📖 EndianBinaryIO

This .NET library provides a simple API to read/write bytes from/to streams and spans using user-specified endianness. By default, supported types include primitives, enums, arrays, strings, and some common .NET struct types. Objects can also be read/written from/to streams via reflection and attributes. The developer can use the API even if their target behavior or data is not directly supported by using the IBinarySerializable interface, inheritting from the reader/writer, or using the manual Span<T>/ReadOnlySpan<T> methods without streams. Performance is the focus when not using reflection; no allocations unless absolutely necessary!

The IBinarySerializable interface allows an object to be read and written in a customizable fashion during reflection. Also included are attributes that can make reading and writing objects less of a headache. For example, classes and structs in C# cannot have ignored members when marshalling, but EndianBinaryIO has a BinaryIgnoreAttribute that will ignore properties when reading and writing.

The EndianBinaryPrimitives static class which resembles System.Buffers.Binary.BinaryPrimitives is an API that converts to/from data types using Span<T>/ReadOnlySpan<T> with specific endianness, rather than streams.

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Changelog For v2.1.1

Check the comment on the release page!

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🚀 Usage:

Add the EndianBinaryIO NuGet package to your project or download the .dll from the releases tab.

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Examples:

Assume we have the following definitions:

C#:

enum ByteSizedEnum : byte
{
	Val1 = 0x20,
	Val2 = 0x80,
}
enum ShortSizedEnum : short
{
	Val1 = 0x40,
	Val2 = 0x800,
}

class MyBasicObj
{
	// Properties
	public ShortSizedEnum Type { get; set; }
	public short Version { get; set; }
	public DateTime Date { get; set; }
	public Int128 Int128 { get; set; }

	// Property that is ignored when reading and writing
	[BinaryIgnore]
	public ByteSizedEnum DoNotReadOrWrite { get; set; }

	// Arrays work as well
	[BinaryArrayFixedLength(16)]
	public uint[] ArrayWith16Elements { get; set; }

	// Boolean that occupies 4 bytes instead of one
	[BinaryBooleanSize(BooleanSize.U32)]
	public bool Bool32 { get; set; }

	// String encoded in ASCII
	// Reads chars until the stream encounters a '\0'
	// Writing will append a '\0' at the end of the string
	[BinaryASCII]
	[BinaryStringNullTerminated]
	public string NullTerminatedASCIIString { get; set; }

	// String encoded in UTF16-LE that will only read/write 10 chars
	// The BinaryStringTrimNullTerminatorsAttribute will indicate that every char from the first \0 will be removed from the string. This attribute also works with char arrays
	[BinaryStringFixedLength(10)]
	[BinaryStringTrimNullTerminators]
	public string UTF16String { get; set; }
}

And assume these are our input bytes (in little endian):

Input Bytes (Little Endian):

0x00, 0x08, // ShortSizedEnum.Val2
0xFF, 0x01, // (short)511
0x00, 0x00, 0x4A, 0x7A, 0x9E, 0x01, 0xC0, 0x08, // (DateTime)Dec. 30, 1998
0x48, 0x49, 0x80, 0x44, 0x82, 0x44, 0x88, 0xC0, 0x42, 0x24, 0x88, 0x12, 0x44, 0x44, 0x25, 0x24, // (Int128)48,045,707,429,126,174,655,160,174,263,614,327,112

0x00, 0x00, 0x00, 0x00, // (uint)0
0x01, 0x00, 0x00, 0x00, // (uint)1
0x02, 0x00, 0x00, 0x00, // (uint)2
0x03, 0x00, 0x00, 0x00, // (uint)3
0x04, 0x00, 0x00, 0x00, // (uint)4
0x05, 0x00, 0x00, 0x00, // (uint)5
0x06, 0x00, 0x00, 0x00, // (uint)6
0x07, 0x00, 0x00, 0x00, // (uint)7
0x08, 0x00, 0x00, 0x00, // (uint)8
0x09, 0x00, 0x00, 0x00, // (uint)9
0x0A, 0x00, 0x00, 0x00, // (uint)10
0x0B, 0x00, 0x00, 0x00, // (uint)11
0x0C, 0x00, 0x00, 0x00, // (uint)12
0x0D, 0x00, 0x00, 0x00, // (uint)13
0x0E, 0x00, 0x00, 0x00, // (uint)14
0x0F, 0x00, 0x00, 0x00, // (uint)15

0x00, 0x00, 0x00, 0x00, // (bool32)false

0x45, 0x6E, 0x64, 0x69, 0x61, 0x6E, 0x42, 0x69, 0x6E, 0x61, 0x72, 0x79, 0x49, 0x4F, 0x00, // (ASCII)"EndianBinaryIO\0"

0x4B, 0x00, 0x65, 0x00, 0x72, 0x00, 0x6D, 0x00, 0x61, 0x00, 0x6C, 0x00, 0x69, 0x00, 0x73, 0x00, 0x00, 0x00, 0x00, 0x00, // (UTF16-LE)"Kermalis\0\0"

