ClickHouse/dbms/src/DataStreams/AddingDefaultBlockOutputStream.h

49 lines
1.2 KiB
C++

#pragma once
#include <DataStreams/IBlockOutputStream.h>
#include <Columns/ColumnConst.h>
#include <Storages/ColumnDefault.h>
#include <Interpreters/Context.h>
#include <Interpreters/evaluateMissingDefaults.h>
namespace DB
{
/** Adds missing columns to the block with default values.
* These columns are materialized (not constants).
*/
class AddingDefaultBlockOutputStream : public IBlockOutputStream
{
public:
AddingDefaultBlockOutputStream(
const BlockOutputStreamPtr & output_,
const Block & header_,
NamesAndTypesList required_columns_,
const ColumnDefaults & column_defaults_,
const Context & context_)
: output(output_), header(header_), required_columns(required_columns_),
column_defaults(column_defaults_), context(context_)
{
}
Block getHeader() const override { return header; }
void write(const Block & block) override;
void flush() override;
void writePrefix() override;
void writeSuffix() override;
private:
BlockOutputStreamPtr output;
Block header;
NamesAndTypesList required_columns;
const ColumnDefaults column_defaults;
const Context & context;
};
}