# https://perlmonks.org/?node_id=11152186
$ ./rtoa-pgatram-allinone2 t1.txt t1.txt t1.txt t1.txt | cksum
do_it_all time    :    0.515 secs  fast_io scan, line_get
do_it_all time    :    0.490 secs  fast_io memory mapping
737201628 75552000

##</code><code>##

// Read an input file of Roman Numerals and do it all
static void do_it_all(
   std::string_view fname       //  in: file name containing a list of Roman Numerals
)
{
   try {
   #if 1
      // Load entire file to memory through memory mapping.
      using file_loader_type = fast_io::native_file_loader;
      file_loader_type loader(fname, fast_io::open_mode::in | fast_io::open_mode::follow);
      // Loop through contiguous container of the file.
      for (char const *first{loader.data()}, *last{loader.data()+loader.size()}; first!=last; ) {
         auto start_ptr{first}; first = fast_io::find_lf(first, last); auto end_ptr{first};
         if (start_ptr == end_ptr) continue;
         int dec = roman_to_dec(std::string_view(start_ptr, end_ptr - start_ptr));
         fast_io::io::println(dec);
         ++first;
      }
   #else
      fast_io::filebuf_file fbf(fname, fast_io::open_mode::in | fast_io::open_mode::follow);
      for (std::string line; fast_io::io::scan<true>(fbf, fast_io::mnp::line_get(line)); ) {
         fast_io::io::println(roman_to_dec(line));
      }
   #endif
   }
   catch (fast_io::error e) {
      fast_io::io::perrln("Error opening '", fname, "' : ", e);
   };
}

##</code><code>##

# https://perlmonks.org/?node_id=11152186
$ time ./rtoa-pgatram-allinone2 t1.txt t1.txt t1.txt t1.txt | cksum
do_it_all time    :    0.490 secs  fast_io memory mapping
737201628 75552000

real    0m0.492s
user    0m0.471s
sys     0m0.037s

# https://perlmonks.org/?node_id=11152168 max_workers => 32
$ time perl rtoa-pgatram-mce.pl t1.txt t1.txt t1.txt t1.txt | cksum
rtoa pgatram start
time 0.480 secs
737201628 75552000

real    0m0.504s
user    0m13.887s
sys     0m0.231s

# https://perlmonks.org/?node_id=11152168 max_workers => 64
$ time perl rtoa-pgatram-mce.pl t1.txt t1.txt t1.txt t1.txt | cksum
rtoa pgatram start
time 0.425 secs
737201628 75552000

real    0m0.449s
user    0m21.884s
sys     0m0.592s

##</code><code>##

      user_func   => sub {
         my ( $mce, $slurp_ref, $chunk_id, $output ) = ( @_, '' );
       # open my $fh, '<', $slurp_ref;
       # while ( <$fh> ) {
       #    chomp;
       #    my $n = 0;
       #    $n += $_ - $n % $_ * 2 for @rtoa[ unpack 'c*', $_ ];
       #    $output .= "$n\n";
       # }
       # close $fh;
         # output orderly
         MCE::relay {
       #    print $output;
         };
      }

##</code><code>##

# max_workers => 32
$ time perl rtoa-pgatram-mce.pl t1.txt t1.txt t1.txt t1.txt
rtoa pgatram start
time 0.052 secs

real    0m0.075s
user    0m0.122s
sys     0m0.170s

# max_workers => 64
$ time perl rtoa-pgatram-mce.pl t1.txt t1.txt t1.txt t1.txt
rtoa pgatram start
time 0.070 secs

real    0m0.093s
user    0m0.195s
sys     0m0.441s