feat: Base64 decoding

Author: rafamizes

CHANGELOG.md

@@ -1,5 +1,3 @@
-<!--todo: release initial version -->
-
 # Changelog
 
 All notable changes to this project will be documented in this file.
@@ -13,6 +11,20 @@ and this project adheres to [Dart Package Versioning](https://dart.dev/tools/pub
 
 - Base64 and Base64Url encoding schemes —
   [12](https://github.com/dartoos-dev/dartoos/issues/12)
+- Base64Decode class for decoding base64-encoded text —
+  [19](https://github.com/dartoos-dev/dartoos/issues/19).
+- Base64Norm class for normalizing base64-encoded texts.
+- Dartoos base64-encoding/decoding benchmark executable in 'example'.
+
+### Changed
+
+- Rand class accept as source of characters both plain and Future values.
+- BytesOf constructors accept both plain and Future values.
+
+### Removed
+
+- Rand.str constructor — **Breaking Change**.
+- FutureWrap.value constructor — **Breaking Change**.
 
 ## [0.1.0] - 2021-10-05
 

example/base64_benchmark.dart

@@ -0,0 +1,68 @@
+// ignore_for_file: avoid_print
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'package:dartoos/dartoos.dart';
+
+/// Dartoos base64-encoder/decoder vs. Dart's built-in base64-encoder/decoder.
+///
+/// Running:
+/// ```dart /example/base64_benchmark.dart```
+///
+/// or
+/// 
+/// Compile to 'jit'.
+/// ```dart compile jit-snapshot example/base64_benchmark.dart```
+/// ```dart /example/base64_benchmark.jit```
+Future<void> main() async {
+  print("Dartoos base64 vs. Dart's built-in base64...");
+
+  const wordLength = 15000000; const elegibleChars =
+      r'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-*/|\;:?[]{}()!@#$%*';
+  // The bytes of a randomly generated word whose length is [wordLength]
+  // characters.
+  final bytes = await BytesOf.utf8(Rand(wordLength, elegibleChars));
+
+  final dartEncodingStart = DateTime.now().millisecondsSinceEpoch;
+  final dartEncoded = base64Encode(bytes);
+  final dartEncodingTime =
+      DateTime.now().millisecondsSinceEpoch - dartEncodingStart;
+
+  final dartDecodingStart = DateTime.now().millisecondsSinceEpoch;
+  final dartDecoded = base64Decode(dartEncoded);
+  final dartDecodingTime =
+      DateTime.now().millisecondsSinceEpoch - dartDecodingStart;
+
+  final dartoosEncodingStart = DateTime.now().millisecondsSinceEpoch;
+  final dartoosEncoded = await Base64(bytes);
+  final dartoosEncodingTime =
+      DateTime.now().millisecondsSinceEpoch - dartoosEncodingStart;
+
+  final dartoosDecodingStart = DateTime.now().millisecondsSinceEpoch;
+  final dartoosDecoded = await Base64Decode(dartoosEncoded);
+  final dartoosDecodingTime =
+      DateTime.now().millisecondsSinceEpoch - dartoosDecodingStart;
+
+  print('\n--- Encoding elapsed times ---'); 
+  print('Dartoos base64-encoding: $dartoosEncodingTime ms');
+  print('Builtin base64-encoding: $dartEncodingTime ms');
+  print('\n--- Decoding elapsed times ---'); 
+  print('Dartoos base64-decoding: $dartoosDecodingTime ms');
+  print('Builtin base64-decoding: $dartDecodingTime ms');
+  print('\n--- Encoding/decoding results comparison ---');
+  print('dartoosEncoded == dartEncoded? ${dartoosEncoded == dartEncoded}');
+  print(
+    'dartoosDecoded == dartDecoded? ${decodedEqual(dartoosDecoded, dartDecoded)}',
+  );
+  print('\nEncoded text length: $wordLength characters.');
+}
+
+bool decodedEqual(Uint8List first, Uint8List second) {
+  if (first.length != second.length) return false;
+  final length = first.length;
+  int i = 0;
+  while (i < length && first[i] == second[i]) {
+    ++i;
+  }
+  return i == length;
+}

example/dartoos_example.dart

@@ -7,3 +7,5 @@
 library base64;
 
 export 'src/base64/base64.dart';
+export 'src/base64/base64_norm.dart';
+export 'src/base64/base64decode.dart';

lib/base64.dart

@@ -1,6 +1,5 @@
 /// Collection of object-oriented utility classes for Dart/Flutter development.
 ///
-///
 /// Inspired by [Cactoos](https://github.com/yegor256/cactoos)
 library dartoos;