jsFind/trunk/jsFind.pm

package jsFind;

use 5.008004;
use strict;
use warnings;
use HTML::Entities;

our $VERSION = '0.03';

use Exporter 'import';
use Carp;

our @ISA = qw(Exporter);

BEGIN {
        import 'jsFind::Node';
}

=head1 NAME

jsFind - generate index for jsFind using B-Tree

=head1 SYNOPSIS

  use jsFind;
  my $t = new jsFind(B => 4);
  my $f = 1;
  foreach my $k (qw{minima ut dolorem sapiente voluptatem}) {
        $t->B_search(Key => $k,
                Data => {
                        "path" => {
                        t => "word $k",
                        f => $f },
                },
                Insert => 1,
                Append => 1,
        );
  }

=head1 DESCRIPTION

This module can be used to create index files for jsFind, powerful tool for
adding a search engine to a CDROM archive or catalog without requiring the
user to install anything. 

Main difference between this module and scripts delivered with jsFind are:

=over 5

=item *

You don't need to use swish-e to create index

=item *

You can programatically (and incrementaly) create index for jsFind

=back

=head1 jsFind methods

C<jsFind> is mode implementing methods which you, the user, are going to
use to create indexes.

=head2 new

Create new tree. Arguments are C<B> which is maximum numbers of keys in
each node and optional C<Root> node. Each root node may have child nodes.

All nodes are objects from C<jsFind::Node>.

 my $t = new jsFind(B => 4);

=cut

my $DEBUG = 1;

sub new {
  my $package = shift;
  my %ARGV = @_;
  croak "Usage: {$package}::new(B => number [, Root => root node ])"
      unless exists $ARGV{B};
  if ($ARGV{B} % 2) {
    my $B = $ARGV{B} + 1;
    carp "B must be an even number.  Using $B instead.";
    $ARGV{B} = $B;
  }
    
  my $B = $ARGV{B};
  my $Root = exists($ARGV{Root}) ? $ARGV{Root} : jsFind::Node->emptynode;
  bless { B => $B, Root => $Root } => $package;
}

=head2 B_search

Search, insert, append or replace data in B-Tree

 $t->B_search(
        Key => 'key value',
        Data => { "path" => {
                        "t" => "title of document",
                        "f" => 99,
                        },
                },
        Insert => 1,
        Append => 1,
 );

Semantics:

If key not found, insert it iff C<Insert> argument is present.

If key B<is> found, replace existing data iff C<Replace> argument
is present or add new datum to existing iff C<Append> argument is present.

=cut

sub B_search {
  my $self = shift;
  my %args = @_;
  my $cur_node = $self->root;
  my $k = $args{Key};
  my $d = $args{Data};
  my @path;

  if ($cur_node->is_empty) {    # Special case for empty root
    if ($args{Insert}) {
      $cur_node->kdp_insert($k => $d);
      return $d;
    } else {
      return undef;
    }
  }

  # Descend tree to leaf
  for (;;) {

    # Didn't hit bottom yet.

    my($there, $where) = $cur_node->locate_key($k);
    if ($there) {               # Found it!
      if ($args{Replace}) {
        $cur_node->kdp_replace($where, $k => $d);
      } elsif ($args{Append}) {
        $cur_node->kdp_append($where, $k => $d);
      }
      return $cur_node->data($where);
    }
    
    # Not here---must be in a subtree.
    
    if ($cur_node->is_leaf) {   # But there are no subtrees
      return undef unless $args{Insert}; # Search failed
      # Stuff it in
      $cur_node->kdp_insert($k => $d);
      if ($self->node_overfull($cur_node)) { # Oops--there was no room.
        $self->split_and_promote($cur_node, @path);
      } 
      return $d;
    }

    # There are subtrees, and the key is in one of them.

    push @path, [$cur_node, $where];    # Record path from root.

    # Move down to search the subtree
    $cur_node = $cur_node->subnode($where);

    # and start over.
  }                             # for (;;) ...

  croak ("How did I get here?");
}


sub split_and_promote_old {
  my $self = shift;
  my ($cur_node, @path) = @_;
  
  for (;;) {
    my ($newleft, $newright, $kdp) = $cur_node->halves($self->B / 2);
    my ($up, $where) = @{pop @path};
    if ($up) {
      $up->kdp_insert(@$kdp);
      my ($tthere, $twhere) = $up->locate_key($kdp->[0]);
      croak "Couldn't find key `$kdp->[0]' in node after just inserting it!"
          unless $tthere;
      croak "`$kdp->[0]' went into node at `$twhere' instead of expected `$where'!"
          unless $twhere == $where;
      $up->subnode($where,   $newleft);
      $up->subnode($where+1, $newright);
      return unless $self->node_overfull($up);
      $cur_node = $up;
    } else { # We're at the top; make a new root.
      my $newroot = new jsFind::Node ([$kdp->[0]], 
                                     [$kdp->[1]], 
                                     [$newleft, $newright]);
      $self->root($newroot);
      return;
    }
  }
  
