ClickHouse/base/poco/Foundation/src/FileStream_POSIX.cpp
2023-02-14 22:09:58 +00:00

167 lines
2.7 KiB
C++

//
// FileStream_POSIX.cpp
//
// Library: Foundation
// Package: Streams
// Module: FileStream
//
// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#include "Poco/FileStream.h"
#include "Poco/File.h"
#include "Poco/Exception.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
namespace Poco {
FileStreamBuf::FileStreamBuf():
BufferedBidirectionalStreamBuf(BUFFER_SIZE, std::ios::in | std::ios::out),
_fd(-1),
_pos(0)
{
}
FileStreamBuf::~FileStreamBuf()
{
close();
}
void FileStreamBuf::open(const std::string& path, std::ios::openmode mode)
{
poco_assert (_fd == -1);
_pos = 0;
_path = path;
setMode(mode);
resetBuffers();
int flags(0);
if (mode & std::ios::trunc)
flags |= O_TRUNC;
if (mode & std::ios::app)
flags |= O_APPEND;
if (mode & std::ios::out)
flags |= O_CREAT;
if ((mode & std::ios::in) && (mode & std::ios::out))
flags |= O_RDWR;
else if (mode & std::ios::in)
flags |= O_RDONLY;
else
flags |= O_WRONLY;
_fd = ::open(path.c_str(), flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
if (_fd == -1)
File::handleLastError(_path);
if ((mode & std::ios::app) || (mode & std::ios::ate))
seekoff(0, std::ios::end, mode);
}
int FileStreamBuf::readFromDevice(char* buffer, std::streamsize length)
{
if (_fd == -1) return -1;
if (getMode() & std::ios::out)
sync();
int n = read(_fd, buffer, length);
if (n == -1)
File::handleLastError(_path);
_pos += n;
return n;
}
int FileStreamBuf::writeToDevice(const char* buffer, std::streamsize length)
{
if (_fd == -1) return -1;
int n = write(_fd, buffer, length);
if (n == -1)
File::handleLastError(_path);
_pos += n;
return n;
}
bool FileStreamBuf::close()
{
bool success = true;
if (_fd != -1)
{
try
{
sync();
}
catch (...)
{
success = false;
}
::close(_fd);
_fd = -1;
}
return success;
}
std::streampos FileStreamBuf::seekoff(std::streamoff off, std::ios::seekdir dir, std::ios::openmode mode)
{
if (_fd == -1 || !(getMode() & mode))
return -1;
if (getMode() & std::ios::out)
sync();
std::streamoff adj;
if (mode & std::ios::in)
adj = static_cast<std::streamoff>(egptr() - gptr());
else
adj = 0;
resetBuffers();
int whence = SEEK_SET;
if (dir == std::ios::cur)
{
whence = SEEK_CUR;
off -= adj;
}
else if (dir == std::ios::end)
{
whence = SEEK_END;
}
_pos = lseek(_fd, off, whence);
return _pos;
}
std::streampos FileStreamBuf::seekpos(std::streampos pos, std::ios::openmode mode)
{
if (_fd == -1 || !(getMode() & mode))
return -1;
if (getMode() & std::ios::out)
sync();
resetBuffers();
_pos = lseek(_fd, pos, SEEK_SET);
return _pos;
}
} // namespace Poco