Add read/write logic for all ints and floats

1 files changed, 276 insertions, 2 deletions

diff --git a/core/src/Utils/IO/DataStream.cpp b/core/src/Utils/IO/DataStream.cpp
index 0e0a37b..95e0b09 100644
--- a/core/src/Utils/IO/DataStream.cpp
+++ b/core/src/Utils/IO/DataStream.cpp
@@ -1,6 +1,280 @@
 #include "DataStream.hpp"
 
-DataStream::DataStream()
-	: mEndian{ LittleEndian }
+#include <bit>
+#include <limits>
+
+static_assert(std::numeric_limits<float>::is_iec559, "Non IEE754/IEC559 'float' is not supported.");
+static_assert(std::numeric_limits<double>::is_iec559, "Non IEE754/IEC559 'double' is not supported.");
+
+static_assert(std::endian::native == std::endian::little || std::endian::native == std::endian::big, "Mixed endian is not supported.");
+
+DataStream::DataStream(std::fstream stream)
+	: mBackend{ std::move(stream) }
+	, mEndian{ std::endian::big }
+{
+}
+
+DataStream::~DataStream() = default;
+
+std::endian DataStream::GetEndianness() const
+{
+	return mEndian;
+}
+
+void DataStream::SetEndianness(std::endian endianness)
+{
+	mEndian = endianness;
+}
+
+void DataStream::ReadBytes(size_t byteCount, std::byte* buffer)
+{
+	mBackend.read(reinterpret_cast<char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+void DataStream::ReadBytes(size_t byteCount, char* buffer)
+{
+	mBackend.read(reinterpret_cast<char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+void DataStream::ReadBytes(size_t byteCount, signed char* buffer)
+{
+	mBackend.read(reinterpret_cast<char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+void DataStream::ReadBytes(size_t byteCount, unsigned char* buffer)
+{
+	mBackend.read(reinterpret_cast<char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+void DataStream::WriteBytes(size_t byteCount, const std::byte* buffer)
+{
+	mBackend.write(reinterpret_cast<const char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+void DataStream::WriteBytes(size_t byteCount, const char* buffer)
+{
+	mBackend.write(reinterpret_cast<const char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+void DataStream::WriteBytes(size_t byteCount, const signed char* buffer)
+{
+	mBackend.write(reinterpret_cast<const char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+void DataStream::WriteBytes(size_t byteCount, const unsigned char* buffer)
+{
+	mBackend.write(reinterpret_cast<const char*>(buffer), static_cast<std::streamsize>(byteCount));
+}
+
+// Reading/writing signed integer byte-by-byte is fine, since the representation got fixed to 2's complements in C++20
+
+uint16_t ByteSwap(uint16_t n)
+{
+	auto bytes = reinterpret_cast<std::byte*>(n);
+	std::swap(bytes[0], bytes[1]);
+	return n;
+}
+
+uint32_t ByteSwap(uint32_t n)
+{
+#ifdef _MSC_VER
+	// TODO
+#else
+	return __builtin_bswap32(n);
+#endif
+}
+
+uint64_t ByteSwap(uint64_t n)
+{
+#ifdef _MSC_VER
+	// TODO
+#else
+	return __builtin_bswap64(n);
+#endif
+}
+
+template <class TSigned>
+TSigned ByteSwap(TSigned n)
+{
+	using Unsigned = std::make_unsigned_t<TSigned>;
+
+	auto swapped = ::ByteSwap(std::bit_cast<Unsigned>(n));
+	return std::bit_cast<TSigned>(swapped);
+}
+
+void DataStream::Write(int8_t n)
+{
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Write(int16_t n)
+{
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(n);
+	}
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Write(int32_t n)
+{
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(n);
+	}
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Write(int64_t n)
+{
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(n);
+	}
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Read(int8_t& n)
+{
+	// sizeof() of a reference type yields the size of the reference
+	mBackend.read(reinterpret_cast<char*>(&n), sizeof(n));
+}
+
+void DataStream::Read(int16_t& n)
+{
+	int16_t tmp;
+	mBackend.read(reinterpret_cast<char*>(&tmp), sizeof(tmp));
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(tmp);
+	} else {
+		n = tmp;
+	}
+}
+
+void DataStream::Read(int32_t& n)
+{
+	int32_t tmp;
+	mBackend.read(reinterpret_cast<char*>(&tmp), sizeof(tmp));
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(tmp);
+	} else {
+		n = tmp;
+	}
+}
+
+void DataStream::Read(int64_t& n)
+{
+	int64_t tmp;
+	mBackend.read(reinterpret_cast<char*>(&tmp), sizeof(tmp));
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(tmp);
+	} else {
+		n = tmp;
+	}
+}
+
+void DataStream::Write(uint8_t n)
+{
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Write(uint16_t n)
+{
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(n);
+	}
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Write(uint32_t n)
+{
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(n);
+	}
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Write(uint64_t n)
 {
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(n);
+	}
+	mBackend.write(reinterpret_cast<const char*>(&n), sizeof(n));
+}
+
+void DataStream::Read(uint8_t& n)
+{
+	mBackend.read(reinterpret_cast<char*>(&n), sizeof(n));
+}
+
+void DataStream::Read(uint16_t& n)
+{
+	uint16_t tmp;
+	mBackend.read(reinterpret_cast<char*>(&tmp), sizeof(tmp));
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(tmp);
+	} else {
+		n = tmp;
+	}
+}
+
+void DataStream::Read(uint32_t& n)
+{
+	uint32_t tmp;
+	mBackend.read(reinterpret_cast<char*>(&tmp), sizeof(tmp));
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(tmp);
+	} else {
+		n = tmp;
+	}
+}
+
+void DataStream::Read(uint64_t& n)
+{
+	uint64_t tmp;
+	mBackend.read(reinterpret_cast<char*>(&tmp), sizeof(tmp));
+	if (mEndian != std::endian::native) {
+		n = ::ByteSwap(tmp);
+	} else {
+		n = tmp;
+	}
+}
+
+void DataStream::Write(float n)
+{
+	auto buffer = std::bit_cast<uint32_t>(n);
+	if (mEndian != std::endian::native) {
+		buffer = ::ByteSwap(buffer);
+	}
+	mBackend.read(reinterpret_cast<char*>(&buffer), sizeof(buffer));
+}
+
+void DataStream::Write(double n)
+{
+	auto buffer = std::bit_cast<uint64_t>(n);
+	if (mEndian != std::endian::native) {
+		buffer = ::ByteSwap(buffer);
+	}
+	mBackend.read(reinterpret_cast<char*>(&buffer), sizeof(buffer));
+}
+
+void DataStream::Read(float& n)
+{
+	uint32_t buffer;
+	Read(buffer);
+
+	if (mEndian != std::endian::native) {
+		buffer = ::ByteSwap(buffer);
+	}
+
+	n = std::bit_cast<float>(buffer);
+}
+
+void DataStream::Read(double& n)
+{
+	uint64_t buffer;
+	Read(buffer);
+
+	if (mEndian != std::endian::native) {
+		buffer = ::ByteSwap(buffer);
+	}
+
+	n = std::bit_cast<double>(buffer);
 }