      std::unique_ptr<BluetoothGattAttributeValueDelegate> delegate,
       const std::string& uuid,
       const std::vector<std::string>& flags,
       const std::vector<std::string>& permissions,
@@ -45,7 +42,7 @@ class BluetoothGattCharacteristicServiceProviderImpl
       : origin_thread_id_(base::PlatformThread::CurrentId()),
         uuid_(uuid),
         bus_(bus),
-        delegate_(delegate),
+        delegate_(std::move(delegate)),
         object_path_(object_path),
         service_path_(service_path),
         weak_ptr_factory_(this) {
@@ -162,7 +159,7 @@ class BluetoothGattCharacteristicServiceProviderImpl
     // If getting the "Value" property, obtain the value from the delegate.
     if (property_name == bluetooth_gatt_characteristic::kValueProperty) {
       DCHECK(delegate_);
-      delegate_->GetCharacteristicValue(
+      delegate_->GetValue(
           base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnGet,
                      weak_ptr_factory_.GetWeakPtr(), method_call,
                      response_sender),
@@ -264,7 +261,7 @@ class BluetoothGattCharacteristicServiceProviderImpl
     // Pass the set request onto the delegate.
     std::vector<uint8_t> value(bytes, bytes + length);
     DCHECK(delegate_);
-    delegate_->SetCharacteristicValue(
+    delegate_->SetValue(
         value,
         base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnSet,
                    weak_ptr_factory_.GetWeakPtr(), method_call,
@@ -307,7 +304,7 @@ class BluetoothGattCharacteristicServiceProviderImpl
     // Try to obtain the value from the delegate. We will construct the
     // response in the success callback.
     DCHECK(delegate_);
-    delegate_->GetCharacteristicValue(
+    delegate_->GetValue(
         base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnGetAll,
                    weak_ptr_factory_.GetWeakPtr(), method_call,
                    response_sender),
@@ -336,11 +333,18 @@ class BluetoothGattCharacteristicServiceProviderImpl
     std::unique_ptr<dbus::Response> response =
         dbus::Response::FromMethodCall(method_call);

[scheib, 2016/04/28 04:54:28]

Are protections against the callback being called twice prudent?

[rkc, 2016/04/28 18:13:23]

I'm pretty certain that our DBus client code has protections against multiple
responses being sent for the same request. I'll verify though.

     dbus::MessageWriter writer(response.get());
+    WriteProperties(&writer, &value);
+    response_sender.Run(std::move(response));
+  }
+
+  // Writes an array of the service's properties into the provided writer.
+  void WriteProperties(dbus::MessageWriter* writer,
+                       const std::vector<uint8_t>* value) override {
     dbus::MessageWriter array_writer(NULL);
     dbus::MessageWriter dict_entry_writer(NULL);
     dbus::MessageWriter variant_writer(NULL);
 
-    writer.OpenArray("{sv}", &array_writer);
+    writer->OpenArray("{sv}", &array_writer);
 
     array_writer.OpenDictEntry(&dict_entry_writer);
     dict_entry_writer.AppendString(
@@ -354,20 +358,20 @@ class BluetoothGattCharacteristicServiceProviderImpl
     dict_entry_writer.AppendVariantOfObjectPath(service_path_);
     array_writer.CloseContainer(&dict_entry_writer);
 
-    array_writer.OpenDictEntry(&dict_entry_writer);
-    dict_entry_writer.AppendString(
-        bluetooth_gatt_characteristic::kValueProperty);
-    dict_entry_writer.OpenVariant("ay", &variant_writer);
-    variant_writer.AppendArrayOfBytes(value.data(), value.size());
-    dict_entry_writer.CloseContainer(&variant_writer);
-    array_writer.CloseContainer(&dict_entry_writer);
+    if (value) {
+      array_writer.OpenDictEntry(&dict_entry_writer);
+      dict_entry_writer.AppendString(
+          bluetooth_gatt_characteristic::kValueProperty);
+      dict_entry_writer.OpenVariant("ay", &variant_writer);
+      variant_writer.AppendArrayOfBytes(value->data(), value->size());
+      dict_entry_writer.CloseContainer(&variant_writer);
+      array_writer.CloseContainer(&dict_entry_writer);
+    }
 
     // TODO(armansito): Process Flags & Permissions properties.
 
-    writer.CloseContainer(&array_writer);
-
-    response_sender.Run(std::move(response));
-  }
+    writer->CloseContainer(&array_writer);
+  };
 
   // Called by the Delegate in response to a successful method call to get the
   // characteristic value.
@@ -407,6 +411,8 @@ class BluetoothGattCharacteristicServiceProviderImpl
     response_sender.Run(std::move(error_response));
   }
 
+  const dbus::ObjectPath& object_path() const override { return object_path_; }
+
   // Origin thread (i.e. the UI thread in production).
   base::PlatformThreadId origin_thread_id_;
 
@@ -420,7 +426,7 @@ class BluetoothGattCharacteristicServiceProviderImpl
   // Incoming methods to get and set the "Value" property are passed on to the
   // delegate and callbacks passed to generate a reply. |delegate_| is generally
   // the object that owns this one and must outlive it.
-  Delegate* delegate_;
+  std::unique_ptr<BluetoothGattAttributeValueDelegate> delegate_;
 
   // D-Bus object path of object we are exporting, kept so we can unregister
   // again in our destructor.
@@ -454,17 +460,18 @@ BluetoothGattCharacteristicServiceProvider*
 BluetoothGattCharacteristicServiceProvider::Create(
     dbus::Bus* bus,
     const dbus::ObjectPath& object_path,
-    Delegate* delegate,
+    std::unique_ptr<BluetoothGattAttributeValueDelegate> delegate,
     const std::string& uuid,
     const std::vector<std::string>& flags,
     const std::vector<std::string>& permissions,
     const dbus::ObjectPath& service_path) {
   if (!bluez::BluezDBusManager::Get()->IsUsingFakes()) {
     return new BluetoothGattCharacteristicServiceProviderImpl(
-        bus, object_path, delegate, uuid, flags, permissions, service_path);
+        bus, object_path, std::move(delegate), uuid, flags, permissions,
+        service_path);
   }
   return new FakeBluetoothGattCharacteristicServiceProvider(
-      object_path, delegate, uuid, flags, permissions, service_path);
+      object_path, std::move(delegate), uuid, flags, permissions, service_path);
 }
 
 }  // namespace bluez