2 files changed, 396 insertions, 112 deletions

diff --git a/src/common/file_util.cpp b/src/common/file_util.cpp
index d5f6ea2ee..18fbfa25b 100644
--- a/src/common/file_util.cpp
+++ b/src/common/file_util.cpp
@@ -3,7 +3,6 @@
 // Refer to the license.txt file included.
 
 #include <array>
-#include <filesystem>
 #include <limits>
 #include <memory>
 #include <sstream>
@@ -68,102 +67,290 @@
 #include <algorithm>
 #include <sys/stat.h>
 
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m)&S_IFMT) == S_IFDIR)
+#endif
+
+// This namespace has various generic functions related to files and paths.
+// The code still needs a ton of cleanup.
+// REMEMBER: strdup considered harmful!
 namespace Common::FS {
-namespace fs = std::filesystem;
 
-bool Exists(const fs::path& path) {
-    std::error_code ec;
-    return fs::exists(path, ec);
+// Remove any ending forward slashes from directory paths
+// Modifies argument.
+static void StripTailDirSlashes(std::string& fname) {
+    if (fname.length() <= 1) {
+        return;
+    }
+
+    std::size_t i = fname.length();
+    while (i > 0 && fname[i - 1] == DIR_SEP_CHR) {
+        --i;
+    }
+    fname.resize(i);
 }
 
-bool IsDirectory(const fs::path& path) {
-    std::error_code ec;
-    return fs::is_directory(path, ec);
+bool Exists(const std::string& filename) {
+    struct stat file_info;
+
+    std::string copy(filename);
+    StripTailDirSlashes(copy);
+
+#ifdef _WIN32
+    // Windows needs a slash to identify a driver root
+    if (copy.size() != 0 && copy.back() == ':')
+        copy += DIR_SEP_CHR;
+
+    int result = _wstat64(Common::UTF8ToUTF16W(copy).c_str(), &file_info);
+#else
+    int result = stat(copy.c_str(), &file_info);
+#endif
+
+    return (result == 0);
 }
 
-bool Delete(const fs::path& path) {
-    LOG_TRACE(Common_Filesystem, "file {}", path.string());
+bool IsDirectory(const std::string& filename) {
+    struct stat file_info;
 
-    // Return true because we care about the file no
-    // being there, not the actual delete.
-    if (!Exists(path)) {
-        LOG_DEBUG(Common_Filesystem, "{} does not exist", path.string());
-        return true;
+    std::string copy(filename);
+    StripTailDirSlashes(copy);
+
+#ifdef _WIN32
+    // Windows needs a slash to identify a driver root
+    if (copy.size() != 0 && copy.back() == ':')
+        copy += DIR_SEP_CHR;
+
+    int result = _wstat64(Common::UTF8ToUTF16W(copy).c_str(), &file_info);
+#else
+    int result = stat(copy.c_str(), &file_info);
+#endif
+
+    if (result < 0) {
+        LOG_DEBUG(Common_Filesystem, "stat failed on {}: {}", filename, GetLastErrorMsg());
+        return false;
     }
 
-    std::error_code ec;
-    return fs::remove(path, ec);
+    return S_ISDIR(file_info.st_mode);
 }
 
-bool CreateDir(const fs::path& path) {
-    LOG_TRACE(Common_Filesystem, "directory {}", path.string());
+bool Delete(const std::string& filename) {
+    LOG_TRACE(Common_Filesystem, "file {}", filename);
 
-    std::error_code ec;
-    const bool success = fs::create_directory(path, ec);
+    // Return true because we care about the file no
+    // being there, not the actual delete.
+    if (!Exists(filename)) {
+        LOG_DEBUG(Common_Filesystem, "{} does not exist", filename);
+        return true;
+    }
+
+    // We can't delete a directory
+    if (IsDirectory(filename)) {
+        LOG_ERROR(Common_Filesystem, "Failed: {} is a directory", filename);
+        return false;
+    }
 
