ClickHouse/dbms/include/DB/DataStreams/IRowInputStream.h
2017-02-02 19:30:27 +03:00

43 lines
1.1 KiB
C++

#pragma once
#include <boost/noncopyable.hpp>
#include <memory>
#include <string>
namespace DB
{
class Block;
/** Interface of stream, that allows to read data by rows.
*/
class IRowInputStream : private boost::noncopyable
{
public:
/** Read next row and append it to block.
* If no more rows - return false.
*/
virtual bool read(Block & block) = 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<IRowInputStream>;
}