Separate filestream.h into OS specific implementation files (#190)

src/Common/unix/FileStream_unix.h

@@ -0,0 +1,56 @@
+#pragma once
+#include "Common/precompiled.h"
+
+class FileStream
+{
+ public:
+	static FileStream* openFile(std::string_view path);
+	static FileStream* openFile(const wchar_t* path, bool allowWrite = false);
+	static FileStream* openFile2(const fs::path& path, bool allowWrite = false);
+
+	static FileStream* createFile(const wchar_t* path);
+	static FileStream* createFile(std::string_view path);
+	static FileStream* createFile2(const fs::path& path);
+
+	// helper function to load a file into memory
+	static std::optional<std::vector<uint8>> LoadIntoMemory(const fs::path& path);
+
+	// size and seek
+	void SetPosition(uint64 pos);
+
+	uint64 GetSize();
+	bool SetEndOfFile();
+	void extract(std::vector<uint8>& data);
+
+	// reading
+	uint32 readData(void* data, uint32 length);
+	bool readU64(uint64& v);
+	bool readU32(uint32& v);
+	bool readU16(uint16& v);
+	bool readU8(uint8& v);
+	bool readLine(std::string& line);
+
+	// writing (binary)
+	sint32 writeData(const void* data, sint32 length);
+	void writeU64(uint64 v);
+	void writeU32(uint32 v);
+	void writeU16(uint16 v);
+	void writeU8(uint8 v);
+
+	// writing (strings)
+	void writeStringFmt(const char* format, ...);
+	void writeString(const char* str);
+	void writeLine(const char* str);
+
+	~FileStream();
+	FileStream() {};
+
+ private:
+	void SyncReadWriteSeek(bool nextOpIsWrite);
+	FileStream(const fs::path& path, bool isOpen, bool isWriteable);
+
+	bool m_isValid{};
+	std::fstream m_fileStream;
+	bool m_prevOperationWasWrite{false};
+
+};