net.sf.jrtps.message.Gap Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jrtps Show documentation

jRTPS - An implementation of RTPS protocol by OMG

There is a newer version: 1.5.1

package net.sf.jrtps.message;

import net.sf.jrtps.transport.RTPSByteBuffer;
import net.sf.jrtps.types.EntityId;
import net.sf.jrtps.types.SequenceNumber;
import net.sf.jrtps.types.SequenceNumberSet;

/**
 * This Submessage is sent from an RTPS Writer to an RTPS Reader and indicates
 * to the RTPS Reader that a range of sequence numbers is no longer relevant.
 * The set may be a contiguous range of sequence numbers or a specific set of
 * sequence numbers.
 * 
 * 
 * see 8.3.7.4 Gap, 9.4.5.5 Gap Submessage
 * 
 * @author mcr70
 * 
 */
public class Gap extends SubMessage {
    public static final int KIND = 0x08;

    private EntityId readerId;
    private EntityId writerId;
    private SequenceNumber gapStart;
    private SequenceNumberSet gapList;

    public Gap(SubMessageHeader smh, RTPSByteBuffer bb) {
        super(smh);

        readMessage(bb);
    }

    /**
     * Get the Reader Entity that is being informed of the irrelevance of a set
     * of sequence numbers.
     */
    public EntityId getReaderId() {
        return readerId;
    }

    /**
     * Get the Writer Entity to which the range of sequence numbers applies.
     */
    public EntityId getWriterId() {
        return writerId;
    }

    /**
     * Identifies the first sequence number in the interval of irrelevant
     * sequence numbers.
     * 
     * @return First irrelevant sequence number
     */
    public SequenceNumber getGapStart() {
        return gapStart;
    }

    /**
     * SequenceNumberSet.bitmapBase is the last sequence number of irrelevant
     * seq nums. SequenceNumberSet.bitmaps identifies additional irrelevant
     * sequence numbers.
     * 
     * @return SequenceNumberSet
     */
    public SequenceNumberSet getGapList() {
        return gapList;
    }

    private void readMessage(RTPSByteBuffer bb) {
        this.readerId = EntityId.readEntityId(bb);
        this.writerId = EntityId.readEntityId(bb);

        this.gapStart = new SequenceNumber(bb);
        this.gapList = new SequenceNumberSet(bb);
    }

    @Override
    public void writeTo(RTPSByteBuffer buffer) {
        readerId.writeTo(buffer);
        writerId.writeTo(buffer);
        gapStart.writeTo(buffer);
        gapList.writeTo(buffer);
    }

    public String toString() {
        return super.toString() + " " + gapStart + ", " + gapList;
    }
}