}

sub split_and_promote {
  my $self = shift;
  my ($cur_node, @path) = @_;
  
  for (;;) {
    my ($newleft, $newright, $kdp) = $cur_node->halves($self->B / 2);
    my ($up, $where) = @{pop @path} if (@path);
    if ($up) {
      $up->kdp_insert(@$kdp);
      if ($DEBUG) {
        my ($tthere, $twhere) = $up->locate_key($kdp->[0]);
        croak "Couldn't find key `$kdp->[0]' in node after just inserting it!"
          unless $tthere;
        croak "`$kdp->[0]' went into node at `$twhere' instead of expected `$where'!"
          unless $twhere == $where;
      }
      $up->subnode($where,   $newleft);
      $up->subnode($where+1, $newright);
      return unless $self->node_overfull($up);
      $cur_node = $up;
    } else { # We're at the top; make a new root.
      my $newroot = new jsFind::Node([$kdp->[0]], 
                                     [$kdp->[1]], 
                                     [$newleft, $newright]);
      $self->root($newroot);
      return;
    }
  }
}

=head2 B

Return B (maximum number of keys)

 my $max_size = $t->B;

=cut

sub B {
  $_[0]{B};
}

=head2 root

Returns root node

 my $root = $t->root;

=cut

sub root {
  my ($self, $newroot) = @_;
  $self->{Root} = $newroot if defined $newroot;
  $self->{Root};
}

=head2 node_overfull

Returns if node is overfull

 if ($node->node_overfull) { something }

=cut

sub node_overfull {
  my $self = shift;
  my $node = shift;
  $node->size > $self->B;
}

=head2 to_string

Returns your tree as formatted string.

 my $text = $root->to_string;

Mostly usefull for debugging as output leaves much to be desired.

=cut

sub to_string {
  $_[0]->root->to_string;
}

=head2 to_dot

Create Graphviz graph of your tree

 my $dot_graph = $root->to_dot;

=cut

sub to_dot {
        my $self = shift;

        my $dot = qq/digraph dns {\nrankdir=LR;\n/;
        $dot .= $self->root->to_dot;
        $dot .= qq/\n}\n/;

        return $dot;
}

=head2 to_jsfind

Create xml index files for jsFind. This should be called after
your B-Tree has been filled with data.

 $root->to_jsfind('/full/path/to/index/dir/');

Returns number of nodes in created tree.

There is also longer version if you want to recode your data charset
into different one (probably UTF-8):

 $root->to_jsfind('/full/path/to/index/dir/','ISO-8859-2','UTF-8');

Destination encoding is UTF-8 by default, so you don't have to specify it.

 $root->to_jsfind('/full/path/to/index/dir/','WINDOWS-1250');

=cut

my $iconv;
my $iconv_l1;

sub to_jsfind {
        my $self = shift;

        my $path = shift || confess "to_jsfind need path to your index!";

        my ($from_cp,$to_cp) = @_;

        $to_cp ||= 'UTF-8';

        if ($from_cp && $to_cp) {
                $iconv = Text::Iconv->new($from_cp,$to_cp);
        }
        $iconv_l1 = Text::Iconv->new('ISO-8859-1',$to_cp);

        $path .= "/" if ($path =~ /\/$/);
        #carp "creating directory for index '$path'" if (! -w $path);

        return $self->root->to_jsfind($path,"0");
}


# private, default cmd function
sub default_cmp {
  $_[0] cmp $_[1];
}

=head2 _recode

This is internal function to recode charset.

It will also try to decode entities in data using L<HTML::Entities>.

=cut

sub _recode {
        my $self = shift;
        my $text = shift || return;

        sub _decode_html_entities {
                my $data = shift || return;
                $data = $iconv_l1->convert(decode_entities($data)) || croak "entity decode problem: $data";
        }

        if ($iconv) {
                $text = $iconv->convert($text) || $text && carp "convert problem: $text";
                $text =~ s/(\&\w+;)/_decode_html_entities($1)/ges;
        }

        return $text;
}

#####################################################################

=head1 jsFind::Node methods

Each node has C<k> key-data pairs, with C<B> <= C<k> <= C<2B>, and 
each has C<k+1> subnodes, which might be null.

