Virtual Filesystem (#597)

* Add VfsFile and VfsDirectory classes

* Finish abstract Vfs classes

* Implement RealVfsFile (computer fs backend)

* Finish RealVfsFile and RealVfsDirectory

* Finished OffsetVfsFile

* More changes

* Fix import paths

* Major refactor

* Remove double const

* Use experimental/filesystem or filesystem depending on compiler

* Port partition_filesystem

* More changes

* More Overhaul

* FSP_SRV fixes

* Fixes and testing

* Try to get filesystem to compile

* Filesystem on linux

* Remove std::filesystem and document/test

* Compile fixes

* Missing include

* Bug fixes

* Fixes

* Rename v_file and v_dir

* clang-format fix

* Rename NGLOG_* to LOG_*

* Most review changes

* Fix TODO

* Guess 'main' to be Directory by filename

src/common/file_util.h

@@ -150,6 +150,31 @@ size_t ReadFileToString(bool text_file, const char* filename, std::string& str);
 void SplitFilename83(const std::string& filename, std::array<char, 9>& short_name,
                      std::array<char, 4>& extension);
 
+// Splits the path on '/' or '\' and put the components into a vector
+// i.e. "C:\Users\Yuzu\Documents\save.bin" becomes {"C:", "Users", "Yuzu", "Documents", "save.bin" }
+std::vector<std::string> SplitPathComponents(const std::string& filename);
+
+// Gets all of the text prior to the last '/' or '\' in the path.
+std::string GetParentPath(const std::string& path);
+
+// Gets the filename of the path
+std::string GetFilename(std::string path);
+
+// Gets the extension of the filename
+std::string GetExtensionFromFilename(const std::string& name);
+
+// Removes the final '/' or '\' if one exists
+std::string RemoveTrailingSlash(const std::string& path);
+
+// Creates a new vector containing indices [first, last) from the original.
+template <typename T>
+std::vector<T> SliceVector(const std::vector<T>& vector, size_t first, size_t last) {
+    if (first >= last)
+        return {};
+    last = std::min<size_t>(last, vector.size());
+    return std::vector<T>(vector.begin() + first, vector.begin() + first + last);
+}
+
 // simple wrapper for cstdlib file functions to
 // hopefully will make error checking easier
 // and make forgetting an fclose() harder
@@ -172,41 +197,27 @@ public:
     bool Close();
 
     template <typename T>
-    size_t ReadArray(T* data, size_t length) {
+    size_t ReadArray(T* data, size_t length) const {
         static_assert(std::is_trivially_copyable<T>(),
                       "Given array does not consist of trivially copyable objects");
 
-        if (!IsOpen()) {
-            m_good = false;
+        if (!IsOpen())
             return -1;
-        }
 
-        size_t items_read = std::fread(data, sizeof(T), length, m_file);
-        if (items_read != length)
-            m_good = false;
-
-        return items_read;
+        return std::fread(data, sizeof(T), length, m_file);
     }
 
     template <typename T>
     size_t WriteArray(const T* data, size_t length) {
         static_assert(std::is_trivially_copyable<T>(),
                       "Given array does not consist of trivially copyable objects");
-
-        if (!IsOpen()) {
-            m_good = false;
+        if (!IsOpen())
             return -1;
-        }
-
-        size_t items_written = std::fwrite(data, sizeof(T), length, m_file);
-        if (items_written != length)
-            m_good = false;
-
-        return items_written;
+        return std::fwrite(data, sizeof(T), length, m_file);
     }
 
     template <typename T>
-    size_t ReadBytes(T* data, size_t length) {
+    size_t ReadBytes(T* data, size_t length) const {
         static_assert(std::is_trivially_copyable<T>(), "T must be trivially copyable");
         return ReadArray(reinterpret_cast<char*>(data), length);
     }
@@ -231,15 +242,7 @@ public:
         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();
-    }
-
-    bool Seek(s64 off, int origin);
+    bool Seek(s64 off, int origin) const;
     u64 Tell() const;
     u64 GetSize() const;
     bool Resize(u64 size);
@@ -247,13 +250,11 @@ public:
 
     // clear error state
     void Clear() {
-        m_good = true;
         std::clearerr(m_file);
     }
 
 private:
     std::FILE* m_file = nullptr;
-    bool m_good = true;
 };
 
 } // namespace FileUtil