Enable to query the control metrics from remote node

Change-Id: Ifef1c6eafd7cc79ed99be51f7faa26d97aeb2f67
diff --git a/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlLoadSnapshot.java b/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlLoadSnapshot.java
new file mode 100644
index 0000000..36e436a
--- /dev/null
+++ b/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlLoadSnapshot.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2016-present 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.cpman;
+
+import com.google.common.base.MoreObjects;
+
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * A container class that is used to wrap the control metric response.
+ */
+public class ControlLoadSnapshot {
+
+    private final long latest;
+    private final long average;
+    private final long time;
+
+    /**
+     * Instantiates a new control metric response with given latest, average, time.
+     *
+     * @param latest latest value of control metric
+     * @param average average value of control metric
+     * @param time last logging time fo control metric
+     */
+    public ControlLoadSnapshot(long latest, long average, long time) {
+        this.latest = latest;
+        this.average = average;
+        this.time = time;
+    }
+
+    /**
+     * Returns latest value of control metric.
+     *
+     * @return latest value of control metric
+     */
+    public long latest() {
+        return latest;
+    }
+
+    /**
+     * Returns last logging time of control metric.
+     *
+     * @return last logging time of control metric
+     */
+    public long time() {
+        return time;
+    }
+
+    /**
+     * Returns average value of control metric.
+     *
+     * @return average value of control metric
+     */
+    public long average() {
+        return average;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(latest, average, time);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof ControlLoadSnapshot) {
+            final ControlLoadSnapshot other = (ControlLoadSnapshot) obj;
+            return Objects.equals(this.latest, other.latest) &&
+                    Objects.equals(this.average, other.average) &&
+                    Objects.equals(this.time, other.time);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        MoreObjects.ToStringHelper helper;
+        helper = toStringHelper(this)
+                .add("latest", latest)
+                .add("average", average)
+                .add("time", time);
+        return helper.toString();
+    }
+}
diff --git a/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlMetricsRequest.java b/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlMetricsRequest.java
new file mode 100644
index 0000000..8ee505a
--- /dev/null
+++ b/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlMetricsRequest.java
@@ -0,0 +1,174 @@
+/*
+ * Copyright 2016-present 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.cpman;
+
+import com.google.common.base.MoreObjects;
+import org.onosproject.net.DeviceId;
+
+import java.util.Objects;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * A container class that is used to request control metric of remote node.
+ */
+public class ControlMetricsRequest {
+    private final ControlMetricType type;
+    private Optional<DeviceId> deviceId;
+    private String resourceName;
+    private int duration;
+    private TimeUnit unit;
+
+    /**
+     * Instantiates a new control metric request of the control metric type and
+     * device identifier.
+     *
+     * @param type     control metric type
+     * @param deviceId device identifier
+     */
+    public ControlMetricsRequest(ControlMetricType type, Optional<DeviceId> deviceId) {
+        this.type = type;
+        this.deviceId = deviceId;
+    }
+
+    /**
+     * Instantiates a new control metric request of the control metric type and
+     * device identifier with the given projected time range.
+     *
+     * @param type     control metric type
+     * @param duration projected time duration
+     * @param unit     projected time unit
+     * @param deviceId device dientifer
+     */
+    public ControlMetricsRequest(ControlMetricType type, int duration, TimeUnit unit,
+                                 Optional<DeviceId> deviceId) {
+        this.type = type;
+        this.deviceId = deviceId;
+        this.duration = duration;
+        this.unit = unit;
+    }
+
+    /**
+     * Instantiates a new control metric request of the control metric type and
+     * resource name.
+     *
+     * @param type         control metric type
+     * @param resourceName resource name
+     */
+    public ControlMetricsRequest(ControlMetricType type, String resourceName) {
+        this.type = type;
+        this.resourceName = resourceName;
+    }
+
+    /**
+     * Instantiates a new control metric request of the control metric type and
+     * resource name with the given projected time range.
+     *
+     * @param type         control metric type
+     * @param duration     projected time duration
+     * @param unit         projected time unit
+     * @param resourceName resource name
+     */
+    public ControlMetricsRequest(ControlMetricType type, int duration, TimeUnit unit,
+                                 String resourceName) {
+        this.type = type;
+        this.resourceName = resourceName;
+        this.duration = duration;
+        this.unit = unit;
+    }
+
+    /**
+     * Obtains control metric type.
+     *
+     * @return control metric type
+     */
+    public ControlMetricType getType() {
+        return type;
+    }
+
+    /**
+     * Obtains resource name.
+     *
+     * @return resource name
+     */
+    public String getResourceName() {
+        return resourceName;
+    }
+
+    /**
+     * Obtains device identifier.
+     *
+     * @return device identifier
+     */
+    public Optional<DeviceId> getDeviceId() {
+        return deviceId;
+    }
+
+    /**
+     * Obtains projected time duration.
+     *
+     * @return projected time duration
+     */
+    public int getDuration() {
+        return duration;
+    }
+
+    /**
+     * Obtains projected time unit.
+     *
+     * @return projected time unit
+     */
+    public TimeUnit getUnit() {
+        return unit;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(type, deviceId, resourceName, duration, unit.toString());
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof ControlMetricsRequest) {
+            final ControlMetricsRequest other = (ControlMetricsRequest) obj;
+            return Objects.equals(this.type, other.type) &&
+                    Objects.equals(this.deviceId, other.deviceId) &&
+                    Objects.equals(this.resourceName, other.resourceName) &&
+                    Objects.equals(this.duration, other.duration) &&
+                    Objects.equals(this.unit, other.unit);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        MoreObjects.ToStringHelper helper;
+        helper = toStringHelper(this)
+                .add("type", type)
+                .add("resourceName", resourceName)
+                .add("duration", duration)
+                .add("timeUnit", unit);
+        if (deviceId != null) {
+            helper.add("deviceId", deviceId.get());
+        }
+        return helper.toString();
+    }
+}
diff --git a/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlPlaneMonitorService.java b/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlPlaneMonitorService.java
index 9a9930f..32ccdd6 100644
--- a/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlPlaneMonitorService.java
+++ b/apps/cpman/api/src/main/java/org/onosproject/cpman/ControlPlaneMonitorService.java
@@ -21,8 +21,9 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
 