The node is a blessed reference to a list with three elements:

  ($keylist, $datalist, $subnodelist)

each is a reference to a list list.

The null node is represented by a blessed reference to an empty list.

=cut

package jsFind::Node;

use warnings;
use strict;

use Carp;
use File::Path;
use Text::Iconv;

use base 'jsFind';

my $KEYS = 0;
my $DATA = 1;
my $SUBNODES = 2;

=head2 new

Create New node

 my $node = new jsFind::Node ($keylist, $datalist, $subnodelist);

You can also mit argument list to create empty node.

 my $empty_node = new jsFind::Node;

=cut

sub new {
  my $self = shift;
  my $package = ref $self || $self;
  croak "Internal error:  jsFind::Node::new called with wrong number of arguments."
      unless @_ == 3 || @_ == 0;
  bless [@_] => $package;
}

=head2 locate_key

Locate key in node using linear search. This should probably be replaced
by binary search for better performance.

 my ($found, $index) = $node->locate_key($key, $cmp_coderef);

Argument C<$cmp_coderef> is optional reference to custom comparison
operator.

Returns (1, $index) if $key[$index] eq $key.

Returns (0, $index) if key could be found in $subnode[$index].

In scalar context, just returns 1 or 0.

=cut

sub locate_key {
  # Use linear search for testing, replace with binary search.
  my $self = shift;
  my $key = shift;
  my $cmp = shift || \&jsFind::default_cmp;
  my $i;
  my $cmp_result;
  my $N = $self->size;
  for ($i = 0; $i < $N; $i++) {
    $cmp_result = &$cmp($key, $self->key($i));
    last if $cmp_result <= 0;
  }
  
  # $i is now the index of the first node-key greater than $key
  # or $N if there is no such.  $cmp_result is 0 iff the key was found.
  (!$cmp_result, $i);
}


=head2 emptynode

Creates new empty node

 $node = $root->emptynode;
 $new_node = $node->emptynode;

=cut

sub emptynode {
  new($_[0]);                   # Pass package name, but not anything else.
}

=head2 is_empty

Test if node is empty

 if ($node->is_empty) { something }

=cut

# undef is empty; so is a blessed empty list.
sub is_empty {
  my $self = shift;
  !defined($self) || $#$self < 0;
}

=head2 key

Return C<$i>th key from node

 my $key = $node->key($i);

=cut

sub key {
#  my ($self, $n) = @_;
#  $self->[$KEYS][$n];

#       speedup
   $_[0]->[$KEYS][$_[1]];
}

=head2 data

Return C<$i>th data from node

 my $data = $node->data($i);

=cut

sub data {
  my ($self, $n) = @_;
  $self->[$DATA][$n];
}

=head2 kdp_replace

Set key data pair for C<$i>th element in node

 $node->kdp_replace($i, "key value" => {
        "data key 1" => "data value 1",
        "data key 2" => "data value 2",
 };

=cut

sub kdp_replace {
  my ($self, $n, $k => $d) = @_;
  if (defined $k) {
    $self->[$KEYS][$n] = $k;
    $self->[$DATA][$n] = $d;
  }
  [$self->[$KEYS][$n], 
   $self->[$DATA][$n]];
}

=head2 kdp_insert

Insert key/data pair in tree

  $node->kdp_insert("key value" => "data value");

No return value.

=cut

sub kdp_insert {
  my $self = shift;
  my ($k => $d) = @_;
  my ($there, $where) = $self->locate_key($k) unless $self->is_empty;

  if ($there) { croak("Tried to insert `$k => $d' into node where `$k' was already present."); }

  # undef fix
  $where ||= 0;

  splice(@{$self->[$KEYS]}, $where, 0, $k);
  splice(@{$self->[$DATA]}, $where, 0, $d);
  splice(@{$self->[$SUBNODES]}, $where, 0, undef);
}

=head2 kdp_append

Adds new data keys and values to C<$i>th element in node

 $node->kdp_append($i, "key value" => {
        "added data key" => "added data value",
 };

=cut

sub kdp_append {
  my ($self, $n, $k => $d) = @_;
  if (defined $k) {
    $self->[$KEYS][$n] = $k;
    my ($kv,$dv) = %{$d};
    $self->[$DATA][$n]->{$kv} = $dv;
  }
  [$self->[$KEYS][$n], 
   $self->[$DATA][$n]];
}

=head2 subnode

Set new or return existing subnode

 # return 4th subnode
 my $my_node = $node->subnode(4);

 # create new subnode 5 from $my_node
 $node->subnode(5, $my_node);

=cut

sub subnode {
  my ($self, $n, $newnode) = @_;
  $self->[$SUBNODES][$n] = $newnode if defined $newnode;
  $self->[$SUBNODES][$n];
}

