Jon Portnoy > IRC-Server-Tree-0.05 > IRC::Server::Tree

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Module Version: 0.05   Source  

NAME ^

IRC::Server::Tree - Manipulate an IRC "spanning tree"

SYNOPSIS ^

  ## Basic path-tracing usage:
  my $tree = IRC::Server::Tree->new;

  $tree->add_node_to_top($_) for qw/ peerA peerB /;

  $tree->add_node_to_name('peerA', 'leafA');
  $tree->add_node_to_name('peerA', 'leafB');

  $tree->add_node_to_name('peerB', 'hubA');
  $tree->add_node_to_name('hubA', 'peerB');

  ## ARRAY of hop names between root and peerB:
  my $hop_names = $tree->trace( 'peerB' );

See IRC::Server::Tree::Network for a simpler and more specialized interface to the tree.

See the DESCRIPTION for a complete method list.

DESCRIPTION ^

This piece was split out of a pending project because it may prove otherwise useful. See IRC::Server::Tree::Network for higher-level (and simpler) methods pertaining to manipulation of an IRC network specifically; a Network instance also provides an optional memory-for-speed tradeoff via memoization of traced paths.

IRC servers are linked to form a network. An IRC network is defined as a 'spanning tree' per RFC1459; this module is an array-type object representing such a tree, with convenient path resolution methods for determining route "hops" and extending or shrinking the tree.

An IRC network tree is essentially unordered; any node can have any number of child nodes, with the only rules being that:

Currently, this module doesn't enforce the listed rules for performance reasons, but things will break if you add non-uniquely-named nodes. Be warned. In fact, this module doesn't sanity check very much of anything; an IRC::Server::Tree::Network does much more to validate the tree and passed arguments.

A new Tree can be created from an existing Tree:

  my $new_tree = IRC::Server::Tree->new( $old_tree );

In principle, the general structure of the tree is your average deep array-of-arrays:

  $self => [
    hubA => [
      leafA => [],
      leafB => [],
    ],

    hubB => [
      leafC => [],
      leafD => [],
    ],
  ],

The methods provided below can be used to manipulate the tree and determine hops in a path to an arbitrary node using a breadth-first search.

Currently routes are not memoized; that's left to a higher layer or subclass.

new

Create a new network tree:

  my $tree = IRC::Server::Tree->new;

Create a new network tree from an old one or part of one (see "child_node_for" and "del_node_by_name"):

  my $tree = IRC::Server::Tree->new( $old_tree );

(Note that this will clone the old Tree object.)

Optionally create a tree from an ARRAY, if you really know what you're doing:

  my $tree = IRC::Server::Tree->new(
    [
      hubA => [
        hubB => [
          hubBleaf1 => [],
        ],
        leaf1 => [],
        leaf2 => [],
      ],
    ],
  );

add_node_to_parent_ref

  ## Add empty node to parent ref:
  $tree->add_node_to_parent_ref( $parent_ref, $new_name );
  ## Add existing node to parent ref:
  $tree->add_node_to_parent_ref( $parent_ref, $new_name, $new_ref );

Adds an empty or preexisting node to a specified parent reference.

Also see "add_node_to_top", "add_node_to_name"

add_node_to_top

  $tree->add_node_to_top( $new_name );
  $tree->add_node_to_top( $new_name, $new_ref );

Also see "add_node_to_parent_ref", "add_node_to_name"

add_node_to_name

  $tree->add_node_to_name( $parent_name, $name );
  $tree->add_node_to_name( $parent_name, $name, $new_ref );

Adds an empty or specified node to the specified parent name.

For example:

  $tree->add_node_to_top( 'MyHub1' );
  $tree->add_node_to_name( 'MyHub1', 'MyLeafA' );

  ## Existing nodes under our new node
  my $new_node = [ 'MyLeafB' => [] ];
  $tree->add_node_to_name( 'MyHub1', 'MyHub2', $new_node );

as_hash

  my $hash_ref = $tree->as_hash;
  my $hash_ref = $tree->as_hash( $parent_ref );

Get a (possibly deep) HASH describing the state of the tree underneath the specified parent reference, or the entire tree if none is specified.

For example:

  my $hash_ref = $tree->as_hash( $self->child_node_for('MyHub1') );

Also see "child_node_for"

as_list

  my @tree = $tree->as_list;
  my @tree = $tree->as_list( $parent_ref );

Returns the tree in list format.

Not useful for most purposes and may be removed.

child_node_for

  my $child_node = $tree->child_node_for( $parent_name );
  my $child_node = $tree->child_node_for( $parent_name, $start_ref );

Finds and returns the named child node from the tree.

Starts at the root of the tree or the specified parent reference.

del_node_by_name

  $tree->del_node_by_name( $parent_name );
  $tree->del_node_by_name( $parent_name, $start_ref );

Finds and deletes the named child from the tree.

Returns the deleted node.

names_beneath

  my $names = $tree->names_beneath( $parent_name );
  my $names = $tree->names_beneath( $parent_ref );

Return an arrayref of all names in the tree beneath the specified parent node.

Takes either the name of a node in the tree or a reference to a node.

path_by_indexes

  my $names = $tree->path_by_indexes( $index_route );
  my $names = $tree->path_by_indexes( $index_route, $parent_ref );

Given an array of index hops as retrieved by "trace_indexes", retrieve the name for each hop.

This is mostly used internally by "trace".

print_map

  $tree->print_map;
  $tree->print_map( $start_ref );

Prints a visualization of the network map to STDOUT.

trace

  my $names = $tree->trace( $parent_name );
  my $names = $tree->trace( $parent_name, $start_ref );

Returns an arrayref of the names of every hop in the path to the specified parent name.

Starts tracing from the root of the tree unless a parent node reference is also specified.

The last hop returned is the target's name.

trace_indexes

Primarily intended for internal use. This is the breadth-first search that other methods use to find a node. There is nothing very useful you can do with this externally except count hops; it is documented here to show how path resolution works.

Returns an arrayref consisting of the index of every hop taken to get to the node reference belonging to the specified node name starting from the root of the tree or the specified parent node reference.

Given a network:

  hubA
    leafA
    leafB
    hubB
      leafC
      leafD

trace_indexes('leafD') would return:

  [ 1, 5, 1 ]

These are the indexes into the node references (arrays) owned by each hop, including the last hop. Retrieving their names requires subtracting one from each index; "trace" handles this.

AUTHOR ^

Jon Portnoy <avenj@cobaltirc.org>

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