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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% --

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

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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