-import static org.onosproject.cpman.ControlResource.*;
+import static org.onosproject.cpman.ControlResource.Type;
 
 /**
  * Control Plane Statistics Service Interface.
@@ -52,50 +53,65 @@
                       String resourceName);
 
     /**
-     * Obtains local control plane load of a specific device.
+     * Obtains snapshot of control plane load of a specific device.
      * The metrics range from control messages and system metrics
-     * (e.g., CPU and memory info)
-     *
-     * @param type     control metric type
-     * @param deviceId device identifier
-     * @return control plane load
-     */
-    ControlLoad getLocalLoad(ControlMetricType type, Optional<DeviceId> deviceId);
-
-    /**
-     * Obtains local control plane load of a specific resource.
-     * The metrics range from I/O device metrics
-     * (e.g., disk and network interface)
-     *
-     * @param type         control metric type
-     * @param resourceName resource name
-     * @return control plane load
-     */
-    ControlLoad getLocalLoad(ControlMetricType type, String resourceName);
-
-    /**
-     * Obtains remote control plane load of a specific device.
+     * (e.g., CPU and memory info).
+     * If the device id is not specified, it returns system metrics, otherwise,
+     * it returns control message stats of the given device.
      *
      * @param nodeId   node identifier
      * @param type     control metric type
      * @param deviceId device identifier
-     * @return completable future object of control load
+     * @return completable future object of control load snapshot
      */
-    CompletableFuture<ControlLoad> getRemoteLoad(NodeId nodeId,
-                                                 ControlMetricType type,
-                                                 Optional<DeviceId> deviceId);
+    CompletableFuture<ControlLoadSnapshot> getLoad(NodeId nodeId,
+                                                   ControlMetricType type,
+                                                   Optional<DeviceId> deviceId);
 
     /**
-     * Obtains remote control plane load of a specific resource.
+     * Obtains snapshot of control plane load of a specific resource.
+     * The metrics include I/O device metrics (e.g., disk and network metrics).
      *
      * @param nodeId       node identifier
      * @param type         control metric type
      * @param resourceName resource name
-     * @return completable future object of control load
+     * @return completable future object of control load snapshot
      */
-    CompletableFuture<ControlLoad> getRemoteLoad(NodeId nodeId,
-                                                 ControlMetricType type,
-                                                 String resourceName);
+    CompletableFuture<ControlLoadSnapshot> getLoad(NodeId nodeId,
+                                                   ControlMetricType type,
+                                                   String resourceName);
+
+    /**
+     * Obtains snapshot of control plane load of a specific device with the
+     * projected range.
+     *
+     * @param nodeId   node identifier
+     * @param type     control metric type
+     * @param duration projected duration
+     * @param unit     projected time unit
+     * @param deviceId device identifier
+     * @return completable future object of control load snapshot
+     */
+    CompletableFuture<ControlLoadSnapshot> getLoad(NodeId nodeId,
+                                                   ControlMetricType type,
+                                                   int duration, TimeUnit unit,
+                                                   Optional<DeviceId> deviceId);
+
+    /**
+     * Obtains snapshot of control plane load of a specific resource with the
+     * projected range.
+     *
+     * @param nodeId       node identifier
+     * @param type         control metric type
+     * @param duration     projected duration
+     * @param unit         projected time unit
+     * @param resourceName resource name
+     * @return completable future object of control load snapshot
+     */
+    CompletableFuture<ControlLoadSnapshot> getLoad(NodeId nodeId,
+                                                   ControlMetricType type,
+                                                   int duration, TimeUnit unit,
+                                                   String resourceName);
 
     /**
      * Obtains a list of names of available resources.