-    if (!success) {
-        LOG_ERROR(Common_Filesystem, "Unable to create directory: {}", ec.message());
+#ifdef _WIN32
+    if (!DeleteFileW(Common::UTF8ToUTF16W(filename).c_str())) {
+        LOG_ERROR(Common_Filesystem, "DeleteFile failed on {}: {}", filename, GetLastErrorMsg());
+        return false;
+    }
+#else
+    if (unlink(filename.c_str()) == -1) {
+        LOG_ERROR(Common_Filesystem, "unlink failed on {}: {}", filename, GetLastErrorMsg());
         return false;
     }
+#endif
 
     return true;
 }
 
-bool CreateFullPath(const fs::path& path) {
-    LOG_TRACE(Common_Filesystem, "path {}", path.string());
+bool CreateDir(const std::string& path) {
+    LOG_TRACE(Common_Filesystem, "directory {}", path);
+#ifdef _WIN32
+    if (::CreateDirectoryW(Common::UTF8ToUTF16W(path).c_str(), nullptr))
+        return true;
+    DWORD error = GetLastError();
+    if (error == ERROR_ALREADY_EXISTS) {
+        LOG_DEBUG(Common_Filesystem, "CreateDirectory failed on {}: already exists", path);
+        return true;
+    }
+    LOG_ERROR(Common_Filesystem, "CreateDirectory failed on {}: {}", path, error);
+    return false;
+#else
+    if (mkdir(path.c_str(), 0755) == 0)
+        return true;
 
-    std::error_code ec;
-    const bool success = fs::create_directories(path, ec);
+    int err = errno;
 
-    if (!success) {
-        LOG_ERROR(Common_Filesystem, "Unable to create full path: {}", ec.message());
-        return false;
+    if (err == EEXIST) {
+        LOG_DEBUG(Common_Filesystem, "mkdir failed on {}: already exists", path);
+        return true;
     }
 
-    return true;
+    LOG_ERROR(Common_Filesystem, "mkdir failed on {}: {}", path, strerror(err));
+    return false;
+#endif
 }
 
-bool Rename(const fs::path& src, const fs::path& dst) {
-    LOG_TRACE(Common_Filesystem, "{} --> {}", src.string(), dst.string());
+bool CreateFullPath(const std::string& fullPath) {
+    int panicCounter = 100;
+    LOG_TRACE(Common_Filesystem, "path {}", fullPath);
+
+    if (Exists(fullPath)) {
+        LOG_DEBUG(Common_Filesystem, "path exists {}", fullPath);
+        return true;
+    }
+
+    std::size_t position = 0;
+    while (true) {
+        // Find next sub path
+        position = fullPath.find(DIR_SEP_CHR, position);
 
-    std::error_code ec;
-    fs::rename(src, dst, ec);
+        // we're done, yay!
+        if (position == fullPath.npos)
+            return true;
 
-    if (ec) {
-        LOG_ERROR(Common_Filesystem, "Unable to rename file from {} to {}: {}", src.string(),
-                  dst.string(), ec.message());
+        // Include the '/' so the first call is CreateDir("/") rather than CreateDir("")
+        std::string const subPath(fullPath.substr(0, position + 1));
+        if (!IsDirectory(subPath) && !CreateDir(subPath)) {
+            LOG_ERROR(Common, "CreateFullPath: directory creation failed");
+            return false;
+        }
+
+        // A safety check
+        panicCounter--;
+        if (panicCounter <= 0) {
+            LOG_ERROR(Common, "CreateFullPath: directory structure is too deep");
+            return false;
+        }
+        position++;
+    }
+}
+
+bool DeleteDir(const std::string& filename) {
+    LOG_TRACE(Common_Filesystem, "directory {}", filename);
+
+    // check if a directory
+    if (!IsDirectory(filename)) {
+        LOG_ERROR(Common_Filesystem, "Not a directory {}", filename);
         return false;
     }
 
