ffmpeg/libavutil/wchar_filename.h

281 lines
8.7 KiB
C

/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_WCHAR_FILENAME_H
#define AVUTIL_WCHAR_FILENAME_H
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include "mem.h"
av_warn_unused_result
static inline int utf8towchar(const char *filename_utf8, wchar_t **filename_w)
{
int num_chars;
num_chars = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, filename_utf8, -1, NULL, 0);
if (num_chars <= 0) {
*filename_w = NULL;
errno = EINVAL;
return -1;
}
*filename_w = (wchar_t *)av_calloc(num_chars, sizeof(wchar_t));
if (!*filename_w) {
errno = ENOMEM;
return -1;
}
MultiByteToWideChar(CP_UTF8, 0, filename_utf8, -1, *filename_w, num_chars);
return 0;
}
av_warn_unused_result
static inline int wchartocp(unsigned int code_page, const wchar_t *filename_w,
char **filename)
{
DWORD flags = code_page == CP_UTF8 ? WC_ERR_INVALID_CHARS : 0;
int num_chars = WideCharToMultiByte(code_page, flags, filename_w, -1,
NULL, 0, NULL, NULL);
if (num_chars <= 0) {
*filename = NULL;
errno = EINVAL;
return -1;
}
*filename = (char*)av_malloc_array(num_chars, sizeof *filename);
if (!*filename) {
errno = ENOMEM;
return -1;
}
WideCharToMultiByte(code_page, flags, filename_w, -1,
*filename, num_chars, NULL, NULL);
return 0;
}
av_warn_unused_result
static inline int wchartoutf8(const wchar_t *filename_w, char **filename)
{
return wchartocp(CP_UTF8, filename_w, filename);
}
av_warn_unused_result
static inline int wchartoansi(const wchar_t *filename_w, char **filename)
{
return wchartocp(CP_ACP, filename_w, filename);
}
av_warn_unused_result
static inline int utf8toansi(const char *filename_utf8, char **filename)
{
wchar_t *filename_w = NULL;
int ret = -1;
if (utf8towchar(filename_utf8, &filename_w))
return -1;
if (!filename_w) {
*filename = NULL;
return 0;
}
ret = wchartoansi(filename_w, filename);
av_free(filename_w);
return ret;
}
/**
* Checks for extended path prefixes for which normalization needs to be skipped.
* see .NET6: PathInternal.IsExtended()
* https://github.com/dotnet/runtime/blob/9260c249140ef90b4299d0fe1aa3037e25228518/src/libraries/Common/src/System/IO/PathInternal.Windows.cs#L165
*/
static inline int path_is_extended(const wchar_t *path)
{
if (path[0] == L'\\' && (path[1] == L'\\' || path[1] == L'?') && path[2] == L'?' && path[3] == L'\\')
return 1;
return 0;
}
/**
* Checks for a device path prefix.
* see .NET6: PathInternal.IsDevice()
* we don't check forward slashes and extended paths (as already done)
* https://github.com/dotnet/runtime/blob/9260c249140ef90b4299d0fe1aa3037e25228518/src/libraries/Common/src/System/IO/PathInternal.Windows.cs#L132
*/
static inline int path_is_device_path(const wchar_t *path)
{
if (path[0] == L'\\' && path[1] == L'\\' && path[2] == L'.' && path[3] == L'\\')
return 1;
return 0;
}
/**
* Performs path normalization by calling GetFullPathNameW().
* see .NET6: PathHelper.GetFullPathName()
* https://github.com/dotnet/runtime/blob/2a99e18eedabcf1add064c099da59d9301ce45e0/src/libraries/System.Private.CoreLib/src/System/IO/PathHelper.Windows.cs#L70
*/
static inline int get_full_path_name(wchar_t **ppath_w)
{
int num_chars;
wchar_t *temp_w;
num_chars = GetFullPathNameW(*ppath_w, 0, NULL, NULL);
if (num_chars <= 0) {
errno = EINVAL;
return -1;
}
temp_w = (wchar_t *)av_calloc(num_chars, sizeof(wchar_t));
if (!temp_w) {
errno = ENOMEM;
return -1;
}
num_chars = GetFullPathNameW(*ppath_w, num_chars, temp_w, NULL);
if (num_chars <= 0) {
av_free(temp_w);
errno = EINVAL;
return -1;
}
av_freep(ppath_w);
*ppath_w = temp_w;
return 0;
}
/**
* Normalizes a Windows file or folder path.
