dolphin/Source/Core/Common/FileUtil.h
Lioncash 045a8400e6 IOFile: Make the move constructor and move assignment operator noexcept
Certain parts of the standard library try to determine whether or not a
transfer operation should either be a copy or a move. The prevalent notion
of move constructors/assignment operators is that they should not throw,
they simply move an already existing resource somewhere else.

This is typically done with 'std::move_if_noexcept'. Like the name says,
if a type's move constructor is noexcept, then the functions retrieves an
r-value reference (for move semantics), or an l-value (for copy semantics)
if it is not noexcept.

As IOFile deletes the copy constructor and copy assignment operators,
using IOFile with certain parts of the standard library can fail in
unexcepted ways (especially when used with various container
implementations). This prevents that.
2017-01-04 18:37:48 -05:00

250 lines
6.7 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#pragma once
#include <cstddef>
#include <cstdio>
#include <fstream>
#include <string>
#include <vector>
#include "Common/CommonTypes.h"
#include "Common/NonCopyable.h"
#ifdef _WIN32
#include "Common/StringUtil.h"
#endif
// User directory indices for GetUserPath
enum
{
D_USER_IDX,
D_GCUSER_IDX,
D_WIIROOT_IDX, // always points to User/Wii or global user-configured directory
D_SESSION_WIIROOT_IDX, // may point to minimal temporary directory for determinism
D_CONFIG_IDX, // global settings
D_GAMESETTINGS_IDX, // user-specified settings which override both the global and the default
// settings (per game)
D_MAPS_IDX,
D_CACHE_IDX,
D_SHADERCACHE_IDX,
D_SHADERS_IDX,
D_STATESAVES_IDX,
D_SCREENSHOTS_IDX,
D_HIRESTEXTURES_IDX,
D_DUMP_IDX,
D_DUMPFRAMES_IDX,
D_DUMPAUDIO_IDX,
D_DUMPTEXTURES_IDX,
D_DUMPDSP_IDX,
D_DUMPSSL_IDX,
D_LOAD_IDX,
D_LOGS_IDX,
D_MAILLOGS_IDX,
D_THEMES_IDX,
D_PIPES_IDX,
D_MEMORYWATCHER_IDX,
F_DOLPHINCONFIG_IDX,
F_DEBUGGERCONFIG_IDX,
F_LOGGERCONFIG_IDX,
F_MAINLOG_IDX,
F_RAMDUMP_IDX,
F_ARAMDUMP_IDX,
F_FAKEVMEMDUMP_IDX,
F_GCSRAM_IDX,
F_MEMORYWATCHERLOCATIONS_IDX,
F_MEMORYWATCHERSOCKET_IDX,
F_WIISDCARD_IDX,
NUM_PATH_INDICES
};
namespace File
{
// FileSystem tree node/
struct FSTEntry
{
bool isDirectory;
u64 size; // File length, or for directories, recursive count of children
std::string physicalName; // Name on disk
std::string virtualName; // Name in FST names table
std::vector<FSTEntry> children;
};
// Returns true if file filename exists
bool Exists(const std::string& filename);
// Returns true if filename is a directory
bool IsDirectory(const std::string& filename);
// Returns the size of filename (64bit)
u64 GetSize(const std::string& filename);
// Overloaded GetSize, accepts file descriptor
u64 GetSize(const int fd);
// Overloaded GetSize, accepts FILE*
u64 GetSize(FILE* f);
// Returns true if successful, or path already exists.
bool CreateDir(const std::string& filename);
// Creates the full path of fullPath returns true on success
bool CreateFullPath(const std::string& fullPath);
// Deletes a given filename, return true on success
// Doesn't supports deleting a directory
bool Delete(const std::string& filename);
// Deletes a directory filename, returns true on success
bool DeleteDir(const std::string& filename);
// renames file srcFilename to destFilename, returns true on success
bool Rename(const std::string& srcFilename, const std::string& destFilename);
// ditto, but syncs the source file and, on Unix, syncs the directories after rename
bool RenameSync(const std::string& srcFilename, const std::string& destFilename);
// copies file srcFilename to destFilename, returns true on success
bool Copy(const std::string& srcFilename, const std::string& destFilename);
