ClickHouse/dbms/include/DB/IO/ReadBufferFromFile.h
2014-04-08 11:31:51 +04:00

43 lines
995 B
C++

#pragma once
#include <fcntl.h>
#include <DB/IO/ReadBufferFromFileDescriptor.h>
namespace DB
{
/** Принимает имя файла. Самостоятельно открывает и закрывает файл.
*/
class ReadBufferFromFile : public ReadBufferFromFileDescriptor
{
private:
std::string file_name;
public:
ReadBufferFromFile(const std::string & file_name_, size_t buf_size = DBMS_DEFAULT_BUFFER_SIZE, int flags = -1,
char * existing_memory = nullptr, size_t alignment = 0)
: ReadBufferFromFileDescriptor(-1, buf_size, existing_memory, alignment), file_name(file_name_)
{
ProfileEvents::increment(ProfileEvents::FileOpen);
fd = open(file_name.c_str(), flags == -1 ? O_RDONLY : flags);
if (-1 == fd)
throwFromErrno("Cannot open file " + file_name, errno == ENOENT ? ErrorCodes::FILE_DOESNT_EXIST : ErrorCodes::CANNOT_OPEN_FILE);
}
virtual ~ReadBufferFromFile()
{
close(fd);
}
virtual std::string getFileName()
{
return file_name;
}
};
}