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.pig;
  
  import org.apache.calcite.plan.RelOptCluster;
  import org.apache.calcite.plan.RelOptTable;
  import org.apache.calcite.plan.RelOptTable.ToRelContext;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rel.type.RelDataTypeFactory;
  import org.apache.calcite.schema.TranslatableTable;
  import org.apache.calcite.schema.impl.AbstractTable;
  
  import org.apache.pig.data.DataType;
  
  /**
   * Represents a Pig relation that is created by Pig Latin
   * <a href="https://pig.apache.org/docs/r0.13.0/basic.html#load">
   * <code>LOAD</code></a> statement.
   *
   * <p>Only the default load function is supported at this point (PigStorage()).
   *
   * <p>Only VARCHAR (CHARARRAY in Pig) type supported at this point.
   *
   * @see PigTableFactory
   */
  public class PigTable extends AbstractTable implements TranslatableTable {
  
    private final String filePath;
    private final String[] fieldNames;
  
    /** Creates a PigTable. */
    public PigTable(String filePath, String[] fieldNames) {
      this.filePath = filePath;
      this.fieldNames = fieldNames;
    }
  
    @Override public RelDataType getRowType(RelDataTypeFactory typeFactory) {
      final RelDataTypeFactory.Builder builder = typeFactory.builder();
      for (String fieldName : fieldNames) {
        // only supports CHARARRAY types for now
        final RelDataType relDataType = typeFactory
            .createSqlType(PigDataType.valueOf(DataType.CHARARRAY).getSqlType());
        final RelDataType nullableRelDataType = typeFactory
            .createTypeWithNullability(relDataType, true);
        builder.add(fieldName, nullableRelDataType);
      }
      return builder.build();
    }
  
    public String getFilePath() {
      return filePath;
    }
  
    @Override public RelNode toRel(ToRelContext context, RelOptTable relOptTable) {
      final RelOptCluster cluster = context.getCluster();
      return new PigTableScan(cluster, cluster.traitSetOf(PigRel.CONVENTION), relOptTable);
    }
  }
  