=head2 is_leaf

Test if node is leaf

 if ($node->is_leaf) { something }

=cut

sub is_leaf {
  my $self = shift;
  ! defined $self->[$SUBNODES][0]; # undefined subnode means leaf node.
}

=head2 size

Return number of keys in the node

 my $nr = $node->size;

=cut

sub size {
  my $self = shift;
  return scalar(@{$self->[$KEYS]});
}

=head2 halves

Split node into two halves so that keys C<0 .. $n-1> are in one node
and keys C<$n+1 ... $size> are in the other.

  my ($left_node, $right_node, $kdp) = $node->halves($n);

=cut

sub halves {
  my $self = shift;
  my $n = shift;
  my $s = $self->size;
  my @right;
  my @left;

  $left[$KEYS] = [@{$self->[$KEYS]}[0 .. $n-1]];
  $left[$DATA] = [@{$self->[$DATA]}[0 .. $n-1]];
  $left[$SUBNODES] = [@{$self->[$SUBNODES]}[0 .. $n]];

  $right[$KEYS] = [@{$self->[$KEYS]}[$n+1 .. $s-1]];
  $right[$DATA] = [@{$self->[$DATA]}[$n+1 .. $s-1]];
  $right[$SUBNODES] = [@{$self->[$SUBNODES]}[$n+1 .. $s]];

  my @middle = ($self->[$KEYS][$n], $self->[$DATA][$n]);

  ($self->new(@left), $self->new(@right), \@middle);
}

=head2 to_string

Dumps tree as string

 my $str = $root->to_string;

=cut

sub to_string {
  my $self = shift;
  my $indent = shift || 0;
  my $I = ' ' x $indent;
  return '' if $self->is_empty;
  my ($k, $d, $s) = @$self;
  my $result = '';
  $result .= defined($s->[0]) ? $s->[0]->to_string($indent+2) : '';
  my $N = $self->size;
  my $i;
  for ($i = 0; $i < $N; $i++) {
#    $result .= $I . "$k->[$i] => $d->[$i]\n";
    $result .= $I . "$k->[$i]\n";
    $result .= defined($s->[$i+1]) ? $s->[$i+1]->to_string($indent+2) : '';
  }
  $result;
}

=begin comment

use Data::Dumper;

sub to_string {
  my $self = shift;
  my $indent = shift || 0;
  my $path = shift || '0';
  return '' if $self->is_empty;
  my ($k, $d, $s) = @$self;
  my $result = '';
  $result .= defined($s->[0]) ? $s->[0]->to_string($indent+1,"$path/0") : '';
  my $N = $self->size;
  for (my $i = 0; $i < $N; $i++) {
        my $dump = Dumper($d->[$i]);
        $dump =~ s/[\n\r\s]+/ /gs;
        $dump =~ s/\$VAR1\s*=\s*//;
    $result .= sprintf("%-5s [%2d] %2s: %s => %s\n", $path, $i, $indent, $k->[$i], $dump);
    $result .= defined($s->[$i+1]) ? $s->[$i+1]->to_string($indent+1,"$path/$i") : '';
  }
  $result;
}

=end comment

=head2 to_dot

Recursivly walk nodes of tree

=cut

sub to_dot {
        my $self = shift;
        my $parent = shift;

        return '' if $self->is_empty;

        my $dot = '';

        my ($k, $d, $s) = @$self;
        my $N = $self->size;

        my @dot_keys;

        my $node_name = $parent || '_';
        $node_name =~ s/\W+//g;
        $node_name .= " [$N]";

        for (my $i = 0; $i <= $N; $i++) {
                if (my $key = $k->[$i]) {
                        push @dot_keys, qq{<$i>$key};
                }
                $dot .= $s->[$i]->to_dot(qq{"$node_name":$i}) if ($s->[$i]);
        }
        push @dot_keys, qq{<$N>...} if (! $self->is_leaf);

        my $label = join("|",@dot_keys);
        $dot .= qq{"$node_name" [ shape=record, label="$label" ];\n};

        $dot .= qq{$parent -> "$node_name";\n} if ($parent);

        $dot;
}

=head2 to_xml

Escape <, >, & and ", and to produce valid XML

=cut

my %escape = ('<'=>'&lt;', '>'=>'&gt;', '&'=>'&amp;', '"'=>'&quot;');
my $escape_re  = join '|' => keys %escape;

sub to_xml {
        my $self = shift || confess "you should call to_xml as object!";

        my $d = shift || return;
        $d = $self->SUPER::_recode($d);
        confess "escape_re undefined!" unless ($escape_re);
        $d =~ s/($escape_re)/$escape{$1}/g;
        return $d;
}

