Method cloneAndLoadDataPartOnSameDisk

src/MergeTreeCommon/MergeTreeMetaBase.cpp:614–667

}

MergeTreeMetaBase::MutableDataPartPtr MergeTreeMetaBase::cloneAndLoadDataPartOnSameDisk(
    const MergeTreeMetaBase::DataPartPtr & src_part,
    const String & tmp_part_prefix,
    const MergeTreePartInfo & dst_part_info,
    const StorageMetadataPtr & metadata_snapshot)
{
    /// Check that the storage policy contains the disk where the src_part is located.
    bool does_storage_policy_allow_same_disk = false;
    for (const DiskPtr & disk : getStoragePolicy(IStorage::StorageLocation::MAIN)->getDisks())
    {
        if (disk->getName() == src_part->volume->getDisk()->getName())
        {
            does_storage_policy_allow_same_disk = true;
            break;
        }
    }
    if (!does_storage_policy_allow_same_disk)
        throw Exception(
            "Could not clone and load part " + quoteString(src_part->getFullPath()) + " because disk does not belong to storage policy",
            ErrorCodes::BAD_ARGUMENTS);

    String dst_part_name = src_part->getNewName(dst_part_info);
    String tmp_dst_part_name = tmp_part_prefix + dst_part_name;

    auto reservation = reserveSpace(src_part->getBytesOnDisk(), src_part->volume->getDisk());
    auto disk = reservation->getDisk();
    String src_part_path = src_part->getFullRelativePath();
    String dst_part_path = relative_data_path + tmp_dst_part_name;

    if (disk->exists(dst_part_path))
        throw Exception("Part in " + fullPath(disk, dst_part_path) + " already exists", ErrorCodes::DIRECTORY_ALREADY_EXISTS);

    /// If source part is in memory, flush it to disk and clone it already in on-disk format
    if (auto src_part_in_memory = asInMemoryPart(src_part))
    {
        const auto & src_relative_data_path = src_part_in_memory->storage.getRelativeDataPath(IStorage::StorageLocation::MAIN);
        auto flushed_part_path = src_part_in_memory->getRelativePathForPrefix(tmp_part_prefix, /*is_detach*/false);
        src_part_in_memory->flushToDisk(src_relative_data_path, flushed_part_path, metadata_snapshot);
        src_part_path = fs::path(src_relative_data_path) / flushed_part_path / "";
    }

    LOG_DEBUG(log, "Cloning part {} to {}", fullPath(disk, src_part_path), fullPath(disk, dst_part_path));
    localBackup(disk, src_part_path, dst_part_path);
    disk->removeFileIfExists(fs::path(dst_part_path) / IMergeTreeDataPart::DELETE_ON_DESTROY_MARKER_FILE_NAME);

    auto single_disk_volume = std::make_shared<SingleDiskVolume>(disk->getName(), disk, 0);
    auto dst_data_part = createPart(dst_part_name, dst_part_info, single_disk_volume, tmp_dst_part_name);

    dst_data_part->is_temp = true;

    dst_data_part->loadColumnsChecksumsIndexes(require_part_metadata, true);
    dst_data_part->modification_time = disk->getLastModified(dst_part_path).epochTime();
    return dst_data_part;
}

String MergeTreeMetaBase::getFullPathOnDisk(StorageLocation location, const DiskPtr & disk) const
{