ClickHouse/dbms/include/DB/IO/WriteBufferFromTemporaryFile.h
2017-03-28 20:46:16 +03:00

35 lines
811 B
C++

#include <DB/IO/WriteBuffer.h>
#include <DB/IO/IReadableWriteBuffer.h>
#include <DB/IO/WriteBufferFromFile.h>
#include <Poco/TemporaryFile.h>
namespace DB
{
/// Rereadable WriteBuffer, could be used as disk buffer
/// Creates unique temporary in directory (and directory itself)
class WriteBufferFromTemporaryFile : public WriteBufferFromFile, public IReadableWriteBuffer
{
public:
using Ptr = std::shared_ptr<WriteBufferFromTemporaryFile>;
static Ptr create(const std::string & tmp_dir);
~WriteBufferFromTemporaryFile() override;
protected:
WriteBufferFromTemporaryFile(std::unique_ptr<Poco::TemporaryFile> && tmp_file);
std::shared_ptr<ReadBuffer> getReadBufferImpl() override;
protected:
std::unique_ptr<Poco::TemporaryFile> tmp_file;
friend class ReadBufferFromTemporaryWriteBuffer;
};
}