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 com.alimama.mdrill.utils.zip;
  
  /**
   * Wrapper for extra field data that doesn't conform to the recommended format of header-tag + size + data.
   *
   * <p>The header-id is artificial (and not listed as a known ID in
   * {@link <a href="http://www.pkware.com/documents/casestudies/APPNOTE.TXT">
   * APPNOTE.TXT</a>}).  Since it isn't used anywhere except to satisfy the
   * ZipExtraField contract it shouldn't matter anyway.</p>
   *
   * @since Ant 1.8.1
   */
  public final class UnparseableExtraFieldData
      implements CentralDirectoryParsingZipExtraField {
  
      private static final ZipShort HEADER_ID = new ZipShort(0xACC1);
  
      private byte[] localFileData;
      private byte[] centralDirectoryData;
  
      /**
       * The Header-ID.
       *
       * @return a completely arbitrary value that should be ignored.
       */
      public ZipShort getHeaderId() {
          return HEADER_ID;
      }
  
      /**
       * Length of the complete extra field in the local file data.
       *
       * @return The LocalFileDataLength value
       */
      public ZipShort getLocalFileDataLength() {
          return new ZipShort(localFileData == null ? 0 : localFileData.length);
      }
  
      /**
       * Length of the complete extra field in the central directory.
       *
       * @return The CentralDirectoryLength value
       */
      public ZipShort getCentralDirectoryLength() {
          return centralDirectoryData == null
              ? getLocalFileDataLength()
              : new ZipShort(centralDirectoryData.length);
      }
  
      /**
       * The actual data to put into local file data.
       *
       * @return The LocalFileDataData value
       */
      public byte[] getLocalFileDataData() {
          return ZipUtil.copy(localFileData);
      }
  
      /**
       * The actual data to put into central directory.
       *
       * @return The CentralDirectoryData value
       */
      public byte[] getCentralDirectoryData() {
          return centralDirectoryData == null
              ? getLocalFileDataData() : ZipUtil.copy(centralDirectoryData);
      }
  
      /**
       * Populate data from this array as if it was in local file data.
       *
       * @param buffer the buffer to read data from
       * @param offset offset into buffer to read data
       * @param length the length of data
       */
      public void parseFromLocalFileData(byte[] buffer, int offset, int length) {
          localFileData = new byte[length];
          System.arraycopy(buffer, offset, localFileData, 0, length);
      }
  
      /**
       * Populate data from this array as if it was in central directory data.
       *
       * @param buffer the buffer to read data from
       * @param offset offset into buffer to read data
       * @param length the length of data
       */
      public void parseFromCentralDirectoryData(byte[] buffer, int offset,
                                                int length) {
          centralDirectoryData = new byte[length];
          System.arraycopy(buffer, offset, centralDirectoryData, 0, length);
          if (localFileData == null) {
              parseFromLocalFileData(buffer, offset, length);
          }
      }
  
  }
  