RecordConstants.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.hadoop.chukwa.util;


public class RecordConstants {
  static final char[] CTRL_A = { '\u0001' };
  static final char[] CTRL_B = { '\u0002' };
  static final char[] CTRL_C = { '\u0003' };
  static final char[] CTRL_D = { '\u0004' };
  // public static final String FIELD_SEPARATOR = new String(CTRL_A);
  public static final String DEFAULT_FIELD_SEPARATOR = "-#-";
  public static final String DEFAULT_RECORD_SEPARATOR = "\n";
  public static final String RECORD_SEPARATOR_ESCAPE_SEQ = new String(CTRL_D);// may
                                                                              // want
                                                                              // this
                                                                              // to
                                                                              // be
                                                                              // very
                                                                              // obscure
                                                                              // ,
                                                                              // e
                                                                              // .
                                                                              // g
                                                                              // .
                                                                              // new
                                                                              // String
                                                                              // (
                                                                              // CTRL_B
                                                                              // )
                                                                              // +
                                                                              // new
                                                                              // String
                                                                              // (
                                                                              // CTRL_C
                                                                              // )
                                                                              // +
                                                                              // new
                                                                              // String
                                                                              // (
                                                                              // CTRL_D
                                                                              // )

  /**
   * Insert the default chukwa escape sequence in <code>record</code> before all
   * occurances of <code>recordSeparator</code> <i>except</i> the final one if
   * the final record separator occurs at the end of the <code>record</code>
   * 
   * @param recordSeparator The record separator that we are escaping. This is
   *        chunk source application specific
   * @param record The string representing the entire record, including the
   *        final record delimiter
   * @return The string with appropriate <code>recordSeparator</code>s escaped
   */
  public static String escapeAllButLastRecordSeparator(String recordSeparator,
      String record) {
    String escapedRecord = "";
    if (record.endsWith(recordSeparator)) {
      escapedRecord = record.substring(0,
          record.length() - recordSeparator.length()).replaceAll(
          recordSeparator, RECORD_SEPARATOR_ESCAPE_SEQ + recordSeparator)
          + recordSeparator;
    }
    return escapedRecord;
  }

  /**
   * Insert the default chukwa escape sequence in <code>record</code> before all
   * occurances of <code>recordSeparator</code>. This is assuming that you are
   * not passing the final record separator in with the <code>record</code>,
   * because it would be escaped too.
   * 
   * @param recordSeparator The record separator that we are escaping. This is
   *        chunk source application specific
   * @param record The string representing the entire record, including the
   *        final record delimiter
   * @return The string with all <code>recordSeparator</code>s escaped
   */
  public static String escapeAllRecordSeparators(String recordSeparator,
      String record) {
    return record.replaceAll(recordSeparator, RECORD_SEPARATOR_ESCAPE_SEQ
        + recordSeparator);
  }

  public static String recoverRecordSeparators(String recordSeparator,
      String record) {
    return record.replaceAll(RECORD_SEPARATOR_ESCAPE_SEQ + recordSeparator,
        recordSeparator);
  }

}