Added portable file and directory operations (thanks @icculus!)

src/filesystem/windows/SDL_sysfsops.c

@@ -0,0 +1,188 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "SDL_internal.h"
+
+#if defined(SDL_FSOPS_WINDOWS)
+
+#include "../../core/windows/SDL_windows.h"
+#include "../SDL_sysfilesystem.h"
+
+int SDL_SYS_FSenumerate(const char *fullpath, const char *dirname, SDL_EnumerateDirectoryCallback cb, void *userdata)
+{
+    int retval = 1;
+    if (*fullpath == '\0') {  // if empty (completely at the root), we need to enumerate drive letters.
+        const DWORD drives = GetLogicalDrives();
+        char name[3] = { 0, ':', '\0' };
+        for (int i = 'A'; (retval == 1) && (i <= 'Z'); i++) {
+            if (drives & (1 << (i - 'A'))) {
+                name[0] = (char) i;
+                retval = cb(userdata, NULL, dirname, name);
+            }
+        }
+    } else {
+        const size_t patternlen = SDL_strlen(fullpath) + 3;
+        char *pattern = (char *) SDL_malloc(patternlen);
+        if (!pattern) {
+            return -1;
+        }
+
+        // you need a wildcard to enumerate through FindFirstFileEx(), but the wildcard is only checked in the
+        // filename element at the end of the path string, so always tack on a "\\*" to get everything, and
+        // also prevent any wildcards inserted by the app from being respected.
+        SDL_snprintf(pattern, patternlen, "%s\\*", fullpath);
+    
+        WCHAR *wpattern = WIN_UTF8ToString(pattern);
+        SDL_free(pattern);
+        if (!wpattern) {
+            return -1;
+        }
+
+        WIN32_FIND_DATAW entw;
+        HANDLE dir = FindFirstFileExW(wpattern, FindExInfoStandard, &entw, FindExSearchNameMatch, NULL, 0);
+        SDL_free(wpattern);
+        if (dir == INVALID_HANDLE_VALUE) {
+            return WIN_SetError("Failed to enumerate directory");
+        }
+
+        do {
+            const WCHAR *fn = entw.cFileName;
+
+            if (fn[0] == '.') {  // ignore "." and ".."
+                if ((fn[1] == '\0') || ((fn[1] == '.') && (fn[2] == '\0'))) {
+                    continue;
+                }
+            }
+
+            char *utf8fn = WIN_StringToUTF8(fn);
+            if (!utf8fn) {
+                retval = -1;
+            } else {
+                retval = cb(userdata, NULL, dirname, utf8fn);
+                SDL_free(utf8fn);
+            }
+        } while ((retval == 1) && (FindNextFileW(dir, &entw) != 0));
+
+        FindClose(dir);
+    }
+
+    return retval;
+}
+
+int SDL_SYS_FSremove(const char *fullpath)
+{
+    WCHAR *wpath = WIN_UTF8ToString(fullpath);
+    if (!wpath) {
+        return -1;
+    }
+
+    WIN32_FILE_ATTRIBUTE_DATA info;
+    if (!GetFileAttributesExW(wpath, GetFileExInfoStandard, &info)) {
+        if (GetLastError() == ERROR_FILE_NOT_FOUND) {
+            // Note that ERROR_PATH_NOT_FOUND means a parent dir is missing, and we consider that an error.
+            return 0;  // thing is already gone, call it a success.
+        }
+        return WIN_SetError("Couldn't get path's attributes");
+    }
+
+    const int isdir = (info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY);
+    const BOOL rc = isdir ? RemoveDirectoryW(wpath) : DeleteFileW(wpath);
+    SDL_free(wpath);
+    return !rc ? WIN_SetError("Couldn't remove path") : 0;
+}
+
+int SDL_SYS_FSrename(const char *oldfullpath, const char *newfullpath)
+{
+    WCHAR *woldpath = WIN_UTF8ToString(oldfullpath);
+    if (!woldpath) {
+        return -1;
+    }
+
+    WCHAR *wnewpath = WIN_UTF8ToString(newfullpath);
+    if (!wnewpath) {
+        SDL_free(woldpath);
+        return -1;
+    }
+
+    const BOOL rc = MoveFileExW(woldpath, wnewpath, MOVEFILE_REPLACE_EXISTING);
+    SDL_free(wnewpath);
+    SDL_free(woldpath);
+    return !rc ? WIN_SetError("Couldn't rename path") : 0;
+}
+
+int SDL_SYS_FSmkdir(const char *fullpath)
+{
+    WCHAR *wpath = WIN_UTF8ToString(fullpath);
+    if (!wpath) {
+        return -1;
+    }
+
+    const DWORD rc = CreateDirectoryW(wpath, NULL);
+    SDL_free(wpath);
+    return !rc ? WIN_SetError("Couldn't create directory") : 0;
+}
+
+static Sint64 FileTimeToSDLTime(const FILETIME *ft)
+{
+    const Uint64 delta_1601_epoch_100ns = 11644473600ull * 10000000ull; // [100ns] (100-ns chunks between 1/1/1601 and 1/1/1970, 11644473600 seconds * 10000000)
+    ULARGE_INTEGER large;
+    large.LowPart = ft->dwLowDateTime;
+    large.HighPart = ft->dwHighDateTime;
+    if (large.QuadPart == 0) {
+        return 0;  // unsupported on this filesystem...0 is fine, I guess.
+    }
+    return (Sint64) ((((Uint64)large.QuadPart) - delta_1601_epoch_100ns) / (SDL_NS_PER_SECOND / 100ull));  // [secs] (adjust to epoch and convert 1/100th nanosecond units to seconds).
+}
+
+int SDL_SYS_FSstat(const char *fullpath, SDL_PathInfo *info)
+{
+    WCHAR *wpath = WIN_UTF8ToString(fullpath);
+    if (!wpath) {
+        return -1;
+    }
+
+    WIN32_FILE_ATTRIBUTE_DATA winstat;
+    const BOOL rc = GetFileAttributesExW(wpath, GetFileExInfoStandard, &winstat);
+    SDL_free(wpath);
+    if (!rc) {
+        return WIN_SetError("Can't stat");
+    }
+
+    if (winstat.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+        info->type = SDL_PATHTYPE_DIRECTORY;
+        info->size = 0;
+    } else if (winstat.dwFileAttributes & (FILE_ATTRIBUTE_OFFLINE | FILE_ATTRIBUTE_DEVICE)) {
+        info->type = SDL_PATHTYPE_OTHER;
+        info->size = ((((Uint64) winstat.nFileSizeHigh) << 32) | winstat.nFileSizeLow);
+    } else {
+        info->type = SDL_PATHTYPE_FILE;
+        info->size = ((((Uint64) winstat.nFileSizeHigh) << 32) | winstat.nFileSizeLow);
+    }
+
+    info->create_time = FileTimeToSDLTime(&winstat.ftCreationTime);
+    info->modify_time = FileTimeToSDLTime(&winstat.ftLastWriteTime);
+    info->access_time = FileTimeToSDLTime(&winstat.ftLastAccessTime);
+
+    return 1;
+}
+
+#endif
+