[tpm] OID sorting

Uri Guttman uri at stemsystems.com
Fri May 1 12:15:19 PDT 2009

>>>>> "HB" == Henry Baragar <Henry.Baragar at instantiated.ca> writes:

  HB> #! /usr/bin/perl -w

use warnings is better these days.
  HB> use strict;

  HB> sub oid_tree_add {
  HB>     my ($tree, $oid, $value) = @_;
  HB>     my @oid = split /\b/, $oid;

why are you splitting on \b? you could just split on /\./ and get the
oid numbers. then you can simplify (and speed up) the code below.

  HB>     _oid_node_add($tree,$value, at oid);
  HB> }

  HB> sub _oid_node_add {
  HB>     my ($tree, $value, $key, @suboid) = @_;
  HB>     die "Expecting integer, got '$key'" unless $key =~/^\d+/;
  HB>     my $node = $tree->{$key};
  HB>     if (my $dot = shift @suboid) {
  HB> 	die "Expecting '.', got '$dot'" unless $dot eq ".";
  HB> 	$node->{subtree} = _oid_node_add($node->{subtree}, $value, @suboid);

i won't get into detail here but if you split on . as i said above, you
can just delete the check for dot. i can't see any reason to keep that

  HB>     }
  HB>     else {
  HB> 	$node->{value} = $value;
  HB>     }
  HB>     $tree->{$key} = $node;

i don't see $node being modified anywhere. you modify its keys/values
but $node is still the same hashref. so that line probably could go.
  HB>     $tree;

use explicit return statements vs implicit last value returns. this is a
bug waiting to happen if you ever add/modify code in that section. you
may forget what was being returned and return some other expression.

  HB> }

  HB> sub oid_tree_sorted {
  HB>     my ($tree) = @_;
  HB>     my @sorted;
  HB>     for my $key (sort {$a <=> $b} keys %$tree) {
  HB> 	my $node = $tree->{$key};
  HB> 	push @sorted, $node->{value} if $node->{value};
  HB> 	push @sorted, oid_tree_sorted($node->{subtree})
  HB> 	    if $node->{subtree};

if a node has a value it won't have a subtree. so you don't need the
second test. in general you could have eliminated the need for the
value/subtree keys and just used the value or hash ref. then you can
tell if it is a value or tree node with ref(). it is a simpler and
cleaner data tree design. again, i could be wrong in your details but
this is a common design idea in perl.

i leave the actual rewrite as an exercise as i am not up for it at the
moment. :)



Uri Guttman  ------  uri at stemsystems.com  --------  http://www.sysarch.com --
-----  Perl Code Review , Architecture, Development, Training, Support ------
--------- Free Perl Training --- http://perlhunter.com/college.html ---------
---------  Gourmet Hot Cocoa Mix  ----  http://bestfriendscocoa.com ---------

More information about the toronto-pm mailing list