[ONOS-2408]Data model and utility class about RFC 7047 (ovsdb protocol).
The whole lib of ovsdb provides the function of encode to jasonRPC and
decode to Pojo to consumer, the bussiness of coordination of
communication is implemented by adapter.

Change-Id: I4c35426273394c1699207e5a4f2e98cead59f1e1
diff --git a/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/message/RowUpdate.java b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/message/RowUpdate.java
new file mode 100644
index 0000000..db11edd
--- /dev/null
+++ b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/message/RowUpdate.java
@@ -0,0 +1,97 @@
+/*
+ * 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.ovsdb.rfc.message;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Objects;
+
+import org.onosproject.ovsdb.rfc.notation.Row;
+import org.onosproject.ovsdb.rfc.notation.UUID;
+
+/**
+ * A TableUpdate is an object that maps from the row's UUID to a RowUpdate object.
+ * A RowUpdate is an object with the following members: "old": row, "new": row.
+ * Refer to RFC 7047 Section 4.1.6.
+ */
+public final class RowUpdate {
+    private final UUID uuid;
+    private final Row oldRow;
+    private final Row newRow;
+
+    /**
+     * Constructs a RowUpdate object.
+     * @param uuid UUID
+     * @param oldRow present for "delete" and "modify" updates
+     * @param newRow present for "initial", "insert", and "modify" updates
+     */
+    public RowUpdate(UUID uuid, Row oldRow, Row newRow) {
+        checkNotNull(uuid, "uuid is not null");
+        this.uuid = uuid;
+        this.oldRow = oldRow;
+        this.newRow = newRow;
+    }
+
+    /**
+     * Return uuid.
+     * @return uuid
+     */
+    public UUID uuid() {
+        return this.uuid;
+    }
+
+    /**
+     * Return oldRow.
+     * @return oldRow
+     */
+    public Row oldRow() {
+        return oldRow;
+    }
+
+    /**
+     * Return newRow.
+     * @return newRow
+     */
+    public Row newRow() {
+        return newRow;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(uuid, oldRow, newRow);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof RowUpdate) {
+            final RowUpdate other = (RowUpdate) obj;
+            return Objects.equals(this.uuid, other.uuid)
+                    && Objects.equals(this.oldRow, other.oldRow)
+                    && Objects.equals(this.newRow, other.newRow);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("uuid", uuid).add("oldRow", oldRow)
+                .add("newRow", newRow).toString();
+    }
+}