ClickHouse/src/Processors/Formats/Impl/CapnProtoRowInputFormat.h
2022-02-06 07:14:01 +03:00

56 lines
1.5 KiB
C++

#pragma once
#include "config_formats.h"
#if USE_CAPNP
#include <Core/Block.h>
#include <Formats/CapnProtoUtils.h>
#include <Processors/Formats/IRowInputFormat.h>
#include <Processors/Formats/ISchemaReader.h>
namespace DB
{
class FormatSchemaInfo;
class ReadBuffer;
/** A stream for reading messages in Cap'n Proto format in given schema.
* Like Protocol Buffers and Thrift (but unlike JSON or MessagePack),
* Cap'n Proto messages are strongly-typed and not self-describing.
* The schema in this case cannot be compiled in, so it uses a runtime schema parser.
* See https://capnproto.org/cxx.html
*/
class CapnProtoRowInputFormat final : public IRowInputFormat
{
public:
CapnProtoRowInputFormat(ReadBuffer & in_, Block header, Params params_, const FormatSchemaInfo & info, const FormatSettings & format_settings_);
String getName() const override { return "CapnProtoRowInputFormat"; }
private:
bool readRow(MutableColumns & columns, RowReadExtension &) override;
kj::Array<capnp::word> readMessage();
std::shared_ptr<CapnProtoSchemaParser> parser;
capnp::StructSchema root;
const FormatSettings format_settings;
DataTypes column_types;
Names column_names;
};
class CapnProtoSchemaReader : public IExternalSchemaReader
{
public:
explicit CapnProtoSchemaReader(const FormatSettings & format_settings_);
NamesAndTypesList readSchema() override;
private:
const FormatSettings format_settings;
};
}
#endif // USE_CAPNP