GitHub - coplt/Coplt.Mar: Simple uncompressed random access archive format

Memory mapped ARchiver format

Random Access
No compression
No hash verification (CRC SHA ...)
Get ReadOnlySpan<byte> directly through memory mapping

Detail

File layout:

<Head> <Version> <Data> <Data> ... <Manifest> <Tail>

Head

"\0MAR📦" in utf8, 📦 is emoji
00 4D 41 52 F0 9F 93 A6
Version

(int Major, int Minor, int Patch) ser by MsgPack
It is the format version, not the library version
0.1.0 is 93 00 01 00
Data

Just simply bytes
Manifest

Dictionary<string, (ulong Offset, ulong Size)> ser by MsgPack
Tail

Little endian uint manifest size

Usage

{
    await using var builder = await MarBuilder.CreateAsync("./test.mar");
    await builder.AddFileAsync("test.txt", "Hello, World!");
    // await builder.AddFileAsync("test.txt", "Hello, World!", Encoding.Utf16); // Specify encoding
    await builder.AddFileAsync("some.bin", new byte[] { 1, 2, 3, 4, 5 });
    // await builder.AddFileAsync("test.txt", SomeStream);
}

{
    using var mar = MarArchive.Open("./test.mar");
    
    mar.TryGetString("test.txt", out string data);
    Console.WriteLine(data);
    // Output: Hello, World!
    
    mar.TryGet("test.txt", out ReadOnlySpan<byte> span);
    Console.WriteLine(string.Join(", ", span.ToArray()));
    // Output: 1, 2, 3, 4, 5
    
    Console.WriteLine(mar.TryGet("asd", out _));
    // Output: False
}