Add TypedData instance kinds.

runtime/observatory/lib/base64.dart

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library base64;
+
+import 'dart:typed_data';
+
+const _decodeTable =
+    const [null, null, null, null, null, null, null, null,
+           null, null, null, null, null, null, null, null,
+           null, null, null, null, null, null, null, null,
+           null, null, null, null, null, null, null, null,
+           null, null, null, null, null, null, null, null,
+           null, null, null, 62, null, null, null, 63,
+           52, 53, 54, 55, 56, 57, 58, 59,
+           60, 61, null, null, null, 0, null, null,
+           null, 0, 1, 2, 3, 4, 5, 6,
+           7, 8, 9, 10, 11, 12, 13, 14,
+           15, 16, 17, 18, 19, 20, 21, 22,
+           23, 24, 25, null, null, null, null, null,
+           null, 26, 27, 28, 29, 30, 31, 32,
+           33, 34, 35, 36, 37, 38, 39, 40,
+           41, 42, 43, 44, 45, 46, 47, 48,
+           49, 50, 51];
+
+Uint8List decodeBase64(String s) {
+  if (s.length % 4 != 0) throw "Malformed Base64: $s";
+
+  var odd_bits = 0;
+  if (s[s.length - 1] == '=') {
+    if (s[s.length - 2] == '=') {
+      odd_bits = 2;
+    } else {
+      odd_bits = 1;
+    }
+  }
+
+  var decodedByteLength = s.length ~/ 4 * 3 - odd_bits;
+  var result = new Uint8List(decodedByteLength);
+  var limit = s.length;
+  if (odd_bits != 0) {
+    limit = limit - 4;
+  }
+
+  var i = 0, j = 0;
+  while (i < limit) {
+    var triple = _decodeTable[s.codeUnitAt(i++)];
+    triple = (triple << 6) | _decodeTable[s.codeUnitAt(i++)];
+    triple = (triple << 6) | _decodeTable[s.codeUnitAt(i++)];
+    triple = (triple << 6) | _decodeTable[s.codeUnitAt(i++)];
+    result[j++] = triple >> 16;
+    result[j++] = (triple >> 8) & 255;
+    result[j++] = triple & 255;
+  }
+
+  if (odd_bits != 0) {
+    var triple = _decodeTable[s.codeUnitAt(i++)];
+    triple = (triple << 6) | _decodeTable[s.codeUnitAt(i++)];
+    triple = (triple << 6) | _decodeTable[s.codeUnitAt(i++)];
+    triple = (triple << 6) | _decodeTable[s.codeUnitAt(i++)];
+    result[j++] = triple >> 16;
+    if (odd_bits == 1) {
+      result[j++] = (triple >> 8) & 255;
+    }
+  }
+  assert(j == decodedByteLength);
+  return result;
+}