mpd/src/fs/io/FileOutputStream.hxx

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/*
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* Copyright (C) 2003-2015 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_FILE_OUTPUT_STREAM_HXX
#define MPD_FILE_OUTPUT_STREAM_HXX
#include "check.h"
#include "OutputStream.hxx"
#include "fs/AllocatedPath.hxx"
#include "Compiler.h"
#ifndef WIN32
#include "system/FileDescriptor.hxx"
#endif
#include <assert.h>
#ifdef WIN32
#include <windows.h>
#endif
class Path;
class BaseFileOutputStream : public OutputStream {
const AllocatedPath path;
#ifdef WIN32
HANDLE handle;
#else
FileDescriptor fd;
#endif
protected:
#ifdef WIN32
template<typename P>
BaseFileOutputStream(P &&_path)
:path(std::forward<P>(_path)),
handle(INVALID_HANDLE_VALUE) {}
#else
template<typename P>
BaseFileOutputStream(P &&_path)
:path(std::forward<P>(_path)),
fd(FileDescriptor::Undefined()) {}
#endif
~BaseFileOutputStream() {
assert(!IsDefined());
}
#ifdef WIN32
void SetHandle(HANDLE _handle) {
assert(!IsDefined());
handle = _handle;
assert(IsDefined());
}
#else
FileDescriptor &SetFD() {
assert(!IsDefined());
return fd;
}
const FileDescriptor &GetFD() const {
return fd;
}
#endif
bool Close() {
assert(IsDefined());
#ifdef WIN32
CloseHandle(handle);
handle = INVALID_HANDLE_VALUE;
return true;
#else
return fd.Close();
#endif
}
#ifdef WIN32
bool SeekEOF() {
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return SetFilePointer(handle, 0, nullptr,
FILE_END) != 0xffffffff;
}
#endif
public:
bool IsDefined() const {
#ifdef WIN32
return handle != INVALID_HANDLE_VALUE;
#else
return fd.IsDefined();
#endif
}
Path GetPath() const {
return path;
}
gcc_pure
uint64_t Tell() const;
/* virtual methods from class OutputStream */
bool Write(const void *data, size_t size, Error &error) override;
};
class FileOutputStream final : public BaseFileOutputStream {
#ifdef HAVE_LINKAT
/**
* Was O_TMPFILE used? If yes, then linkat() must be used to
* create a link to this file.
*/
bool is_tmpfile;
#endif
public:
FileOutputStream(Path _path, Error &error);
~FileOutputStream() {
if (IsDefined())
Cancel();
}
static FileOutputStream *Create(Path path, Error &error);
bool Commit(Error &error);
void Cancel();
};
class AppendFileOutputStream final : public BaseFileOutputStream {
public:
AppendFileOutputStream(Path _path, Error &error);
~AppendFileOutputStream() {
if (IsDefined())
Close();
}
bool Commit(Error &error);
};
#endif