arc: bluetooth: Add SDP host side support

components/arc/bluetooth/bluetooth_struct_traits.h

 // 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.
 
 #ifndef COMPONENTS_ARC_BLUETOOTH_BLUETOOTH_STRUCT_TRAITS_H_
 #define COMPONENTS_ARC_BLUETOOTH_BLUETOOTH_STRUCT_TRAITS_H_
 
+#include <map>
+#include <utility>
+#include <vector>
+
 #include "components/arc/common/bluetooth.mojom.h"
 #include "device/bluetooth/bluetooth_common.h"
+#include "device/bluetooth/bluez/bluetooth_service_attribute_value_bluez.h"
+#include "device/bluetooth/bluez/bluetooth_service_record_bluez.h"
+#include "ipc/ipc_message_utils.h"
 
 namespace mojo {
 
 template <>
 struct EnumTraits<arc::mojom::BluetoothDeviceType,
     device::BluetoothTransport> {
   static arc::mojom::BluetoothDeviceType ToMojom(
       device::BluetoothTransport type) {
     switch (type) {
       case device::BLUETOOTH_TRANSPORT_CLASSIC:
@@ skipping 22 matching lines @@
         *type = device::BLUETOOTH_TRANSPORT_DUAL;
         break;
       default:
         NOTREACHED() << "Invalid type: " << static_cast<uint32_t>(mojom_type);
         return false;
     }
     return true;
   }
 };
 
+template <>
+struct EnumTraits<arc::mojom::BluetoothSdpAttrType,
+                  bluez::BluetoothServiceAttributeValueBlueZ::Type> {
+  static arc::mojom::BluetoothSdpAttrType ToMojom(
+      bluez::BluetoothServiceAttributeValueBlueZ::Type input);
+  static bool FromMojom(
+      arc::mojom::BluetoothSdpAttrType input,
+      bluez::BluetoothServiceAttributeValueBlueZ::Type* output);
+};
+
+template <>
+struct StructTraits<arc::mojom::BluetoothSdpServiceAttr,
+                    bluez::BluetoothServiceAttributeValueBlueZ> {
+  static bluez::BluetoothServiceAttributeValueBlueZ::Type type(
+      const bluez::BluetoothServiceAttributeValueBlueZ& value) {
+    return value.type();
+  }
+
+  static size_t type_size(
+      const bluez::BluetoothServiceAttributeValueBlueZ& value) {
+    return value.size();
+  }
+
+  static const base::ListValue& value(
+      const bluez::BluetoothServiceAttributeValueBlueZ& value) {
+    base::ListValue list_value;
+    list_value.Append(value.value().CreateDeepCopy());
+    return std::move(list_value);

[dcheng, 2016/08/20 02:39:19]

Nit: std::move() has no effect here.

More problematically, this is actually called twice during serialization, so
it's a bit inefficient: what's the reason for wrapping it in a ListValue here
rather than just using a base::Value directly?

[yzshen1, 2016/08/22 23:42:14]

Ah, I think that is because we don't have any IPC::ParamTraits support from
converting to/from std::unique_ptr<base::Value>.

We could write a new IPC::ParamTraits or mojo::StructTraits for that.

+1 for dcheng's comment, this getter is called twice. So it would be nice if we
can avoid deep copy like this.

[Miao, 2016/08/25 16:51:36]

Added the SetUpContext / TearDownContext feature for deep copying.
value.value()'s return type is const reference, and we need to give the
ownership of a base::Value to the base::ListValue, so we still need
CreateDeepCopy().

+  }
+
+  static const std::vector<bluez::BluetoothServiceAttributeValueBlueZ>&
+  sequence(const bluez::BluetoothServiceAttributeValueBlueZ& value) {
+    return value.sequence();
+  }
+
+  static bool Read(arc::mojom::BluetoothSdpServiceAttrDataView data,
+                   bluez::BluetoothServiceAttributeValueBlueZ* output);
+};
+
+template <>
+struct StructTraits<arc::mojom::BluetoothSdpRecord,
+                    bluez::BluetoothServiceRecordBlueZ> {
+  static const std::map<uint16_t, bluez::BluetoothServiceAttributeValueBlueZ>
+  attrs(const bluez::BluetoothServiceRecordBlueZ& value) {
+    std::map<uint16_t, bluez::BluetoothServiceAttributeValueBlueZ> attributes;

[dcheng, 2016/08/20 02:39:19]

Similar comment here: if we really need to create an intermediate data
structure, we can use the SetUpContext / TearDownContext feature from
https://www.chromium.org/developers/design-documents/mojo/type-mapping#TOC-St...
to avoid building this map twice for each serialization.

[Miao, 2016/08/25 16:51:36]

Done.

+    std::vector<uint16_t> attribute_ids = value.GetAttributeIds();
+
+    for (auto it : attribute_ids) {
+      attributes[it] = std::move(bluez::BluetoothServiceAttributeValueBlueZ(

[dcheng, 2016/08/20 02:39:19]

Note that std::move() here doesn't have an effect, since the argument is already
an rvalue (http://en.cppreference.com/w/cpp/language/value_category#rvalue).

[Miao, 2016/08/25 16:51:36]

Done.

+          value.GetAttributeValue(it)));
+    }
+
+    return attributes;
+  }
+
+  static bool Read(arc::mojom::BluetoothSdpRecordDataView data,
+                   bluez::BluetoothServiceRecordBlueZ* output);
+};
+
 }  // namespace mojo
 
 #endif  // COMPONENTS_ARC_BLUETOOTH_BLUETOOTH_STRUCT_TRAITS_H_