com.hazelcast.org.apache.calcite.rex.RexExecutorImpl Maven / Gradle / Ivy
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* 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.
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package com.hazelcast.org.apache.calcite.rex;
import com.hazelcast.org.apache.calcite.DataContext;
import com.hazelcast.org.apache.calcite.adapter.enumerable.EnumUtils;
import com.hazelcast.org.apache.calcite.adapter.enumerable.RexToLixTranslator;
import com.hazelcast.org.apache.calcite.adapter.enumerable.RexToLixTranslator.InputGetter;
import com.hazelcast.org.apache.calcite.adapter.java.JavaTypeFactory;
import com.hazelcast.org.apache.calcite.config.CalciteSystemProperty;
import com.hazelcast.org.apache.calcite.jdbc.JavaTypeFactoryImpl;
import com.hazelcast.org.apache.calcite.linq4j.tree.BlockBuilder;
import com.hazelcast.org.apache.calcite.linq4j.tree.Expression;
import com.hazelcast.org.apache.calcite.linq4j.tree.Expressions;
import com.hazelcast.org.apache.calcite.linq4j.tree.IndexExpression;
import com.hazelcast.org.apache.calcite.linq4j.tree.MethodCallExpression;
import com.hazelcast.org.apache.calcite.linq4j.tree.MethodDeclaration;
import com.hazelcast.org.apache.calcite.linq4j.tree.ParameterExpression;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeFactory;
import com.hazelcast.org.apache.calcite.sql.validate.SqlConformance;
import com.hazelcast.org.apache.calcite.sql.validate.SqlConformanceEnum;
import com.hazelcast.org.apache.calcite.util.BuiltInMethod;
import com.hazelcast.org.apache.calcite.util.Util;
import com.hazelcast.com.google.common.collect.ImmutableList;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.List;
/**
* Evaluates a {@link RexNode} expression.
*
* For this impl, all the public methods should be
* static except that it inherits from {@link RexExecutor}.
* This pretends that other code in the project assumes
* the executor instance is {@link RexExecutorImpl}.
*/
public class RexExecutorImpl implements RexExecutor {
private final DataContext dataContext;
public RexExecutorImpl(DataContext dataContext) {
this.dataContext = dataContext;
}
private static String compile(RexBuilder rexBuilder, List constExps,
RexToLixTranslator.InputGetter getter) {
final RelDataTypeFactory typeFactory = rexBuilder.getTypeFactory();
final RelDataType emptyRowType = typeFactory.builder().build();
return compile(rexBuilder, constExps, getter, emptyRowType);
}
private static String compile(RexBuilder rexBuilder, List constExps,
RexToLixTranslator.InputGetter getter, RelDataType rowType) {
final RexProgramBuilder programBuilder =
new RexProgramBuilder(rowType, rexBuilder);
for (RexNode node : constExps) {
programBuilder.addProject(
node, "c" + programBuilder.getProjectList().size());
}
final JavaTypeFactoryImpl javaTypeFactory =
new JavaTypeFactoryImpl(rexBuilder.getTypeFactory().getTypeSystem());
final BlockBuilder blockBuilder = new BlockBuilder();
final ParameterExpression root0_ =
Expressions.parameter(Object.class, "root0");
final ParameterExpression root_ = DataContext.ROOT;
blockBuilder.add(
Expressions.declare(
Modifier.FINAL, root_,
Expressions.convert_(root0_, DataContext.class)));
final SqlConformance conformance = SqlConformanceEnum.DEFAULT;
final RexProgram program = programBuilder.getProgram();
final List expressions =
RexToLixTranslator.translateProjects(program, javaTypeFactory,
conformance, blockBuilder, null, root_, getter, null);
blockBuilder.add(
Expressions.return_(null,
Expressions.newArrayInit(Object[].class, expressions)));
final MethodDeclaration methodDecl =
Expressions.methodDecl(Modifier.PUBLIC, Object[].class,
BuiltInMethod.FUNCTION1_APPLY.method.getName(),
ImmutableList.of(root0_), blockBuilder.toBlock());
String code = Expressions.toString(methodDecl);
if (CalciteSystemProperty.DEBUG.value()) {
Util.debugCode(System.out, code);
}
return code;
}
/**
* Creates an {@link RexExecutable} that allows to apply the
* generated code during query processing (filter, projection).
*
* @param rexBuilder Rex builder
* @param exps Expressions
* @param rowType describes the structure of the input row.
*/
public static RexExecutable getExecutable(RexBuilder rexBuilder, List exps,
RelDataType rowType) {
final JavaTypeFactoryImpl typeFactory =
new JavaTypeFactoryImpl(rexBuilder.getTypeFactory().getTypeSystem());
final InputGetter getter = new DataContextInputGetter(rowType, typeFactory);
final String code = compile(rexBuilder, exps, getter, rowType);
return new RexExecutable(code, "generated Rex code");
}
/**
* Do constant reduction using generated code.
*/
public void reduce(RexBuilder rexBuilder, List constExps,
List reducedValues) {
final String code = compile(rexBuilder, constExps,
(list, index, storageType) -> {
throw new UnsupportedOperationException();
});
final RexExecutable executable = new RexExecutable(code, constExps);
executable.setDataContext(dataContext);
executable.reduce(rexBuilder, constExps, reducedValues);
}
/**
* Implementation of
* {@link com.hazelcast.org.apache.calcite.adapter.enumerable.RexToLixTranslator.InputGetter}
* that reads the values of input fields by calling
* {@link com.hazelcast.org.apache.calcite.DataContext#get}("inputRecord").
*/
private static class DataContextInputGetter implements InputGetter {
private final RelDataTypeFactory typeFactory;
private final RelDataType rowType;
DataContextInputGetter(RelDataType rowType,
RelDataTypeFactory typeFactory) {
this.rowType = rowType;
this.typeFactory = typeFactory;
}
public Expression field(BlockBuilder list, int index, Type storageType) {
MethodCallExpression recFromCtx = Expressions.call(
DataContext.ROOT,
BuiltInMethod.DATA_CONTEXT_GET.method,
Expressions.constant("inputRecord"));
Expression recFromCtxCasted =
EnumUtils.convert(recFromCtx, Object[].class);
IndexExpression recordAccess = Expressions.arrayIndex(recFromCtxCasted,
Expressions.constant(index));
if (storageType == null) {
final RelDataType fieldType =
rowType.getFieldList().get(index).getType();
storageType = ((JavaTypeFactory) typeFactory).getJavaClass(fieldType);
}
return EnumUtils.convert(recordAccess, storageType);
}
}
}