com.hazelcast.query.impl.predicates.VisitorUtils Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2016, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.query.impl.predicates;
import com.hazelcast.query.Predicate;
import com.hazelcast.query.VisitablePredicate;
import com.hazelcast.query.impl.Indexes;
import static com.hazelcast.util.collection.ArrayUtils.createCopy;
public final class VisitorUtils {
private VisitorUtils() {
}
/**
* Accept visitor by all predicates. It treats the input array as immutable.
*
* It's Copy-On-Write: If at least one predicate returns a different instance
* then this method returns a copy of the passed arrays.
*
* @param predicates
* @param visitor
* @return
*/
public static Predicate[] acceptVisitor(Predicate[] predicates, Visitor visitor, Indexes indexes) {
Predicate[] target = predicates;
boolean copyCreated = false;
for (int i = 0; i < predicates.length; i++) {
Predicate predicate = predicates[i];
if (predicate instanceof VisitablePredicate) {
Predicate transformed = ((VisitablePredicate) predicate).accept(visitor, indexes);
if (transformed != predicate) {
if (!copyCreated) {
copyCreated = true;
target = createCopy(target);
}
target[i] = transformed;
}
}
}
return target;
}
}