HCOLL-147 factored ChronicleMap 'default-valuing' configuration from MapEventListener

src/main/java/net/openhft/chronicle/map/NullValueProvider.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2014 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.map;
+
+enum NullValueProvider implements DefaultValueProvider {
+    INSTANCE;
+
+    @Override
+    public Object get(Object key, Object usingValue) {
+        return null;
+    }
+}