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/*
 * Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata
 *
 * Portions of this software were developed by the Unidata Program at the
 * University Corporation for Atmospheric Research.
 *
 * Access and use of this software shall impose the following obligations
 * and understandings on the user. The user is granted the right, without
 * any fee or cost, to use, copy, modify, alter, enhance and distribute
 * this software, and any derivative works thereof, and its supporting
 * documentation for any purpose whatsoever, provided that this entire
 * notice appears in all copies of the software, derivative works and
 * supporting documentation.  Further, UCAR requests that the user credit
 * UCAR/Unidata in any publications that result from the use of this
 * software or in any product that includes this software. The names UCAR
 * and/or Unidata, however, may not be used in any advertising or publicity
 * to endorse or promote any products or commercial entity unless specific
 * written permission is obtained from UCAR/Unidata. The user also
 * understands that UCAR/Unidata is not obligated to provide the user with
 * any support, consulting, training or assistance of any kind with regard
 * to the use, operation and performance of this software nor to provide
 * the user with any updates, revisions, new versions or "bug fixes."
 *
 * THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
 */
package ucar.nc2;

import ucar.ma2.*;
import ucar.nc2.util.CancelTask;

import java.io.IOException;

/**
 * A ProxyReader for logical sections of a Variable.
 *
 * @author caron
 * @see Variable#section(Section subsection)
 */

class SectionReader implements ProxyReader {
  static private org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(SectionReader.class);
  private Section orgSection;   // section of the original
  private Variable orgClient;

  // section must be filled
  SectionReader(Variable orgClient, Section section) throws InvalidRangeException {
    this.orgClient = orgClient;
    this.orgSection = section.isImmutable() ? section : new Section(section.getRanges());
  }

  @Override
  public Array reallyRead(Variable client, CancelTask cancelTask) throws IOException {
    try {
      return orgClient._read( orgSection);
    } catch (InvalidRangeException e) {
      throw new RuntimeException(e);
    }
  }

  @Override
  public Array reallyRead(Variable client, Section section, CancelTask cancelTask) throws IOException, InvalidRangeException {
    Section want = orgSection.compose( section);
    return orgClient._read( want);
  }

}