content: /*
   * Copyright 2020 Alibaba Group Holding Limited.
   *
   * Licensed 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 com.alibaba.graphscope.common.ir.meta.glogue.calcite.handler;
  
  import com.alibaba.graphscope.common.ir.rel.GraphPattern;
  import com.alibaba.graphscope.common.ir.rel.metadata.glogue.GlogueEdge;
  import com.alibaba.graphscope.common.ir.rel.metadata.glogue.GlogueQuery;
  import com.google.common.base.Preconditions;
  
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.metadata.RelMetadataQuery;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.Set;
  
  public class GraphGlogueEdgesHandler implements ExternalMetaData.GlogueEdges.Handler {
      private final GlogueQuery glogueQuery;
  
      public GraphGlogueEdgesHandler(GlogueQuery glogueQuery) {
          this.glogueQuery = glogueQuery;
      }
  
      @Override
      public @Nullable Set<GlogueEdge> getGlogueEdges(RelNode node, RelMetadataQuery mq) {
          Preconditions.checkArgument(
                  node instanceof GraphPattern,
                  "can not find incoming glogue edges for the node=" + node.getClass());
          return glogueQuery.getInEdges(((GraphPattern) node).getPattern());
      }
  }
  