ClickHouse/dbms/src/Formats/ODBCDriver2BlockOutputStream.h
2018-12-14 23:21:47 +03:00

52 lines
1.3 KiB
C++

#pragma once
#include <string>
#include <Core/Block.h>
#include <DataStreams/IBlockOutputStream.h>
#include <Formats/FormatSettings.h>
namespace DB
{
class WriteBuffer;
/** A data format designed to simplify the implementation of the ODBC driver.
* ODBC driver is designed to be build for different platforms without dependencies from the main code,
* so the format is made that way so that it can be as easy as possible to parse it.
* A header is displayed with the required information.
* The data is then output in the order of the rows. Each value is displayed as follows: length in Int32 format (-1 for NULL), then data in text form.
*/
class ODBCDriver2BlockOutputStream final : public IBlockOutputStream
{
public:
ODBCDriver2BlockOutputStream(WriteBuffer & out_, const Block & header_, const FormatSettings & format_settings);
Block getHeader() const override
{
return header;
}
void write(const Block & block) override;
void writePrefix() override;
void writeSuffix() override;
void flush() override;
std::string getContentType() const override
{
return "application/octet-stream";
}
void setTotals(const Block & totals_) override { totals = totals_; }
private:
WriteBuffer & out;
const Block header;
const FormatSettings format_settings;
protected:
Block totals;
};
}