GOSSIP-53 CRDT types

src/main/java/org/apache/gossip/crdt/Crdt.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.gossip.crdt;
+/**
+ * 
+ * Immutable type 
+ *
+ * @param <SetType>
+ * @param <MergeReturnType>
+ */
+public interface Crdt<SetType, MergeReturnType extends Crdt<SetType, MergeReturnType>> {
+
+ 
+  MergeReturnType merge(MergeReturnType other);
+  SetType value();
+  /**
+   * Called to self optimize. Some CRDTs may use some mechanism to clean up be 
+   * removing obsolete data outside the scope of merging. IE this could clean up 
+   * temporal values, old copies etc. 
+   * @return the Crdt structure optimized 
+   */
+  MergeReturnType optimize();
+
+}