Add chunked input stream

tests/standalone/src/ChunkedStreamTest.dart

+// Copyright (c) 2011, 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.
+
+class ListInputStream implements InputStream {
+  List<int> read() {
+    var result = _data;
+    _data = null;
+    return result;
+  }
+
+  void set dataHandler(void callback()) {
+    _dataHandler = callback;
+  }
+
+  void set closeHandler(void callback()) {
+    _closeHandler = callback;
+  }
+
+  void set errorHandler(void callback(int error)) {
+  }
+
+  void write(List<int> data) {
+    Expect.equals(null, _data);
+    _data = data;
+    if (_dataHandler != null) {
+      // Data handler is not called through the event loop here.
+      _dataHandler();
+    }
+  }
+
+  void close() {
+    Expect.equals(null, _data);
+    // Close handler is not called through the event loop here.
+    if (_closeHandler != null) _closeHandler();
+  }
+
+  List<int> _data;
+  var _dataHandler;
+  var _closeHandler;
+}
+
+void test1() {
+  void testWithChunkSize(var data, int chunkSize, Function testDone) {
+    InputStream s = new ListInputStream();
+    ChunkedInputStream stream = new ChunkedInputStream(s);
+    int chunkCount = 0;
+    int byteCount = 0;
+    void chunkData() {
+      List<int> chunk = stream.read();
+      if (byteCount + chunkSize < data.length) {
+        Expect.equals(chunkSize, chunk.length);
+      } else {
+        if (byteCount == data.length) {
+          Expect.equals(null, chunk);
+        } else {
+          Expect.equals(data.length - byteCount, chunk.length);
+        }
+      }
+      if (chunk != null) {
+        for (int i = 0; i < chunk.length;i++) {
+          Expect.equals(data[byteCount], chunk[i]);
+          byteCount++;
+        }
+        chunkCount++;
+      }
+    }
+
+    void closeHandler() {
+      Expect.equals(data.length, byteCount);
+      testDone(byteCount);
+    }
+
+    stream.dataHandler = chunkData;
+    stream.closeHandler = closeHandler;
+    stream.chunkSize = chunkSize;
+    s.write(data);
+    s.close();
+  }
+
+  for (int i = 1; i <= 10; i++) {
+    var data = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+
+    void testDone(int byteCount) {
+      Expect.equals(data.length, byteCount);
+    }
+
+    testWithChunkSize(data, i, testDone);
+  }
+
+  var _16k = 1024 * 16;

[Mads Ager (google), 2011/12/06 14:05:02]

Is the underscore needed here?

[Søren Gjesse, 2011/12/07 07:58:29]

Yes, a variable cannot start with a digit.

+  var data = new List<int>(_16k);
+  for (int i = 0; i < _16k; i++) { data[i] = i % 256; }
+
+  void testDone(int byteCount) {
+    Expect.equals(data.length, byteCount);
+  }
+
+  testWithChunkSize(data, 512, testDone);
+  testWithChunkSize(data, 1024, testDone);
+  testWithChunkSize(data, 2048, testDone);
+}
+
+
+void test2() {
+  InputStream s = new ListInputStream();
+  ChunkedInputStream stream = new ChunkedInputStream(s);
+  stream.chunkSize = 5;
+
+  var stage = 0;
+
+  void chunkData() {
+    var chunk;
+    if (stage == 0) {
+      chunk = stream.read();

[Mads Ager (google), 2011/12/06 14:05:02]

Maybe add comments here static how many bytes are expected to be in the stream
at each point? Here it is 7.

[Søren Gjesse, 2011/12/07 07:58:29]

Done.

+      Expect.equals(stream.chunkSize, chunk.length);
+      chunk = stream.read();
+      Expect.equals(null, chunk);
+      stage++;
+      s.write([7, 8, 9]);
+    } else if (stage == 1) {
+      chunk = stream.read();
+      Expect.equals(stream.chunkSize, chunk.length);
+      chunk = stream.read();
+      Expect.equals(null, chunk);
+      stage++;
+      s.write([10, 11, 12, 13, 14, 15, 16]);
+    } else if (stage == 2) {
+      chunk = stream.read();
+      Expect.equals(stream.chunkSize, chunk.length);
+      chunk = stream.read();
+      Expect.equals(null, chunk);
+      stage++;
+      s.close();
+    } else if (stage == 3) {
+      chunk = stream.read();
+      Expect.equals(2, chunk.length);
+      chunk = stream.read();
+      Expect.equals(null, chunk);
+      stage++;
+    }
+  }
+
+  void streamClosed() {
+    Expect.equals(4, stage);
+  }
+
+  stream.dataHandler = chunkData;
+  stream.closeHandler = streamClosed;
+  s.write([0, 1, 2, 3]);
+  Expect.equals(0, stage);
+  s.write([4, 5, 6]);
+  Expect.equals(3, stage);
+}
+
+

[Mads Ager (google), 2011/12/06 14:05:02]

It would be nice to also have a test that changes the chunkSize in the
dataHandler. Potentially just an extra stage above.

[Søren Gjesse, 2011/12/07 07:58:29]

Good point. Done.

+main() {
+  test1();
+  test2();
+}