DBus changes for implementing local GATT attributes.

device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.cc

 // Copyright 2014 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 "device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider.h"
 
 #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"
 
 namespace bluez {
 namespace {
 const char kErrorInvalidArgs[] = "org.freedesktop.DBus.Error.InvalidArgs";
 const char kErrorPropertyReadOnly[] =
     "org.freedesktop.DBus.Error.PropertyReadOnly";
 const char kErrorFailed[] = "org.freedesktop.DBus.Error.Failed";
 }  // namespace
 
 // The BluetoothGattCharacteristicServiceProvider implementation used in
 // production.
 class BluetoothGattCharacteristicServiceProviderImpl
     : public BluetoothGattCharacteristicServiceProvider {
  public:
   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,
       const dbus::ObjectPath& service_path)
       : 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) {
     VLOG(1) << "Created Bluetooth GATT characteristic: " << object_path.value()
             << " UUID: " << uuid;
     DCHECK(bus_);
     DCHECK(delegate_);
     DCHECK(!uuid_.empty());
     DCHECK(object_path_.IsValid());
     DCHECK(service_path_.IsValid());
@@ skipping 96 matching lines @@
           dbus::ErrorResponse::FromMethodCall(
               method_call, kErrorInvalidArgs,
               "No such interface: '" + interface_name + "'.");
       response_sender.Run(std::move(error_response));
       return;
     }
 
     // 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),
           base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnFailure,
                      weak_ptr_factory_.GetWeakPtr(), method_call,
                      response_sender));
       return;
     }
 
     std::unique_ptr<dbus::Response> response =
@@ skipping 81 matching lines @@
           dbus::ErrorResponse::FromMethodCall(
               method_call, kErrorInvalidArgs,
               "Property '" + property_name + "' has type 'ay'.");
       response_sender.Run(std::move(error_response));
       return;
     }
 
     // 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,
                    response_sender),
         base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnFailure,
                    weak_ptr_factory_.GetWeakPtr(), method_call,
                    response_sender));
   }
 
   // Called by dbus:: when the Bluetooth daemon fetches all properties of the
@@ skipping 22 matching lines @@
           dbus::ErrorResponse::FromMethodCall(
               method_call, kErrorInvalidArgs,
               "No such interface: '" + interface_name + "'.");
       response_sender.Run(std::move(error_response));
       return;
     }
 
     // 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),
         base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnFailure,
                    weak_ptr_factory_.GetWeakPtr(), method_call,
                    response_sender));
   }
 
   // Called by dbus:: when a method is exported.
   void OnExported(const std::string& interface_name,
                   const std::string& method_name,
                   bool success) {
     LOG_IF(WARNING, !success) << "Failed to export " << interface_name << "."
                               << method_name;
   }
 
   // Called by the Delegate in response to a method to call to get all
   // properties, in which the delegate has successfully returned the
   // characteristic value.
   void OnGetAll(dbus::MethodCall* method_call,
                 dbus::ExportedObject::ResponseSender response_sender,
                 const std::vector<uint8_t>& value) {
     VLOG(2) << "Characteristic value obtained from delegate. Responding to "
             << "GetAll.";
 
     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(
         bluetooth_gatt_characteristic::kUUIDProperty);
     dict_entry_writer.AppendVariantOfString(uuid_);
     array_writer.CloseContainer(&dict_entry_writer);
 
     array_writer.OpenDictEntry(&dict_entry_writer);
     dict_entry_writer.AppendString(
         bluetooth_gatt_characteristic::kServiceProperty);
     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.
   void OnGet(dbus::MethodCall* method_call,
              dbus::ExportedObject::ResponseSender response_sender,
              const std::vector<uint8_t>& value) {
     VLOG(2) << "Returning characteristic value obtained from delegate.";
     std::unique_ptr<dbus::Response> response =
         dbus::Response::FromMethodCall(method_call);
     dbus::MessageWriter writer(response.get());
@@ skipping 19 matching lines @@
   void OnFailure(dbus::MethodCall* method_call,
                  dbus::ExportedObject::ResponseSender response_sender) {
     VLOG(2) << "Failed to get/set characteristic value. Report error.";
     std::unique_ptr<dbus::ErrorResponse> error_response =
         dbus::ErrorResponse::FromMethodCall(
             method_call, kErrorFailed,
             "Failed to get/set characteristic value.");
     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_;
 
   // 128-bit characteristic UUID of this object.
   std::string uuid_;
 
   // D-Bus bus object is exported on, not owned by this object and must
   // outlive it.
   dbus::Bus* bus_;
 
   // 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.
   dbus::ObjectPath object_path_;
 
   // Object path of the GATT service that the exported characteristic belongs
   // to.
   dbus::ObjectPath service_path_;
 
   // D-Bus object we are exporting, owned by this object.
@@ skipping 13 matching lines @@
     BluetoothGattCharacteristicServiceProvider() {}
 
 BluetoothGattCharacteristicServiceProvider::
     ~BluetoothGattCharacteristicServiceProvider() {}
 
 // static
 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