1 files changed, 72 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/serializers/UnmodifiableNavigableSetSerializer.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/serializers/UnmodifiableNavigableSetSerializer.java
new file mode 100644
index 0000000000..7785b6327d
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/serializers/UnmodifiableNavigableSetSerializer.java
@@ -0,0 +1,72 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.skyframe.serialization.serializers;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableSortedSet;
+import com.google.common.collect.Sets;
+import java.lang.reflect.Field;
+import java.util.NavigableSet;
+import java.util.TreeSet;
+
+/** A {@link Serializer} for {@link ImmutableSortedSet}. */
+class UnmodifiableNavigableSetSerializer extends Serializer<NavigableSet<?>> {
+
+  private final Field delegate;
+
+  private UnmodifiableNavigableSetSerializer() {
+    setImmutable(true);
+    try {
+      Class<?> clazz = Class.forName(Sets.class.getCanonicalName() + "$UnmodifiableNavigableSet");
+      delegate = clazz.getDeclaredField("delegate");
+      delegate.setAccessible(true);
+    } catch (ReflectiveOperationException e) {
+      throw new IllegalStateException("Issues reflectively writing UnmodifiableNavigableSet", e);
+    }
+  }
+
+  private Object getDelegateFromUnmodifiableNavigableSet(NavigableSet<?> object) {
+    try {
+      return delegate.get(object);
+    } catch (IllegalAccessException e) {
+      throw new IllegalStateException("Issues reflectively writing UnmodifiableNavigableSet", e);
+    }
+  }
+
+  @Override
+  public void write(Kryo kryo, Output output, NavigableSet<?> object) {
+    // We want to preserve the underlying delegate class, so we need to reflectively get it and
+    // write it directly via kryo
+    kryo.writeClassAndObject(output, getDelegateFromUnmodifiableNavigableSet(object));
+  }
+
+  @Override
+  public NavigableSet<?> read(Kryo kryo, Input input, Class<NavigableSet<?>> type) {
+    return Sets.unmodifiableNavigableSet((NavigableSet<?>) kryo.readClassAndObject(input));
+  }
+
+  static void registerSerializers(Kryo kryo) {
+    kryo.register(getSerializedClass(), new UnmodifiableNavigableSetSerializer());
+  }
+
+  @VisibleForTesting
+  static @SuppressWarnings("rawtypes") Class<? extends NavigableSet> getSerializedClass() {
+    return Sets.unmodifiableNavigableSet(new TreeSet<Object>()).getClass();
+  }
+}