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/*
* Copyright 2003-2017 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>
#include <stdint.h>
#ifdef WIN32
#include <windows.h>
#endif
class Path;
class FileOutputStream final : public OutputStream {
const AllocatedPath path;
#ifdef WIN32
HANDLE handle = INVALID_HANDLE_VALUE;
#else
FileDescriptor fd = FileDescriptor::Undefined();
#endif
#ifdef HAVE_LINKAT
/**
* Was O_TMPFILE used? If yes, then linkat() must be used to
* create a link to this file.
*/
bool is_tmpfile = false;
#endif
public:
enum class Mode : uint8_t {
/**
* Create a new file, or replace an existing file.
* File contents may not be visible until Commit() has
* been called.
*/
CREATE,
/**
* Like #CREATE, but no attempt is made to hide file
* contents during the transaction (e.g. via O_TMPFILE
* or a hidden temporary file).
*/
CREATE_VISIBLE,
/**
* Append to a file that already exists. If it does
* not, an exception is thrown.
*/
APPEND_EXISTING,
/**
* Like #APPEND_EXISTING, but create the file if it
* does not exist.
*/
APPEND_OR_CREATE,
};
private:
Mode mode;
public:
explicit FileOutputStream(Path _path, Mode _mode=Mode::CREATE);
~FileOutputStream() {
if (IsDefined())
Cancel();
}
public:
Path GetPath() const {
return path;
}
gcc_pure
uint64_t Tell() const;
/* virtual methods from class OutputStream */
void Write(const void *data, size_t size) override;
void Commit();
void Cancel();
private:
void OpenCreate(bool visible);
void OpenAppend(bool create);
bool Close() {
assert(IsDefined());
#ifdef WIN32
CloseHandle(handle);
handle = INVALID_HANDLE_VALUE;
return true;
#else
return fd.Close();
#endif
}
#ifdef WIN32
bool SeekEOF() {
return SetFilePointer(handle, 0, nullptr,
FILE_END) != 0xffffffff;
}
#endif
bool IsDefined() const {
#ifdef WIN32
return handle != INVALID_HANDLE_VALUE;
#else
return fd.IsDefined();
#endif
}
};
#endif