code: public static long readLong(DataInput in) throws IOException {
          byte len=in.readByte();
          if(len == 0)
              return 0;
          return makeLong(in, len);
      }
docs: Reads a variable-length encoded long from an input stream.  Note that currently variable-length encoding is <em>not</em>
  used (a similar mechanism is used); this will be implemented later.
  @param in the input stream
  @return the long read from the input stream
  @throws IOException