We can read/write the object manually or automatically (with reflection):

Reading Manually:

var reader = new EndianBinaryReader(stream, endianness: Endianness.LittleEndian, booleanSize: BooleanSize.U32);
var obj = new MyBasicObj();

obj.Type = reader.ReadEnum<ShortSizedEnum>(); // Reads the enum type based on the amount of bytes of the enum's underlying type (short/2 in this case)
obj.Version = reader.ReadInt16(); // Reads a 'short' (2 bytes)
obj.Date = reader.ReadDateTime(); // Reads a 'DateTime' (8 bytes)
obj.Int128 = reader.ReadInt128(); // Reads an 'Int128' (16 bytes)

obj.ArrayWith16Elements = new uint[16];
reader.ReadUInt32s(obj.ArrayWith16Elements); // Reads 16 'uint's (4 bytes each)

obj.Bool32 = reader.ReadBoolean(); // Reads a 'bool' (4 bytes in this case, since the reader's current bool state is BooleanSize.U32)

reader.ASCII = true; // Set the reader's ASCII state to true
obj.NullTerminatedASCIIString = reader.ReadString_NullTerminated(); // Reads ASCII chars until a '\0' is read, then returns a 'string'

reader.ASCII = false; // Set the reader's ASCII state to false (UTF16-LE)
obj.UTF16String = reader.ReadString_Count_TrimNullTerminators(10); // Reads 10 UTF16-LE chars as a 'string' with the '\0's removed

Reading Automatically (With Reflection):

var reader = new EndianBinaryReader(stream, endianness: Endianness.LittleEndian);
var obj = reader.ReadObject<MyBasicObj>(); // Create a 'MyBasicObj' and read all properties in order, ignoring any with a 'BinaryIgnoreAttribute'
// Other objects that are properties in this object will also be read in the same way recursively

Writing Manually:

var obj = new MyBasicObj
{
	Type = ShortSizedEnum.Val2,
	Version = 511,
	Date = new DateTime(1998, 12, 30),
	Int128 = Int128.Parse("48,045,707,429,126,174,655,160,174,263,614,327,112", NumberStyles.AllowThousands, NumberFormatInfo.InvariantInfo),

	DoNotReadOrWrite = ByteSizedEnum.Val1,

	ArrayWith16Elements = new uint[16]
	{
		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
	},

	Bool32 = false,

	NullTerminatedASCIIString = "EndianBinaryIO",
	UTF16String = "Kermalis",
};

var writer = new EndianBinaryWriter(stream, endianness: Endianness.LittleEndian, booleanSize: BooleanSize.U32);
writer.WriteEnum(obj.Type); // Writes the enum type based on the amount of bytes of the enum's underlying type (short/2 in this case)
writer.WriteInt16(obj.Version); // Writes a 'short' (2 bytes)
writer.WriteDateTime(obj.Date); // Writes a 'DateTime' (8 bytes)
writer.WriteInt128(obj.Int128); // Writes an 'Int128' (16 bytes)
writer.WriteUInt32s(obj.ArrayWith16Elements); // Writes 16 'uint's (4 bytes each)
writer.WriteBoolean(obj.Bool32); // Writes a 'bool' (4 bytes in this case, since the reader's current bool state is BooleanSize.U32)

writer.ASCII = true; // Set the reader's ASCII state to true
writer.WriteChars_NullTerminated(obj.NullTerminatedASCIIString); // Writes the chars in the 'string' as ASCII and appends a '\0' at the end

writer.ASCII = false; // Set the reader's ASCII state to false (UTF16-LE)
writer.WriteChars_Count(obj.UTF16String, 10); // Writes 10 UTF16-LE chars as a 'string'. If the string has more than 10 chars, it is truncated; if it has less, it is padded with '\0'

Writing Automatically (With Reflection):

var writer = new EndianBinaryWriter(stream, endianness: Endianness.LittleEndian);
writer.Write(obj); // Write all properties in the 'MyBasicObj' in order, ignoring any with a 'BinaryIgnoreAttribute'
// Other objects that are properties in this object will also be written in the same way recursively

EndianBinaryPrimitives Example:

byte[] bytes = new byte[] { 0xFF, 0x00, 0x00, 0x00, 0xBB, 0xEE, 0xEE, 0xFF };
uint value = EndianBinaryPrimitives.ReadUInt32(bytes, Endianness.LittleEndian); // Will return 255

value = 128;
EndianBinaryPrimitives.WriteUInt32(bytes.AsSpan(4, 4), value, Endianness.LittleEndian); // bytes is now { 0xFF, 0x00, 0x00, 0x00, 0x80, 0x00, 0x00, 0x00 }

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EndianBinaryIOTests Uses:

• xUnit.net