From 6cf03ad3dc98fe96893aec41b91b8f92c0a82e93 Mon Sep 17 00:00:00 2001
From: rtk0c <mail.tianyig@gmail.com>
Date: Sun, 29 Aug 2021 10:10:58 -0700
Subject: Initial draft of FileStream

---
 core/src/Utils/IO/FileStream.hpp | 86 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 core/src/Utils/IO/FileStream.hpp

(limited to 'core/src/Utils/IO/FileStream.hpp')

diff --git a/core/src/Utils/IO/FileStream.hpp b/core/src/Utils/IO/FileStream.hpp
new file mode 100644
index 0000000..224f3b6
--- /dev/null
+++ b/core/src/Utils/IO/FileStream.hpp
@@ -0,0 +1,86 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <filesystem>
+#include <memory>
+
+struct IoResult
+{
+	enum ErrorKind
+	{
+		ERR_None,
+		ERR_PermissionDenied,
+		ERR_UnexpectedEof,
+		ERR_Unsupported,
+		ERR_OutOfSpace,
+		ERR_Other,
+	};
+
+	ErrorKind Error;
+	int32_t SystemError;
+	size_t BytesMoved;
+};
+
+class InputFileStream
+{
+private:
+	alignas(void*) char mOsFileHandle[sizeof(void*)];
+
+	// mBuffer is always mReadInSize size
+	std::unique_ptr<std::byte[]> mBuffer;
+	int mReadInSize = 1024;
+
+	int mFirstByteIdx = 0;
+	int mAvailableBytes = 0;
+
+	bool mEof = false;
+
+public:
+	InputFileStream(const std::filesystem::path& path);
+	~InputFileStream();
+
+	InputFileStream(const InputFileStream&) = delete;
+	InputFileStream& operator=(const InputFileStream&) = delete;
+	InputFileStream(InputFileStream&&) = default;
+	InputFileStream& operator=(InputFileStream&&) = default;
+
+	int GetReadInSize() const;
+	void SetReadInSize(int size);
+
+	bool IsEof() const;
+
+	IoResult ReadBytes(size_t bufferLength, std::byte* buffer);
+};
+
+class OutputFileStream
+{
+public:
+	enum WriteMode
+	{
+		AppendFile,
+		TruncateFile,
+	};
+
+private:
+	alignas(void*) char mOsFileHandle[sizeof(void*)];
+	std::unique_ptr<std::byte[]> mBuffer;
+	int mMaxBufferSize = 1024;
+	int mCurrentBufferSize = 0;
+
+public:
+	OutputFileStream(const std::filesystem::path& path, WriteMode mode);
+	~OutputFileStream();
+
+	OutputFileStream(const OutputFileStream&) = delete;
+	OutputFileStream& operator=(const OutputFileStream&) = delete;
+	OutputFileStream(OutputFileStream&&) = default;
+	OutputFileStream& operator=(OutputFileStream&&) = default;
+
+	int GetMaxBufferSize() const;
+	void SetMaxBufferSize(int maxSize);
+
+	IoResult WriteBytes(size_t bufferLength, const std::byte* buffer);
+
+	void FlushBuffer();
+};
-- 
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