private void readOplogMagicSeqRecord(DataInput dis, File f, OPLOG_TYPE type) throws IOException {
    byte[] seq = new byte[OPLOG_TYPE.getLen()];
    dis.readFully(seq);
    for (int i = 0; i < OPLOG_TYPE.getLen(); i++) {
      if (seq[i] != type.getBytes()[i]) {
        if (logger.isTraceEnabled(LogMarker.PERSIST_RECOVERY_VERBOSE)) {
          logger.trace(LogMarker.PERSIST_RECOVERY_VERBOSE,
              "oplog magic code mismatched at byte:{}, value:{}", (i + 1), seq[i]);
        }
        throw new DiskAccessException("Invalid oplog (" + type.name() + ") file provided: " + f,
            getParent());
      }
    }
    if (logger.isTraceEnabled(LogMarker.PERSIST_RECOVERY_VERBOSE)) {
      StringBuilder sb = new StringBuilder();
      for (int i = 0; i < OPLOG_TYPE.getLen(); i++) {
        sb.append(" ").append(seq[i]);
      }
      logger.trace(LogMarker.PERSIST_RECOVERY_VERBOSE, "oplog magic code: {}", sb);
    }
    readEndOfRecord(dis);
  }
@throws DiskAccessException if this file does not belong to our parent
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java