That line below your signature is somewhat enigmatic:

The code present a class:BiMap, which supports the following methods: 7 ) { strncpy( (char*)( iHash script for RAD and testing), and a brief description. , CLEAN_AFTER_BUILD =used, newSize ); for( i = 0; i = pair; bm--1

I've tried setting up a bidirectional hash using XS code. It makes both key and values into keys and misuses the IV slot of SV of a hash entry to store the pointer to the crossover hash key.

However, the benchmarks are disappointing: 

use blib;
use Hash::Bidirectional;
use Benchmark qw(cmpthese);
use Devel::Size qw(total_size);

use strict;
use warnings;

my $hn = {};
my $hb = bless {}, 'Hash::Bidirectional';

my $i = 0;
for ( 'aaaaz' .. 'zzzzz') {
    $i++;
    $hn->{$_} = $i;   # - normal hash
    $hn->{$i} = $_;   # /
    $hb->pair($_,$i); # - bidirectional hash
}
print "size normal hash: ", total_size($hn),"\n";
print "size bi_dir hash: ", total_size($hb),"\n";

cmpthese( 10000000, {
    normal => sub { $hn->{$hn->{shmem}} },
    bi_dir => sub { $hb->get($hb->get('shmem')) },
});
__END__
size normal hash: 3025679168
size bi_dir hash: 2360323536
            Rate bi_dir normal
bi_dir 2801120/s     --   -62%
normal 7407407/s   164%     --

[download]

Improvement of 22% in memory and more than double time for lookup? Why? Is it due to method call/XS overhead? XS code below.

<Reveal this spoiler or all in this thread>
perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

In reply to Re^2: Bidirectional lookup algorithm? (poor XS solution) by shmem
in thread Bidirectional lookup algorithm? (Updated: further info.) by BrowserUk

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