gecko-dev/mfbt/FStream.h
Masatoshi Kimura 9bbb2153d4 Bug 1428614 - Implement mozilla::IFStream and mozilla::OFStream. r=froydnj
This is drop-in replacements of std::ifstream and std::ofstream, but supports
widechar filenames on Windows. This is just an alias of std::ofstream on other
platforms.

MozReview-Commit-ID: FHNatG5595k

--HG--
extra : rebase_source : 0805153dd13907a6c3b6971bfc0b499a31416b9a
extra : intermediate-source : 3113df1e69bf7444105953df8610b8bbf5d4d41e
extra : source : 750263b126963d2634a89de0a2aac63efa4b49e6
2018-01-07 18:31:31 +09:00

138 lines
3.5 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// Similar to std::ifstream/ofstream, but takes char16ptr_t on Windows.
// Until C++17, std functions can only take char* filenames. So Unicode
// filenames were lost on Windows. To address this limitations, this wrapper
// uses proprietary wchar_t* overloads on MSVC, and __gnu_cxx::stdio_filebuf
// extension on MinGW. Once we can use C++17 filesystem API everywhere,
// we will be able to avoid this wrapper.
#ifndef mozilla_FStream_h
#define mozilla_FStream_h
#include "mozilla/Char16.h"
#include <iostream>
#include <fstream>
#if defined(__MINGW32__)
#include "mozilla/UniquePtr.h"
#include <fcntl.h>
#include <ext/stdio_filebuf.h>
#endif
namespace mozilla {
#if defined(__MINGW32__)
// MinGW does not support wchar_t* overloads that are MSVC extension until
// C++17, so we have to implement widechar wrappers using a GNU extension.
class IFStream : public std::istream
{
public:
explicit IFStream(char16ptr_t filename, openmode mode = in);
std::filebuf* rdbuf() const { return mFileBuf.get(); }
bool is_open() const { return mFileBuf && mFileBuf->is_open(); }
void open(char16ptr_t filename, openmode mode = in);
void close() { mFileBuf && mFileBuf->close(); }
private:
UniquePtr<std::filebuf> mFileBuf;
};
inline
IFStream::IFStream(char16ptr_t filename, openmode mode)
: std::istream(nullptr)
{
open(filename, mode);
}
inline void
IFStream::open(char16ptr_t filename, openmode mode)
{
int fmode = _O_RDONLY;
if (mode & binary) {
fmode |= _O_BINARY;
} else {
fmode |= _O_TEXT;
}
int fd = _wopen(filename, fmode);
mFileBuf = MakeUnique<__gnu_cxx::stdio_filebuf<char>>(fd, mode);
std::istream::rdbuf(mFileBuf.get());
}
class OFStream : public std::ostream
{
public:
explicit OFStream(char16ptr_t filename, openmode mode = out);
std::filebuf* rdbuf() const { return mFileBuf.get(); }
bool is_open() const { return mFileBuf && mFileBuf->is_open(); }
void open(char16ptr_t filename, openmode mode = out);
void close() { mFileBuf && mFileBuf->close(); }
private:
UniquePtr<std::filebuf> mFileBuf;
};
inline
OFStream::OFStream(char16ptr_t filename, openmode mode)
: std::ostream(nullptr)
{
open(filename, mode);
}
inline void
OFStream::open(char16ptr_t filename, openmode mode)
{
int fmode = _O_WRONLY;
if (mode & binary) {
fmode |= _O_BINARY;
} else {
fmode |= _O_TEXT;
}
if (mode & trunc) {
fmode |= _O_CREAT | _O_TRUNC;
}
int fd = _wopen(filename, fmode);
mFileBuf = MakeUnique<__gnu_cxx::stdio_filebuf<char>>(fd, mode);
std::ostream::rdbuf(mFileBuf.get());
}
#elif defined(XP_WIN)
class IFStream : public std::ifstream
{
public:
explicit IFStream(char16ptr_t filename, openmode mode = in)
: std::ifstream(filename, mode) {}
void open(char16ptr_t filename, openmode mode = in)
{
std::ifstream::open(filename, mode);
}
};
class OFStream : public std::ofstream
{
public:
explicit OFStream(char16ptr_t filename, openmode mode = out)
: std::ofstream(filename, mode) {}
void open(char16ptr_t filename, openmode mode = out)
{
std::ofstream::open(filename, mode);
}
};
#else
using IFStream = std::ifstream;
using OFStream = std::ofstream;
#endif
} // namespace mozilla
#endif /* mozilla_FStream_h */