001 /*
002 * Cumulus4j - Securing your data in the cloud - http://cumulus4j.org
003 * Copyright (C) 2011 NightLabs Consulting GmbH
004 *
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program. If not, see <http://www.gnu.org/licenses/>.
017 */
018 package org.cumulus4j.store;
019
020 import java.util.Properties;
021
022 import javax.jdo.PersistenceManager;
023
024 import org.cumulus4j.store.Cumulus4jConnectionFactory.Cumulus4jManagedConnection;
025 import org.cumulus4j.store.crypto.CryptoContext;
026 import org.cumulus4j.store.model.Sequence2;
027 import org.cumulus4j.store.model.Sequence2DAO;
028 import org.datanucleus.store.ExecutionContext;
029 import org.datanucleus.store.valuegenerator.AbstractDatastoreGenerator;
030 import org.datanucleus.store.valuegenerator.ValueGenerationBlock;
031 import org.datanucleus.store.valuegenerator.ValueGenerator;
032
033 /**
034 * {@link ValueGenerator} implementation generating values by incrementing a counter.
035 * @author Marco หงุ่ยตระกูล-Schulze - marco at nightlabs dot de
036 */
037 public class Cumulus4jIncrementGenerator extends AbstractDatastoreGenerator
038 {
039 private String sequenceName;
040
041 /**
042 * Create an instance. This is called by DataNucleus.
043 * @param name symbolic name for the generator.
044 * @param props Properties controlling the behaviour of the generator.
045 */
046 public Cumulus4jIncrementGenerator(String name, Properties props) {
047 super(name, props);
048 allocationSize = 5;
049
050 // TODO Check these names and what we want to use for Cumulus4j (classname or fieldname)
051 if (properties.getProperty("sequence-name") != null) {
052 // Specified sequence-name so use that
053 sequenceName = properties.getProperty("sequence-name");
054 }
055 else if (properties.getProperty("field-name") != null) {
056 // Use field name as the sequence name so we have one sequence per field on the class
057 sequenceName = properties.getProperty("field-name");
058 }
059 else {
060 // Use actual class name as the sequence name so we have one sequence per class
061 sequenceName = properties.getProperty("class-name");
062 }
063 }
064
065 @Override
066 protected ValueGenerationBlock reserveBlock(long size) {
067 if (size > Integer.MAX_VALUE)
068 throw new IllegalStateException("Cannot reserve a block of more than " + Integer.MAX_VALUE + " values!");
069
070 Long[] values = new Long[(int)size];
071 Cumulus4jManagedConnection mconn = (Cumulus4jManagedConnection) connectionProvider.retrieveConnection();
072 try {
073 PersistenceManagerConnection pmConn = (PersistenceManagerConnection)mconn.getConnection();
074 PersistenceManager pm = pmConn.getDataPM();
075 Cumulus4jStoreManager storeManager = (Cumulus4jStoreManager) storeMgr;
076
077 CryptoContext cryptoContext = new CryptoContext(
078 storeManager.getEncryptionCoordinateSetManager(),
079 storeManager.getKeyStoreRefManager(),
080 (ExecutionContext) mconn.getPoolKey(), // TODO find a better way! That this is the ExecutionContext is nowhere documented, but it works and unfortunately it is the only way to obtain it I found :-(
081 pmConn
082 );
083 storeManager.getDatastoreVersionManager().applyOnce(cryptoContext);
084
085 pm.currentTransaction().setSerializeRead(true);
086 try {
087 Sequence2 sequence = new Sequence2DAO(pm, cryptoContext.getKeyStoreRefID()).createSequence2(sequenceName);
088 long nextValue = sequence.getNextValue();
089 for (int idx = 0; idx < values.length; ++idx) {
090 values[idx] = nextValue++;
091 }
092 sequence.setNextValue(nextValue);
093 } finally {
094 pm.currentTransaction().setSerializeRead(false);
095 }
096 } finally {
097 connectionProvider.releaseConnection();
098 }
099 return new ValueGenerationBlock(values);
100 }
101 }