ClickHouse/dbms/Storages/MergeTree/MergedColumnOnlyOutputStream.h
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

39 lines
1.4 KiB
C++

#pragma once
#include <Storages/MergeTree/IMergedBlockOutputStream.h>
namespace DB
{
class MergeTreeDataPartWriterWide;
/// Writes only those columns that are in `header`
class MergedColumnOnlyOutputStream final : public IMergedBlockOutputStream
{
public:
/// skip_offsets: used when ALTERing columns if we know that array offsets are not altered.
/// Pass empty 'already_written_offset_columns' first time then and pass the same object to subsequent instances of MergedColumnOnlyOutputStream
/// if you want to serialize elements of Nested data structure in different instances of MergedColumnOnlyOutputStream.
MergedColumnOnlyOutputStream(
const MergeTreeDataPartPtr & data_part, const Block & header_, bool sync_,
CompressionCodecPtr default_codec_, bool skip_offsets_,
const std::vector<MergeTreeIndexPtr> & indices_to_recalc_,
WrittenOffsetColumns * offset_columns_ = nullptr,
const MergeTreeIndexGranularity & index_granularity = {},
const MergeTreeIndexGranularityInfo * index_granularity_info_ = nullptr,
bool is_writing_temp_files = false);
Block getHeader() const override { return header; }
void write(const Block & block) override;
void writeSuffix() override;
MergeTreeData::DataPart::Checksums
writeSuffixAndGetChecksums(MergeTreeData::MutableDataPartPtr & new_part, MergeTreeData::DataPart::Checksums & all_checksums);
private:
Block header;
bool sync;
};
}