-    return true;
+#ifdef _WIN32
+    if (::RemoveDirectoryW(Common::UTF8ToUTF16W(filename).c_str()))
+        return true;
+#else
+    if (rmdir(filename.c_str()) == 0)
+        return true;
+#endif
+    LOG_ERROR(Common_Filesystem, "failed {}: {}", filename, GetLastErrorMsg());
+
+    return false;
+}
+
+bool Rename(const std::string& srcFilename, const std::string& destFilename) {
+    LOG_TRACE(Common_Filesystem, "{} --> {}", srcFilename, destFilename);
+#ifdef _WIN32
+    if (_wrename(Common::UTF8ToUTF16W(srcFilename).c_str(),
+                 Common::UTF8ToUTF16W(destFilename).c_str()) == 0)
+        return true;
+#else
+    if (rename(srcFilename.c_str(), destFilename.c_str()) == 0)
+        return true;
+#endif
+    LOG_ERROR(Common_Filesystem, "failed {} --> {}: {}", srcFilename, destFilename,
+              GetLastErrorMsg());
+    return false;
 }
 
-bool Copy(const fs::path& src, const fs::path& dst) {
-    LOG_TRACE(Common_Filesystem, "{} --> {}", src.string(), dst.string());
+bool Copy(const std::string& srcFilename, const std::string& destFilename) {
+    LOG_TRACE(Common_Filesystem, "{} --> {}", srcFilename, destFilename);
+#ifdef _WIN32
+    if (CopyFileW(Common::UTF8ToUTF16W(srcFilename).c_str(),
+                  Common::UTF8ToUTF16W(destFilename).c_str(), FALSE))
+        return true;
 
-    std::error_code ec;
-    const bool success = fs::copy_file(src, dst, fs::copy_options::overwrite_existing, ec);
+    LOG_ERROR(Common_Filesystem, "failed {} --> {}: {}", srcFilename, destFilename,
+              GetLastErrorMsg());
+    return false;
+#else
+    using CFilePointer = std::unique_ptr<FILE, decltype(&std::fclose)>;
 
-    if (!success) {
-        LOG_ERROR(Common_Filesystem, "Unable to copy file {} to {}: {}", src.string(), dst.string(),
-                  ec.message());
+    // Open input file
+    CFilePointer input{fopen(srcFilename.c_str(), "rb"), std::fclose};
+    if (!input) {
+        LOG_ERROR(Common_Filesystem, "opening input failed {} --> {}: {}", srcFilename,
+                  destFilename, GetLastErrorMsg());
         return false;
     }
 
+    // open output file
+    CFilePointer output{fopen(destFilename.c_str(), "wb"), std::fclose};
+    if (!output) {
+        LOG_ERROR(Common_Filesystem, "opening output failed {} --> {}: {}", srcFilename,
+                  destFilename, GetLastErrorMsg());
+        return false;
+    }
+
+    // copy loop
+    std::array<char, 1024> buffer;
+    while (!feof(input.get())) {
+        // read input
+        std::size_t rnum = fread(buffer.data(), sizeof(char), buffer.size(), input.get());
+        if (rnum != buffer.size()) {
+            if (ferror(input.get()) != 0) {
+                LOG_ERROR(Common_Filesystem, "failed reading from source, {} --> {}: {}",
+                          srcFilename, destFilename, GetLastErrorMsg());
+                return false;
+            }
+        }
+
+        // write output
+        std::size_t wnum = fwrite(buffer.data(), sizeof(char), rnum, output.get());
+        if (wnum != rnum) {
+            LOG_ERROR(Common_Filesystem, "failed writing to output, {} --> {}: {}", srcFilename,
+                      destFilename, GetLastErrorMsg());
+            return false;
+        }
+    }
+
     return true;
+#endif
 }
 
