1 files changed, 101 insertions, 0 deletions
diff --git a/tools/ahat/src/heapdump/DiffedFieldValue.java b/tools/ahat/src/heapdump/DiffedFieldValue.java
new file mode 100644
index 0000000000..e2dcf3e8f0
--- /dev/null
+++ b/tools/ahat/src/heapdump/DiffedFieldValue.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2017 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;
+
+import java.util.Objects;
+
+/** DiffedFieldValue is used by the DiffedField class to return the result of
+ * diffing two collections of fields.
+ */
+public class DiffedFieldValue {
+  public final String name;
+  public final String type;
+  public final Value current;
+  public final Value baseline;
+
+  public final Status status;
+
+  public static enum Status {
+    ADDED,      // The current field has no matching baseline value.
+    MATCHED,    // The current field has a matching baseline value.
+    DELETED     // The baseline field has no matching current value.
+  };
+
+  /**
+   * Return a DiffedFieldValue where there is both a current and baseline.
+   */
+  public static DiffedFieldValue matched(FieldValue current, FieldValue baseline) {
+    return new DiffedFieldValue(current.name,
+                                current.type,
+                                current.value,
+                                baseline.value,
+                                Status.MATCHED);
+  }
+
+  /**
+   * Return a DiffedFieldValue where there is no baseline.
+   */
+  public static DiffedFieldValue added(FieldValue current) {
+    return new DiffedFieldValue(current.name, current.type, current.value, null, Status.ADDED);
+  }
+
+  /**
+   * Return a DiffedFieldValue where there is no current.
+   */
+  public static DiffedFieldValue deleted(FieldValue baseline) {
+    return new DiffedFieldValue(baseline.name, baseline.type, null, baseline.value, Status.DELETED);
+  }
+
+  private DiffedFieldValue(String name, String type, Value current, Value baseline, Status status) {
+    this.name = name;
+    this.type = type;
+    this.current = current;
+    this.baseline = baseline;
+    this.status = status;
+  }
+
+  @Override
+  public boolean equals(Object otherObject) {
+    if (otherObject instanceof DiffedFieldValue) {
+      DiffedFieldValue other = (DiffedFieldValue)otherObject;
+      return name.equals(other.name)
+        && type.equals(other.type)
+        && Objects.equals(current, other.current)
+        && Objects.equals(baseline, other.baseline)
+        && Objects.equals(status, other.status);
+    }
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    switch (status) {
+      case ADDED:
+        return "(" + name + " " + type + " +" + current + ")";
+
+      case MATCHED:
+        return "(" + name + " " + type + " " + current + " " + baseline + ")";
+
+      case DELETED:
+        return "(" + name + " " + type + " -" + baseline + ")";
+
+      default:
+        // There are no other members.
+        throw new AssertionError("unsupported enum member");
+    }
+  }
+}