ClickHouse/src/Storages/MergeTree/MergeTreeMarksLoader.h

#pragma once
#include <Storages/MergeTree/IDataPartStorage.h>
#include <Storages/MarkCache.h>
#include <IO/ReadSettings.h>

namespace DB
{

struct MergeTreeIndexGranularityInfo;

class MergeTreeMarksLoader
{
public:
    using MarksPtr = MarkCache::MappedPtr;

    MergeTreeMarksLoader(
        DataPartStoragePtr data_part_storage_,
        MarkCache * mark_cache_,
        const String & mrk_path,
        size_t marks_count_,
        const MergeTreeIndexGranularityInfo & index_granularity_info_,
        bool save_marks_in_cache_,
        const ReadSettings & read_settings_,
        size_t columns_in_mark_ = 1);

    const MarkInCompressedFile & getMark(size_t row_index, size_t column_index = 0);

    bool initialized() const { return marks != nullptr; }

private:
    DataPartStoragePtr data_part_storage;
    MarkCache * mark_cache = nullptr;
    String mrk_path;
    size_t marks_count;
    const MergeTreeIndexGranularityInfo & index_granularity_info;
    bool save_marks_in_cache = false;
    size_t columns_in_mark;
    MarkCache::MappedPtr marks;
    ReadSettings read_settings;

    void loadMarks();
    MarkCache::MappedPtr loadMarksImpl();
};

}