#pragma once #include #include namespace DB { /** Преобразует столбцы-константы в полноценные столбцы ("материализует" их). */ class MaterializingBlockOutputStream : public IBlockOutputStream { public: MaterializingBlockOutputStream(const BlockOutputStreamPtr & output) : output{output} {} void write(const Block & block) override { output->write(materialize(block)); } void flush() override { output->flush(); } void writePrefix() override { output->writePrefix(); } void writeSuffix() override { output->writeSuffix(); } void setRowsBeforeLimit(size_t rows_before_limit) override { output->setRowsBeforeLimit(rows_before_limit); } void setTotals(const Block & totals) override { output->setTotals(materialize(totals)); } void setExtremes(const Block & extremes) override { output->setExtremes(materialize(extremes)); } void onProgress(const Progress & progress) override { output->onProgress(progress); } String getContentType() const override { return output->getContentType(); } private: BlockOutputStreamPtr output; static Block materialize(const Block & original_block); }; }