=head2 to_jsfind

Create jsFind xml files

 my $nr=$tree->to_jsfind('/path/to/index','0');

Returns number of elements created

=cut


sub to_jsfind {
        my $self = shift;
        my ($path,$file) = @_;

        return 0 if $self->is_empty;

        confess("path is undefined.") unless ($path);
        confess("file is undefined. Did you call \$t->root->to_jsfind(..) instead of \$t->to_jsfind(..) ?") unless (defined($file));

        my $nr_keys = 0;

        my ($k, $d, $s) = @$self;
        my $N = $self->size;

        my ($key_xml, $data_xml) = ("<n>","<d>");

        for (my $i = 0; $i <= $N; $i++) {
                my $key = lc($k->[$i]);

                if ($key) {
                        $key_xml .= '<k>'.$self->to_xml($key).'</k>';
                        $data_xml .= '<e>';
        #use Data::Dumper;
        #print Dumper($d->[$i]);
                        foreach my $path (keys %{$d->[$i]}) {
                                $data_xml .= '<l f="'.($d->[$i]->{$path}->{'f'} || 1).'" t="'.$self->to_xml($d->[$i]->{$path}->{'t'} || 'no title').'">'.$self->to_xml($path).'</l>';
                                $nr_keys++;
                        }
                        $data_xml .= '</e>';
                }

                $nr_keys += $s->[$i]->to_jsfind("$path/$file","$i") if ($s->[$i]);
        }

        $key_xml .= '</n>';
        $data_xml .= '</d>';

        if (! -e $path) {
                mkpath($path) || croak "can't create dir '$path': $!";
        }

        open(K, "> ${path}/${file}.xml") || croak "can't open '$path/$file.xml': $!";
        open(D, "> ${path}/_${file}.xml") || croak "can't open '$path/_$file.xml': $!";

        print K $key_xml;
        print D $data_xml;

        close(K);
        close(D);

        return $nr_keys;
}

1;
__END__

=head1 SEE ALSO

jsFind web site L<http://www.elucidsoft.net/projects/jsfind/>

B-Trees in perl web site L<http://perl.plover.com/BTree/>

=head1 AUTHORS

Mark-Jonson Dominus E<lt>mjd@pobox.comE<gt> wrote C<BTree.pm> which was
base for this module

Shawn P. Garbett E<lt>shawn@elucidsoft.netE<gt> wrote jsFind

Dobrica Pavlinusic E<lt>dpavlin@rot13.orgE<gt> wrote this module

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2004 by Dobrica Pavlinusic

This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your option)
any later version. This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.

