Protocol Buffer runtime library and 'protoc' plugin

lib/protobuf/runtime/PbReader.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.
+
+/**
+ * The PbReader reads bytes from some source, careful not to read more bytes
+ * than requested on destructive reads.
+ */
+interface PbReader {
+  /**
+   * Returns whether more data may be available on this PbReader.
+   */
+  bool get closed();
+
+  /**
+   * Provides the position within the current PbReader.
+   */
+  int get position();
+
+  /**
+   * Reads a single byte and makes it available as a Future.
+   */
+  Future<int> readByte();
+
+  /**
+   * Reads the bytes requested and makes them available as a Future.
+   * Unspecified byte count instructs the method to read to the end.
+   */
+  Future<List<int>> readBytes([int count]);
+
+  /**
+   * Permits reads beyond current readBytes target for efficiency
+   */
+  void setReadAhead([int count]);
+}
+
+class PbBufferReader {
+  PbBufferReader(List<int> bytes) {
+    _buffer = new PbByteBuffer();
+    _buffer.add(bytes);
+  }
+
+  bool get closed() => _buffer.isEmpty;
+
+  int get position() => _position;
+
+  Future<int> readByte() {
+    int byte = _buffer.readByte();
+    if (byte != null) _position++;
+    return new Future.immediate(byte);
+  }
+
+  Future<List<int>> readBytes([int count = -1]) {
+    List<int> bytes = _buffer.readBytes(count);
+    if (bytes != null) _position += bytes.length;
+    return new Future.immediate(bytes);
+  }
+
+  void setReadAhead([int count = -1]) {}
+
+  PbByteBuffer _buffer;
+  int _position = 0;
+}