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107 lines
2.3 KiB
C++
107 lines
2.3 KiB
C++
#pragma once
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#include <DB/DataStreams/IProfilingBlockInputStream.h>
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#include <DB/Storages/IStorage.h>
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#include <DB/Common/PODArray.h>
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namespace DB
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{
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/// Tiny struct, stores number of a Part from which current row was fetched, and insertion flag.
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struct RowSourcePart
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{
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RowSourcePart() = default;
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RowSourcePart(size_t source_num, bool flag = false)
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{
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static_assert(sizeof(*this) == 1, "Size of RowSourcePart is too big due to compiler settings");
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setSourceNum(source_num);
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setSkipFlag(flag);
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}
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/// is equal to getSourceNum() if flag is false
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size_t getData() const { return data; }
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size_t getSourceNum()const { return data & MASK_NUMBER; }
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/// In CollapsingMergeTree case flag means "skip this rows"
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bool getSkipFlag() const { return (data & MASK_FLAG) != 0; }
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void setSourceNum(size_t source_num)
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{
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data = (data & MASK_FLAG) | (static_cast<UInt8>(source_num) & MASK_NUMBER);
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}
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void setSkipFlag(bool flag)
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{
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data = flag ? data | MASK_FLAG : data & ~MASK_FLAG;
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}
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static constexpr size_t MAX_PARTS = 0x7F;
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static constexpr UInt8 MASK_NUMBER = 0x7F;
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static constexpr UInt8 MASK_FLAG = 0x80;
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private:
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UInt8 data;
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};
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using MergedRowSources = PODArray<RowSourcePart>;
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/** Gather single stream from multiple streams according to streams mask.
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* Stream mask maps row number to index of source stream.
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* Streams should conatin exactly one column.
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*/
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class ColumnGathererStream : public IProfilingBlockInputStream
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{
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public:
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ColumnGathererStream(const BlockInputStreams & source_streams, const String & column_name_,
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const MergedRowSources & row_source_, size_t block_size_ = DEFAULT_MERGE_BLOCK_SIZE);
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String getName() const override { return "ColumnGatherer"; }
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String getID() const override;
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Block readImpl() override;
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void readSuffixImpl() override;
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private:
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String name;
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ColumnWithTypeAndName column;
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const MergedRowSources & row_source;
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/// Cache required fileds
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struct Source
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{
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const IColumn * column;
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size_t pos;
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size_t size;
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Block block;
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Source(Block && block_, const String & name) : block(std::move(block_))
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{
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update(name);
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}
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void update(const String & name)
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{
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column = block.getByName(name).column.get();
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size = block.rows();
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pos = 0;
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}
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};
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std::vector<Source> sources;
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size_t pos_global_start = 0;
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size_t block_size;
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Logger * log = &Logger::get("ColumnGathererStream");
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};
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}
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