Moving meter store implementation to use map events

Change-Id: I338473b7286d7b9e5cdfb938f16c7b6155d4cbb5
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/meter/MeterStoreResult.java b/incubator/api/src/main/java/org/onosproject/incubator/net/meter/MeterStoreResult.java
new file mode 100644
index 0000000..8ad5aa6
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/meter/MeterStoreResult.java
@@ -0,0 +1,66 @@
+/*
+ * 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.incubator.net.meter;
+
+import java.util.Optional;
+
+/**
+ * An entity used to indicate whether the store operation passed.
+ */
+public final class MeterStoreResult {
+
+
+    private final Type type;
+    private final Optional<MeterFailReason> reason;
+
+    public enum Type {
+        SUCCESS,
+        FAIL
+    }
+
+    private MeterStoreResult(Type type, MeterFailReason reason) {
+        this.type = type;
+        this.reason = Optional.ofNullable(reason);
+    }
+
+    public Type type() {
+        return type;
+    }
+
+    public Optional<MeterFailReason> reason() {
+        return reason;
+    }
+
+    /**
+     * A successful store opertion.
+     *
+     * @return a meter store result
+     */
+    public static MeterStoreResult success() {
+        return new MeterStoreResult(Type.SUCCESS, null);
+    }
+
+    /**
+     * A failed store operation.
+     *
+     * @param reason a failure reason
+     * @return a meter store result
+     */
+    public static MeterStoreResult fail(MeterFailReason reason) {
+        return new MeterStoreResult(Type.FAIL, reason);
+    }
+
+}