core/src/main/java/org/apache/calcite/runtime/RecordEnumeratorCursor.java

/*
 * 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.runtime;

import org.apache.calcite.linq4j.Enumerator;

/**
 * Implementation of {@link org.apache.calcite.avatica.util.Cursor} on top of an
 * {@link org.apache.calcite.linq4j.Enumerator} that
 * returns a record for each row. The record is a synthetic class whose fields
 * are all public.
 *
 * @param <E> Element type
 */
public class RecordEnumeratorCursor<E> extends EnumeratorCursor<E> {
  private final Class<E> clazz;

  /**
   * Creates a RecordEnumeratorCursor.
   *
   * @param enumerator Enumerator
   * @param clazz Element type
   */
  public RecordEnumeratorCursor(
      Enumerator<E> enumerator,
      Class<E> clazz) {
    super(enumerator);
    this.clazz = clazz;
  }

  @Override protected Getter createGetter(int ordinal) {
    return new FieldGetter(clazz.getFields()[ordinal]);
  }
}