NAME
    NetAddr::IP::Count - Count hosts in named subnets

SYNOPSIS
      use NetAddr::IP::Count;
      use NetAddr::IP;

      my $counter = new NetAddr::IP::Count;

      $counter->add('subnet-00', new NetAddr::IP("10.0.0.0/24"));
      $counter->add('other', @array_of_ip_addresses);
      $counter->add('other', @another_array_of_ip_addresses);

      $counter->cache(10);

      $counter->count(new NetAddr::IP("10.0.3.17"));
      $counter->count(@array_of_ip_addresses);

      $counter->valcount(new NetAddr::IP("10.0.3.17"), 23);
      @array_of_ipaddr_and_values = (new NetAddr::IP("10.0.3.17"), 23,
                                    new NetAddr::IP("101.0.23.107"), 2);
      $counter->valcount(@array_of_ipaddr_and_values);

      my $r_count = $counter->result;

      foreach my $subnet (keys %{$r_count}) {
          print "Subnet $subnet had ", $r_count->{$subnet}, " visits.\n";
      }

DESCRIPTION
    This module implements a symplistic way to match individual IP Addresses
    to subnets. It can be used to, among other things, help analyze HTTPD
    logs.

    The following methods are implemented.

    `->new'
        Creates a new counter. This method can be called passing as argument
        a hash where the keys are the name of the subnet group and the
        values are references to arrays of `NetAddr::IP' objects referencing
        each specific subnet. This is probably ok for static
        initializations.

    `->add'
        Adds a subnet group. The first parameter is the name of the group
        being added. If it's a new name, a new entry will be created. Else
        the given subnets are added to the existing ones, like in the
        example above.

    `->count'
        Verifies if the `NetAddr::IP'es are contained in any of the given
        subnets. If this is the case, the corresponding totals are updated.

    `->valcount'
        The same as `->count' but the argument is an array consisting of
        `NetAddr::IP'es and value pairs.

    `->result'
        Returns a reference to a hash containing the respective totals for
        each subnet group. The key to the hash is the subnet name given with
        `->add', the value is how many `NetAddr::IP' objects have been found
        to match that subnet group.

    `->cache'
        Since in usual applications `NetAddr::IPes' from the same subnet
        will tend to be grouped in clusters like in the case of HTTPD logs
        some caching is attempted to speed things up. The caching consists
        in storing the last few entries matched in an LRU list which is
        checked before going through all the stored subnets.

        This can improve response times if tuned sensibly, however consider
        that every miss will cause every entry in the cache to be checked
        twice, one in the cache and one in the normal process so it's
        important to tune the cache.

        The default cache size is 5, which can be changed by calling the
        `->cache' method as in the example. The old value of the cache size
        is returned.

AUTHOR
    Luis E. Munoz <lem@cantv.net>. Alvaro Carvajal <alvaro@cantv.net>
    contributed the valcount method.

SEE ALSO
    perl(1), NetAddr::IP(1).

