How to use

create

method

in

org.apache.hadoop.hdfs.server.namenode.FSEditLogOp$Reader

 private void dumpRemainingEditLogs() {
  byte[] buf = this.getData();
  byte[] remainingRawEdits = Arrays.copyOfRange(buf, 0, this.size());
  ByteArrayInputStream bis = new ByteArrayInputStream(remainingRawEdits);
  DataInputStream dis = new DataInputStream(bis);
  FSEditLogLoader.PositionTrackingInputStream tracker =
    new FSEditLogLoader.PositionTrackingInputStream(bis);
  FSEditLogOp.Reader reader = FSEditLogOp.Reader.create(dis, tracker,
    NameNodeLayoutVersion.CURRENT_LAYOUT_VERSION);
  FSEditLogOp op;
  LOG.warn("The edits buffer is " + size() + " bytes long with " + numTxns +
    " unflushed transactions. " +
    "Below is the list of unflushed transactions:");
  int numTransactions = 0;
  try {
   while ((op = reader.readOp(false)) != null) {
    LOG.warn("Unflushed op [" + numTransactions + "]: " + op);
    numTransactions++;
   }
  } catch (IOException ioe) {
   // If any exceptions, print raw bytes and stop.
   LOG.warn("Unable to dump remaining ops. Remaining raw bytes: " +
     Hex.encodeHexString(remainingRawEdits), ioe);
  }
 }
}

void setBytes(byte[] newBytes, int version) throws IOException {
 inner.setData(newBytes);
 tracker = new FSEditLogLoader.PositionTrackingInputStream(inner);
 in = new DataInputStream(tracker);
 this.version = version;
 reader = FSEditLogOp.Reader.create(in, tracker, version);
}

reader = FSEditLogOp.Reader.create(dataIn, tracker, logVersion);
reader.setMaxOpSize(maxOpSize);
state = State.OPEN;