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.List;
024 import java.util.Map;
025 import java.util.Set;
026
027 import javax.jdo.PersistenceManager;
028
029 import org.cumulus4j.store.Cumulus4jStoreManager;
030 import org.cumulus4j.store.PersistenceManagerConnection;
031 import org.cumulus4j.store.model.ClassMeta;
032 import org.datanucleus.query.evaluator.JPQLEvaluator;
033 import org.datanucleus.query.evaluator.JavaQueryEvaluator;
034 import org.datanucleus.store.ExecutionContext;
035 import org.datanucleus.store.StoreManager;
036 import org.datanucleus.store.connection.ManagedConnection;
037 import org.datanucleus.store.query.AbstractJPQLQuery;
038 import org.datanucleus.util.NucleusLogger;
039
040 /**
041 * JPQL query implementation. Delegates to the query-language-agnostic {@link QueryEvaluator} via
042 * its thin wrapper sub-class {@link JDOQueryEvaluator}.
043 */
044 public class JPQLQuery extends AbstractJPQLQuery {
045
046 private static final long serialVersionUID = 1L;
047
048 // BEGIN DataNucleus 3.0.0-m6 and 3.0.0-release
049 // public JPQLQuery(ExecutionContext ec, AbstractJPQLQuery q) {
050 // super(ec, q);
051 // }
052 //
053 // public JPQLQuery(ExecutionContext ec, String query) {
054 // super(ec, query);
055 // }
056 //
057 // public JPQLQuery(ExecutionContext ec) {
058 // super(ec);
059 // }
060 // END DataNucleus 3.0.0-m6 and 3.0.0-release
061
062 // BEGIN DataNucleus 3.0.1 and newer
063 public JPQLQuery(StoreManager storeMgr, ExecutionContext ec, AbstractJPQLQuery q) {
064 super(storeMgr, ec, q);
065 }
066
067 public JPQLQuery(StoreManager storeMgr, ExecutionContext ec, String query) {
068 super(storeMgr, ec, query);
069 }
070
071 public JPQLQuery(StoreManager storeMgr, ExecutionContext ec) {
072 super(storeMgr, ec);
073 }
074 // END DataNucleus 3.0.1 and newer
075
076 @Override
077 protected Object performExecute(@SuppressWarnings("rawtypes") Map parameters) {
078 ManagedConnection mconn = ec.getStoreManager().getConnection(ec);
079 try {
080 PersistenceManagerConnection pmConn = (PersistenceManagerConnection)mconn.getConnection();
081 PersistenceManager pmData = pmConn.getDataPM();
082
083 boolean inMemory = evaluateInMemory();
084 boolean inMemory_applyFilter = true;
085 List<Object> candidates = null;
086 if (this.candidateCollection != null) {
087 if (candidateCollection.isEmpty()) {
088 return Collections.EMPTY_LIST;
089 }
090
091 @SuppressWarnings("unchecked")
092 Collection<? extends Object> c = this.candidateCollection;
093 candidates = new ArrayList<Object>(c);
094 }
095 else {
096 if (candidateExtent != null) {
097 this.setCandidateClass(candidateExtent.getCandidateClass());
098 this.setSubclasses(candidateExtent.hasSubclasses());
099 }
100
101 if (inMemory) {
102 // Retrieve all candidates and perform all evaluation in-memory
103 Set<ClassMeta> classMetas = QueryHelper.getCandidateClassMetas((Cumulus4jStoreManager) ec.getStoreManager(),
104 ec, candidateClass, subclasses);
105 candidates = QueryHelper.getAllPersistentObjectsForCandidateClasses(pmData, ec, classMetas);
106 }
107 else {
108 try
109 {
110 // Apply filter in datastore
111 @SuppressWarnings("unchecked")
112 Map<String, Object> parameterValues = parameters;
113 JDOQueryEvaluator queryEvaluator = new JDOQueryEvaluator(this, compilation, parameterValues, clr, pmConn);
114 candidates = queryEvaluator.execute();
115 if (queryEvaluator.isComplete()) {
116 inMemory_applyFilter = false;
117 }
118 else {
119 NucleusLogger.QUERY.debug("Query evaluation of filter in datastore was incomplete so doing further work in-memory");
120 }
121 }
122 catch (UnsupportedOperationException uoe) {
123 // Some part of the filter is not yet supported, so fallback to in-memory evaluation
124 // Retrieve all candidates and perform all evaluation in-memory
125 NucleusLogger.QUERY.info("Query filter is not totally evaluatable in-datastore using Cumulus4j currently, so evaluating in-memory : "+uoe.getMessage());
126 Set<ClassMeta> classMetas = QueryHelper.getCandidateClassMetas((Cumulus4jStoreManager) ec.getStoreManager(),
127 ec, candidateClass, subclasses);
128 candidates = QueryHelper.getAllPersistentObjectsForCandidateClasses(pmData, ec, classMetas);
129 }
130 }
131 }
132
133 // Evaluate any remaining query components in-memory
134 JavaQueryEvaluator evaluator = new JPQLEvaluator(this, candidates, compilation, parameters, ec.getClassLoaderResolver());
135 return evaluator.execute(inMemory_applyFilter, true, true, true, true);
136 } finally {
137 mconn.release();
138 }
139 }
140 }