ClickHouse/dbms/include/DB/DataStreams/MaterializingBlockOutputStream.h

#pragma once

#include <DB/Core/Block.h>
#include <DB/DataStreams/IBlockOutputStream.h>


namespace DB
{

/** Преобразует столбцы-константы в полноценные столбцы ("материализует" их).
  */
class MaterializingBlockOutputStream : public IBlockOutputStream
{
public:
	MaterializingBlockOutputStream(const BlockOutputStreamPtr & output)
		: output{output} {}

	void write(const Block & block) override
	{
		output->write(materialize(block));
	}

	void flush() 										override { output->flush(); }
	void writePrefix() 									override { output->writePrefix(); }
	void writeSuffix() 									override { output->writeSuffix(); }
	void setRowsBeforeLimit(size_t rows_before_limit) 	override { output->setRowsBeforeLimit(rows_before_limit); }
	void setTotals(const Block & totals) 				override { output->setTotals(materialize(totals)); }
	void setExtremes(const Block & extremes) 			override { output->setExtremes(materialize(extremes)); }
	void onProgress(const Progress & progress) 			override { output->onProgress(progress); }
	String getContentType() const 						override { return output->getContentType(); }

private:
	BlockOutputStreamPtr output;

	static Block materialize(const Block & original_block);
};

}