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.calcite.adapter.enumerable;
  
  import org.apache.calcite.plan.RelOptTable;
  import org.apache.calcite.rel.RelCollation;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.core.CorrelationId;
  import org.apache.calcite.rel.hint.RelHint;
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rex.RexNode;
  import org.apache.calcite.rex.RexUtil;
  import org.apache.calcite.sql.validate.SqlValidatorUtil;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.List;
  import java.util.Set;
  
  import static com.google.common.base.Preconditions.checkArgument;
  
  /**
   * Contains factory interface and default implementation for creating various
   * rel nodes.
   */
  public class EnumerableRelFactories {
  
    public static final org.apache.calcite.rel.core.RelFactories.TableScanFactory
        ENUMERABLE_TABLE_SCAN_FACTORY = new TableScanFactoryImpl();
  
    public static final org.apache.calcite.rel.core.RelFactories.ProjectFactory
        ENUMERABLE_PROJECT_FACTORY = new ProjectFactoryImpl();
  
    public static final org.apache.calcite.rel.core.RelFactories.FilterFactory
        ENUMERABLE_FILTER_FACTORY = new FilterFactoryImpl();
  
    public static final org.apache.calcite.rel.core.RelFactories.SortFactory
        ENUMERABLE_SORT_FACTORY = new SortFactoryImpl();
  
    /**
     * Implementation of {@link org.apache.calcite.rel.core.RelFactories.TableScanFactory} that
     * returns a vanilla {@link EnumerableTableScan}.
     */
    private static class TableScanFactoryImpl
        implements org.apache.calcite.rel.core.RelFactories.TableScanFactory {
      @Override public RelNode createScan(RelOptTable.ToRelContext toRelContext, RelOptTable table) {
        return EnumerableTableScan.create(toRelContext.getCluster(), table);
      }
    }
  
    /**
     * Implementation of {@link org.apache.calcite.rel.core.RelFactories.ProjectFactory} that
     * returns a vanilla {@link EnumerableProject}.
     */
    private static class ProjectFactoryImpl
        implements org.apache.calcite.rel.core.RelFactories.ProjectFactory {
      @Override public RelNode createProject(RelNode input, List<RelHint> hints,
          List<? extends RexNode> childExprs,
          @Nullable List<? extends @Nullable String> fieldNames,
          Set<CorrelationId> variablesSet) {
        checkArgument(variablesSet.isEmpty(),
            "EnumerableProject does not allow variables");
        final RelDataType rowType =
            RexUtil.createStructType(input.getCluster().getTypeFactory(), childExprs,
                fieldNames, SqlValidatorUtil.F_SUGGESTER);
        return EnumerableProject.create(input, childExprs, rowType);
      }
    }
  
    /**
     * Implementation of {@link org.apache.calcite.rel.core.RelFactories.FilterFactory} that
     * returns a vanilla {@link EnumerableFilter}.
     */
    private static class FilterFactoryImpl
        implements org.apache.calcite.rel.core.RelFactories.FilterFactory {
      @Override public RelNode createFilter(RelNode input, RexNode condition,
                           Set<CorrelationId> variablesSet) {
        return EnumerableFilter.create(input, condition);
      }
    }
  
    /**
     * Implementation of {@link org.apache.calcite.rel.core.RelFactories.SortFactory} that
     * returns a vanilla {@link EnumerableSort}.
     */
    private static class SortFactoryImpl
        implements org.apache.calcite.rel.core.RelFactories.SortFactory {
      @Override public RelNode createSort(RelNode input, RelCollation collation,
          @Nullable RexNode offset, @Nullable RexNode fetch) {
        return EnumerableSort.create(input, collation, offset, fetch);
      }
    }
  
    private EnumerableRelFactories() {
    }
  }
  