| /* |
| * 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; |
| |
| import org.apache.calcite.plan.RelOptRule; |
| import org.apache.calcite.plan.RelOptRuleCall; |
| import org.apache.calcite.rel.core.Filter; |
| import org.apache.calcite.rel.core.RelFactories; |
| import org.apache.calcite.rex.RexBuilder; |
| import org.apache.calcite.rex.RexNode; |
| import org.apache.calcite.rex.RexProgram; |
| import org.apache.calcite.rex.RexProgramBuilder; |
| import org.apache.calcite.rex.RexUtil; |
| |
| /** |
| * MergeFilterRule implements the rule for combining two {@link Filter}s |
| */ |
| public class DrillMergeFilterRule extends RelOptRule { |
| public static final DrillMergeFilterRule INSTANCE = |
| new DrillMergeFilterRule(RelFactories.DEFAULT_FILTER_FACTORY); |
| |
| private final RelFactories.FilterFactory filterFactory; |
| |
| |
| //~ Constructors ----------------------------------------------------------- |
| |
| /** |
| * Creates a MergeFilterRule. |
| */ |
| private DrillMergeFilterRule(RelFactories.FilterFactory filterFactory) { |
| super( |
| operand(Filter.class, |
| operand(Filter.class, any()))); |
| this.filterFactory = filterFactory; |
| } |
| |
| //~ Methods ---------------------------------------------------------------- |
| |
| // implement RelOptRule |
| public void onMatch(RelOptRuleCall call) { |
| Filter topFilter = call.rel(0); |
| Filter bottomFilter = call.rel(1); |
| |
| // use RexPrograms to merge the two FilterRels into a single program |
| // so we can convert the two FilterRel conditions to directly |
| // reference the bottom FilterRel's child |
| RexBuilder rexBuilder = topFilter.getCluster().getRexBuilder(); |
| RexProgram bottomProgram = createProgram(bottomFilter); |
| RexProgram topProgram = createProgram(topFilter); |
| |
| RexProgram mergedProgram = |
| RexProgramBuilder.mergePrograms( |
| topProgram, |
| bottomProgram, |
| rexBuilder); |
| |
| RexNode newCondition = |
| mergedProgram.expandLocalRef( |
| mergedProgram.getCondition()); |
| |
| // if(!RexUtil.isFlat(newCondition)){ |
| // RexCall newCall = (RexCall) newCondition; |
| // newCondition = rexBuilder.makeFlatCall( newCall.getOperator(), newCall.getOperands()); |
| // } |
| |
| Filter newFilterRel = |
| (Filter) filterFactory.createFilter( |
| bottomFilter.getInput(), |
| RexUtil.flatten(rexBuilder, newCondition)); |
| |
| call.transformTo(newFilterRel); |
| } |
| |
| /** |
| * Creates a RexProgram corresponding to a LogicalFilter |
| * |
| * @param filterRel the LogicalFilter |
| * @return created RexProgram |
| */ |
| private RexProgram createProgram(Filter filterRel) { |
| RexProgramBuilder programBuilder = |
| new RexProgramBuilder( |
| filterRel.getRowType(), |
| filterRel.getCluster().getRexBuilder()); |
| programBuilder.addIdentity(); |
| programBuilder.addCondition(filterRel.getCondition()); |
| return programBuilder.getProgram(); |
| } |
| } |