=cut
1	dpavlin	1	package jsFind;
2
3			use 5.008004;
4			use strict;
5			use warnings;
6	dpavlin	11	use HTML::Entities;
7	dpavlin	1
8	dpavlin	11	our $VERSION = '0.03';
9	dpavlin	1
10	dpavlin	12	use Exporter 'import';
11			use Carp;
12
13			our @ISA = qw(Exporter);
14
15			BEGIN {
16			import 'jsFind::Node';
17			}
18
19	dpavlin	1	=head1 NAME
20
21			jsFind - generate index for jsFind using B-Tree
22
23			=head1 SYNOPSIS
24
25			use jsFind;
26	dpavlin	12	my $t = new jsFind(B => 4);
27			my $f = 1;
28			foreach my $k (qw{minima ut dolorem sapiente voluptatem}) {
29			$t->B_search(Key => $k,
30			Data => {
31			"path" => {
32			t => "word $k",
33			f => $f },
34			},
35			Insert => 1,
36			Append => 1,
37			);
38			}
39	dpavlin	1
40			=head1 DESCRIPTION
41
42			This module can be used to create index files for jsFind, powerful tool for
43			adding a search engine to a CDROM archive or catalog without requiring the
44			user to install anything.
45
46			Main difference between this module and scripts delivered with jsFind are:
47
48			=over 5
49
50			=item *
51
52			You don't need to use swish-e to create index
53
54			=item *
55
56			You can programatically (and incrementaly) create index for jsFind
57
58			=back
59
60	dpavlin	12	=head1 jsFind methods
61	dpavlin	1
62	dpavlin	12	C<jsFind> is mode implementing methods which you, the user, are going to
63			use to create indexes.
64	dpavlin	1
65	dpavlin	12	=head2 new
66	dpavlin	1
67			Create new tree. Arguments are C<B> which is maximum numbers of keys in
68			each node and optional C<Root> node. Each root node may have child nodes.
69
70			All nodes are objects from C<jsFind::Node>.
71
72			my $t = new jsFind(B => 4);
73
74			=cut
75
76			my $DEBUG = 1;
77
78			sub new {
79			my $package = shift;
80			my %ARGV = @_;
81			croak "Usage: {$package}::new(B => number [, Root => root node ])"
82			unless exists $ARGV{B};
83			if ($ARGV{B} % 2) {
84			my $B = $ARGV{B} + 1;
85			carp "B must be an even number. Using $B instead.";
86			$ARGV{B} = $B;
87			}
88
89			my $B = $ARGV{B};
90			my $Root = exists($ARGV{Root}) ? $ARGV{Root} : jsFind::Node->emptynode;
91			bless { B => $B, Root => $Root } => $package;
92			}
93
94	dpavlin	12	=head2 B_search
95	dpavlin	1
96			Search, insert, append or replace data in B-Tree
97
98	dpavlin	5	$t->B_search(
99			Key => 'key value',
100			Data => { "path" => {
101			"t" => "title of document",
102			"f" => 99,
103	dpavlin	7	},
104	dpavlin	5	},
105			Insert => 1,
106			Append => 1,
107			);
108	dpavlin	1
109			Semantics:
110
111			If key not found, insert it iff C<Insert> argument is present.
112
113			If key B<is> found, replace existing data iff C<Replace> argument
114			is present or add new datum to existing iff C<Append> argument is present.
115
116			=cut
117
118			sub B_search {
119			my $self = shift;
120			my %args = @_;
121			my $cur_node = $self->root;
122			my $k = $args{Key};
123			my $d = $args{Data};
124			my @path;
125
126			if ($cur_node->is_empty) { # Special case for empty root
127			if ($args{Insert}) {
128			$cur_node->kdp_insert($k => $d);
129			return $d;
130			} else {
131			return undef;
132			}
133			}
134
135			# Descend tree to leaf
136			for (;;) {
137
138			# Didn't hit bottom yet.
139
140			my($there, $where) = $cur_node->locate_key($k);
141			if ($there) { # Found it!
142			if ($args{Replace}) {
143			$cur_node->kdp_replace($where, $k => $d);
144			} elsif ($args{Append}) {
145			$cur_node->kdp_append($where, $k => $d);
146			}
147			return $cur_node->data($where);
148			}
149
150			# Not here---must be in a subtree.
151
152			if ($cur_node->is_leaf) { # But there are no subtrees
153			return undef unless $args{Insert}; # Search failed
154			# Stuff it in
155			$cur_node->kdp_insert($k => $d);
156			if ($self->node_overfull($cur_node)) { # Oops--there was no room.
157			$self->split_and_promote($cur_node, @path);
158			}
159			return $d;
160			}
161
162			# There are subtrees, and the key is in one of them.
163
164			push @path, [$cur_node, $where]; # Record path from root.
165
166			# Move down to search the subtree
167			$cur_node = $cur_node->subnode($where);
168
169			# and start over.
170			} # for (;;) ...
171
172			croak ("How did I get here?");
173			}
174
175
176
177			sub split_and_promote_old {
178			my $self = shift;
179			my ($cur_node, @path) = @_;
180
181			for (;;) {
182			my ($newleft, $newright, $kdp) = $cur_node->halves($self->B / 2);
