1 files changed, 67 insertions, 0 deletions
diff --git a/third_party/protobuf/3.4.0/javanano/src/main/java/com/google/protobuf/nano/MapFactories.java b/third_party/protobuf/3.4.0/javanano/src/main/java/com/google/protobuf/nano/MapFactories.java
new file mode 100644
index 0000000000..98fa4877bc
--- /dev/null
+++ b/third_party/protobuf/3.4.0/javanano/src/main/java/com/google/protobuf/nano/MapFactories.java
@@ -0,0 +1,67 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf.nano;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Utility class for maps support.
+ */
+public final class MapFactories {
+  public static interface MapFactory {
+    <K, V> Map<K, V> forMap(Map<K, V> oldMap);
+  }
+
+  // NOTE(liujisi): The factory setter is temporarily marked as package private.
+  // The way to provide customized implementations of maps for different
+  // platforms are still under discussion.  Mark it as private to avoid exposing
+  // the API in proto3 alpha release.
+  /* public */ static void setMapFactory(MapFactory newMapFactory) {
+    mapFactory = newMapFactory;
+  }
+
+  public static MapFactory getMapFactory() {
+    return mapFactory;
+  }
+
+  private static class DefaultMapFactory implements MapFactory {
+    public <K, V> Map<K, V> forMap(Map<K, V> oldMap) {
+      if (oldMap == null) {
+        return new HashMap<K, V>();
+      }
+      return oldMap;
+    }
+  }
+  private static volatile MapFactory mapFactory = new DefaultMapFactory();
+
+  private MapFactories() {}
+}