com.hazelcast.org.apache.calcite.rel.hint.NodeTypeHintPredicate Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License, Version 2.0
* (the "License"); you may not use this file except in com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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.org.apache.calcite.rel.hint;
import com.hazelcast.org.apache.calcite.rel.RelNode;
import com.hazelcast.org.apache.calcite.rel.core.Aggregate;
import com.hazelcast.org.apache.calcite.rel.core.Calc;
import com.hazelcast.org.apache.calcite.rel.core.Join;
import com.hazelcast.org.apache.calcite.rel.core.Project;
import com.hazelcast.org.apache.calcite.rel.core.TableScan;
/**
* A hint predicate that specifies which kind of relational
* expression the hint can be applied to.
*/
public class NodeTypeHintPredicate implements HintPredicate {
/**
* Enumeration of the relational expression types that the hints
* may be propagated to.
*/
enum NodeType {
/**
* The hint is used for the whole query, kind of like a query config.
* This kind of hints would never be propagated.
*/
SET_VAR(RelNode.class),
/**
* The hint would be propagated to the Join nodes.
*/
JOIN(Join.class),
/**
* The hint would be propagated to the TableScan nodes.
*/
TABLE_SCAN(TableScan.class),
/**
* The hint would be propagated to the Project nodes.
*/
PROJECT(Project.class),
/**
* The hint would be propagated to the Aggregate nodes.
*/
AGGREGATE(Aggregate.class),
/**
* The hint would be propagated to the Calc nodes.
*/
CALC(Calc.class);
/** Relational expression clazz that the hint can apply to. */
private Class relClazz;
NodeType(Class relClazz) {
this.relClazz = relClazz;
}
}
private NodeType nodeType;
public NodeTypeHintPredicate(NodeType nodeType) {
this.nodeType = nodeType;
}
@Override public boolean apply(RelHint hint, RelNode rel) {
switch (this.nodeType) {
// Hints of SET_VAR type never propagate.
case SET_VAR:
return false;
default:
return this.nodeType.relClazz.isInstance(rel);
}
}
}