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.FieldMeta;
030 import org.cumulus4j.store.model.IndexEntry;
031 import org.cumulus4j.store.model.IndexEntryFactory;
032 import org.cumulus4j.store.model.IndexValue;
033 import org.cumulus4j.store.query.QueryEvaluator;
034 import org.cumulus4j.store.query.eval.ExpressionHelper;
035 import org.cumulus4j.store.query.eval.InvokeExpressionEvaluator;
036 import org.cumulus4j.store.query.eval.PrimaryExpressionResolver;
037 import org.cumulus4j.store.query.eval.ResultDescriptor;
038 import org.datanucleus.query.expression.Expression;
039 import org.datanucleus.query.expression.PrimaryExpression;
040 import org.datanucleus.store.ExecutionContext;
041
042 /**
043 * Evaluator for "{String}.equals(arg)".
044 */
045 public class StringEqualsEvaluator extends AbstractMethodEvaluator
046 {
047 /* (non-Javadoc)
048 * @see org.cumulus4j.store.query.method.MethodEvaluator#evaluate(org.cumulus4j.store.query.QueryEvaluator, org.datanucleus.query.expression.InvokeExpression, org.datanucleus.query.expression.Expression, org.cumulus4j.store.query.eval.ResultDescriptor)
049 */
050 @Override
051 public Set<Long> evaluate(QueryEvaluator queryEval, InvokeExpressionEvaluator invokeExprEval,
052 Expression invokedExpr, ResultDescriptor resultDesc) {
053 if (invokeExprEval.getExpression().getArguments().size() != 1)
054 throw new IllegalStateException("{String}.equals(...) expects exactly one argument, but there are " +
055 invokeExprEval.getExpression().getArguments().size());
056
057 // Evaluate the invoke argument
058 Object invokeArgument = ExpressionHelper.getEvaluatedInvokeArgument(queryEval, invokeExprEval.getExpression());
059
060 if (invokedExpr instanceof PrimaryExpression) {
061 return new MethodResolver(queryEval, (PrimaryExpression) invokedExpr, invokeArgument, resultDesc.isNegated()).query();
062 }
063 else {
064 if (!invokeExprEval.getLeft().getResultSymbols().contains(resultDesc.getSymbol()))
065 return null;
066 return queryEvaluate(queryEval, resultDesc.getFieldMeta(), invokeArgument, resultDesc.isNegated());
067 }
068 }
069
070 private Set<Long> queryEvaluate(
071 QueryEvaluator queryEval,
072 FieldMeta fieldMeta,
073 Object invokeArgument, // the xxx in 'equals(xxx)'
074 boolean negate
075 ) {
076 CryptoContext cryptoContext = queryEval.getCryptoContext();
077 ExecutionContext executionContext = queryEval.getExecutionContext();
078 IndexEntryFactory indexEntryFactory = queryEval.getStoreManager().getIndexFactoryRegistry().getIndexEntryFactory(
079 executionContext, fieldMeta, true
080 );
081
082 Query q = queryEval.getPersistenceManagerForIndex().newQuery(indexEntryFactory.getIndexEntryClass());
083 q.setFilter(
084 "this.fieldMeta == :fieldMeta && " +
085 (negate ? "!this.indexKey == :invokeArg" : "this.indexKey == :invokeArg")
086 );
087 Map<String, Object> params = new HashMap<String, Object>(3);
088 params.put("fieldMeta", fieldMeta);
089 params.put("invokeArg", invokeArgument);
090
091 @SuppressWarnings("unchecked")
092 Collection<? extends IndexEntry> indexEntries = (Collection<? extends IndexEntry>) q.executeWithMap(params);
093
094 Set<Long> result = new HashSet<Long>();
095 for (IndexEntry indexEntry : indexEntries) {
096 IndexValue indexValue = queryEval.getEncryptionHandler().decryptIndexEntry(cryptoContext, indexEntry);
097 result.addAll(indexValue.getDataEntryIDs());
098 }
099 q.closeAll();
100 return result;
101 }
102
103 private class MethodResolver extends PrimaryExpressionResolver
104 {
105 private Object invokeArgument;
106 private boolean negate;
107
108 public MethodResolver(
109 QueryEvaluator queryEvaluator, PrimaryExpression primaryExpression,
110 Object invokeArgument, // the xxx in 'equals(xxx)'
111 boolean negate
112 )
113 {
114 super(queryEvaluator, primaryExpression);
115 this.invokeArgument = invokeArgument;
116 this.negate = negate;
117 }
118
119 @Override
120 protected Set<Long> queryEnd(FieldMeta fieldMeta) {
121 return queryEvaluate(queryEvaluator, fieldMeta, invokeArgument, negate);
122 }
123 }
124 }