Pamoja.Codec 0.1.17

Pamoja.Codec

CBOR, JSON, and raw codecs behind one trait, delta and varint batch packing, and an f32 quantizer for metered links. One capability of pamoja, one memory-safe Rust core with bindings for TypeScript, Python, and C#.

Install

dotnet add package Pamoja.Codec

using Pamoja.Codec;

This pulls in Pamoja.Native, the compiled engine. dotnet add package Pamoja is the whole framework in one package.

Example

The guide project's example, spliced here as it ran in CI.

From bindings/dotnet/samples/Pamoja.Guides/CodecGuide.cs:

// The same reading as JSON and as CBOR. Nothing is lost, and 21.5 rides as a
// half-precision float, the shortest form RFC 8949 allows for it.
byte[] asJson = Encoding.UTF8.GetBytes("{\"c\":21.5,\"ok\":true}");
byte[] cbor = Codec.JsonToCbor(asJson);
Console.WriteLine($"json      {asJson.Length} bytes");
Console.WriteLine($"cbor      {cbor.Length} bytes");

// A gateway that speaks JSON gets it back unchanged, so the compact form is a
// transport choice rather than a different data model.
byte[] restored = Codec.CborToJson(cbor);
Console.WriteLine($"back to json, unchanged: {restored.SequenceEqual(asJson)}");

// A batch of readings packs to a count, then the difference between each sample
// and the one before it. Successive readings differ by very little, so the
// differences cost about a byte each where the samples would cost eight.
long[] samples = [10, 11, 13, 12, 900];
byte[] packed = Codec.PackSamples(samples);
Console.WriteLine($"batch     {samples.Length} samples in {packed.Length} bytes");
Console.WriteLine($"unpacked  {string.Join(", ", Codec.UnpackSamples(packed))}");

// Readings that arrive as floats pack the same way once a scale is chosen. Nothing
// in the bytes records that scale, so sender and receiver have to agree on it.
var quantizer = new Quantizer(100.0f);
float[] celsius = [20.0f, 20.1f, 20.2f, 20.3f];
byte[] packedCelsius = quantizer.Encode(celsius);
float[] recovered = quantizer.Decode(packedCelsius);
Console.WriteLine($"degrees   {celsius.Length} readings in {packedCelsius.Length} bytes");
Console.WriteLine($"recovered {string.Join(", ", recovered.Select(v => v.ToString("F1")))}");

The same capability in every language

Documentation

• Pamoja.Codec reference, every type in this namespace.
• The Codecs guide, with the same example in Rust, TypeScript, and Python.
• Every capability, and the install page.

License

MIT