public Path getCurrentPath() {
    // if we've read some WAL entries, get the Path we read from
    WALEntryBatch batchQueueHead = entryBatchQueue.peek();
    if (batchQueueHead != null) {
      return batchQueueHead.getLastWalPath();
    }
    // otherwise, we must be currently reading from the head of the log queue
    return logQueue.getQueue(walGroupId).peek();
  }
Creates a reader worker for a given WAL queue. Reads WAL entries off a given queue, batches the
entries, and puts them on a batch queue.
@param fs            the files system to use
@param conf          configuration to use
@param logQueue      The WAL queue to read off of
@param startPosition position in the first WAL to start reading from
@param filter        The filter to use while reading
@param source        replication source
hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/ReplicationSourceWALReader.java