[ONOS-7704] device memory/cpu stats for pica8 switch using Switch_Inventory DB

Change-Id: I1956d06ab373119da59561252f5b35561f8f5619
diff --git a/core/api/src/main/java/org/onosproject/net/behaviour/DeviceMemoryStats.java b/core/api/src/main/java/org/onosproject/net/behaviour/DeviceMemoryStats.java
new file mode 100644
index 0000000..e90d9e8
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/behaviour/DeviceMemoryStats.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2016-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.net.behaviour;
+
+import com.google.common.base.MoreObjects;
+
+import java.util.Objects;
+
+/**
+ * A representation of memory stats of device.
+ */
+
+public class DeviceMemoryStats {
+    private long free = 0;  // in Bytes
+    private long used = 0;
+    private long total = 0;
+
+    /**
+     * Instantiates DeviceMemoryStats object.
+     */
+    public DeviceMemoryStats() {
+    }
+
+    /**
+     * Creates DeviceMemoryStats object with given data.
+     *
+     * @param free free memory
+     * @param used used memory
+     * @param total total memory
+     */
+    public DeviceMemoryStats(long free, long used, long total) {
+        this.free = free;
+        this.used = used;
+        this.total = total;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("free", free)
+                .add("used", used)
+                .add("total", total)
+                .toString();
+    }
+
+    /**
+     * Get total memory of device.
+     *
+     * @return totalMmeory, total memory
+     */
+    public long getTotal() {
+        return total;
+    }
+
+    /**
+     * Get used memory of device.
+     *
+     * @return usedMemory, used memory
+     */
+    public long getUsed() {
+        return used;
+    }
+
+    /**
+     * Get free memory of device.
+     *
+     * @return freeMemory, free memory
+     */
+    public long getFree() {
+        return free;
+    }
+
+    /**
+     * Set free memory of device.
+     *
+     * @param free free memory stats of device
+     */
+    public void setFree(long free) {
+        this.free = free;
+    }
+
+    /**
+     * Set used memory of device.
+     *
+     * @param used used memory stats of device
+     */
+    public void setUsed(long used) {
+        this.used = used;
+    }
+
+    /**
+     * Set total memory of device.
+     *
+     * @param total total memory stats of device
+     */
+    public void setTotal(long total) {
+        this.total = total;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        DeviceMemoryStats that = (DeviceMemoryStats) o;
+        return free == that.free &&
+                used == that.used &&
+                total == that.total;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(free, used, total);
+    }
+}
+