codatid.java

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

/*
 *
 * $Id: CodatID.java,v 1.17 2005/12/07 04:42:33 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 java.io.InputStream;
import java.security.MessageDigest;

import java.io.IOException;
import java.security.ProviderException;
import java.security.NoSuchAlgorithmException;

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

/**
 *  An implementation of the {@link net.jxta.codat.CodatID} ID Type.
 **/
public class CodatID extends net.jxta.codat.CodatID {
    
    /**
     *  Log4J Logger
     **/
    private static final transient Logger LOG = Logger.getLogger( CodatID.class.getName());
    
    /**
     * size of a SHA1 hash. I would use MessageDigest.getDigestLength, but
     * possible exceptions make it difficult to do.
     */
    protected final static int hashSize = 20;
    
    /**
     *  Location of the group id in the byte array.
     **/
    protected final static int groupIdOffset = 0;
    
    /**
     *  Location of the randomly chosen portion of the id within the byte array.
     **/
    protected final static int idOffset = CodatID.groupIdOffset + IDFormat.uuidSize;
    
    /**
     *  Location of the hash value portion of the id within the byte array.
     **/
    protected final static int codatHashOffset = CodatID.idOffset + IDFormat.uuidSize;
    
    /**
     *  Location of the begining of pad (unused space) within the byte array.
     **/
    protected final static int padOffset = CodatID.codatHashOffset + CodatID.hashSize;
    
    /**
     * Size of the pad.
     **/
    protected final static int padSize = IDFormat.flagsOffset - CodatID.padOffset;
    
    /**
     *  The id data
     **/
    protected IDBytes id;
    
    /**
     * Internal constructor
     **/
    protected CodatID() {
        super();
        id = new IDBytes();
        id.bytes[IDFormat.flagsOffset + IDFormat.flagsIdTypeOffset] = IDFormat.flagCodatID;
    }
    
    /**
     * Intializes contents from provided bytes.
     *
     * @param id    the ID data
     **/
    protected CodatID( IDBytes id ) {
        super();
        this.id = id;
    }
    
    
    protected CodatID( UUID groupUUID, UUID idUUID ) {
        this();
        
        id.longIntoBytes( CodatID.groupIdOffset, groupUUID.getMostSignificantBits() );
        id.longIntoBytes( CodatID.groupIdOffset + 8, groupUUID.getLeastSignificantBits() );
        
        id.longIntoBytes( CodatID.idOffset, idUUID.getMostSignificantBits() );
        id.longIntoBytes( CodatID.idOffset + 8, idUUID.getLeastSignificantBits() );
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newCodatID(net.jxta.peergroup.PeerGroupID)}.
     **/
    public CodatID( PeerGroupID groupID ) {
        this( groupID.getUUID(), UUIDFactory.newUUID() );
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newCodatID(net.jxta.peergroup.PeerGroupID,byte[])}.
     **/
    public CodatID( PeerGroupID groupID, byte [] seed ) {
        this( );
        
        UUID groupUUID = groupID.getUUID();
        
        id.longIntoBytes( CodatID.groupIdOffset, groupUUID.getMostSignificantBits() );
        id.longIntoBytes( CodatID.groupIdOffset + 8, groupUUID.getLeastSignificantBits() );
        
        System.arraycopy( seed, 0, id.bytes, CodatID.idOffset, Math.min( IDFormat.uuidSize, seed.length ) );
        
        // make it a valid UUID
        id.bytes[CodatID.idOffset + 6] &= 0x0f;
        id.bytes[CodatID.idOffset + 6] |= 0x40; /* version 4 */
        id.bytes[CodatID.idOffset + 8] &= 0x3f;
        id.bytes[CodatID.idOffset + 8] |= 0x80; /* IETF variant */
        id.bytes[CodatID.idOffset + 10] &= 0x3f;
        id.bytes[CodatID.idOffset + 10] |= 0x80; /* multicast bit */
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newCodatID(net.jxta.peergroup.PeerGroupID,InputStream)}.
     **/
    public CodatID( PeerGroupID groupID, InputStream in ) throws IOException {
        this( groupID );
        
        setHash( in );
    }
    
    /**
     *  See {@link net.jxta.id.IDFactory.Instantiator#newCodatID(net.jxta.peergroup.PeerGroupID,InputStream)}.
     **/
    public CodatID( PeerGroupID groupID, byte [] seed, InputStream in ) throws IOException {
        this( groupID, seed );
        
        setHash( in );
    }
    
    /**
     *  {@inheritDoc}
     **/
    public boolean equals( Object target ) {
        if (this == target) {
            return true;
        }
        
        if (target instanceof CodatID ) {
            CodatID codatTarget = (CodatID)target;
            
            if( !getIDFormat().equals( codatTarget.getIDFormat() ) ) {
                return false;
            }
            
            if( id == codatTarget.id ) {
                return true;
            }
            
            boolean result = id.equals( codatTarget.id );
            
            // if true then we can have the two ids share the id bytes
            if( result ) {
                codatTarget.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.id.ID getPeerGroupID() {
        UUID groupUUID = new UUID(
                id.bytesIntoLong( CodatID.groupIdOffset ),
                id.bytesIntoLong( CodatID.groupIdOffset + 8 ) );
        
        PeerGroupID groupID = new PeerGroupID( groupUUID );
        
        // convert to the generic world PGID as necessary
        return IDFormat.translateToWellKnown( groupID );
    }
    
    /**
     *  {@inheritDoc}
     **/
    public boolean isStatic() {
        for( int eachHashByte = CodatID.codatHashOffset; eachHashByte < (CodatID.padOffset); eachHashByte++ ) {
            if( 0 != id.bytes[eachHashByte] ) {
                return true;
            }
        }
        
        return false;
    }
    
    /**
     *  Calculates the SHA-1 hash of a stream.
     *
     *  @param in The InputStream.
     **/
    protected void setHash( InputStream in ) throws IOException {
        MessageDigest dig = null;
        try {
            dig = MessageDigest.getInstance( "SHA-1" );
        } catch( NoSuchAlgorithmException caught ) {
            dig = null;
        }
        
        if (dig == null) {
            throw new ProviderException("SHA-1 digest algorithm not found");
        }
        
        dig.reset();
        
        byte [] chunk = new byte[1024];
        
        try {
            do {
                int read = in.read(chunk);
                if( read == -1 ) {
                    break;
                }
                
                dig.update( chunk, 0, read );
            } while( true );
        } finally {
            in.close();
        }
        
        byte [] result = dig.digest( );
        System.arraycopy( result, 0, id.bytes, CodatID.codatHashOffset, CodatID.hashSize );
    }
}