Add chunked conversion to converters.

tests/lib/convert/chunked_conversion_utf88_test.dart

+// Copyright (c) 2013, 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 utf8_test;
+import "package:expect/expect.dart";
+import 'dart:convert';
+
+List<int> encode(String str) {
+  List<int> bytes;
+  ChunkedConversionSink byteSink =
+      new ByteConversionSink.withCallback((result) => bytes = result);
+  var stringConversionSink = new Utf8Encoder().startChunkedConversion(byteSink);
+  stringConversionSink.add(str);
+  stringConversionSink.close();
+  return bytes;
+}
+
+List<int> encode2(String str) {
+  List<int> bytes;
+  ChunkedConversionSink byteSink =
+      new ByteConversionSink.withCallback((result) => bytes = result);
+  var stringConversionSink = new Utf8Encoder().startChunkedConversion(byteSink);
+  ClosableStringSink stringSink = stringConversionSink.asStringSink();
+  stringSink.write(str);
+  stringSink.close();
+  return bytes;
+}
+
+List<int> encode3(String str) {
+  List<int> bytes;
+  ChunkedConversionSink byteSink =
+      new ByteConversionSink.withCallback((result) => bytes = result);
+  var stringConversionSink = new Utf8Encoder().startChunkedConversion(byteSink);
+  ClosableStringSink stringSink = stringConversionSink.asStringSink();
+  str.codeUnits.forEach(stringSink.writeCharCode);
+  stringSink.close();
+  return bytes;
+}
+
+List<int> encode4(String str) {
+  List<int> bytes;
+  ChunkedConversionSink byteSink =
+      new ByteConversionSink.withCallback((result) => bytes = result);
+  var stringConversionSink = new Utf8Encoder().startChunkedConversion(byteSink);
+  ClosableStringSink stringSink = stringConversionSink.asStringSink();
+  str.runes.forEach(stringSink.writeCharCode);
+  stringSink.close();
+  return bytes;
+}
+
+List<int> encode5(String str) {
+  List<int> bytes;
+  ChunkedConversionSink byteSink =
+      new ByteConversionSink.withCallback((result) => bytes = result);
+  var stringConversionSink = new Utf8Encoder().startChunkedConversion(byteSink);
+  ByteConversionSink inputByteSink = stringConversionSink.asUtf8Sink(false);
+  List<int> tmpBytes = UTF8.encode(str);
+  inputByteSink.add(tmpBytes);
+  inputByteSink.close();
+  return bytes;
+}
+
+List<int> encode6(String str) {
+  List<int> bytes;
+  ChunkedConversionSink byteSink =
+      new ByteConversionSink.withCallback((result) => bytes = result);
+  var stringConversionSink = new Utf8Encoder().startChunkedConversion(byteSink);
+  ByteConversionSink inputByteSink = stringConversionSink.asUtf8Sink(false);
+  List<int> tmpBytes = UTF8.encode(str);
+  tmpBytes.forEach((b) => inputByteSink.addSlice([0, b, 1], 1, 2, false));
+  inputByteSink.close();
+  return bytes;
+}
+
+List<int> encode7(String str) {
+  List<int> bytes;
+  ChunkedConversionSink byteSink =
+      new ByteConversionSink.withCallback((result) => bytes = result);
+  var stringConversionSink = new Utf8Encoder().startChunkedConversion(byteSink);
+  stringConversionSink.addSlice("1" + str + "2", 1, str.length + 1, false);
+  stringConversionSink.close();
+  return bytes;
+}
+
+
+int _nextPowerOf2(v) {
+  assert(v > 0);
+  v--;
+  v |= v >> 1;
+  v |= v >> 2;
+  v |= v >> 4;
+  v |= v >> 8;
+  v |= v >> 16;
+  v++;
+  return v;
+}
+
+main() {
+  const LEADING_SURROGATE = 0xd801;
+  const TRAILING_SURROGATE = 0xdc12;
+  const UTF8_ENCODING = const [0xf0, 0x90, 0x90, 0x92];
+  const UTF8_LEADING = const [0xed, 0xa0, 0x81];
+  const UTF8_TRAILING = const [0xed, 0xb0, 0x92];
+  const CHAR_A = 0x61;
+
+  // Test surrogates at all kinds of locations.
+  var tests = [];
+  List codeUnits = <int>[];
+  for (int i = 0; i < 2049; i++) {
+    // Invariant: codeUnits[0..i - 1] is filled with CHAR_A (character 'a').
+    codeUnits.length = i + 1;
+    codeUnits[i] = CHAR_A;
+
+    // Only test for problem zones, close to powers of two.
