/*
 * Copyright 2014 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.onlab.onos.net.packet;

/**
 * Service for intercepting data plane packets and for emitting synthetic
 * outbound packets.
 */
public interface PacketService {

    // TODO: ponder better ordering scheme that does not require absolute numbers

    /**
     * Adds the specified processor to the list of packet processors.
     * It will be added into the list in the order of priority. The higher
     * numbers will be processing the packets after the lower numbers.
     *
     * @param processor processor to be added
     * @param priority  priority in the reverse natural order
     * @throws java.lang.IllegalArgumentException if a processor with the
     *                                            given priority already exists
     */
    void addProcessor(PacketProcessor processor, int priority);

    /**
     * Removes the specified processor from the processing pipeline.
     *
     * @param processor packet processor
     */
    void removeProcessor(PacketProcessor processor);

    /**
     * Emits the specified outbound packet onto the network.
     *
     * @param packet outbound packet
     */
    void emit(OutboundPacket packet);

}