* Expansion of short paths (with 8.3 path components) is currently omitted
* as it is not required for accessing long paths.
* see .NET6: PathHelper.Normalize()
* https://github.com/dotnet/runtime/blob/2a99e18eedabcf1add064c099da59d9301ce45e0/src/libraries/System.Private.CoreLib/src/System/IO/PathHelper.Windows.cs#L25
*/
static inline int path_normalize(wchar_t **ppath_w)
{
int ret;
if ((ret = get_full_path_name(ppath_w)) < 0)
return ret;
/* What .NET does at this point is to call PathHelper.TryExpandShortFileName()
* in case the path contains a '~' character.
* We don't need to do this as we don't need to normalize the file name
* for presentation, and the extended path prefix works with 8.3 path
* components as well
*/
return 0;
}
/**
* Adds an extended path or UNC prefix to longs paths or paths ending
* with a space or a dot. (' ' or '.').
* This function expects that the path has been normalized before by
* calling path_normalize() and it doesn't check whether the path is
* actually long (> MAX_PATH).
* see .NET6: PathInternal.EnsureExtendedPrefix()
* https://github.com/dotnet/runtime/blob/9260c249140ef90b4299d0fe1aa3037e25228518/src/libraries/Common/src/System/IO/PathInternal.Windows.cs#L107
*/
static inline int add_extended_prefix(wchar_t **ppath_w)
{
const wchar_t *unc_prefix = L"\\\\?\\UNC\\";
const wchar_t *extended_path_prefix = L"\\\\?\\";
const wchar_t *path_w = *ppath_w;
const size_t len = wcslen(path_w);
wchar_t *temp_w;
/* We're skipping the check IsPartiallyQualified() because
* we expect to have called GetFullPathNameW() already. */
if (len < 2 || path_is_extended(*ppath_w) || path_is_device_path(*ppath_w)) {
return 0;
}
if (path_w[0] == L'\\' && path_w[1] == L'\\') {
/* unc_prefix length is 8 plus 1 for terminating zeros,
* we subtract 2 for the leading '\\' of the original path */
temp_w = (wchar_t *)av_calloc(len - 2 + 8 + 1, sizeof(wchar_t));
if (!temp_w) {
errno = ENOMEM;
return -1;
}
wcscpy(temp_w, unc_prefix);
wcscat(temp_w, path_w + 2);
} else {
// The length of extended_path_prefix is 4 plus 1 for terminating zeros
temp_w = (wchar_t *)av_calloc(len + 4 + 1, sizeof(wchar_t));
if (!temp_w) {
errno = ENOMEM;
return -1;
}
wcscpy(temp_w, extended_path_prefix);
wcscat(temp_w, path_w);
}
av_freep(ppath_w);
*ppath_w = temp_w;
return 0;
}
/**
* Converts a file or folder path to wchar_t for use with Windows file
* APIs. Paths with extended path prefix (either '\\?\' or \??\') are
* left unchanged.
* All other paths are normalized and converted to absolute paths.
* Longs paths (>= MAX_PATH) are prefixed with the extended path or extended
* UNC path prefix.
* see .NET6: Path.GetFullPath() and Path.GetFullPathInternal()
* https://github.com/dotnet/runtime/blob/2a99e18eedabcf1add064c099da59d9301ce45e0/src/libraries/System.Private.CoreLib/src/System/IO/Path.Windows.cs#L126
*/
static inline int get_extended_win32_path(const char *path, wchar_t **ppath_w)
{
int ret;
size_t len;
if ((ret = utf8towchar(path, ppath_w)) < 0)
return ret;
if (path_is_extended(*ppath_w)) {
/* Paths prefixed with '\\?\' or \??\' are considered normalized by definition.
* Windows doesn't normalize those paths and neither should we.
*/
return 0;
}
if ((ret = path_normalize(ppath_w)) < 0) {
av_freep(ppath_w);
return ret;
}
/* see .NET6: PathInternal.EnsureExtendedPrefixIfNeeded()
* https://github.com/dotnet/runtime/blob/9260c249140ef90b4299d0fe1aa3037e25228518/src/libraries/Common/src/System/IO/PathInternal.Windows.cs#L92
*/
len = wcslen(*ppath_w);
if (len >= MAX_PATH) {
if ((ret = add_extended_prefix(ppath_w)) < 0) {
av_freep(ppath_w);
return ret;
}
}
return 0;
}
#endif
#endif /* AVUTIL_WCHAR_FILENAME_H */