#pragma once #include #include #include #include namespace DB { /** Interface of stream, that allows to read data by rows. */ class IRowInputStream : private boost::noncopyable { public: /** Read next row and append it to the columns. * If no more rows - return false. */ virtual bool read(MutableColumns & columns) = 0; virtual void readPrefix() {}; /// delimiter before begin of result virtual void readSuffix() {}; /// delimiter after end of result /// Skip data until next row. /// This is intended for text streams, that allow skipping of errors. /// By default - throws not implemented exception. virtual bool allowSyncAfterError() const { return false; } virtual void syncAfterError(); /// In case of parse error, try to roll back and parse last one or two rows very carefully /// and collect as much as possible diagnostic information about error. /// If not implemented, returns empty string. virtual std::string getDiagnosticInfo() { return {}; }; virtual ~IRowInputStream() {} }; using RowInputStreamPtr = std::shared_ptr; }