1 files changed, 85 insertions, 0 deletions

diff --git a/framework/src/onos/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/UpdateResult.java b/framework/src/onos/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/UpdateResult.java
new file mode 100644
index 00000000..50b78dd4
--- /dev/null
+++ b/framework/src/onos/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/UpdateResult.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.store.consistent.impl;
+
+import java.util.function.Function;
+
+import org.onosproject.store.service.MapEvent;
+import org.onosproject.store.service.Versioned;
+
+/**
+ * Result of a update operation.
+ * <p>
+ * Both old and new values are accessible along with a flag that indicates if the
+ * the value was updated. If flag is false, oldValue and newValue both
+ * point to the same unmodified value.
+ * @param <V> result type
+ */
+public class UpdateResult<K, V> {
+
+    private final boolean updated;
+    private final String mapName;
+    private final K key;
+    private final Versioned<V> oldValue;
+    private final Versioned<V> newValue;
+
+    public UpdateResult(boolean updated, String mapName, K key, Versioned<V> oldValue, Versioned<V> newValue) {
+        this.updated = updated;
+        this.mapName = mapName;
+        this.key = key;
+        this.oldValue = oldValue;
+        this.newValue = newValue;
+    }
+
+    public boolean updated() {
+        return updated;
+    }
+
+    public String mapName() {
+        return mapName;
+    }
+
+    public K key() {
+        return key;
+    }
+
+    public Versioned<V> oldValue() {
+        return oldValue;
+    }
+
+    public Versioned<V> newValue() {
+        return newValue;
+    }
+
+    public <K1, V1> UpdateResult<K1, V1> map(Function<K, K1> keyTransform, Function<V, V1> valueMapper) {
+        return new UpdateResult<>(updated,
+                mapName,
+                keyTransform.apply(key),
+                oldValue == null ? null : oldValue.map(valueMapper),
+                newValue == null ? null : newValue.map(valueMapper));
+    }
+
+    public MapEvent<K, V> toMapEvent() {
+        if (!updated) {
+            return null;
+        } else {
+            MapEvent.Type eventType = oldValue == null ?
+                    MapEvent.Type.INSERT : newValue == null ? MapEvent.Type.REMOVE : MapEvent.Type.UPDATE;
+            Versioned<V> eventValue = eventType == MapEvent.Type.REMOVE ? oldValue : newValue;
+            return new MapEvent<>(mapName(), eventType, key(), eventValue);
+        }
+    }
+}
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