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.query;
019
020 import java.util.ArrayList;
021 import java.util.Collection;
022 import java.util.Collections;
023 import java.util.HashMap;
024 import java.util.HashSet;
025 import java.util.List;
026 import java.util.Map;
027 import java.util.Set;
028
029 import javax.jdo.PersistenceManager;
030
031 import org.cumulus4j.store.Cumulus4jStoreManager;
032 import org.cumulus4j.store.crypto.CryptoContext;
033 import org.cumulus4j.store.model.ClassMeta;
034 import org.cumulus4j.store.model.ClassMetaDAO;
035 import org.cumulus4j.store.model.DataEntry;
036 import org.datanucleus.ClassLoaderResolver;
037 import org.datanucleus.ExecutionContext;
038 import org.datanucleus.identity.IdentityUtils;
039
040 /**
041 * Helper methods for querying.
042 */
043 public class QueryHelper {
044
045 /**
046 * Access the data entry ids for a candidate.
047 * @param cryptoContext the crypto-context (containing the {@link ExecutionContext} and other context data + API).
048 * @param pmData PersistenceManager for the backend data
049 * @param candidateCls Candidate class
050 * @param subclasses Whether to include subclasses
051 * @return The data entry ids
052 */
053 public static Set<Long> getAllDataEntryIdsForCandidate(CryptoContext cryptoContext, PersistenceManager pmData, Class<?> candidateCls, boolean subclasses) {
054 ExecutionContext ec = cryptoContext.getExecutionContext();
055 javax.jdo.Query q = pmData.newQuery(DataEntry.class);
056 q.setResult("this.dataEntryID");
057
058 Object queryParam_classMeta;
059 Set<ClassMeta> classMetas = QueryHelper.getCandidateClassMetas(
060 (Cumulus4jStoreManager) ec.getStoreManager(), ec, candidateCls, subclasses
061 );
062 StringBuilder filter = new StringBuilder();
063 filter.append("this.keyStoreRefID == :keyStoreRefID && ");
064 if (classMetas.size() == 1) {
065 filter.append("this.classMeta == :classMeta");
066 queryParam_classMeta = classMetas.iterator().next();
067 }
068 else {
069 filter.append(":classMetas.contains(this.classMeta)");
070 queryParam_classMeta = classMetas;
071 }
072 q.setFilter(filter.toString());
073
074 @SuppressWarnings("unchecked")
075 Collection<Object[]> c = (Collection<Object[]>) q.execute(cryptoContext.getKeyStoreRefID(), queryParam_classMeta);
076 Set<Long> resultList = new HashSet<Long>(c.size());
077 for (Object[] oa : c) {
078 resultList.add((Long)oa[0]);
079 }
080 q.closeAll();
081 return resultList;
082 }
083
084 /**
085 * Convenience method to return the persistent objects for the classes with the provided ClassMetas.
086 * @param cryptoContext the crypto-context (containing the {@link ExecutionContext} and other context data + API).
087 * @param pmData PersistenceManager for the backend data
088 * @param candidateClassMetas The class metas defining the required classes
089 * @return The persistent objects
090 */
091 public static List<Object> getAllPersistentObjectsForCandidateClasses(CryptoContext cryptoContext, PersistenceManager pmData,
092 Set<ClassMeta> candidateClassMetas)
093 {
094 ExecutionContext ec = cryptoContext.getExecutionContext();
095 Cumulus4jStoreManager storeManager = (Cumulus4jStoreManager) ec.getStoreManager();
096
097 javax.jdo.Query q = pmData.newQuery(DataEntry.class);
098 q.setResult("this.classMeta_classID, this.objectID");
099
100 Map<String, Object> queryParams = new HashMap<String, Object>();
101 StringBuilder filter = new StringBuilder();
102
103 filter.append("this.keyStoreRefID == :keyStoreRefID && ");
104 queryParams.put("keyStoreRefID", cryptoContext.getKeyStoreRefID());
105
106 filter.append(ClassMetaDAO.getMultiClassMetaOrFilterPart(queryParams, candidateClassMetas));
107
108 q.setFilter(filter.toString());
109
110 @SuppressWarnings("unchecked")
111 Collection<Object[]> c = (Collection<Object[]>) q.executeWithMap(queryParams);
112 List<Object> resultList = new ArrayList<Object>(c.size());
113 for (Object[] oa : c) {
114 Long classID = (Long) oa[0];
115 if (classID == null)
116 throw new IllegalStateException("Query returned classMeta_classID == null!");
117
118 ClassMeta classMeta = storeManager.getClassMeta(ec, classID, true);
119 String objectIDString = (String) oa[1];
120 Object obj = IdentityUtils.getObjectFromIdString(objectIDString, classMeta.getDataNucleusClassMetaData(ec), ec, true);
121 resultList.add(obj);
122 }
123 q.closeAll();
124 return resultList;
125 }
126
127 /**
128 * Convenience method to return the ClassMeta objects for the specified class (and subclasses if required).
129 * @param storeMgr Cumulus4J StoreManager
130 * @param ec ExecutionContext
131 * @param candidateClass The class required
132 * @param withSubclasses Whether to return subclasses too
133 * @return The ClassMeta objects
134 */
135 public static Set<ClassMeta> getCandidateClassMetas(Cumulus4jStoreManager storeMgr, ExecutionContext ec,
136 Class<?> candidateClass, boolean withSubclasses)
137 {
138 Set<? extends Class<?>> candidateClasses;
139 if (withSubclasses) {
140 ClassLoaderResolver clr = ec.getClassLoaderResolver();
141 Collection<String> classNames = storeMgr.getSubClassesForClass(candidateClass.getName(), true, clr);
142 Set<Class<?>> classes = new HashSet<Class<?>>(classNames.size() + 1);
143 classes.add(candidateClass);
144 for (String className : classNames) {
145 Class<?> clazz = clr.classForName(className);
146 classes.add(clazz);
147 }
148 candidateClasses = classes;
149 }
150 else
151 candidateClasses = Collections.singleton(candidateClass);
152
153 Set<ClassMeta> candidateClassMetas = new HashSet<ClassMeta>(candidateClasses.size());
154 for (Class<?> c : candidateClasses) {
155 ClassMeta cm = storeMgr.getClassMeta(ec, c);
156 candidateClassMetas.add(cm);
157 }
158
159 return candidateClassMetas;
160 }
161 }