// Copyright 2017 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.

module arc.mojom;

import "arc_camera3.mojom";

// The ARC++ camera HAL v3 Mojo dispatcher.  The dispatcher acts as a proxy and
// waits for the server and the clients to register.  There can only be one
// server registered, with multiple clients requesting connections to the
// server.  For each client, the dispatcher is responsible for creating a Mojo
// channel to the server and pass the established Mojo channel to the client in
// order to set up a Mojo channel between the client and the server.
//
// The CameraHalDispatcher is designed to help the server and the clients to
// recover from errors easily.  For example, when the camera HAL process crashes
// the CameraHalDispatcher can still hold the connections of the clients. When
// the camera HAL reconnects the CameraHalDispatcher can then quickly restore
// the Mojo channels between the clients and the camera HAL process by calling
// CameraHalClient::SetUpChannel() in RegiserServer().
interface CameraHalDispatcher {
  // A CameraHalServer calls RegisterServer to register itself with the
  // dispatcher.
  RegisterServer@0(CameraHalServer server);

  // A CameraHalClient calls RegisterClient to register itself with the
  // dispatcher.
  RegisterClient@1(CameraHalClient client);
};

// The ARC++ camera HAL v3 Mojo server.
interface CameraHalServer {
  // A caller calls CreateChannel to create a new Mojo channel to the camera
  // HAL v3 adapter.  Upon successfully binding of |camera_module_request|, the
  // caller will have a established Mojo channel to the camera HAL v3 adapter
  // process.
  CreateChannel@0(CameraModule& camera_module_request);
};

// The ARC++ camera HAL v3 Mojo client.
interface CameraHalClient {
  // A caller calls SetUpChannel to dispatch the established Mojo channel
  // |camera_module_ptr| to the client.  The CameraHalClient can create a
  // Mojo channel to the camera HAL v3 adapter process with |camera_module_ptr|.
  // SetUpChannel may be called multiple times.
  SetUpChannel@0(CameraModule camera_module_ptr);
};