Stop using parts.

lib/src/hash.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 crypto.hash;
+
+/**
+ * Interface for cryptographic hash functions.
+ *
+ * The [add] method is used to add data to the hash. The [close] method
+ * is used to extract the message digest.
+ *
+ * Once the [close] method has been called no more data can be added using the
+ * [add] method. If [add] is called after the first call to [close] a
+ * HashException is thrown.
+ *
+ * If multiple instances of a given Hash is needed the [newInstance]
+ * method can provide a new instance.
+ */
+// TODO(floitsch): make Hash implement Sink, EventSink or similar.
+abstract class Hash {
+  /**
+   * Add a list of bytes to the hash computation.
+   */
+  void add(List<int> data);
+
+  /**
+   * Finish the hash computation and extract the message digest as
+   * a list of bytes.
+   */
+  List<int> close();
+
+  /**
+   * Returns a new instance of this hash function.
+   */
+  Hash newInstance();
+
+  /**
+   * Internal block size of the hash in bytes.
+   *
+   * This is exposed for use by the HMAC class which needs to know the
+   * block size for the [Hash] it is using.
+   */
+  int get blockSize;
+}