| /* |
| * 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.drill.exec.planner.logical.partition; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.calcite.rel.type.RelDataType; |
| import org.apache.calcite.rex.RexBuilder; |
| import org.apache.calcite.rex.RexCall; |
| import org.apache.calcite.rex.RexCorrelVariable; |
| import org.apache.calcite.rex.RexDynamicParam; |
| import org.apache.calcite.rex.RexFieldAccess; |
| import org.apache.calcite.rex.RexInputRef; |
| import org.apache.calcite.rex.RexLiteral; |
| import org.apache.calcite.rex.RexLocalRef; |
| import org.apache.calcite.rex.RexNode; |
| import org.apache.calcite.rex.RexOver; |
| import org.apache.calcite.rex.RexRangeRef; |
| import org.apache.calcite.rex.RexVisitorImpl; |
| import org.apache.calcite.sql.SqlKind; |
| import org.apache.calcite.sql.SqlOperator; |
| |
| import org.apache.drill.shaded.guava.com.google.common.collect.ImmutableList; |
| import org.apache.drill.shaded.guava.com.google.common.collect.Lists; |
| |
| /** |
| * Rewrites an expression tree, replacing OR and AND operators with more than 2 operands with a chained operators |
| * each with only 2 operands. |
| * |
| * e.g. |
| * |
| * OR(A, B, C) ---> OR(A, OR(B, C)) |
| */ |
| public class RewriteAsBinaryOperators extends RexVisitorImpl<RexNode> { |
| |
| RexBuilder builder; |
| public RewriteAsBinaryOperators(boolean deep, RexBuilder builder) { |
| super(deep); |
| this.builder = builder; |
| } |
| |
| @Override |
| public RexNode visitInputRef(RexInputRef inputRef) { |
| return inputRef; |
| } |
| |
| @Override |
| public RexNode visitLiteral(RexLiteral literal) { |
| return literal; |
| } |
| |
| @Override |
| public RexNode visitOver(RexOver over) { |
| return over; |
| } |
| |
| @Override |
| public RexNode visitCorrelVariable(RexCorrelVariable correlVariable) { |
| return correlVariable; |
| } |
| |
| @Override |
| public RexNode visitCall(RexCall call) { |
| SqlOperator op = call.getOperator(); |
| SqlKind kind = op.getKind(); |
| RelDataType type = call.getType(); |
| if (kind == SqlKind.OR || kind == SqlKind.AND) { |
| if (call.getOperands().size() > 2) { |
| List<RexNode> children = new ArrayList<>(call.getOperands()); |
| RexNode left = children.remove(0).accept(this); |
| RexNode right = builder.makeCall(type, op, children).accept(this); |
| return builder.makeCall(type, op, ImmutableList.of(left, right)); |
| } |
| } |
| return builder.makeCall(type, op, visitChildren(call)); |
| } |
| |
| private List<RexNode> visitChildren(RexCall call) { |
| List<RexNode> children = Lists.newArrayList(); |
| for (RexNode child : call.getOperands()) { |
| children.add(child.accept(this)); |
| } |
| return ImmutableList.copyOf(children); |
| } |
| |
| @Override |
| public RexNode visitDynamicParam(RexDynamicParam dynamicParam) { |
| return dynamicParam; |
| } |
| |
| @Override |
| public RexNode visitRangeRef(RexRangeRef rangeRef) { |
| return rangeRef; |
| } |
| |
| @Override |
| public RexNode visitFieldAccess(RexFieldAccess fieldAccess) { |
| return fieldAccess; |
| } |
| |
| @Override |
| public RexNode visitLocalRef(RexLocalRef localRef) { |
| return localRef; |
| } |
| } |