ClickHouse/dbms/src/Processors/Formats/Impl/ProtobufRowOutputFormat.h
2019-08-02 19:34:20 +03:00

54 lines
1.5 KiB
C++

#pragma once
#include <Common/config.h>
#if USE_PROTOBUF
#include <Core/Block.h>
#include <Formats/FormatSettings.h>
#include <Formats/ProtobufWriter.h>
#include <Formats/FormatSchemaInfo.h>
#include <Processors/Formats/IRowOutputFormat.h>
namespace google
{
namespace protobuf
{
class Message;
}
}
namespace DB
{
/** Stream designed to serialize data in the google protobuf format.
* Each row is written as a separated message.
* These messages are delimited according to documentation
* https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/util/delimited_message_util.h
* Serializing in the protobuf format requires the 'format_schema' setting to be set, e.g.
* SELECT * from table FORMAT Protobuf SETTINGS format_schema = 'schema:Message'
* where schema is the name of "schema.proto" file specifying protobuf schema.
*/
class ProtobufRowOutputFormat : public IRowOutputFormat
{
public:
ProtobufRowOutputFormat(
WriteBuffer & out_,
const Block & header,
const FormatSchemaInfo & format_schema);
String getName() const override { return "ProtobufRowOutputFormat"; }
void write(const Columns & columns, size_t row_num) override;
void writeField(const IColumn &, const IDataType &, size_t) override {}
std::string getContentType() const override { return "application/octet-stream"; }
private:
DataTypes data_types;
ProtobufWriter writer;
std::vector<size_t> value_indices;
};
}
#endif