/*
// 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 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 org.eigenbase.rex;
import java.io.IOException;
import java.io.Serializable;
import java.io.StringReader;
import java.util.Arrays;
import java.util.List;
import org.eigenbase.util.Pair;
import net.hydromatic.linq4j.function.Function1;
import net.hydromatic.optiq.DataContext;
import net.hydromatic.optiq.runtime.Hook;
import net.hydromatic.optiq.runtime.Utilities;
import org.codehaus.commons.compiler.CompileException;
import org.codehaus.janino.ClassBodyEvaluator;
import org.codehaus.janino.Scanner;
/**
* Result of compiling code generated from a {@link RexNode} expression.
*/
public class RexExecutable {
public static final String GENERATED_CLASS_NAME = "Reducer";
private final Function1<DataContext, Object[]> compiledFunction;
private final String code;
private DataContext dataContext;
public RexExecutable(String code, Object reason) {
try {
//noinspection unchecked
compiledFunction =
(Function1) ClassBodyEvaluator.createFastClassBodyEvaluator(
new Scanner(null, new StringReader(code)),
GENERATED_CLASS_NAME,
Utilities.class,
new Class[] {Function1.class, Serializable.class},
getClass().getClassLoader());
} catch (CompileException e) {
throw new RuntimeException("While compiling " + reason, e);
} catch (IOException e) {
throw new RuntimeException("While compiling " + reason, e);
}
this.code = code;
}
public void setDataContext(DataContext dataContext) {
this.dataContext = dataContext;
}
public void reduce(RexBuilder rexBuilder, List<RexNode> constExps,
List<RexNode> reducedValues) {
Object[] values = compiledFunction.apply(dataContext);
assert values.length == constExps.size();
final List<Object> valueList = Arrays.asList(values);
for (Pair<RexNode, Object> value : Pair.zip(constExps, valueList)) {
reducedValues.add(
rexBuilder.makeLiteral(value.right, value.left.getType(), true));
}
Hook.EXPRESSION_REDUCER.run(Pair.of(code, values));
}
public Function1<DataContext, Object[]> getFunction() {
return compiledFunction;
}
public Object[] execute() {
return compiledFunction.apply(dataContext);
}
public String getSource() {
return code;
}
}
// End RexExecutable.java