ClickHouse/src/Storages/Freeze.h

#pragma once

#include <Storages/StorageReplicatedMergeTree.h>
#include <Storages/MergeTree/MergeTreeData.h>

namespace DB
{

/// Special metadata used during freeze table. Required for zero-copy
/// replication.
struct FreezeMetaData
{
public:
    void fill(const StorageReplicatedMergeTree & storage);

    void save(DiskPtr data_disk, const String & path) const;

    bool load(DiskPtr data_disk, const String & path);

    static void clean(DiskPtr data_disk, const String & path);

private:
    static String getFileName(const String & path);

public:
    int version = 2;
    String replica_name;
    String zookeeper_name;
    String table_shared_id;
};

class Unfreezer
{
public:
    Unfreezer(ContextPtr local_context) : local_context_(local_context) { zookeeper_ = local_context->getZooKeeper(); }
    PartitionCommandsResultInfo unfreezePartitionsFromTableDirectory(MergeTreeData::MatcherFn matcher, const String & backup_name, const Disks & disks, const fs::path & table_directory, std::optional<MergeTreeDataFormatVersion> format_version);
    BlockIO unfreeze(const String & backup_name);
private:
    ContextPtr local_context_;
    zkutil::ZooKeeperPtr zookeeper_;
    Poco::Logger * log = &Poco::Logger::get("Unfreezer");
    static constexpr std::string_view backup_directory_prefix = "shadow";
    static bool removeFreezedPart(DiskPtr disk, const String & path, const String & part_name, ContextPtr local_context,  zkutil::ZooKeeperPtr zookeeper);
};

}