A flexible and efficient Dart package for encoding and decoding Base32 data. This package provides a Codec-based API that aligns with dart:convert conventions, making it easy to work with synchronous and asynchronous data streams.

Features

• Multiple Variants: Supports RFC 4648, RFC 4648 "Hex", and Crockford's Base32 alphabets.
• Stream-Compatible: Implements chunked conversion, allowing it to be used as a StreamTransformer for efficient processing of large data.
• Dart Native: A pure Dart implementation with no platform-specific dependencies.
• Well-Tested: Comes with a comprehensive test suite, including RFC 4648 test vectors.

Getting started

Add this package to your pubspec.yaml file:

dependencies:
  base32_codec: ^1.0.0 # Replace with the latest version

Then, run pub get or flutter pub get to install the package.

Usage

Synchronous Conversion

For simple, in-memory encoding and decoding, you can use the encode and decode methods directly.

Default (RFC 4648)

import 'dart:convert';
import 'package:base32_codec/base32_codec.dart';

void main() {
  final codec = Base32Codec();
  final data = ascii.encode('foobar');

  final encoded = codec.encode(data);
  print(encoded); // MZXW6YTBOI======

  final decoded = codec.decode(encoded);
  print(ascii.decode(decoded)); // foobar
}

Crockford Variant

To use a different variant, instantiate the corresponding codec.

import 'dart:convert';
import 'package:base32_codec/base32_codec.dart';

void main() {
  final codec = Base32Codec.crockford();
  final data = ascii.encode('foobar');

  final encoded = codec.encode(data);
  print(encoded); // CSQPYRK1E8

  final decoded = codec.decode(encoded);
  print(ascii.decode(decoded)); // foobar

  // Crockford decoding also ignores hyphens for readability.
  print(ascii.decode(codec.decode('CSQPY-RK1E8'))); // foobar
}

Asynchronous (Stream) Conversion

For handling larger data, like files or network streams, you can use the codec's encoder and decoder as a StreamTransformer.

import 'dart:convert';
import 'dart:io';
import 'package:base32_codec/base32_codec.dart';

Future<void> main() async {
  // Create a stream from a file or network source
  final inputStream = Stream.value(ascii.encode('foobar'));

  // Transform the stream by encoding it
  final encodedStream = inputStream.transform(Base32Codec().encoder);

  // Print each chunk of the encoded output
  await for (final chunk in encodedStream) {
    print(chunk); // MZXW6YTBOI======
  }

  // You can also pipe the stream to a file
  // await inputStream
  //     .transform(Base32Codec().encoder)
  //     .pipe(File('output.txt').openWrite());
}

Performance Benchmarks

This package includes a suite of performance benchmarks to measure the speed of encoding and decoding operations across different Base32 variants and conversion types (synchronous and asynchronous).

To run the benchmarks, execute the following command from the project root:

dart run benchmark/base32_codec_benchmark.dart

Contributing

This package is open source and contributions are welcome!

If you find a bug or have a feature request, please file an issue on the GitHub issue tracker. When filing an issue, please provide a clear description of the problem and include a minimal, reproducible example if possible.

If you would like to contribute code, please fork the repository and submit a pull request.