| /* |
| * 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.apache.calcite.rex; |
| |
| import org.apache.calcite.linq4j.Linq4j; |
| import org.apache.calcite.plan.RelOptPredicateList; |
| import org.apache.calcite.rel.metadata.NullSentinel; |
| import org.apache.calcite.util.NlsString; |
| import org.apache.calcite.util.Pair; |
| import org.apache.calcite.util.Util; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableMap; |
| |
| import java.math.BigDecimal; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** Analyzes an expression, figures out what are the unbound variables, |
| * assigns a variety of values to each unbound variable, and evaluates |
| * the expression. */ |
| public class RexAnalyzer { |
| public final RexNode e; |
| public final List<RexNode> variables; |
| public final int unsupportedCount; |
| |
| /** Creates a RexAnalyzer. */ |
| public RexAnalyzer(RexNode e, RelOptPredicateList predicates) { |
| this.e = e; |
| final VariableCollector variableCollector = new VariableCollector(); |
| e.accept(variableCollector); |
| variableCollector.visitEach(predicates.pulledUpPredicates); |
| variables = ImmutableList.copyOf(variableCollector.builder); |
| unsupportedCount = variableCollector.unsupportedCount; |
| } |
| |
| /** Generates a map of variables and lists of values that could be assigned |
| * to them. */ |
| @SuppressWarnings("BetaApi") |
| public Iterable<Map<RexNode, Comparable>> assignments() { |
| final List<List<Comparable>> generators = |
| variables.stream().map(RexAnalyzer::getComparables) |
| .collect(Util.toImmutableList()); |
| final Iterable<List<Comparable>> product = Linq4j.product(generators); |
| return Util.transform(product, |
| values -> ImmutableMap.copyOf(Pair.zip(variables, values))); |
| } |
| |
| private static List<Comparable> getComparables(RexNode variable) { |
| final ImmutableList.Builder<Comparable> values = ImmutableList.builder(); |
| switch (variable.getType().getSqlTypeName()) { |
| case BOOLEAN: |
| values.add(true); |
| values.add(false); |
| break; |
| case INTEGER: |
| values.add(BigDecimal.valueOf(-1L)); |
| values.add(BigDecimal.valueOf(0L)); |
| values.add(BigDecimal.valueOf(1L)); |
| values.add(BigDecimal.valueOf(1_000_000L)); |
| break; |
| case DECIMAL: |
| values.add(BigDecimal.valueOf(-100L)); |
| values.add(BigDecimal.valueOf(100L)); |
| break; |
| case VARCHAR: |
| values.add(new NlsString("", null, null)); |
| values.add(new NlsString("hello", null, null)); |
| break; |
| case TIMESTAMP: |
| values.add(0L); // 1970-01-01 00:00:00 |
| break; |
| case DATE: |
| values.add(0); // 1970-01-01 |
| values.add(365); // 1971-01-01 |
| values.add(-365); // 1969-01-01 |
| break; |
| case TIME: |
| values.add(0); // 00:00:00.000 |
| values.add(86_399_000); // 23:59:59.000 |
| break; |
| default: |
| throw new AssertionError("don't know values for " + variable |
| + " of type " + variable.getType()); |
| } |
| if (variable.getType().isNullable()) { |
| values.add(NullSentinel.INSTANCE); |
| } |
| return values.build(); |
| } |
| |
| /** Collects the variables (or other bindable sites) in an expression, and |
| * counts features (such as CAST) that {@link RexInterpreter} cannot |
| * handle. */ |
| private static class VariableCollector extends RexVisitorImpl<Void> { |
| private final Set<RexNode> builder = new LinkedHashSet<>(); |
| private int unsupportedCount = 0; |
| |
| VariableCollector() { |
| super(true); |
| } |
| |
| @Override public Void visitInputRef(RexInputRef inputRef) { |
| builder.add(inputRef); |
| return super.visitInputRef(inputRef); |
| } |
| |
| @Override public Void visitFieldAccess(RexFieldAccess fieldAccess) { |
| if (fieldAccess.getReferenceExpr() instanceof RexDynamicParam) { |
| builder.add(fieldAccess); |
| return null; |
| } else { |
| return super.visitFieldAccess(fieldAccess); |
| } |
| } |
| |
| @Override public Void visitCall(RexCall call) { |
| switch (call.getKind()) { |
| case CAST: |
| case OTHER_FUNCTION: |
| ++unsupportedCount; |
| return null; |
| default: |
| return super.visitCall(call); |
| } |
| } |
| } |
| } |