-u64 GetSize(const fs::path& path) {
-    std::error_code ec;
-    const auto size = fs::file_size(path, ec);
+u64 GetSize(const std::string& filename) {
+    if (!Exists(filename)) {
+        LOG_ERROR(Common_Filesystem, "failed {}: No such file", filename);
+        return 0;
+    }
 
-    if (ec) {
-        LOG_ERROR(Common_Filesystem, "Unable to retrieve file size ({}): {}", path.string(),
-                  ec.message());
+    if (IsDirectory(filename)) {
+        LOG_ERROR(Common_Filesystem, "failed {}: is a directory", filename);
         return 0;
     }
 
-    return size;
+    struct stat buf;
+#ifdef _WIN32
+    if (_wstat64(Common::UTF8ToUTF16W(filename).c_str(), &buf) == 0)
+#else
+    if (stat(filename.c_str(), &buf) == 0)
+#endif
+    {
+        LOG_TRACE(Common_Filesystem, "{}: {}", filename, buf.st_size);
+        return buf.st_size;
+    }
+
+    LOG_ERROR(Common_Filesystem, "Stat failed {}: {}", filename, GetLastErrorMsg());
+    return 0;
+}
+
+u64 GetSize(const int fd) {
+    struct stat buf;
+    if (fstat(fd, &buf) != 0) {
+        LOG_ERROR(Common_Filesystem, "GetSize: stat failed {}: {}", fd, GetLastErrorMsg());
+        return 0;
+    }
+    return buf.st_size;
 }
 
 u64 GetSize(FILE* f) {
@@ -251,58 +438,132 @@ bool ForeachDirectoryEntry(u64* num_entries_out, const std::string& directory,
     return true;
 }
 
-bool DeleteDirRecursively(const fs::path& path) {
-    std::error_code ec;
-    fs::remove_all(path, ec);
+u64 ScanDirectoryTree(const std::string& directory, FSTEntry& parent_entry,
+                      unsigned int recursion) {
+    const auto callback = [recursion, &parent_entry](u64* num_entries_out,
+                                                     const std::string& directory,
+                                                     const std::string& virtual_name) -> bool {
+        FSTEntry entry;
+        entry.virtualName = virtual_name;
+        entry.physicalName = directory + DIR_SEP + virtual_name;
+
+        if (IsDirectory(entry.physicalName)) {
+            entry.isDirectory = true;
+            // is a directory, lets go inside if we didn't recurse to often
+            if (recursion > 0) {
+                entry.size = ScanDirectoryTree(entry.physicalName, entry, recursion - 1);
+                *num_entries_out += entry.size;
+            } else {
+                entry.size = 0;
+            }
+        } else { // is a file
+            entry.isDirectory = false;
+            entry.size = GetSize(entry.physicalName);
+        }
+        (*num_entries_out)++;
 
-    if (ec) {
-        LOG_ERROR(Common_Filesystem, "Unable to completely delete directory {}: {}", path.string(),
-                  ec.message());
-        return false;
-    }
+        // Push into the tree
+        parent_entry.children.push_back(std::move(entry));
+        return true;
+    };
 
-    return true;
+    u64 num_entries;
+    return ForeachDirectoryEntry(&num_entries, directory, callback) ? num_entries : 0;
 }
 
-void CopyDir(const fs::path& src, const fs::path& dst) {
-    constexpr auto copy_flags = fs::copy_options::skip_existing | fs::copy_options::recursive;
+bool DeleteDirRecursively(const std::string& directory, unsigned int recursion) {
+    const auto callback = [recursion](u64*, const std::string& directory,
+                                      const std::string& virtual_name) {
+        const std::string new_path = directory + DIR_SEP_CHR + virtual_name;
 
-    std::error_code ec;
-    fs::copy(src, dst, copy_flags, ec);
+        if (IsDirectory(new_path)) {
+            if (recursion == 0) {
+                return false;
+            }
+            return DeleteDirRecursively(new_path, recursion - 1);
+        }
+        return Delete(new_path);
+    };
 