// creates an empty file filename, returns true on success
bool CreateEmptyFile(const std::string& filename);
// Recursive or non-recursive list of files and directories under directory.
FSTEntry ScanDirectoryTree(const std::string& directory, bool recursive);
// deletes the given directory and anything under it. Returns true on success.
bool DeleteDirRecursively(const std::string& directory);
// Returns the current directory
std::string GetCurrentDir();
// Create directory and copy contents (does not overwrite existing files)
void CopyDir(const std::string& source_path, const std::string& dest_path);
// Set the current directory to given directory
bool SetCurrentDir(const std::string& directory);
// Creates and returns the path to a new temporary directory.
std::string CreateTempDir();
// Get a filename that can hopefully be atomically renamed to the given path.
std::string GetTempFilenameForAtomicWrite(const std::string& path);
// Gets a set user directory path
// Don't call prior to setting the base user directory
const std::string& GetUserPath(unsigned int dir_index);
// Sets a user directory path
// Rebuilds internal directory structure to compensate for the new directory
void SetUserPath(unsigned int dir_index, const std::string& path);
// probably doesn't belong here
std::string GetThemeDir(const std::string& theme_name);
// Returns the path to where the sys file are
std::string GetSysDirectory();
#ifdef __APPLE__
std::string GetBundleDirectory();
#endif
std::string& GetExeDirectory();
bool WriteStringToFile(const std::string& str, const std::string& filename);
bool ReadFileToString(const std::string& filename, std::string& str);
// simple wrapper for cstdlib file functions to
// hopefully will make error checking easier
// and make forgetting an fclose() harder
class IOFile : public NonCopyable
{
public:
IOFile();
IOFile(std::FILE* file);
IOFile(const std::string& filename, const char openmode[]);
~IOFile();
IOFile(IOFile&& other) noexcept;
IOFile& operator=(IOFile&& other) noexcept;
void Swap(IOFile& other) noexcept;
bool Open(const std::string& filename, const char openmode[]);
bool Close();
template <typename T>
bool ReadArray(T* data, size_t length, size_t* pReadBytes = nullptr)
{
size_t read_bytes = 0;
if (!IsOpen() || length != (read_bytes = std::fread(data, sizeof(T), length, m_file)))
m_good = false;
if (pReadBytes)
*pReadBytes = read_bytes;
return m_good;
}
template <typename T>
bool WriteArray(const T* data, size_t length)
{
if (!IsOpen() || length != std::fwrite(data, sizeof(T), length, m_file))
m_good = false;
return m_good;
}
bool ReadBytes(void* data, size_t length)
{
return ReadArray(reinterpret_cast<char*>(data), length);
}
bool WriteBytes(const void* data, size_t length)
{
return WriteArray(reinterpret_cast<const char*>(data), length);
}
bool IsOpen() const { return nullptr != m_file; }
// m_good is set to false when a read, write or other function fails
bool IsGood() const { return m_good; }
explicit operator bool() const { return IsGood(); }
std::FILE* ReleaseHandle();
std::FILE* GetHandle() { return m_file; }
void SetHandle(std::FILE* file);
bool Seek(s64 off, int origin);
u64 Tell() const;
u64 GetSize();
bool Resize(u64 size);
bool Flush();
// clear error state
void Clear()
{
m_good = true;
std::clearerr(m_file);
}
private:
std::FILE* m_file;
bool m_good;
};
} // namespace
// To deal with Windows being dumb at unicode:
template <typename T>
void OpenFStream(T& fstream, const std::string& filename, std::ios_base::openmode openmode)
{
#ifdef _WIN32
fstream.open(UTF8ToTStr(filename).c_str(), openmode);
#else
fstream.open(filename.c_str(), openmode);
#endif
}