1 files changed, 65 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/serializers/UnmodifiableListSerializer.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/serializers/UnmodifiableListSerializer.java
new file mode 100644
index 0000000000..cdc3463382
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/serializers/UnmodifiableListSerializer.java
@@ -0,0 +1,65 @@
+// 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 java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+/** A {@link Serializer} for objects produced by {@link Collections#unmodifiableList}. */
+class UnmodifiableListSerializer extends Serializer<List<Object>> {
+
+  private static final Class<?> RANDOM_ACCESS_TYPE =
+      Collections.unmodifiableList(new ArrayList<Object>()).getClass();
+  private static final Class<?> SEQUENTIAL_ACCESS_TYPE =
+      Collections.unmodifiableList(new LinkedList<Object>()).getClass();
+
+  @Override
+  public void write(Kryo kryo, Output output, List<Object> object) {
+    output.writeInt(object.size(), true);
+    for (Object elt : object) {
+      kryo.writeClassAndObject(output, elt);
+    }
+  }
+
+  @Override
+  public List<Object> read(Kryo kryo, Input input, Class<List<Object>> type) {
+    int size = input.readInt(true);
+    List<Object> list = null;
+    if (type.equals(RANDOM_ACCESS_TYPE)) {
+      list = new ArrayList<>(size);
+    } else if (type.equals(SEQUENTIAL_ACCESS_TYPE)) {
+      list = new LinkedList<>();
+    } else {
+      throw new IllegalArgumentException(
+          "UnmodifiableListSerializer.read called with type: " + type);
+    }
+    for (int i = 0; i < size; ++i) {
+      list.add(kryo.readClassAndObject(input));
+    }
+    return Collections.unmodifiableList(list);
+  }
+
+  static void registerSerializers(Kryo kryo) {
+    UnmodifiableListSerializer serializer = new UnmodifiableListSerializer();
+    kryo.register(RANDOM_ACCESS_TYPE, serializer);
+    kryo.register(SEQUENTIAL_ACCESS_TYPE, serializer);
+  }
+}