SingleStrategyEnumerationImpl.java

/**
 * Copyright (c) 2006-2011 Floggy Open Source Group. All rights reserved.
 *
 * 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 net.sourceforge.floggy.persistence.impl.migration;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;

import java.util.Hashtable;
import java.util.Vector;

import javax.microedition.rms.RecordEnumeration;
import javax.microedition.rms.RecordStore;
import javax.microedition.rms.RecordStoreException;

import net.sourceforge.floggy.persistence.FloggyException;
import net.sourceforge.floggy.persistence.impl.PersistableMetadata;
import net.sourceforge.floggy.persistence.impl.PersistableMetadataManager;
import net.sourceforge.floggy.persistence.impl.RecordStoreManager;
import net.sourceforge.floggy.persistence.impl.Utils;

/**
 * DOCUMENT ME!
 *
 * @author <a href="mailto:thiago.moreira@floggy.org">Thiago Moreira</a>
 * @version $Revision$
  */
public class SingleStrategyEnumerationImpl extends AbstractEnumerationImpl {
	/**
	 * DOCUMENT ME!
	 */
	protected Vector datas;

	/**
	 * DOCUMENT ME!
	 */
	protected Vector ids;

	/**
	 * DOCUMENT ME!
	 */
	protected int currentIndex = 0;

	/**
	 * Creates a new SingleStrategyEnumerationImpl object.
	 *
	 * @param rmsBasedMetadata DOCUMENT ME!
	 * @param classBasedMetadata DOCUMENT ME!
	 * @param enumeration DOCUMENT ME!
	 * @param recordStore DOCUMENT ME!
	 * @param lazy DOCUMENT ME!
	 * @param iterationMode DOCUMENT ME!
	 *
	 * @throws IOException DOCUMENT ME!
	 * @throws RecordStoreException DOCUMENT ME!
	 */
	public SingleStrategyEnumerationImpl(PersistableMetadata rmsBasedMetadata,
		PersistableMetadata classBasedMetadata, RecordEnumeration enumeration,
		RecordStore recordStore, boolean lazy, boolean iterationMode)
		throws IOException, RecordStoreException {
		super(rmsBasedMetadata, classBasedMetadata, enumeration, recordStore, lazy,
			iterationMode);

		datas = new Vector(enumeration.numRecords());
		ids = new Vector(datas.size());

		while (enumeration.hasNextElement()) {
			int id = enumeration.nextRecordId();
			byte[] data = recordStore.getRecord(id);
			String className = Utils.readUTF8(data);

			if (className.equals(rmsBasedMetadata.getClassName())) {
				ids.addElement(new Integer(id));
				datas.addElement(data);
			}
		}
	}

	/**
	 * DOCUMENT ME!
	*
	* @return DOCUMENT ME!
	*/
	public int getSize() {
		return datas.size();
	}

	/**
	 * DOCUMENT ME!
	*
	* @return DOCUMENT ME!
	*/
	public boolean hasMoreElements() {
		return currentIndex < getSize();
	}

	/**
	 * DOCUMENT ME!
	*
	* @return DOCUMENT ME!
	*
	* @throws FloggyException DOCUMENT ME!
	*/
	public Hashtable nextElement() throws FloggyException {
		if ((recordId != -1) && !iterationMode) {
			throw new FloggyException(
				"You should delete or update the current register before step into the next one.");
		}

		Hashtable hashtable = new HashtableValueNullable();

		try {
			byte[] data = (byte[]) datas.elementAt(currentIndex);
			recordId = ((Integer) ids.elementAt(currentIndex)).intValue();

			buildPersistable(rmsBasedMetadata, data, hashtable);

			currentIndex++;
		} catch (Exception ex) {
			throw Utils.handleException(ex);
		}

		return hashtable;
	}

	/**
	 * DOCUMENT ME!
	*
	* @param rmsBasedMetadata DOCUMENT ME!
	* @param data DOCUMENT ME!
	* @param hashtable DOCUMENT ME!
	*
	* @throws Exception DOCUMENT ME!
	*/
	protected void buildPersistable(PersistableMetadata rmsBasedMetadata,
		byte[] data, Hashtable hashtable) throws Exception {
		String[] fieldNames = rmsBasedMetadata.getFieldNames();
		int[] fieldTypes = rmsBasedMetadata.getFieldTypes();

		if (data != null) {
			DataInputStream dis = new DataInputStream(new ByteArrayInputStream(data));

			dis.readUTF();

			for (int i = 0; i < fieldNames.length; i++) {
				int type = fieldTypes[i];

				if (lazy) {
					if (((type & PersistableMetadata.PERSISTABLE) != PersistableMetadata.PERSISTABLE)) {
						Object object;

						if ((type & PersistableMetadata.ARRAY) == PersistableMetadata.ARRAY) {
							type = type & ~PersistableMetadata.ARRAY;
							object = readArray(type, fieldNames[i], dis);
						} else if ((type & PersistableMetadata.PRIMITIVE) == PersistableMetadata.PRIMITIVE) {
							type = type & ~PersistableMetadata.PRIMITIVE;
							object = readPrimitive(type, dis);
						} else {
							object = readObject(type, fieldNames[i], dis);
						}

						hashtable.put(fieldNames[i], object);
					}
				} else {
					Object object;

					if ((type & PersistableMetadata.ARRAY) == PersistableMetadata.ARRAY) {
						type = type & ~PersistableMetadata.ARRAY;
						object = readArray(type, fieldNames[i], dis);
					} else if ((type & PersistableMetadata.PRIMITIVE) == PersistableMetadata.PRIMITIVE) {
						type = type & ~PersistableMetadata.PRIMITIVE;
						object = readPrimitive(type, dis);
					} else {
						object = readObject(type, fieldNames[i], dis);
					}

					hashtable.put(fieldNames[i], object);
				}
			}
		}
	}

	/**
	 * DOCUMENT ME!
	*
	* @throws FloggyException DOCUMENT ME!
	*/
	void finish() throws FloggyException {
		if (!enumeration.hasNextElement()) {
			enumeration.destroy();
			RecordStoreManager.closeRecordStore(recordStore);

			if (rmsBasedMetadata != classBasedMetadata) {
				try {
					classBasedMetadata.setRecordId(rmsBasedMetadata.getRecordId());
					PersistableMetadataManager.saveRMSStructure(classBasedMetadata);
				} catch (Exception ex) {
					throw Utils.handleException(ex);
				}
			}
		} else {
			throw new FloggyException(
				"The enumeration must be whole processed before finish the process!");
		}
	}
}