Method readBackupMetadata

src/Backups/BackupImpl.cpp:497–626

void BackupImpl::readBackupMetadata()
{
    LOG_TRACE(log, "Backup {}: Reading metadata", backup_name_for_logging);
    auto timer = DB::CurrentThread::getProfileEvents().timer(ProfileEvents::BackupReadMetadataMicroseconds);

    using namespace XMLUtils;

    std::unique_ptr<ReadBuffer> in;
    if (use_archive)
    {
        if (!archive_reader->fileExists(".backup"))
            throw Exception(ErrorCodes::BACKUP_NOT_FOUND, "Archive {} is not a backup", backup_name_for_logging);
        setCompressedSize();
        in = archive_reader->readFile(".backup", /*throw_on_not_found=*/true);
    }
    else
    {
        if (!reader->fileExists(".backup"))
            throw Exception(ErrorCodes::BACKUP_NOT_FOUND, "Backup {} not found", backup_name_for_logging);
        in = reader->readFile(".backup");
    }

    String str;
    readStringUntilEOF(str, *in);
    Poco::XML::DOMParser dom_parser;
    Poco::AutoPtr<Poco::XML::Document> config = dom_parser.parseMemory(str.data(), str.size());
    const Poco::XML::Node * config_root = getRootNode(config);
    version = getInt(config_root, "version");
    if ((version < INITIAL_BACKUP_VERSION) || (version > CURRENT_BACKUP_VERSION))
        throw Exception(
            ErrorCodes::BACKUP_VERSION_NOT_SUPPORTED, "Backup {}: Version {} is not supported", backup_name_for_logging, version);

    timestamp = parse<::LocalDateTime>(getString(config_root, "timestamp")).to_time_t();
    uuid = parse<UUID>(getString(config_root, "uuid"));

    if (config_root->getNodeByPath("base_backup") && !base_backup_info)
        base_backup_info = BackupInfo::fromString(getString(config_root, "base_backup"));

    if (config_root->getNodeByPath("base_backup_uuid"))
        base_backup_uuid = parse<UUID>(getString(config_root, "base_backup_uuid"));

    if (config_root->getNodeByPath("original_endpoint"))
        original_endpoint = getString(config_root, "original_endpoint");
    if (config_root->getNodeByPath("original_namespace"))
        original_namespace = getString(config_root, "original_namespace");

    num_files = 0;
    total_size = 0;
    num_entries = 0;
    size_of_entries = 0;

    const auto * contents = config_root->getNodeByPath("contents");
    for (const Poco::XML::Node * child = contents->firstChild(); child; child = child->nextSibling())
    {
        if (child->nodeName() == "file")
        {
            const Poco::XML::Node * file_config = child;
            BackupFileInfo info;