core/api/src/main/java/org/onosproject/net/behaviour/Pipeliner.java

/*
 * Copyright 2015-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 java.util.List;

import org.onosproject.net.DeviceId;
import org.onosproject.net.driver.HandlerBehaviour;
import org.onosproject.net.flowobjective.FilteringObjective;
import org.onosproject.net.flowobjective.ForwardingObjective;
import org.onosproject.net.flowobjective.NextObjective;

/**
 * Behaviour for handling various pipelines.
 */
public interface Pipeliner extends HandlerBehaviour {

    /**
     * Accumulator enabled property. Determines whether the accumulator is enabled.
     * The accumulator is assumed to be disabled if this property is undefined.
     *
     * If enabled, the pipeliner will try to accumulate objectives and create
     * batches of flow rules when possible.
     *
     */
    String ACCUMULATOR_ENABLED = "accumulatorEnabled";

    /**
     * Initializes the driver with context required for its operation.
     *
     * @param deviceId the deviceId
     * @param context  processing context
     */
    void init(DeviceId deviceId, PipelinerContext context);

    /**
     * Installs the filtering rules onto the device.
     *
     * @param filterObjective a filtering objective
     */
    void filter(FilteringObjective filterObjective);

    /**
     * Installs the forwarding rules onto the device.
     *
     * @param forwardObjective a forwarding objective
     */
    void forward(ForwardingObjective forwardObjective);

    /**
     * Installs the next hop elements into the device.
     *
     * @param nextObjective a next objectives
     */
    void next(NextObjective nextObjective);

    /**
     *  Retrieves a mapping of the nextObjective to the groups in the dataplane,
     *  and returns it in a form that can be displayed on the CLI. Typically
     *  group-ids are returned for groups with multiple buckets, where each list element
     *  represents a bucket. For nextObjectives that are converted to flow-actions,
     *  an empty list is returned.
     *
     *  @param nextGroup representation of the nextObjective. This representation
     *                   is stored in the distributed group store
     *  @return a list of preformatted strings representing group information, or
     *          an empty list if no groups were created
     */
    List<String> getNextMappings(NextGroup nextGroup);

    /**
     * Returns pipeliner status.
     *
     * @return true if pipeliner is ready to accept objectives. False otherwise.
     */
    default boolean isReady() {
        return true;
    }

    /**
     * Clean up internal state of the pipeliner.
     * Implementation is pipeliner specific.
     */
    default void cleanUp() {
    }

}