ClickHouse/dbms/include/DB/IO/WriteBufferFromFile.h

48 lines
1.1 KiB
C++

#pragma once
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <DB/IO/WriteBufferFromFileDescriptor.h>
namespace DB
{
/** Принимает имя файла. Самостоятельно открывает и закрывает файл.
*/
class WriteBufferFromFile : public WriteBufferFromFileDescriptor
{
private:
std::string file_name;
public:
WriteBufferFromFile(const std::string & file_name_, size_t buf_size = DBMS_DEFAULT_BUFFER_SIZE, int flags = -1, mode_t mode = 0666)
: WriteBufferFromFileDescriptor(-1, buf_size), file_name(file_name_)
{
fd = open(file_name.c_str(), flags == -1 ? O_WRONLY | O_TRUNC | O_CREAT : flags, mode);
if (-1 == fd)
throwFromErrno("Cannot open file " + file_name, errno == ENOENT ? ErrorCodes::FILE_DOESNT_EXIST : ErrorCodes::CANNOT_OPEN_FILE);
}
~WriteBufferFromFile()
{
bool uncaught_exception = std::uncaught_exception();
if (!uncaught_exception)
next();
if (0 != close(fd) && !uncaught_exception)
throwFromErrno("Cannot close file " + file_name, ErrorCodes::CANNOT_CLOSE_FILE);
}
virtual std::string getFileName()
{
return file_name;
}
};
}