content: /*
   * 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.beam.sdk.extensions.sql.impl.rule;
  
  import org.apache.beam.sdk.extensions.sql.impl.rel.BeamCoGBKJoinRel;
  import org.apache.beam.sdk.extensions.sql.impl.rel.BeamJoinRel;
  import org.apache.beam.sdk.extensions.sql.impl.rel.BeamLogicalConvention;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.plan.RelOptRule;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.plan.RelOptRuleCall;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.RelNode;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.core.Join;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.core.RelFactories;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.logical.LogicalJoin;
  
  /**
   * Rule to convert {@code LogicalJoin} node to {@code BeamCoGBKJoinRel} node.
   *
   * <p>This rule is matched when both the inputs to {@code LogicalJoin} node have the same
   * Boundedness i.e. either when both the inputs are {@code PCollection.IsBounded.BOUNDED} or when
   * both the inputs are {@code PCollection.IsBounded.UNBOUNDED}
   *
   * <p>As {@code BeamSideInputLookupJoinRel} also matches this condition when both the inputs are
   * {@code PCollection.IsBounded.BOUNDED}, to avoid conflicts, this rule is not matched when any of
   * the inputs to {@code LogicalJoin} node are Seekable.
   */
  public class BeamCoGBKJoinRule extends RelOptRule {
    public static final BeamCoGBKJoinRule INSTANCE = new BeamCoGBKJoinRule();
  
    private BeamCoGBKJoinRule() {
      super(
          operand(LogicalJoin.class, operand(RelNode.class, any()), operand(RelNode.class, any())),
          RelFactories.LOGICAL_BUILDER,
          "BeamCoGBKJoinRule");
    }
  
    @Override
    public boolean matches(RelOptRuleCall call) {
      // The Rule does not match when any of the inputs are Seekable
      if (BeamJoinRel.containsSeekableInput(call.rel(0))) {
        return false;
      }
      PCollection.IsBounded boundednessOfLeftRel = BeamJoinRel.getBoundednessOfRelNode(call.rel(1));
      PCollection.IsBounded boundednessOfRightRel = BeamJoinRel.getBoundednessOfRelNode(call.rel(2));
      return (boundednessOfLeftRel == boundednessOfRightRel);
    }
  
    @Override
    public void onMatch(RelOptRuleCall call) {
      Join join = (Join) call.rel(0);
  
      BeamCoGBKJoinRel rel =
          new BeamCoGBKJoinRel(
              join.getCluster(),
              join.getTraitSet().replace(BeamLogicalConvention.INSTANCE),
              convert(
                  join.getLeft(),
                  join.getLeft().getTraitSet().replace(BeamLogicalConvention.INSTANCE)),
              convert(
                  join.getRight(),
                  join.getRight().getTraitSet().replace(BeamLogicalConvention.INSTANCE)),
              join.getCondition(),
              join.getVariablesSet(),
              join.getJoinType());
      call.transformTo(rel);
    }
  }
  