public static int compareTo(byte[] buf1, int o1, int l1, ByteBuffer buf2, int o2, int l2) {
    return ComparerHolder.BEST_COMPARER.compareTo(buf1, o1, l1, buf2, o2, l2);
  }
ByteBuffer to hash offset to start from length to hash
hbase-common/src/main/java/org/apache/hadoop/hbase/util/ByteBufferUtils.java