peergroupid.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

/*
 *
 * $Id: PeerGroupID.java,v 1.16 2005/12/07 04:39:57 bondolo Exp $
 *
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 */

package net.jxta.impl.id.UUID;

import org.apache.log4j.Logger;
import org.apache.log4j.Level;

/**
 *  An implementation of the {@link net.jxta.peergroup.PeerGroupID} ID Type.
 **/
public class PeerGroupID extends net.jxta.peergroup.PeerGroupID {
    
    /**
     *  Log4J categorgy
     **/
    private static final transient Logger LOG = Logger.getLogger( PeerGroupID.class.getName());
    
    /**
     *  Location of the group id UUID within the id bytes.
     **/
    protected final static int groupIdOffset = 0;
    
    /**
     *  Location of the parent group id UUID within the id bytes.
     **/
    protected final static int parentgroupIdOffset = PeerGroupID.groupIdOffset + IDFormat.uuidSize;
    
    /**
     *  Location of the begining of the pad space.
     **/
    protected final static int padOffset = PeerGroupID.parentgroupIdOffset + IDFormat.uuidSize;
    
    /**
     *  size of the pad space.
     **/
    protected final static int padSize = IDFormat.flagsOffset - PeerGroupID.padOffset;
    
    /**
     *  The id data
     **/
    protected IDBytes id;
    
    /**
     * Intializes contents from provided ID.
     *
     * @param id    the ID data
     */
    protected PeerGroupID( IDBytes id ) {
        super();
        this.id = id;
    }
    
    /**
     * Creates a PeerGroupID. A PeerGroupID is provided
     *
     * @param groupUUID    the PeerGroupID to use to construct the new PeerGroupID
     **/
    protected PeerGroupID( UUID groupUUID ) {
        super( );
        id = new IDBytes();
        id.bytes[IDFormat.flagsOffset + IDFormat.flagsIdTypeOffset] = IDFormat.flagPeerGroupID;
        
        id.longIntoBytes(
                PeerGroupID.groupIdOffset, groupUUID.getMostSignificantBits() );
        id.longIntoBytes(
                PeerGroupID.groupIdOffset + 8, groupUUID.getLeastSignificantBits() );
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newPeerGroupID()}.
     **/
    public PeerGroupID( ) {
        this(UUIDFactory.newUUID());
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newPeerGroupID(net.jxta.peergroup.PeerGroupID)}.
     **/
    public PeerGroupID( PeerGroupID parent ) {
        this( UUIDFactory.newUUID() );
        
        for( int eachByte = 0; eachByte < IDFormat.uuidSize; eachByte++ )
            id.bytes[PeerGroupID.parentgroupIdOffset + eachByte] =
                    parent.id.bytes[PeerGroupID.groupIdOffset + eachByte];
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newPeerGroupID(byte[])}.
     **/
    public PeerGroupID( byte [] seed ) {
        super( );
        id = new IDBytes();
        id.bytes[IDFormat.flagsOffset + IDFormat.flagsIdTypeOffset] = IDFormat.flagPeerGroupID;
        
        for( int copySeed = Math.min( IDFormat.uuidSize, seed.length ) - 1;
        copySeed >= 0;
        copySeed-- )
            id.bytes[copySeed + PeerGroupID.groupIdOffset] = seed[copySeed];
        
        // make it a valid UUID
        id.bytes[PeerGroupID.groupIdOffset + 6] &= 0x0f;
        id.bytes[PeerGroupID.groupIdOffset + 6] |= 0x40; /* version 4 */
        id.bytes[PeerGroupID.groupIdOffset + 8] &= 0x3f;
        id.bytes[PeerGroupID.groupIdOffset + 8] |= 0x80; /* IETF variant */
        id.bytes[PeerGroupID.groupIdOffset + 10] &= 0x3f;
        id.bytes[PeerGroupID.groupIdOffset + 10] |= 0x80; /* multicast bit */
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newPeerGroupID(net.jxta.peergroup.PeerGroupID,byte[])}.
     **/
    public PeerGroupID( PeerGroupID parent, byte [] seed ) {
        this( seed );
        
        for( int eachByte = 0; eachByte < IDFormat.uuidSize; eachByte++ )
            id.bytes[PeerGroupID.parentgroupIdOffset + eachByte] =
                    parent.id.bytes[PeerGroupID.groupIdOffset + eachByte];
    }
    
    /**
     *  {@inheritDoc}
     **/
    public boolean equals( Object target ) {
        if (this == target) {
            return true;
        }
        
        if (target instanceof PeerGroupID ) {
            PeerGroupID peergroupTarget = (PeerGroupID)target;
            
            if( !getIDFormat().equals( peergroupTarget.getIDFormat() ) ) {
                return false;
            }
            
            if( id == peergroupTarget.id ) {
                return true;
            }
            
            boolean result = id.equals( peergroupTarget.id );
            
            // if true then we can have the two ids share the id bytes
            if( result ) {
                peergroupTarget.id = id;
            }
            
            return result;
        } else {
            return false;
        }
    }
    
    /**
     *  {@inheritDoc}
     **/
    public int hashCode() {
        return id.hashCode();
    }
    
    /**
     *  {@inheritDoc}
     **/
    public String getIDFormat() {
        return IDFormat.INSTANTIATOR.getSupportedIDFormat();
    }
    
    /**
     *  {@inheritDoc}
     **/
    public Object getUniqueValue() {
        return getIDFormat() + "-" + (String) id.getUniqueValue();
    }
    
    /**
     *  {@inheritDoc}
     **/
    public net.jxta.peergroup.PeerGroupID getParentPeerGroupID() {
        boolean zero = true;
        
        for( int eachByte = 0; eachByte < IDFormat.uuidSize; eachByte++ )
            if ( id.bytes[eachByte + PeerGroupID.parentgroupIdOffset] != 0 ) {
            zero = false;
            break;
            }
        
        // if zero, then there is no parent.
        if( zero ) {
            return null;
        }
        
        UUID groupUUID = new UUID(
                id.bytesIntoLong( PeerGroupID.parentgroupIdOffset ),
                id.bytesIntoLong( PeerGroupID.parentgroupIdOffset + 8 ) );
        
        PeerGroupID groupID = new PeerGroupID( groupUUID );
        
        // convert to the generic world PGID as necessary
        return (net.jxta.peergroup.PeerGroupID) IDFormat.translateToWellKnown( groupID );
    }
    
    /**
     *  Returns the UUID associated with this PeerGroupID.
     *
     *  @return The UUID associated with this PeerGroupID.
     **/
    protected UUID getUUID() {
        return new UUID( id.bytesIntoLong( PeerGroupID.groupIdOffset ),
                id.bytesIntoLong( PeerGroupID.groupIdOffset + 8 ) );
    }
}