Rename L2 load balancer to port load balancer

CLI commands are also renamed to plbs, plb-add and plb-remove

Change-Id: I4c26b390acc5a961594a1dca92a76bee2148c090
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerEvent.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerEvent.java
new file mode 100644
index 0000000..bd9c234
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerEvent.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2018-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.portloadbalancer.api;
+
+import org.onlab.util.Tools;
+import org.onosproject.event.AbstractEvent;
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Port load balancer event.
+ */
+public class PortLoadBalancerEvent extends AbstractEvent<PortLoadBalancerEvent.Type, PortLoadBalancerData> {
+
+    private PortLoadBalancerData prevSubject;
+
+    /**
+     * Port load balancer event type.
+     */
+    public enum Type {
+        /**
+         * Port load balancer creation is requested.
+         */
+        ADDED,
+
+        /**
+         * Port load balancer deletion is requested.
+         */
+        REMOVED,
+
+        /**
+         * Port load balancer update is requested.
+         * E.g. member change.
+         */
+        UPDATED,
+
+        /**
+         * Port load balancer creation/update is completed successfully.
+         */
+        INSTALLED,
+
+        /**
+         * Port load balancer deletion is completed successfully.
+         */
+        UNINSTALLED,
+
+        /**
+         * Error occurs during creation/update/deletion of a port load balancer.
+         */
+        FAILED
+    }
+
+    /**
+     * Constructs a port load balancer event.
+     *
+     * @param type event type
+     * @param subject current port load balancer information
+     * @param prevSubject previous port load balancer information
+     */
+    public PortLoadBalancerEvent(Type type, PortLoadBalancerData subject, PortLoadBalancerData prevSubject) {
+        super(type, subject);
+        this.prevSubject = prevSubject;
+    }
+
+    /**
+     * Gets previous port load balancer information.
+     *
+     * @return previous subject
+     */
+    public PortLoadBalancerData prevSubject() {
+        return prevSubject;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(subject(), time(), prevSubject);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+
+        if (!(other instanceof PortLoadBalancerEvent)) {
+            return false;
+        }
+
+        PortLoadBalancerEvent that = (PortLoadBalancerEvent) other;
+        return Objects.equals(this.subject(), that.subject()) &&
+                Objects.equals(this.type(), that.type()) &&
+                Objects.equals(this.prevSubject, that.prevSubject);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("type", type())
+                .add("subject", subject())
+                .add("prevSubject", prevSubject)
+                .add("time", Tools.defaultOffsetDataTime(time()))
+                .toString();
+    }
+}