ClickHouse/dbms/src/DataStreams/JSONCompactRowOutputStream.cpp

#include <DB/DataStreams/JSONCompactRowOutputStream.h>

#include <DB/IO/WriteHelpers.h>


namespace DB
{

using Poco::SharedPtr;


JSONCompactRowOutputStream::JSONCompactRowOutputStream(WriteBuffer & ostr_, const Block & sample_)
	: JSONRowOutputStream(ostr_, sample_)
{
}


void JSONCompactRowOutputStream::writeField(const Field & field)
{
	fields[field_number].type->serializeTextJSON(field, *ostr);
	++field_number;
}


void JSONCompactRowOutputStream::writeFieldDelimiter()
{
	writeCString(", ", *ostr);
}


void JSONCompactRowOutputStream::writeRowStartDelimiter()
{
	if (row_count > 0)
		writeCString(",\n", *ostr);
	writeCString("\t\t[", *ostr);
}


void JSONCompactRowOutputStream::writeRowEndDelimiter()
{
	writeChar(']', *ostr);
	field_number = 0;
	++row_count;
}


void JSONCompactRowOutputStream::writeTotals()
{
	if (totals)
	{
		writeCString(",\n", *ostr);
		writeChar('\n', *ostr);
		writeCString("\t\"totals\": [", *ostr);

		size_t totals_columns = totals.columns();
		for (size_t i = 0; i < totals_columns; ++i)
		{
			if (i != 0)
				writeChar(',', *ostr);

			const ColumnWithNameAndType & column = totals.getByPosition(i);
			column.type->serializeTextJSON((*column.column)[0], *ostr);
		}

		writeChar(']', *ostr);
	}
}


static void writeExtremesElement(const char * title, const Block & extremes, size_t row_num, WriteBuffer & ostr)
{
	writeCString("\t\t\"", ostr);
	writeCString(title, ostr);
	writeCString("\": [", ostr);

	size_t extremes_columns = extremes.columns();
	for (size_t i = 0; i < extremes_columns; ++i)
	{
		if (i != 0)
			writeChar(',', ostr);

		const ColumnWithNameAndType & column = extremes.getByPosition(i);
		column.type->serializeTextJSON((*column.column)[row_num], ostr);
	}

	writeChar(']', ostr);
}

void JSONCompactRowOutputStream::writeExtremes()
{
	if (extremes)
	{
		writeCString(",\n", *ostr);
		writeChar('\n', *ostr);
		writeCString("\t\"extremes\":\n", *ostr);
		writeCString("\t{\n", *ostr);

		writeExtremesElement("min", extremes, 0, *ostr);
		writeCString(",\n", *ostr);
		writeExtremesElement("max", extremes, 1, *ostr);

		writeChar('\n', *ostr);
		writeCString("\t}", *ostr);
	}
}


}