OFVendorId.java

/*
 * Copyright (c) 2011,2013 Big Switch Networks, Inc.
 *
 * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/legal/epl-v10.html
 *
 * 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.
 *
 * This file incorporates work covered by the following copyright and
 * permission notice:
 *
 *    Originally created by David Erickson & Rob Sherwood, Stanford University 
 *
 *    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.openflow.protocol.vendor;

import java.util.HashMap;
import java.util.Map;

import org.jboss.netty.buffer.ChannelBuffer;

/**
 * Base class for the vendor ID corresponding to vendor extensions from a
 * given vendor. It is responsible for knowing how to parse out some sort of
 * data type value from the vendor data in an OFVendor message so that we can
 * dispatch to the different subclasses of OFVendorData corresponding to the
 * different formats of data for the vendor extensions.
 * 
 * @author Rob Vaterlaus (rob.vaterlaus@bigswitch.com)
 */
public abstract class OFVendorId {
    static Map<Integer, OFVendorId> mapping = new HashMap<Integer, OFVendorId>();

    /**
     * The vendor id value, typically the OUI of the vendor prefixed with 0.
     */
    protected int id;
    
    /**
     * Register a new vendor id.
     * @param vendorId the vendor id to register
     */
    public static void registerVendorId(OFVendorId vendorId) {
        mapping.put(vendorId.getId(), vendorId);
    }
    
    /**
     * Lookup the OFVendorId instance corresponding to the given id value.
     * @param id the integer vendor id value
     * @return the corresponding OFVendorId that's been registered for the
     *     given value, or null if there id has not been registered.
     */
    public static OFVendorId lookupVendorId(int id) {
        return mapping.get(id);
    }
    
    /**
     * Create an OFVendorId with the give vendor id value
     * @param id
     */
    public OFVendorId(int id) {
        this.id = id;
    }
    
    /**
     * @return the vendor id value
     */
    public int getId() {
        return id;
    }
    
    /**
     * This function parses enough of the data from the channel buffer to be
     * able to determine the appropriate OFVendorDataType for the data.
     * 
     * @param data the channel buffer containing the vendor data.
     * @param length the length to the end of the enclosing message
     * @return the OFVendorDataType that can be used to instantiate the
     *         appropriate subclass of OFVendorData.
     */
    public abstract OFVendorDataType parseVendorDataType(ChannelBuffer data, int length);
}