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/* Copyright (C) 2004 - 2005  db4objects Inc.  http://www.db4o.com

This file is part of the db4o open source object database.

db4o is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */
package com.db4o;

import com.db4o.ext.*;
import com.db4o.inside.ix.*;

/**
 * 
 */
class YapFieldUUID extends YapFieldVirtual {
    
    private static final int LINK_LENGTH = YapConst.YAPLONG_LENGTH + YapConst.YAPID_LENGTH;

    YapFieldUUID(YapStream stream) {
        super();
        i_name = YapConst.VIRTUAL_FIELD_PREFIX + "uuid";
        i_handler = new YLong(stream);
    }
    
    void addFieldIndex(YapWriter a_writer, boolean a_new) {

        int offset = a_writer._offset;
        int id = a_writer.readInt();
        long uuid = YLong.readLong(a_writer);
        a_writer._offset = offset;
        
        YapFile yf = (YapFile)a_writer.getStream();
        
        if(id == 0){
            a_writer.writeInt(yf.identity().getID(a_writer.getTransaction()));
        }else{
            a_writer.incrementOffset(YapConst.YAPINT_LENGTH);
        }
        
        if(uuid == 0){
            uuid = yf.bootRecord().newUUID();
        }
        YLong.writeLong(uuid, a_writer);
        
        if(a_new){
            addIndexEntry(a_writer, new Long(uuid));
        }
    }
    
    void delete(YapWriter a_bytes, boolean isUpdate) {
        if(isUpdate){
            a_bytes.incrementOffset(linkLength());
            return;
        }
        a_bytes.incrementOffset(YapConst.YAPINT_LENGTH);
        long longPart = YLong.readLong(a_bytes);
        if(longPart > 0){
            YapStream stream = a_bytes.getStream();
            if (stream.maintainsIndices()){
                removeIndexEntry(a_bytes.getTransaction(), a_bytes.getID(), new Long(longPart));
            }
        }
    }
    
    Index4 getIndex(Transaction a_trans){
        YapFile stream = (YapFile)a_trans.i_stream;
        if(i_index == null){
            i_index = new Index4(stream.getSystemTransaction(), getHandler(), stream.bootRecord().getUUIDMetaIndex(), false);
        }
        return i_index;
    }
    
    void instantiate1(Transaction a_trans, YapObject a_yapObject, YapReader a_bytes) {
        int dbID = a_bytes.readInt();
        YapStream stream = a_trans.i_stream;
        stream.showInternalClasses(true);
        Db4oDatabase db = (Db4oDatabase)stream.getByID2(a_trans, dbID);
        if(db != null && db.i_signature == null){
            stream.activate2(a_trans, db, 2);
        }
        a_yapObject.i_virtualAttributes.i_database = db; 
        a_yapObject.i_virtualAttributes.i_uuid = YLong.readLong(a_bytes);
        stream.showInternalClasses(false);
    }

    public int linkLength() {
        return LINK_LENGTH;
    }
    
    void marshall1(YapObject a_yapObject, YapWriter a_bytes, boolean a_migrating, boolean a_new) {
        YapStream stream = a_bytes.getStream();
        Transaction trans = a_bytes.getTransaction();
        boolean indexEntry = a_new && stream.maintainsIndices();
        int dbID = 0;
		VirtualAttributes attr = a_yapObject.i_virtualAttributes;
		
		boolean linkToDatabase = ! a_migrating;
		if(attr != null && attr.i_database == null) {
			linkToDatabase = true;
		}
        if(linkToDatabase){
            Db4oDatabase db = stream.identity();
            if(db == null){
                // can happen on early classes like Metaxxx, no problem
                attr = null;
            }else{
    	        if (attr.i_database == null) {
    	            attr.i_database = db;
    	            if (stream instanceof YapFile){
                        PBootRecord br = stream.bootRecord();
                        if(br != null){
        					attr.i_uuid = br.newUUID();
        	                indexEntry = true;
                        }
    	            }
    	        }
    	        db = attr.i_database;
    	        if(db != null) {
    	            dbID = db.getID(trans);
    	        }
            }
        }else{
            if(attr != null){
                dbID = attr.i_database.getID(trans);
            }
        }
        a_bytes.writeInt(dbID);
        if(attr != null){
	        YLong.writeLong(attr.i_uuid, a_bytes);
	        if(indexEntry){
	            addIndexEntry(a_bytes, new Long(attr.i_uuid));
	        }
        }else{
            YLong.writeLong(0, a_bytes);
        }
    }
    
    void marshallIgnore(YapWriter writer) {
        writer.writeInt(0);
        YLong.writeLong(0, writer);
    }
 

}