[CORD-2362] dhcp relay v6 counters implementation

Change-Id: I1ec322d6d77ff62ec4ad91632349e3a2c0d058f3
diff --git a/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/store/DistributedDhcpRelayCountersStore.java b/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/store/DistributedDhcpRelayCountersStore.java
new file mode 100644
index 0000000..4b7b26c
--- /dev/null
+++ b/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/store/DistributedDhcpRelayCountersStore.java
@@ -0,0 +1,130 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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.dhcprelay.store;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+
+import org.onlab.util.KryoNamespace;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.store.service.ConsistentMap;
+import org.onosproject.store.service.Serializer;
+import org.onosproject.store.service.StorageService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.onosproject.store.serializers.KryoNamespaces;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import org.onosproject.store.service.Versioned;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+@Component(immediate = true)
+@Service
+public class DistributedDhcpRelayCountersStore implements DhcpRelayCountersStore {
+    private static final KryoNamespace.Builder APP_KYRO = KryoNamespace.newBuilder()
+            .register(KryoNamespaces.API)
+            .register(DhcpRelayCounters.class);
+
+    private Logger log = LoggerFactory.getLogger(getClass());
+    private ConsistentMap<String, DhcpRelayCounters> counters;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected StorageService storageService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CoreService coreService;
+
+
+    @Activate
+    protected void activated() {
+        ApplicationId appId = coreService.getAppId("org.onosproject.Dhcp6HandlerImpl");
+        counters = storageService.<String, DhcpRelayCounters>consistentMapBuilder()
+                .withSerializer(Serializer.using(APP_KYRO.build()))
+                .withName("Dhcp-Relay-Counters")
+                .withApplicationId(appId)
+                .withPurgeOnUninstall()
+                .build();
+    }
+
+    @Deactivate
+    protected void deactivated() {
+        counters.destroy().join();
+    }
+    @Override
+    public void incrementCounter(String coutnerClass, String counterName) {
+        DhcpRelayCounters countersRecord;
+
+        Versioned<DhcpRelayCounters> vCounters = counters.get(coutnerClass);
+        if (vCounters == null) {
+            countersRecord = new DhcpRelayCounters();
+        } else {
+            countersRecord = vCounters.value();
+        }
+        countersRecord.incrementCounter(counterName);
+        counters.put(coutnerClass, countersRecord);
+    }
+
+    @Override
+    public Set<Map.Entry<String, DhcpRelayCounters>> getAllCounters() {
+        final Set<Map.Entry<String, DhcpRelayCounters>> result =
+                new HashSet<Map.Entry<String, DhcpRelayCounters>>();
+        Set<Map.Entry<String, Versioned<DhcpRelayCounters>>> tmpCounters = counters.entrySet();
+        tmpCounters.forEach(entry -> {
+            String key = entry.getKey();
+            DhcpRelayCounters value = entry.getValue().value();
+            ConcurrentHashMap<String, DhcpRelayCounters> newMap = new ConcurrentHashMap();
+            newMap.put(key, value);
+
+            for (Map.Entry m: newMap.entrySet()) {
+                result.add(m);
+            }
+        });
+        return  result;
+    }
+    @Override
+    public Optional<DhcpRelayCounters> getCounters(String counterClass) {
+        DhcpRelayCounters countersRecord;
+        checkNotNull(counterClass, "counter class can't be null");
+        Versioned<DhcpRelayCounters> vCounters = counters.get(counterClass);
+        if (vCounters == null) {
+            return Optional.empty();
+        }
+        return Optional.of(vCounters.value());
+    }
+    @Override
+    public void resetAllCounters() {
+        counters.clear();
+    }
+
+    @Override
+    public void resetCounters(String counterClass) {
+        checkNotNull(counterClass, "counter class can't be null");
+        DhcpRelayCounters countersRecord = counters.get(counterClass).value();
+        countersRecord.resetCounters();
+        counters.put(counterClass, countersRecord);
+    }
+
+}