183			my ($up, $where) = @{pop @path};
184			if ($up) {
185			$up->kdp_insert(@$kdp);
186			my ($tthere, $twhere) = $up->locate_key($kdp->[0]);
187			croak "Couldn't find key `$kdp->[0]' in node after just inserting it!"
188			unless $tthere;
189			croak "`$kdp->[0]' went into node at `$twhere' instead of expected `$where'!"
190			unless $twhere == $where;
191			$up->subnode($where, $newleft);
192			$up->subnode($where+1, $newright);
193			return unless $self->node_overfull($up);
194			$cur_node = $up;
195			} else { # We're at the top; make a new root.
196			my $newroot = new jsFind::Node ([$kdp->[0]],
197			[$kdp->[1]],
198			[$newleft, $newright]);
199			$self->root($newroot);
200			return;
201			}
202			}
203
204			}
205
206			sub split_and_promote {
207			my $self = shift;
208			my ($cur_node, @path) = @_;
209
210			for (;;) {
211			my ($newleft, $newright, $kdp) = $cur_node->halves($self->B / 2);
212			my ($up, $where) = @{pop @path} if (@path);
213			if ($up) {
214			$up->kdp_insert(@$kdp);
215			if ($DEBUG) {
216			my ($tthere, $twhere) = $up->locate_key($kdp->[0]);
217			croak "Couldn't find key `$kdp->[0]' in node after just inserting it!"
218			unless $tthere;
219			croak "`$kdp->[0]' went into node at `$twhere' instead of expected `$where'!"
220			unless $twhere == $where;
221			}
222			$up->subnode($where, $newleft);
223			$up->subnode($where+1, $newright);
224			return unless $self->node_overfull($up);
225			$cur_node = $up;
226			} else { # We're at the top; make a new root.
227			my $newroot = new jsFind::Node([$kdp->[0]],
228			[$kdp->[1]],
229			[$newleft, $newright]);
230			$self->root($newroot);
231			return;
232			}
233			}
234			}
235
236	dpavlin	12	=head2 B
237	dpavlin	1
238			Return B (maximum number of keys)
239
240			my $max_size = $t->B;
241
242			=cut
243
244			sub B {
245			$_[0]{B};
246			}
247
248	dpavlin	12	=head2 root
249	dpavlin	1
250			Returns root node
251
252			my $root = $t->root;
253
254			=cut
255
256			sub root {
257			my ($self, $newroot) = @_;
258			$self->{Root} = $newroot if defined $newroot;
259			$self->{Root};
260			}
261
262	dpavlin	12	=head2 node_overfull
263	dpavlin	1
264			Returns if node is overfull
265
266			if ($node->node_overfull) { something }
267
268			=cut
269
270			sub node_overfull {
271			my $self = shift;
272			my $node = shift;
273			$node->size > $self->B;
274			}
275
276	dpavlin	12	=head2 to_string
277	dpavlin	1
278			Returns your tree as formatted string.
279
280			my $text = $root->to_string;
281
282			Mostly usefull for debugging as output leaves much to be desired.
283
284			=cut
285
286			sub to_string {
287			$_[0]->root->to_string;
288			}
289
290	dpavlin	12	=head2 to_dot
291	dpavlin	1
292			Create Graphviz graph of your tree
293
294			my $dot_graph = $root->to_dot;
295
296			=cut
297
298			sub to_dot {
299			my $self = shift;
300
301			my $dot = qq/digraph dns {\nrankdir=LR;\n/;
302			$dot .= $self->root->to_dot;
303			$dot .= qq/\n}\n/;
304
305			return $dot;
306			}
307
308	dpavlin	12	=head2 to_jsfind
309	dpavlin	1
310			Create xml index files for jsFind. This should be called after
311			your B-Tree has been filled with data.
312
313			$root->to_jsfind('/full/path/to/index/dir/');
314
315			Returns number of nodes in created tree.
316
317	dpavlin	9	There is also longer version if you want to recode your data charset
318			into different one (probably UTF-8):
319
320			$root->to_jsfind('/full/path/to/index/dir/','ISO-8859-2','UTF-8');
321
322	dpavlin	11	Destination encoding is UTF-8 by default, so you don't have to specify it.
323
324			$root->to_jsfind('/full/path/to/index/dir/','WINDOWS-1250');
325
326	dpavlin	1	=cut
327
328	dpavlin	9	my $iconv;
329	dpavlin	11	my $iconv_l1;
330	dpavlin	9
331	dpavlin	1	sub to_jsfind {
332			my $self = shift;
333
334			my $path = shift \|\| confess "to_jsfind need path to your index!";
335
336	dpavlin	9	my ($from_cp,$to_cp) = @_;
337	dpavlin	11
338			$to_cp \|\|= 'UTF-8';
339
340	dpavlin	9	if ($from_cp && $to_cp) {
341			$iconv = Text::Iconv->new($from_cp,$to_cp);
342			}
343	dpavlin	11	$iconv_l1 = Text::Iconv->new('ISO-8859-1',$to_cp);
344	dpavlin	9
345	dpavlin	1	$path .= "/" if ($path =~ /\/$/);
346	dpavlin	11	#carp "creating directory for index '$path'" if (! -w $path);
347	dpavlin	1
348			return $self->root->to_jsfind($path,"0");
349			}
350
351
352			# private, default cmd function
353			sub default_cmp {
