1 files changed, 38 insertions, 0 deletions
diff --git a/tools/ahat/src/heapdump/Diffable.java b/tools/ahat/src/heapdump/Diffable.java
new file mode 100644
index 0000000000..53442c857e
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+++ b/tools/ahat/src/heapdump/Diffable.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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.android.ahat.heapdump;
+
+/**
+ * An interface for objects that have corresponding objects in a baseline heap
+ * dump.
+ */
+public interface Diffable<T> {
+  /**
+   * Return the baseline object that corresponds to this one.
+   */
+  T getBaseline();
+
+  /**
+   * Returns true if this is a placeholder object.
+   * A placeholder object is used to indicate there is some object in the
+   * baseline heap dump that is not in this heap dump. In that case, we create
+   * a dummy place holder object in this heap dump as an indicator of the
+   * object removed from the baseline heap dump.
+   */
+  boolean isPlaceHolder();
+}
+