A (kinda) Circular Cache

[mr.nick]

Category:

Miscellaneous

Description:

A very simple, small, efficient (n) cache that maintains a limited set of items. Accessing an items moves it to the front of the cache which speeds location and refreshes it's age in the cache.

package cache;

use strict;
######################################################################
+########
sub new {
  my $class=shift;
  my $size=shift;
  my $self=bless {};
  
  $size=30 unless $size;

  $self->{array}=[];
  $self->{size}=$size;

  $self;
}

sub ins {
  my $self=shift;
  my $id=shift;
  my $data=shift;

  my $array=$self->{array};

  unshift @$array,[$id,$data];

  if ($#{$array} > $self->{size}) {
    pop @$array;
  }
}

sub get {
  my $self=shift;
  my $id=shift;

  my $array=$self->{array};
  my $data;

  for my $p (0..$#{$array}) {
    if ($array->[$p]->[0] eq $id) {
      $data=$array->[$p]->[1];
      splice(@$array,$p,1);
      unshift @$array,[$id,$data];
      last;
    }
  }

  return unless defined $data;
  $data;
}

sub del {
  my $self=shift;
  my $id=shift;

  my $array=$self->{array};
  my $data;

  for my $p (0..$#{$array}) {
    if ($array->[$p]->[0] eq $id) {
      splice(@$array,$p,1);
      last;
    }
  }
}

sub show {
  my $self=shift;
  my $array=$self->{array};
  local $_;

  for  (@$array) {
    print "id $_->[0] data $_->[1]\n";
  }
}
  

1;