block

block provides a Blob-style immutable binary data API for Dart.

Design

• One minimal, Blob-compatible API surface.
• web: wraps native browser Blob via package:web.
• io: stores block data in temp files and uses finalizers for cleanup.
• Block parts are resolved lazily: bytes are fetched/materialized on first read (arrayBuffer/text/stream).
• slice() strategy on io:
  • <= 64KB: copy to a new temp file
  • > 64KB: share backing file with offset/length view

Installation

dart pub add block

API

import 'package:block/block.dart';

Future<void> main() async {
  final block = Block([
    'hello ',
    'world',
  ], type: 'text/plain');

  final size = block.size;
  final type = block.type;

  final bytes = await block.arrayBuffer();
  final text = await block.text();

  final slice = block.slice(0, 5);

  await for (final chunk in block.stream(chunkSize: 1024)) {
    // handle chunk
  }
}

Supported constructor part types:

• String
• Uint8List
• ByteData
• Block

Additional web-only part types:

• web.Blob
• web.File

Breaking Reset in 1.0.0

This release intentionally removes the previous memory/cache/dedup framework APIs and keeps only the Blob-style core contract.

License

BSD-style. See LICENSE.