Beispiel #1
0
 /**
  * Returns the file name to use for the read-only version of the provided log file.
  *
  * <p>The file name is based on the lowest and highest key in the log file.
  *
  * @return the name to use for the read-only version of the log file
  * @throws ChangelogException If an error occurs.
  */
 private String generateReadOnlyFileName(final LogFile<K, V> logFile) throws ChangelogException {
   final K lowestKey = logFile.getOldestRecord().getKey();
   final K highestKey = logFile.getNewestRecord().getKey();
   return recordParser.encodeKeyToString(lowestKey)
       + LOG_FILE_NAME_SEPARATOR
       + recordParser.encodeKeyToString(highestKey)
       + LOG_FILE_SUFFIX;
 }
Beispiel #2
0
 /**
  * Returns the key bounds for the provided log file.
  *
  * @return the pair of (lowest key, highest key) that correspond to records stored in the
  *     corresponding log file.
  * @throws ChangelogException if an error occurs while retrieving the keys
  */
 private Pair<K, K> getKeyBounds(final LogFile<K, V> logFile) throws ChangelogException {
   try {
     final String name = logFile.getFile().getName();
     final String[] keys =
         name.substring(0, name.length() - Log.LOG_FILE_SUFFIX.length())
             .split(LOG_FILE_NAME_SEPARATOR);
     return Pair.of(
         recordParser.decodeKeyFromString(keys[0]), recordParser.decodeKeyFromString(keys[1]));
   } catch (Exception e) {
     throw new ChangelogException(
         ERR_CHANGELOG_UNABLE_TO_RETRIEVE_KEY_BOUNDS_FROM_FILE.get(logFile.getFile().getPath()),
         e);
   }
 }
Beispiel #3
0
 private void openHeadLogFile() throws ChangelogException {
   final LogFile<K, V> head =
       LogFile.newAppendableLogFile(new File(logPath, HEAD_LOG_FILE_NAME), recordParser);
   final Record<K, V> newestRecord = head.getNewestRecord();
   lastAppendedKey = newestRecord != null ? newestRecord.getKey() : null;
   logFiles.put(recordParser.getMaxKey(), head);
 }
Beispiel #4
0
  /** Update the cursors that were pointing to head after a rotation of the head log file. */
  private void updateOpenedCursorsOnHeadAfterRotation(
      List<Pair<AbortableLogCursor<K, V>, CursorState<K, V>>> cursors) throws ChangelogException {
    for (Pair<AbortableLogCursor<K, V>, CursorState<K, V>> pair : cursors) {
      final CursorState<K, V> cursorState = pair.getSecond();

      // Need to update the cursor only if it is pointing to the head log file
      if (cursorState.isValid() && isHeadLogFile(cursorState.logFile)) {
        final K previousKey = logFiles.lowerKey(recordParser.getMaxKey());
        final LogFile<K, V> logFile = findLogFileFor(previousKey);
        final AbortableLogCursor<K, V> cursor = pair.getFirst();
        cursor.reinitializeTo(
            new CursorState<K, V>(logFile, cursorState.filePosition, cursorState.record));
      }
    }
  }