-    if (ec) {
-        LOG_ERROR(Common_Filesystem, "Error copying directory {} to {}: {}", src.string(),
-                  dst.string(), ec.message());
-        return;
-    }
+    if (!ForeachDirectoryEntry(nullptr, directory, callback))
+        return false;
 
-    LOG_TRACE(Common_Filesystem, "Successfully copied directory.");
+    // Delete the outermost directory
+    DeleteDir(directory);
+    return true;
 }
 
-std::optional<fs::path> GetCurrentDir() {
-    std::error_code ec;
-    auto path = fs::current_path(ec);
+void CopyDir([[maybe_unused]] const std::string& source_path,
+             [[maybe_unused]] const std::string& dest_path) {
+#ifndef _WIN32
+    if (source_path == dest_path) {
+        return;
+    }
+    if (!Exists(source_path)) {
+        return;
+    }
+    if (!Exists(dest_path)) {
+        CreateFullPath(dest_path);
+    }
 
-    if (ec) {
-        LOG_ERROR(Common_Filesystem, "Unable to retrieve current working directory: {}",
-                  ec.message());
-        return std::nullopt;
+    DIR* dirp = opendir(source_path.c_str());
+    if (!dirp) {
+        return;
     }
 
-    return {std::move(path)};
-}
+    while (struct dirent* result = readdir(dirp)) {
+        const std::string virtualName(result->d_name);
+        // check for "." and ".."
+        if (((virtualName[0] == '.') && (virtualName[1] == '\0')) ||
+            ((virtualName[0] == '.') && (virtualName[1] == '.') && (virtualName[2] == '\0'))) {
+            continue;
+        }
 
-bool SetCurrentDir(const fs::path& path) {
-    std::error_code ec;
-    fs::current_path(path, ec);
+        std::string source, dest;
+        source = source_path + virtualName;
+        dest = dest_path + virtualName;
+        if (IsDirectory(source)) {
+            source += '/';
+            dest += '/';
+            if (!Exists(dest)) {
+                CreateFullPath(dest);
+            }
+            CopyDir(source, dest);
+        } else if (!Exists(dest)) {
+            Copy(source, dest);
+        }
+    }
+    closedir(dirp);
+#endif
+}
 
-    if (ec) {
-        LOG_ERROR(Common_Filesystem, "Unable to set {} as working directory: {}", path.string(),
-                  ec.message());
-        return false;
+std::optional<std::string> GetCurrentDir() {
+// Get the current working directory (getcwd uses malloc)
+#ifdef _WIN32
+    wchar_t* dir = _wgetcwd(nullptr, 0);
+    if (!dir) {
+#else
+    char* dir = getcwd(nullptr, 0);
+    if (!dir) {
+#endif
+        LOG_ERROR(Common_Filesystem, "GetCurrentDirectory failed: {}", GetLastErrorMsg());
+        return std::nullopt;
     }
+#ifdef _WIN32
+    std::string strDir = Common::UTF16ToUTF8(dir);
+#else
+    std::string strDir = dir;
+#endif
+    free(dir);
+    return strDir;
+}
 
-    return true;
+bool SetCurrentDir(const std::string& directory) {
+#ifdef _WIN32
+    return _wchdir(Common::UTF8ToUTF16W(directory).c_str()) == 0;
+#else
+    return chdir(directory.c_str()) == 0;
+#endif
 }
 
 #if defined(__APPLE__)
diff --git a/src/common/file_util.h b/src/common/file_util.h
index c2ee7ca27..840cde2a6 100644
--- a/src/common/file_util.h
+++ b/src/common/file_util.h
@@ -6,7 +6,6 @@
 
