Fixed several replication bugs; Value -> Data; extracted ReplicableEntry as a superclass of HashReplicableEntry

src/main/java/net/openhft/chronicle/hash/AbstractData.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2015 Higher Frequency Trading
+ *
+ *  http://www.higherfrequencytrading.com
+ *  
+ *  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 net.openhft.chronicle.hash;
+
+import net.openhft.chronicle.algo.hashing.LongHashFunction;
+
+/**
+ * Defines reasonable defaults for {@code Data}'s {@code equals()}, {@code hashCode()} and
+ * {@code toString()}. They should be default implementations in the {@code Data} interface itself,
+ * but Java 8 doesn't allow to override {@code Object}'s methods by default implementations
+ * in interfaces.
+ */
+public abstract class AbstractData<V, T> implements Data<V, T> {
+
+    /**
+     * Constructor for use by subclasses. 
+     */
+    protected AbstractData() {}
+
+    /**
+     * Computes value's hash code by applying a hash function to {@code Data}'s <i>bytes</i>
+     * representation.
+     */
+    @Override
+    public int hashCode() {
+        return (int) hash(LongHashFunction.city_1_1());
+    }
+
+    /**
+     * Compares {@code Data}s' <i>bytes</i> representations.
+     */
+    @Override
+    public boolean equals(Object obj) {
+        return obj != null &&
+                obj instanceof Data &&
+                Data.bytesEquivalent(this, (Data<?, ?>) obj);
+    }
+
+    /**
+     * Delegates to {@code Data}'s <i>object</i> {@code toString()}.
+     */
+    @Override
+    public String toString() {
+        return get().toString();
+    }
+}