ArrowDirectEnumerator.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.adapter.arrow;

import org.apache.calcite.util.ImmutableIntList;

import org.apache.arrow.vector.ipc.ArrowFileReader;

/**
 * Enumerator that reads projected Arrow value-vectors directly.
 */
class ArrowDirectEnumerator extends AbstractArrowEnumerator {
  private final Runnable onClose;

  ArrowDirectEnumerator(ArrowFileReader arrowFileReader, ImmutableIntList fields,
      Runnable onClose) {
    super(arrowFileReader, fields);
    this.onClose = onClose;
  }

  @Override public boolean moveNext() {
    while (currRowIndex >= rowCount - 1) {
      if (!loadNextNonEmptyArrowBatch()) {
        return false;
      }
    }
    currRowIndex++;
    return true;
  }

  @Override public void close() {
    onClose.run();
  }
}