src/input_sample/driver_compat.h

// Copyright 2022 The Fuchsia 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 FUCHSIA_SDK_EXAMPLES_CC_DRIVER_COMPAT_H_
#define FUCHSIA_SDK_EXAMPLES_CC_DRIVER_COMPAT_H_

#include <fidl/fuchsia.device.fs/cpp/wire.h>
#include <fidl/fuchsia.driver.compat/cpp/wire.h>

namespace input_driver_compat {

// Connect to the fuchsia.devices.fs.Exporter protocol
zx::status<fidl::ClientEnd<fuchsia_device_fs::Exporter>> ConnectToDeviceExporter(
    const driver::Namespace* ns) {
  auto exporter = ns->Connect<fuchsia_device_fs::Exporter>();
  if (exporter.is_error()) {
    return exporter.take_error();
  }
  return exporter;
}

// Create an exported directory handle using fuchsia.devices.fs.Exporter
zx::status<fidl::ServerEnd<fuchsia_io::Directory>> ExportDevfsEntry(const driver::Namespace* ns,
                                                                    fidl::StringView service_dir,
                                                                    fidl::StringView devfs_path,
                                                                    int protocol_id) {
  // Connect to the devfs exporter service
  auto exporter_client = ConnectToDeviceExporter(ns);
  if (exporter_client.is_error()) {
    return exporter_client.take_error();
  }
  auto exporter = fidl::WireSyncClient(std::move(exporter_client.value()));

  // Serve a connection for devfs clients
  auto endpoints = fidl::CreateEndpoints<fuchsia_io::Directory>();
  if (endpoints.is_error()) {
    return endpoints.take_error();
  }

  // Export the client side of the service connection to devfs
  auto result =
      exporter->Export(std::move(endpoints->client), service_dir, devfs_path, protocol_id);
  if (!result.ok()) {
    return zx::error(result.status());
  }
  if (result->is_error()) {
    return zx::error(result->error_value());
  }

  return zx::ok(std::move(endpoints->server));
}

}  // namespace input_driver_compat

#endif  // FUCHSIA_SDK_EXAMPLES_CC_DRIVER_COMPAT_H_