intial commit

source/mijin/virtual_filesystem/filesystem.hpp

@@ -0,0 +1,105 @@
+
+#pragma once
+
+#if !defined(MIJIN_VIRTUAL_FILESYSTEM_FILESYSTEM_HPP_INCLUDED)
+#define MIJIN_VIRTUAL_FILESYSTEM_FILESYSTEM_HPP_INCLUDED 1
+
+#include <array>
+#include <cmath>
+#include <filesystem>
+#include <sstream>
+#include <string>
+#include <vector>
+#include "../io/stream.hpp"
+
+namespace fs = std::filesystem;
+
+namespace mijin
+{
+
+//
+// public defines
+//
+
+//
+// public constants
+//
+
+//
+// public types
+//
+
+struct FileInfo
+{
+    fs::path path;
+    std::size_t size = 0;
+    bool exists : 1 = false;
+    bool isFolder : 1 = false;
+    bool isSymlink : 1 = false;
+    bool isSpecial : 1 = false;
+    bool isHidden : 1 = false;
+};
+
+class FileSystemAdapter
+{
+public:
+    virtual ~FileSystemAdapter() = default;
+
+    [[nodiscard]] virtual std::vector<fs::path> getRoots() = 0;
+    [[nodiscard]] virtual fs::path getHomeFolder() = 0;
+    [[nodiscard]] virtual std::vector<FileInfo> listFiles(const fs::path& folder) = 0;
+    [[nodiscard]] virtual FileInfo getFileInfo(const fs::path& file) = 0;
+    [[nodiscard]] virtual StreamError open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) = 0;
+};
+
+class OSFileSystemAdapter : public FileSystemAdapter
+{
+public:
+    std::vector<fs::path> getRoots() override;
+    fs::path getHomeFolder() override;
+    std::vector<FileInfo> listFiles(const fs::path& folder) override;
+    FileInfo getFileInfo(const fs::path& file) override;
+    StreamError open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
+
+    static OSFileSystemAdapter& getInstance();
+};
+
+//
+// public functions
+//
+
+inline std::string formatFileType(const FileInfo& info)
+{
+    if (info.isFolder) {
+        return "Folder";
+    }
+    if (info.isSpecial) {
+        return "Special";
+    }
+    return "File";
+}
+
+inline std::string formatFileSize(std::size_t sizeInBytes)
+{
+    static constexpr std::array suffixes = {"bytes", "KiB", "MiB", "GiB", "TiB"}; // enough?
+
+    if (sizeInBytes == 0) {
+        return "0 bytes";
+    }
+    const std::size_t pos = std::min(static_cast<std::size_t>(std::ceil(std::log2(sizeInBytes))) / 10, suffixes.size() - 1);
+    std::stringstream oss;
+    oss << std::setprecision(2) << std::fixed;
+    if (pos == 0) {
+        oss << sizeInBytes << " bytes";
+    }
+    else
+    {
+        const float converted = static_cast<float>(sizeInBytes) / std::pow(2.f, 10.f * static_cast<float>(pos));
+        oss << converted << " " << suffixes[pos];
+    }
+    return oss.str();
+}
+
+} // namespace mijin
+
+#endif // !defined(MIJIN_VIRTUAL_FILESYSTEM_FILESYSTEM_HPP_INCLUDED)