default long readLong(long position) throws IOException {
        byte[] valBuffer = new byte[8];
        read(position, valBuffer, 0, 8);
        return Platform.getLong(valBuffer, Platform.BYTE_ARRAY_OFFSET);
    }
Read exactly <i>size</i>s bytes from this ByteBufferReader from <i>position</i> into <i>dst</i>.

Whether this function may or may not change the position of datasource is implementation specific.
indexr-common/src/main/java/io/indexr/io/ByteBufferReader.java