drivers/bmv2/src/main/java/org/onosproject/drivers/bmv2/Bmv2PacketProgrammable.java

/*
 * Copyright 2017-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.drivers.bmv2;

import io.grpc.stub.StreamObserver;
import org.onosproject.grpc.api.GrpcChannelId;
import org.onosproject.grpc.api.GrpcController;
import org.onosproject.grpc.api.GrpcObserverHandler;
import org.onosproject.grpc.api.GrpcServiceId;
import org.onosproject.grpc.api.GrpcStreamObserverId;
import org.onosproject.net.DeviceId;
import org.onosproject.net.driver.AbstractHandlerBehaviour;
import org.onosproject.net.driver.DriverHandler;
import org.onosproject.net.packet.OutboundPacket;
import org.onosproject.net.packet.PacketProgrammable;

import java.util.Optional;

/**
 * Packet Programmable behaviour for BMv2 devices.
 */
public class Bmv2PacketProgrammable extends AbstractHandlerBehaviour implements PacketProgrammable {
    @Override
    public void emit(OutboundPacket packet) {
        DriverHandler handler = handler();
        GrpcController controller = handler.get(GrpcController.class);
        DeviceId deviceId = handler.data().deviceId();
        GrpcChannelId channelId = GrpcChannelId.of(deviceId, "bmv2");
        GrpcServiceId serviceId = GrpcServiceId.of(channelId, "p4runtime");
        GrpcStreamObserverId observerId = GrpcStreamObserverId.of(serviceId,
                this.getClass().getSimpleName());
        Optional<GrpcObserverHandler> manager = controller.getObserverManager(observerId);
        if (!manager.isPresent()) {
            //this is the first time the behaviour is called
            controller.addObserver(observerId, new Bmv2PacketInObserverHandler());
        }
        //other already registered the observer for us.
        Optional<StreamObserver> observer = manager.get().requestStreamObserver();
        observer.ifPresent(objectStreamObserver -> objectStreamObserver.onNext(packet));
    }
}