// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_SERVICES_SHARING_NEARBY_PLATFORM_BLE_V2_GATT_SERVER_H_
#define CHROME_SERVICES_SHARING_NEARBY_PLATFORM_BLE_V2_GATT_SERVER_H_
#include "base/containers/flat_map.h"
#include "base/memory/weak_ptr.h"
#include "chrome/services/sharing/nearby/platform/bluetooth_adapter.h"
#include "device/bluetooth/public/mojom/adapter.mojom.h"
#include "mojo/public/cpp/bindings/pending_remote.h"
#include "mojo/public/cpp/bindings/receiver.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "mojo/public/cpp/bindings/shared_remote.h"
#include "third_party/nearby/src/internal/platform/implementation/ble_v2.h"
namespace nearby::chrome {
class BleV2GattServer : public ::nearby::api::ble_v2::GattServer,
public bluetooth::mojom::GattServiceObserver {
public:
// Representation of the local GattServices hosted in the BleV2GattServer.
struct GattService {
class Factory {
public:
virtual std::unique_ptr<GattService> Create();
virtual ~Factory();
};
GattService();
virtual ~GattService();
GattService(GattService&) = delete;
GattService& operator=(GattService&) = delete;
mojo::SharedRemote<bluetooth::mojom::GattService> gatt_service_remote;
base::flat_map<Uuid, api::ble_v2::GattCharacteristic>
characteristic_uuid_to_characteristic_map;
// Characteristic UUID to value map. The value is set
// in `UpdateCharacteristic()`, and this class is responsible for storing
// the value of a GATT characteristic. See documentation in
// `UpdateCharacteristic()`.
base::flat_map<Uuid, nearby::ByteArray> characteristic_uuid_to_value_map;
};
BleV2GattServer(const mojo::SharedRemote<bluetooth::mojom::Adapter>& adapter,
std::unique_ptr<GattService::Factory> gatt_service_factory =
std::make_unique<GattService::Factory>());
~BleV2GattServer() override;
BleV2GattServer(const BleV2GattServer&) = delete;
BleV2GattServer& operator=(const BleV2GattServer&) = delete;
// nearby::api::ble_v2::GattServer:
BluetoothAdapter& GetBlePeripheral() override;
std::optional<api::ble_v2::GattCharacteristic> CreateCharacteristic(
const Uuid& service_uuid,
const Uuid& characteristic_uuid,
api::ble_v2::GattCharacteristic::Permission permission,
api::ble_v2::GattCharacteristic::Property property) override;
bool UpdateCharacteristic(
const api::ble_v2::GattCharacteristic& characteristic,
const nearby::ByteArray& value) override;
absl::Status NotifyCharacteristicChanged(
const api::ble_v2::GattCharacteristic& characteristic,
bool confirm,
const nearby::ByteArray& new_value) override;
void Stop() override;
// Triggers registration of all `GattService`s known to this
// `BleV2GattServer`, which will make each `GattService` and all of its
// associated attributes available on the local adapters GATT database.
// This should be called once all the requested characteristics have been
// created via `CreateCharacteristic()`, before advertising begins.
void RegisterGattServices(
base::OnceCallback<void(bool)> on_registration_complete_callback);
base::WeakPtr<BleV2GattServer> GetWeakPtr() {
return weak_ptr_factory_.GetWeakPtr();
}
private:
// bluetooth::mojom::GattServiceObserver:
void OnLocalCharacteristicRead(
bluetooth::mojom::DeviceInfoPtr remote_device,
const device::BluetoothUUID& characteristic_uuid,
const device::BluetoothUUID& service_uuid,
uint32_t offset,
OnLocalCharacteristicReadCallback callback) override;
void RegisterGattService(GattService* gatt_service);
void DoRegisterGattService(GattService* gatt_service);
void OnRegisterGattService(
std::optional<device::BluetoothGattService::GattErrorCode> error_code);
void OnGattServiceDisconnected(const Uuid& gatt_service_id);
// Indicates whether registration of this `BleV2GattServer` via `Register` has
// been initiated. If so, this boolean helps enforce that calls to create
// characteristics or add new `GattService`s are not supported, since they
// will not show up on the platform layer to clients.
bool has_registration_started_ = false;
// Once registration has started (indicated by `has_registration_started_`),
// represents the overall registration success of triggering registration on
// the `GattService`s. If any `GattService` fails to be registered, a failure
// is returned back on the callback in `Register()`. For the `BleV2GattServer`
// MVP, only one `GattService` exists at a single time, since there is only
// a single usecase for `GattService`, however, this allows this code to be
// future-proofed and support multiple `GattService`s created at a time.
bool did_any_gatt_services_fail_to_register_ = false;
// `task_runner_` is required to prevent blocking in calls over the Mojo
// remote during GATT service registration.
scoped_refptr<base::SequencedTaskRunner> task_runner_;
// `registration_barrier_` is initialized during `RegisterGattServices()`
// with the number of `GattService`s that need to be registered via
// `RegisterGattService()`. This is needed because `RegisterGattServices()`
// kicks off multiple asynchronous tasks at once, and waits until they are
// all completed. When a `GattService` successfully completes its
// registration, it decrements the `registration_barrier_` count;
// when all tasks are completed successfully, `BleV2GattServer` triggers the
// passed in `on_registration_complete_callback_` to indicate to callers
// success. When a `GattService` unsuccessfully completes its registration,
// it immediately triggers the `on_registration_complete_callback_` with
// failure, and resets the `registration_barrier_` since there is no need to
// continue the registration of all other `GattService`s.
std::unique_ptr<base::AtomicRefCount> registration_barrier_;
base::OnceCallback<void(bool)> on_registration_complete_callback_;
std::unique_ptr<GattService::Factory> gatt_service_factory_;
std::unique_ptr<BluetoothAdapter> bluetooth_adapter_;
base::flat_map<Uuid, std::unique_ptr<GattService>> uuid_to_gatt_service_map_;
mojo::SharedRemote<bluetooth::mojom::Adapter> adapter_remote_;
mojo::Receiver<bluetooth::mojom::GattServiceObserver> gatt_service_observer_{
this};
base::WeakPtrFactory<BleV2GattServer> weak_ptr_factory_{this};
};
} // namespace nearby::chrome
#endif // CHROME_SERVICES_SHARING_NEARBY_PLATFORM_BLE_V2_GATT_SERVER_H_
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