org.onosproject.lisp.msg.protocols.LispMessageReaderFactory.java Source code

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Here is the source code for org.onosproject.lisp.msg.protocols.LispMessageReaderFactory.java

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/*
 * Copyright 2016-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.lisp.msg.protocols;

import io.netty.buffer.ByteBuf;
import org.onlab.util.ByteOperator;
import org.onosproject.lisp.msg.protocols.DefaultLispEncapsulatedControl.EcmReader;
import org.onosproject.lisp.msg.protocols.DefaultLispInfoReply.InfoReplyReader;
import org.onosproject.lisp.msg.protocols.DefaultLispInfoRequest.InfoRequestReader;
import org.onosproject.lisp.msg.protocols.DefaultLispMapNotify.NotifyReader;
import org.onosproject.lisp.msg.protocols.DefaultLispMapRegister.RegisterReader;
import org.onosproject.lisp.msg.protocols.DefaultLispMapReply.ReplyReader;
import org.onosproject.lisp.msg.protocols.DefaultLispMapRequest.RequestReader;

/**
 * A factory class which helps to instantiate LISP reader class.
 */
public final class LispMessageReaderFactory {
    private static final int TYPE_SHIFT_BIT = 4;
    private static final int INFO_REPLY_INDEX = 3;

    private LispMessageReaderFactory() {
    }

    /**
     * Obtains corresponding LISP message reader.
     *
     * @param buffer netty byte buffer
     * @return LISP message reader
     */
    public static LispMessageReader getReader(ByteBuf buffer) {
        LispMessageReader reader;

        LispType type = LispType.valueOf((short) (buffer.getUnsignedByte(0) >> TYPE_SHIFT_BIT));

        switch (type) {
        case LISP_MAP_REQUEST:
            reader = new RequestReader();
            break;
        case LISP_MAP_REPLY:
            reader = new ReplyReader();
            break;
        case LISP_MAP_REGISTER:
            reader = new RegisterReader();
            break;
        case LISP_MAP_NOTIFY:
            reader = new NotifyReader();
            break;
        case LISP_INFO:
            boolean isInfoReply = ByteOperator.getBit((byte) buffer.getUnsignedByte(0), INFO_REPLY_INDEX);
            if (isInfoReply) {
                reader = new InfoReplyReader();
            } else {
                reader = new InfoRequestReader();
            }
            break;
        case LISP_ENCAPSULATED_CONTROL:
            reader = new EcmReader();
            break;
        case UNKNOWN:
            throw new IllegalArgumentException("Unknown message type: " + type);
        default:
            throw new IllegalArgumentException("Undefined message type: " + type);
        }
        return reader;
    }
}