Abstract implementation of a behaviour for P4Runtime

Implements commonality of all other behaviours. Also, simplified
the implementation of all other P4Runtime behaviours by re-using that.

Change-Id: Ibb25bdd1e0d1c6e8863341df87fa83d4a782b8d9
diff --git a/drivers/p4runtime/src/main/java/org/onosproject/drivers/p4runtime/AbstractP4RuntimeHandlerBehaviour.java b/drivers/p4runtime/src/main/java/org/onosproject/drivers/p4runtime/AbstractP4RuntimeHandlerBehaviour.java
new file mode 100644
index 0000000..8a5a2dd
--- /dev/null
+++ b/drivers/p4runtime/src/main/java/org/onosproject/drivers/p4runtime/AbstractP4RuntimeHandlerBehaviour.java
@@ -0,0 +1,116 @@
+/*
+ * 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.drivers.p4runtime;
+
+import io.grpc.ManagedChannelBuilder;
+import io.grpc.netty.NettyChannelBuilder;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.driver.AbstractHandlerBehaviour;
+import org.onosproject.net.pi.model.PiPipeconf;
+import org.onosproject.net.pi.runtime.PiPipeconfService;
+import org.onosproject.p4runtime.api.P4RuntimeClient;
+import org.onosproject.p4runtime.api.P4RuntimeController;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Abstract implementation of a behaviour handler for a P4Runtime device.
+ */
+public class AbstractP4RuntimeHandlerBehaviour extends AbstractHandlerBehaviour {
+
+    public static final String P4RUNTIME_SERVER_ADDR_KEY = "p4runtime_ip";
+    public static final String P4RUNTIME_SERVER_PORT_KEY = "p4runtime_port";
+    public static final String P4RUNTIME_DEVICE_ID_KEY = "p4runtime_deviceId";
+
+    protected final Logger log = LoggerFactory.getLogger(getClass());
+
+    // Initialized by setupBehaviour()
+    protected DeviceId deviceId;
+    protected DeviceService deviceService;
+    protected Device device;
+    protected P4RuntimeController controller;
+    protected PiPipeconf pipeconf;
+    protected P4RuntimeClient client;
+
+    /**
+     * Initializes this behaviour attributes. Returns true if the operation was successful, false otherwise. This method
+     * assumes that the P4runtime controller already has a client for this device and that the device has been created
+     * in the core.
+     *
+     * @return true if successful, false otherwise
+     */
+    protected boolean setupBehaviour() {
+        deviceId = handler().data().deviceId();
+
+        deviceService = handler().get(DeviceService.class);
+        device = deviceService.getDevice(deviceId);
+        if (device == null) {
+            log.warn("Unable to find device with id {}, aborting operation", deviceId);
+            return false;
+        }
+
+        controller = handler().get(P4RuntimeController.class);
+        if (!controller.hasClient(deviceId)) {
+            log.warn("Unable to find client for {}, aborting operation", deviceId);
+            return false;
+        }
+        client = controller.getClient(deviceId);
+
+        PiPipeconfService piPipeconfService = handler().get(PiPipeconfService.class);
+        if (!piPipeconfService.ofDevice(deviceId).isPresent() ||
+                !piPipeconfService.getPipeconf(piPipeconfService.ofDevice(deviceId).get()).isPresent()) {
+            log.warn("Unable to get the pipeconf of {}, aborting operation", deviceId);
+            return false;
+        }
+        pipeconf = piPipeconfService.getPipeconf(piPipeconfService.ofDevice(deviceId).get()).get();
+
+        return true;
+    }
+
+    /**
+     * Create a P4Runtime client for this device. Returns true if the operation was successful, false otherwise.
+     *
+     * @return true if successful, false otherwise
+     */
+    protected boolean createClient() {
+        deviceId = handler().data().deviceId();
+        controller = handler().get(P4RuntimeController.class);
+
+        String serverAddr = this.data().value(P4RUNTIME_SERVER_ADDR_KEY);
+        String serverPortString = this.data().value(P4RUNTIME_SERVER_PORT_KEY);
+        String p4DeviceIdString = this.data().value(P4RUNTIME_DEVICE_ID_KEY);
+
+        if (serverAddr == null || serverPortString == null || p4DeviceIdString == null) {
+            log.warn("Unable to create client for {}, missing driver data key (required is {}, {}, and {})",
+                     deviceId, P4RUNTIME_SERVER_ADDR_KEY, P4RUNTIME_SERVER_PORT_KEY, P4RUNTIME_DEVICE_ID_KEY);
+            return false;
+        }
+
+        ManagedChannelBuilder channelBuilder = NettyChannelBuilder
+                .forAddress(serverAddr, Integer.valueOf(serverPortString))
+                .usePlaintext(true);
+
+        if (!controller.createClient(deviceId, Long.parseUnsignedLong(p4DeviceIdString), channelBuilder)) {
+            log.warn("Unable to create client for {}, aborting operation", deviceId);
+            return false;
+        }
+
+        return true;
+    }
+}