ClickHouse/dbms/src/DataStreams/AddingDefaultsBlockInputStream.h

#pragma once

#include <DataStreams/IBlockInputStream.h>
#include <Storages/ColumnDefault.h>
#include <Interpreters/Context.h>


namespace DB
{

/// Adds defaults to columns using BlockDelayedDefaults bitmask attached to Block by child InputStream.
class AddingDefaultsBlockInputStream : public IBlockInputStream
{
public:
    AddingDefaultsBlockInputStream(
        const BlockInputStreamPtr & input,
        const ColumnDefaults & column_defaults_,
        const Context & context_);

    String getName() const override { return "AddingDefaults"; }
    Block getHeader() const override { return header; }

protected:
    Block readImpl() override;

private:
    Block header;
    const ColumnDefaults column_defaults;
    const Context & context;

    void checkCalculated(const ColumnWithTypeAndName & col_read, const ColumnWithTypeAndName & col_defaults, size_t needed) const;
    MutableColumnPtr mixColumns(const ColumnWithTypeAndName & col_read, const ColumnWithTypeAndName & col_defaults,
                                const BlockMissingValues::RowsBitMask & defaults_mask) const;
    void mixNumberColumns(TypeIndex type_idx, MutableColumnPtr & col_mixed, const ColumnPtr & col_defaults,
                          const BlockMissingValues::RowsBitMask & defaults_mask) const;
};

}