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.method;
019
020 import java.util.Collection;
021 import java.util.HashMap;
022 import java.util.HashSet;
023 import java.util.Map;
024 import java.util.Set;
025
026 import javax.jdo.Query;
027
028 import org.cumulus4j.store.crypto.CryptoContext;
029 import org.cumulus4j.store.model.ClassMeta;
030 import org.cumulus4j.store.model.FieldMeta;
031 import org.cumulus4j.store.model.IndexEntry;
032 import org.cumulus4j.store.model.IndexEntryFactory;
033 import org.cumulus4j.store.model.IndexValue;
034 import org.cumulus4j.store.query.QueryEvaluator;
035 import org.cumulus4j.store.query.eval.ExpressionHelper;
036 import org.cumulus4j.store.query.eval.InvokeExpressionEvaluator;
037 import org.cumulus4j.store.query.eval.PrimaryExpressionResolver;
038 import org.cumulus4j.store.query.eval.ResultDescriptor;
039 import org.datanucleus.query.expression.Expression;
040 import org.datanucleus.query.expression.PrimaryExpression;
041 import org.datanucleus.store.ExecutionContext;
042
043 /**
044 * Evaluator for "String.length(str) {oper} {compareTo}".
045 */
046 public class StringLengthEvaluator extends AbstractMethodEvaluator {
047
048 /* (non-Javadoc)
049 * @see org.cumulus4j.store.query.method.AbstractMethodEvaluator#requiresComparisonArgument()
050 */
051 @Override
052 public boolean requiresComparisonArgument() {
053 return true;
054 }
055
056 /* (non-Javadoc)
057 * @see org.cumulus4j.store.query.method.MethodEvaluator#evaluate(org.cumulus4j.store.query.QueryEvaluator, org.cumulus4j.store.query.eval.InvokeExpressionEvaluator, org.datanucleus.query.expression.Expression, org.cumulus4j.store.query.eval.ResultDescriptor)
058 */
059 @Override
060 public Set<Long> evaluate(QueryEvaluator queryEval,
061 InvokeExpressionEvaluator invokeExprEval, Expression invokedExpr,
062 ResultDescriptor resultDesc) {
063 if (invokeExprEval.getExpression().getArguments().size() != 0)
064 throw new IllegalStateException("String.length() expects no arguments, but there are " +
065 invokeExprEval.getExpression().getArguments().size());
066
067 if (invokedExpr instanceof PrimaryExpression) {
068 return new MethodResolver(invokeExprEval, queryEval, (PrimaryExpression) invokedExpr,
069 compareToArgument, resultDesc.isNegated()).query();
070 }
071 else {
072 if (!invokeExprEval.getLeft().getResultSymbols().contains(resultDesc.getSymbol()))
073 return null;
074
075 return queryEvaluate(invokeExprEval, queryEval, resultDesc.getFieldMeta(),
076 compareToArgument, resultDesc.isNegated());
077 }
078 }
079
080 private Set<Long> queryEvaluate(
081 InvokeExpressionEvaluator invokeExprEval,
082 QueryEvaluator queryEval,
083 FieldMeta fieldMeta,
084 Object compareToArgument, // the yyy in 'length() >= yyy'
085 boolean negate
086 ) {
087 CryptoContext cryptoContext = queryEval.getCryptoContext();
088 ExecutionContext executionContext = queryEval.getExecutionContext();
089 IndexEntryFactory indexEntryFactory = queryEval.getStoreManager().getIndexFactoryRegistry().getIndexEntryFactory(
090 executionContext, fieldMeta, true
091 );
092
093 Query q = queryEval.getPersistenceManagerForIndex().newQuery(indexEntryFactory.getIndexEntryClass());
094 q.setFilter(
095 "this.keyStoreRefID == :keyStoreRefID && this.fieldMeta == :fieldMeta && " +
096 "this.indexKey.length() " +
097 ExpressionHelper.getOperatorAsJDOQLSymbol(invokeExprEval.getParent().getExpression().getOperator(), negate) +
098 " :compareToArgument"
099 );
100 Map<String, Object> params = new HashMap<String, Object>(2);
101 params.put("keyStoreRefID", cryptoContext.getKeyStoreRefID());
102 params.put("fieldMeta", fieldMeta);
103 params.put("compareToArgument", compareToArgument);
104
105 @SuppressWarnings("unchecked")
106 Collection<? extends IndexEntry> indexEntries = (Collection<? extends IndexEntry>) q.executeWithMap(params);
107
108 Set<Long> result = new HashSet<Long>();
109 for (IndexEntry indexEntry : indexEntries) {
110 IndexValue indexValue = queryEval.getEncryptionHandler().decryptIndexEntry(cryptoContext, indexEntry);
111 result.addAll(indexValue.getDataEntryIDs());
112 }
113 q.closeAll();
114 return result;
115 }
116
117 private class MethodResolver extends PrimaryExpressionResolver
118 {
119 private InvokeExpressionEvaluator invokeExprEval;
120 private Object compareToArgument;
121 private boolean negate;
122
123 public MethodResolver(
124 InvokeExpressionEvaluator invokeExprEval,
125 QueryEvaluator queryEvaluator, PrimaryExpression primaryExpression,
126 Object compareToArgument, // the yyy in 'length() >= yyy'
127 boolean negate
128 )
129 {
130 super(queryEvaluator, primaryExpression);
131 this.invokeExprEval = invokeExprEval;
132 this.compareToArgument = compareToArgument;
133 this.negate = negate;
134 }
135
136 @Override
137 protected Set<Long> queryEnd(FieldMeta fieldMeta, ClassMeta classMeta) {
138 return queryEvaluate(invokeExprEval, queryEvaluator, fieldMeta, compareToArgument, negate);
139 }
140 }
141 }