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#pragma once
#include <tuple>
#include <Storages/MarkCache.h>
#include <Storages/MergeTree/MarkRange.h>
#include <Storages/MergeTree/MergeTreeData.h>
#include <Storages/MergeTree/MergeTreeRangeReader.h>
#include <Storages/MergeTree/MergeTreeIndexGranularityInfo.h>
#include <Compression/CachedCompressedReadBuffer.h>
#include <Compression/CompressedReadBufferFromFile.h>
#include <Storages/MergeTree/MergeTreeIOSettings.h>
#include <Storages/MergeTree/MergeTreeMarksLoader.h>
#include <Storages/MergeTree/IMergeTreeDataPartInfoForReader.h>
namespace DB
{
/// Class for reading a single column (or index).
class MergeTreeReaderStream
{
public:
MergeTreeReaderStream(
MergeTreeDataPartInfoForReaderPtr data_part_reader_,
const String & path_prefix_,
const String & data_file_extension_,
size_t marks_count_,
const MarkRanges & all_mark_ranges,
const MergeTreeReaderSettings & settings_,
MarkCache * mark_cache,
UncompressedCache * uncompressed_cache,
size_t file_size_,
const MergeTreeIndexGranularityInfo * index_granularity_info_,
const ReadBufferFromFileBase::ProfileCallback & profile_callback,
clockid_t clock_type,
bool is_low_cardinality_dictionary_,
ThreadPool * load_marks_cache_threadpool_);
void seekToMark(size_t index);
void seekToStart();
/**
* Does buffer need to know something about mark ranges bounds it is going to read?
* (In case of MergeTree* tables). Mostly needed for reading from remote fs.
*/
void adjustRightMark(size_t right_mark);
ReadBuffer * getDataBuffer();
CompressedReadBufferBase * getCompressedDataBuffer();
private:
void init();
size_t getRightOffset(size_t right_mark);
const MergeTreeReaderSettings settings;
const ReadBufferFromFileBase::ProfileCallback profile_callback;
clockid_t clock_type;
const MarkRanges all_mark_ranges;
size_t file_size;
UncompressedCache * uncompressed_cache;
DataPartStoragePtr data_part_storage;
std::string path_prefix;
std::string data_file_extension;
bool is_low_cardinality_dictionary = false;
size_t marks_count;
ReadBuffer * data_buffer;
CompressedReadBufferBase * compressed_data_buffer;
MarkCache * mark_cache;
bool save_marks_in_cache;
bool initialized = false;
std::optional<size_t> last_right_offset;
const MergeTreeIndexGranularityInfo * index_granularity_info;
std::unique_ptr<CachedCompressedReadBuffer> cached_buffer;
std::unique_ptr<CompressedReadBufferFromFile> non_cached_buffer;
MergeTreeMarksLoader marks_loader;
};
}
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