Mark xref

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    1   /***
    2    *
    3    * Copyright 2004 Hiram Chirino
    4    *
    5    * Licensed under the Apache License, Version 2.0 (the "License");
    6    * you may not use this file except in compliance with the License.
    7    * You may obtain a copy of the License at
    8    *
    9    * http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   **/
    18  package org.codehaus.activemq.journal.impl;
    19
    20  import java.io.ByteArrayInputStream;
    21  import java.io.ByteArrayOutputStream;
    22  import java.io.DataInputStream;
    23  import java.io.DataOutputStream;
    24  import java.io.IOException;
    25
    26  /***
    27   * Serializes/Deserializes Mark records.  When a mark is set in the journal, a Mark record
    28   * must be journaled so that on restart the Journal knows what was the last mark.
    29   *
    30   * @version $Revision: 1.1 $
    31   */
    32  class Mark {
    33
    34      public static final int MARK_RECORD_SIZE = 12;
    35
    36      public long sequenceId;
    37      public int offsetId;
    38
    39      public Mark() {}
    40      public Mark(RecordLocationImpl location) {
    41          sequenceId = location.getSequenceId();
    42          offsetId = location.getSegmentOffset();
    43      }
    44
    45      public byte[] writeExternal() throws IOException {
    46          ByteArrayOutputStream stream = new ByteArrayOutputStream(16);
    47          DataOutputStream os = new DataOutputStream(stream);
    48          os.writeLong(sequenceId);
    49          os.writeInt(offsetId);
    50          os.close();
    51          return stream.toByteArray();
    52      }
    53
    54      public void readExternal(byte data[]) throws IOException {
    55          DataInputStream is = new DataInputStream(new ByteArrayInputStream(data));
    56          sequenceId = is.readLong();
    57          offsetId = is.readInt();
    58          is.close();
    59      }
    60      /***
    61       * @param mark
    62       */
    63      public void copy(Mark mark) {
    64          this.offsetId = mark.offsetId;
    65          this.sequenceId = mark.sequenceId;
    66      }
    67
    68  }