ClickHouse/dbms/src/DataStreams/copyData.cpp

#include <DB/DataStreams/RowInputStreamFromBlockInputStream.h>
#include <DB/DataStreams/BlockInputStreamFromRowInputStream.h>

#include <DB/DataStreams/copyData.h>


namespace DB
{

namespace
{

bool isAtomicSet(std::atomic<bool> * val)
{
	return ((val != nullptr) && val->load(std::memory_order_seq_cst));
}

}

void copyData(IBlockInputStream & from, IBlockOutputStream & to, std::atomic<bool> * is_cancelled)
{
	from.readPrefix();
	to.writePrefix();

	while (Block block = from.read())
	{
		if (isAtomicSet(is_cancelled))
			break;

		to.write(block);
	}

	if (isAtomicSet(is_cancelled))
		return;

	/// Для вывода дополнительной информации в некоторых форматах.
	if (IProfilingBlockInputStream * input = dynamic_cast<IProfilingBlockInputStream *>(&from))
	{
		if (input->getInfo().hasAppliedLimit())
			to.setRowsBeforeLimit(input->getInfo().getRowsBeforeLimit());

		to.setTotals(input->getTotals());
		to.setExtremes(input->getExtremes());
	}

	if (isAtomicSet(is_cancelled))
		return;

	from.readSuffix();
	to.writeSuffix();
}


void copyData(IRowInputStream & from, IRowOutputStream & to)
{
	from.readPrefix();
	to.writePrefix();

	bool first = true;
	while (1)
	{
		if (first)
			first = false;
		else
		{
			from.readRowBetweenDelimiter();
			to.writeRowBetweenDelimiter();
		}

		Row row;
		bool has_rows = from.read(row);
		if (!has_rows)
			break;
		to.write(row);
	}

	from.readSuffix();
	to.writeSuffix();
}

}