From 7fe47a9d5b1727a61dc724523b530762f6d6ba19 Mon Sep 17 00:00:00 2001
From: rtk0c <mail.tianyig@gmail.com>
Date: Thu, 30 Jun 2022 21:38:53 -0700
Subject: Restructure project

---
 app/source/Cplt/Utils/IO/Archive.cpp | 57 ++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 app/source/Cplt/Utils/IO/Archive.cpp

(limited to 'app/source/Cplt/Utils/IO/Archive.cpp')

diff --git a/app/source/Cplt/Utils/IO/Archive.cpp b/app/source/Cplt/Utils/IO/Archive.cpp
new file mode 100644
index 0000000..f6e7b27
--- /dev/null
+++ b/app/source/Cplt/Utils/IO/Archive.cpp
@@ -0,0 +1,57 @@
+#include "Archive.hpp"
+
+constexpr uint8_t kMagicNumbers[] = { 0x98, 0xd8, 0xa4, 0x65, 0x18, 0xa2, 0xd6, 0xa0 };
+constexpr size_t kMagicNumberCount = std::size(kMagicNumbers);
+
+constexpr uint8_t kByteOrderMark = []() {
+	switch (std::endian::native) {
+		case std::endian::little: return 0;
+		case std::endian::big: return 1;
+	}
+}();
+
+std::span<const uint8_t, 8> DataArchive::GetMagicNumbers()
+{
+	return std::span<const uint8_t, 8>{ kMagicNumbers };
+}
+
+std::optional<InputDataStream> DataArchive::LoadFile(const std::filesystem::path& path)
+{
+	InputFileStream fileStream(path);
+	fileStream.SetReadInSize(1024);
+	InputDataStream stream(std::move(fileStream));
+
+	uint8_t magicNumbers[kMagicNumberCount];
+	stream.ReadBytes(kMagicNumberCount, magicNumbers);
+
+	for (size_t i = 0; i < kMagicNumberCount; ++i) {
+		if (magicNumbers[i] != kMagicNumbers[i]) {
+			return {};
+		}
+	}
+
+	uint8_t byteOrderMark;
+	stream.Read(byteOrderMark);
+
+	switch (byteOrderMark) {
+		case 0: stream.SetEndianness(std::endian::little); break;
+		case 1: stream.SetEndianness(std::endian::big); break;
+		default: std::abort();
+	}
+
+	return stream;
+}
+
+std::optional<OutputDataStream> DataArchive::SaveFile(const std::filesystem::path& path)
+{
+	OutputFileStream fileStream(path, OutputFileStream::TruncateFile);
+	fileStream.SetMaxBufferSize(1024);
+	OutputDataStream stream(std::move(fileStream));
+
+	stream.WriteBytes(kMagicNumberCount, kMagicNumbers);
+	stream.Write(kByteOrderMark);
+
+	stream.SetEndianness(std::endian::native);
+
+	return stream;
+}
-- 
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