Method getDatabaseDisk

src/Interpreters/Context.cpp:1452–1486

}

std::shared_ptr<IDisk> Context::getDatabaseDisk() const
{
    {
        SharedLockGuard lock(shared->mutex);
        if (shared->default_db_disk)
            return shared->default_db_disk;
    }

    // This is called first time early during the initialization.
    // Even if multiple threads try to get target_db_disk, only the first one will initialize the disks as there is another mutex in `getDiskMap()`
    // It is not necessary to introduce a mutex here.
    auto target_db_disk = [&]() -> std::shared_ptr<IDisk>
    {
        const auto & config = shared->getConfigRef();
        const auto & disk_map = getDisksMap();
        auto disk_name = config.getString("database_disk.disk", DiskSelector::DEFAULT_DISK_NAME);

        LOG_INFO(shared->log, "Database disk name: {}", disk_name);

        auto it = disk_map.find(disk_name);
        if (it == disk_map.end())
            throw Exception(ErrorCodes::UNKNOWN_DISK, "No disk {}", backQuote(disk_name));

        chassert(it->second);

        LOG_INFO(shared->log, "Database disk name: {}, path: {}", disk_name, it->second->getPath());
        return it->second;
    }();

    std::lock_guard lock(shared->mutex);
    if (shared->default_db_disk)
        return shared->default_db_disk;

    return shared->default_db_disk = target_db_disk;
}

String Context::getFilesystemCacheUser() const
{