use strict;
use warnings;
use Benchmark qw(cmpthese);

my @data28 = map {int (rand () * 256)} 1..28;

printf "%02x ", $_ for @data28;
print "\n";
my @xlate = thereAndBack (@data28);
printf "%02x ", $_ for @xlate;
print "\n\n";

my @data280 = map {int (rand () * 256)} 1..280;
my @data2800 = map {int (rand () * 256)} 1..2800;

cmpthese (-1,
    {
        data28 => sub {thereAndBack (@data28)},
        data280 => sub {thereAndBack (@data280)},
        data2800 => sub {thereAndBack (@data2800)},
    }
);


sub thereAndBack {
    return fromKarma (toKarma (@_));
}


sub toKarma {
    die "Blocks must be multiples of 8 bytes" if @_ % 7;
    my @raw = @_;
    my @karma;
    
    while (@raw) {
        my @block = splice @raw, 0, 7;
        my $extra = 0;
        
        for my $byte (@block) {
            $extra |= $byte & 0x80;
            $byte &= 0x7F;
            $extra >>= 1;
        }
        
        push @karma, ($extra, @block);
    }
    
    return @karma;
}


sub fromKarma {
    die "Blocks must be multiples of 8 bytes" if @_ % 8;
    my @karma = @_;
    my @raw;
    
    while (@karma) {
        my @block = splice @karma, 0, 8;
        my $extra = shift @block;
        
        for my $byte (reverse @block) {
            $extra <<= 1;
            $byte |= $extra & 0x80;
        }
        
        push @raw, @block;
    }
    
    return @raw;
}

##</code><code>##

37 8b a0 23 ef 46 68 f8 a1 75 71 de aa eb 0e ee 08 54 c7 77 9f 0b ee d7 d3 f4 34 69 
37 8b a0 23 ef 46 68 f8 a1 75 71 de aa eb 0e ee 08 54 c7 77 9f 0b ee d7 d3 f4 34 69 

           Rate data2800  data280   data28
data2800  124/s       --     -90%     -98%
data280  1228/s     888%       --     -85%
data28   8200/s    6496%     568%       --