 #include <array>
 #include <cstdio>
-#include <filesystem>
 #include <fstream>
 #include <functional>
 #include <limits>
@@ -39,34 +38,48 @@ enum class UserPath {
     UserDir,
 };
 
-// Returns true if the path exists
-[[nodiscard]] bool Exists(const std::filesystem::path& path);
+// FileSystem tree node/
+struct FSTEntry {
+    bool isDirectory;
+    u64 size;                 // file length or number of entries from 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
+[[nodiscard]] bool Exists(const std::string& filename);
 
-// Returns true if path is a directory
-[[nodiscard]] bool IsDirectory(const std::filesystem::path& path);
+// Returns true if filename is a directory
+[[nodiscard]] bool IsDirectory(const std::string& filename);
 
 // Returns the size of filename (64bit)
-[[nodiscard]] u64 GetSize(const std::filesystem::path& path);
+[[nodiscard]] u64 GetSize(const std::string& filename);
+
+// Overloaded GetSize, accepts file descriptor
+[[nodiscard]] u64 GetSize(int fd);
 
 // Overloaded GetSize, accepts FILE*
 [[nodiscard]] u64 GetSize(FILE* f);
 
 // Returns true if successful, or path already exists.
-bool CreateDir(const std::filesystem::path& path);
+bool CreateDir(const std::string& filename);
+
+// Creates the full path of fullPath returns true on success
+bool CreateFullPath(const std::string& fullPath);
 
-// Creates the full path of path. Returns true on success
-bool CreateFullPath(const std::filesystem::path& path);
+// Deletes a given filename, return true on success
+// Doesn't supports deleting a directory
+bool Delete(const std::string& filename);
 
-// Deletes a given file at the path.
-// This will also delete empty directories.
-// Return true on success
-bool Delete(const std::filesystem::path& path);
+// Deletes a directory filename, returns true on success
+bool DeleteDir(const std::string& filename);
 
-// Renames file src to dst, returns true on success
-bool Rename(const std::filesystem::path& src, const std::filesystem::path& dst);
+// renames file srcFilename to destFilename, returns true on success
+bool Rename(const std::string& srcFilename, const std::string& destFilename);
 
-// copies file src to dst, returns true on success
-bool Copy(const std::filesystem::path& src, const std::filesystem::path& dst);
+// 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);
@@ -93,17 +106,27 @@ using DirectoryEntryCallable = std::function<bool(
 bool ForeachDirectoryEntry(u64* num_entries_out, const std::string& directory,
                            DirectoryEntryCallable callback);
 
-// Deletes the given path and anything under it. Returns true on success.
-bool DeleteDirRecursively(const std::filesystem::path& path);
+/**
+ * Scans the directory tree, storing the results.
+ * @param directory the parent directory to start scanning from
+ * @param parent_entry FSTEntry where the filesystem tree results will be stored.
+ * @param recursion Number of children directories to read before giving up.
+ * @return the total number of files/directories found
+ */
+u64 ScanDirectoryTree(const std::string& directory, FSTEntry& parent_entry,
+                      unsigned int recursion = 0);
+
+// deletes the given directory and anything under it. Returns true on success.
+bool DeleteDirRecursively(const std::string& directory, unsigned int recursion = 256);
 
 // Returns the current directory
-[[nodiscard]] std::optional<std::filesystem::path> GetCurrentDir();
+[[nodiscard]] std::optional<std::string> GetCurrentDir();
 
 // Create directory and copy contents (does not overwrite existing files)
-void CopyDir(const std::filesystem::path& src, const std::filesystem::path& dst);
+void CopyDir(const std::string& source_path, const std::string& dest_path);
 
-// Set the current directory to given path
-bool SetCurrentDir(const std::filesystem::path& path);
+// Set the current directory to given directory
+bool SetCurrentDir(const std::string& directory);
 
 // Returns a pointer to a string with a yuzu data dir in the user's home
 // directory. To be used in "multi-user" mode (that is, installed).