TF_WRITABLE_FILE_OPS_ABI, "writable file"));

  if (ops->read_only_memory_region_ops != nullptr)
    TF_RETURN_IF_ERROR(CheckABI(ops->read_only_memory_region_ops_abi,
                                TF_READ_ONLY_MEMORY_REGION_OPS_ABI,
                                "read only memory region"));

  return OkStatus();
}

// Checks if the plugin and core API numbers match, logging mismatches.

  ops->writable_file_ops_size = TF_WRITABLE_FILE_OPS_SIZE;
  ops->read_only_memory_region_ops_abi = TF_READ_ONLY_MEMORY_REGION_OPS_ABI;
  ops->read_only_memory_region_ops_api = TF_READ_ONLY_MEMORY_REGION_OPS_API;
  ops->read_only_memory_region_ops_size = TF_READ_ONLY_MEMORY_REGION_OPS_SIZE;
}

/// Initializes a TensorFlow plugin.
///

      : filesystem_(std::move(filesystem)),
        ops_(std::move(filesystem_ops)),
        random_access_file_ops_(std::move(random_access_file_ops)),
        writable_file_ops_(std::move(writable_file_ops)),
        read_only_memory_region_ops_(std::move(read_only_memory_region_ops)),
        plugin_memory_allocate_(std::move(plugin_memory_allocate)),
        plugin_memory_free_(std::move(plugin_memory_free)) {}

  ops->writable_file_ops->close = tf_writable_file::Close;

  ops->read_only_memory_region_ops = static_cast<TF_ReadOnlyMemoryRegionOps*>(
      plugin_memory_allocate(TF_READ_ONLY_MEMORY_REGION_OPS_SIZE));
  ops->read_only_memory_region_ops->cleanup =
      tf_read_only_memory_region::Cleanup;
  ops->read_only_memory_region_ops->data = tf_read_only_memory_region::Data;

      plugin_status.get());

  if (TF_GetCode(plugin_status.get()) == TF_OK)
    *result = std::make_unique<ModularReadOnlyMemoryRegion>(
        std::move(region), read_only_memory_region_ops_.get());

  return StatusFromTF_Status(plugin_status.get());
}

Status ModularFileSystem::FileExists(const std::string& fname,
                                     TransactionToken* token) {

  ops->writable_file_ops->cleanup = tf_writable_file::Cleanup;

  ops->read_only_memory_region_ops = static_cast<TF_ReadOnlyMemoryRegionOps*>(
      plugin_memory_allocate(TF_READ_ONLY_MEMORY_REGION_OPS_SIZE));
  ops->read_only_memory_region_ops->cleanup =
      tf_read_only_memory_region::Cleanup;
  ops->read_only_memory_region_ops->data = tf_read_only_memory_region::Data;