+    if (i > 20 && _nextPowerOf2(i - 15) - i > 30) continue;
+
+    codeUnits[i] = LEADING_SURROGATE;
+    var str = new String.fromCharCodes(codeUnits);
+    var bytes = new List.filled(i + 3, CHAR_A);
+    bytes[i] = UTF8_LEADING[0];
+    bytes[i + 1] = UTF8_LEADING[1];
+    bytes[i + 2] = UTF8_LEADING[2];
+    tests.add([bytes, str]);
+
+    codeUnits[i] = TRAILING_SURROGATE;
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 3, CHAR_A);
+    bytes[i] = UTF8_TRAILING[0];
+    bytes[i + 1] = UTF8_TRAILING[1];
+    bytes[i + 2] = UTF8_TRAILING[2];
+    tests.add([bytes, str]);
+
+    codeUnits.length = i + 2;
+    codeUnits[i] = LEADING_SURROGATE;
+    codeUnits[i + 1] = TRAILING_SURROGATE;
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 4, CHAR_A);
+    bytes[i] = UTF8_ENCODING[0];
+    bytes[i + 1] = UTF8_ENCODING[1];
+    bytes[i + 2] = UTF8_ENCODING[2];
+    bytes[i + 3] = UTF8_ENCODING[3];
+    tests.add([bytes, str]);
+
+    codeUnits[i] = TRAILING_SURROGATE;
+    codeUnits[i + 1] = TRAILING_SURROGATE;
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 6, CHAR_A);
+    bytes[i] = UTF8_TRAILING[0];
+    bytes[i + 1] = UTF8_TRAILING[1];
+    bytes[i + 2] = UTF8_TRAILING[2];
+    bytes[i + 3] = UTF8_TRAILING[0];
+    bytes[i + 4] = UTF8_TRAILING[1];
+    bytes[i + 5] = UTF8_TRAILING[2];
+    tests.add([bytes, str]);
+
+    codeUnits[i] = LEADING_SURROGATE;
+    codeUnits[i + 1] = LEADING_SURROGATE;
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 6, CHAR_A);
+    bytes[i] = UTF8_LEADING[0];
+    bytes[i + 1] = UTF8_LEADING[1];
+    bytes[i + 2] = UTF8_LEADING[2];
+    bytes[i + 3] = UTF8_LEADING[0];
+    bytes[i + 4] = UTF8_LEADING[1];
+    bytes[i + 5] = UTF8_LEADING[2];
+    tests.add([bytes, str]);
+
+    codeUnits[i] = TRAILING_SURROGATE;
+    codeUnits[i + 1] = LEADING_SURROGATE;
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 6, CHAR_A);
+    bytes[i] = UTF8_TRAILING[0];
+    bytes[i + 1] = UTF8_TRAILING[1];
+    bytes[i + 2] = UTF8_TRAILING[2];
+    bytes[i + 3] = UTF8_LEADING[0];
+    bytes[i + 4] = UTF8_LEADING[1];
+    bytes[i + 5] = UTF8_LEADING[2];
+    tests.add([bytes, str]);
+
+    codeUnits.length = i + 3;
+    codeUnits[i] = LEADING_SURROGATE;
+    codeUnits[i + 1] = TRAILING_SURROGATE;
+    codeUnits[i + 2] = CHAR_A;  // Add trailing 'a'.
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 5, CHAR_A);
+    bytes[i] = UTF8_ENCODING[0];
+    bytes[i + 1] = UTF8_ENCODING[1];
+    bytes[i + 2] = UTF8_ENCODING[2];
+    bytes[i + 3] = UTF8_ENCODING[3];
+    // No need to assign the 'a' character. The whole list is already filled
+    // with it.
+    tests.add([bytes, str]);
+
+    codeUnits[i] = TRAILING_SURROGATE;
+    codeUnits[i + 1] = TRAILING_SURROGATE;
+    codeUnits[i + 2] = CHAR_A;  // Add trailing 'a'.
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 7, CHAR_A);
+    bytes[i] = UTF8_TRAILING[0];
+    bytes[i + 1] = UTF8_TRAILING[1];
+    bytes[i + 2] = UTF8_TRAILING[2];
+    bytes[i + 3] = UTF8_TRAILING[0];
+    bytes[i + 4] = UTF8_TRAILING[1];
+    bytes[i + 5] = UTF8_TRAILING[2];
+    tests.add([bytes, str]);
+
+    codeUnits[i] = LEADING_SURROGATE;
+    codeUnits[i + 1] = LEADING_SURROGATE;
+    codeUnits[i + 2] = CHAR_A;  // Add trailing 'a'.
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 7, CHAR_A);
+    bytes[i] = UTF8_LEADING[0];
+    bytes[i + 1] = UTF8_LEADING[1];
+    bytes[i + 2] = UTF8_LEADING[2];
+    bytes[i + 3] = UTF8_LEADING[0];
+    bytes[i + 4] = UTF8_LEADING[1];
+    bytes[i + 5] = UTF8_LEADING[2];
+    tests.add([bytes, str]);
+
+    codeUnits[i] = TRAILING_SURROGATE;
+    codeUnits[i + 1] = LEADING_SURROGATE;
+    codeUnits[i + 2] = CHAR_A;  // Add trailing 'a'.
+    str = new String.fromCharCodes(codeUnits);
+    bytes = new List.filled(i + 7, CHAR_A);
+    bytes[i] = UTF8_TRAILING[0];
+    bytes[i + 1] = UTF8_TRAILING[1];
+    bytes[i + 2] = UTF8_TRAILING[2];
+    bytes[i + 3] = UTF8_LEADING[0];
+    bytes[i + 4] = UTF8_LEADING[1];
+    bytes[i + 5] = UTF8_LEADING[2];
+    tests.add([bytes, str]);
+
+    // Make sure the invariant is correct.
+    codeUnits[i] = CHAR_A;
+  }
+
+  for (var test in tests) {
+    List<int> bytes = test[0];
+    String string = test[1];
+    Expect.listEquals(bytes, encode(string));
+    Expect.listEquals(bytes, encode2(string));
+    Expect.listEquals(bytes, encode3(string));
+    Expect.listEquals(bytes, encode4(string));
+    Expect.listEquals(bytes, encode5(string));
+    Expect.listEquals(bytes, encode6(string));
+    Expect.listEquals(bytes, encode7(string));
+  }
+}