354			$_[0] cmp $_[1];
355			}
356
357	dpavlin	12	=head2 _recode
358	dpavlin	9
359			This is internal function to recode charset.
360
361	dpavlin	12	It will also try to decode entities in data using L<HTML::Entities>.
362	dpavlin	11
363	dpavlin	9	=cut
364
365			sub _recode {
366			my $self = shift;
367			my $text = shift \|\| return;
368
369	dpavlin	11	sub _decode_html_entities {
370			my $data = shift \|\| return;
371			$data = $iconv_l1->convert(decode_entities($data)) \|\| croak "entity decode problem: $data";
372			}
373
374	dpavlin	9	if ($iconv) {
375	dpavlin	11	$text = $iconv->convert($text) \|\| $text && carp "convert problem: $text";
376			$text =~ s/(\&\w+;)/_decode_html_entities($1)/ges;
377	dpavlin	9	}
378	dpavlin	11
379			return $text;
380	dpavlin	9	}
381
382	dpavlin	1	#####################################################################
383
384	dpavlin	12	=head1 jsFind::Node methods
385	dpavlin	1
386			Each node has C<k> key-data pairs, with C<B> <= C<k> <= C<2B>, and
387			each has C<k+1> subnodes, which might be null.
388
389			The node is a blessed reference to a list with three elements:
390
391			($keylist, $datalist, $subnodelist)
392
393			each is a reference to a list list.
394
395			The null node is represented by a blessed reference to an empty list.
396
397			=cut
398
399			package jsFind::Node;
400
401			use warnings;
402			use strict;
403
404			use Carp;
405			use File::Path;
406	dpavlin	9	use Text::Iconv;
407	dpavlin	1
408	dpavlin	9	use base 'jsFind';
409
410	dpavlin	1	my $KEYS = 0;
411			my $DATA = 1;
412			my $SUBNODES = 2;
413
414	dpavlin	12	=head2 new
415	dpavlin	1
416			Create New node
417
418			my $node = new jsFind::Node ($keylist, $datalist, $subnodelist);
419
420			You can also mit argument list to create empty node.
421
422			my $empty_node = new jsFind::Node;
423
424			=cut
425
426			sub new {
427			my $self = shift;
428			my $package = ref $self \|\| $self;
429			croak "Internal error: jsFind::Node::new called with wrong number of arguments."
430			unless @_ == 3 \|\| @_ == 0;
431			bless [@_] => $package;
432			}
433
434	dpavlin	12	=head2 locate_key
435	dpavlin	1
436			Locate key in node using linear search. This should probably be replaced
437			by binary search for better performance.
438
439			my ($found, $index) = $node->locate_key($key, $cmp_coderef);
440
441			Argument C<$cmp_coderef> is optional reference to custom comparison
442			operator.
443
444			Returns (1, $index) if $key[$index] eq $key.
445
446			Returns (0, $index) if key could be found in $subnode[$index].
447
448			In scalar context, just returns 1 or 0.
449
450			=cut
451
452			sub locate_key {
453			# Use linear search for testing, replace with binary search.
454			my $self = shift;
455			my $key = shift;
456			my $cmp = shift \|\| \&jsFind::default_cmp;
457			my $i;
458			my $cmp_result;
459			my $N = $self->size;
460			for ($i = 0; $i < $N; $i++) {
461			$cmp_result = &$cmp($key, $self->key($i));
462			last if $cmp_result <= 0;
463			}
464
465			# $i is now the index of the first node-key greater than $key
466			# or $N if there is no such. $cmp_result is 0 iff the key was found.
467			(!$cmp_result, $i);
468			}
469
470
471	dpavlin	12	=head2 emptynode
472	dpavlin	1
473			Creates new empty node
474
475			$node = $root->emptynode;
476			$new_node = $node->emptynode;
477
478			=cut
479
480			sub emptynode {
481			new($_[0]); # Pass package name, but not anything else.
482			}
483
484	dpavlin	12	=head2 is_empty
485	dpavlin	1
486			Test if node is empty
487
488			if ($node->is_empty) { something }
489
490			=cut
491
492			# undef is empty; so is a blessed empty list.
493			sub is_empty {
494			my $self = shift;
495			!defined($self) \|\| $#$self < 0;
496			}
497
498	dpavlin	12	=head2 key
499	dpavlin	1
500			Return C<$i>th key from node
501
502			my $key = $node->key($i);
503
504			=cut
505
506			sub key {
507			# my ($self, $n) = @_;
508			# $self->[$KEYS][$n];
509
510			# speedup
511			$_[0]->[$KEYS][$_[1]];
512			}
513
514	dpavlin	12	=head2 data
515	dpavlin	1
516			Return C<$i>th data from node
517
518			my $data = $node->data($i);
519
520			=cut
521
522			sub data {
523			my ($self, $n) = @_;
524			$self->[$DATA][$n];
525			}
526
527	dpavlin	12	=head2 kdp_replace
528	dpavlin	1
529			Set key data pair for C<$i>th element in node
530
531			$node->kdp_replace($i, "key value" => {
532			"data key 1" => "data value 1",
533			"data key 2" => "data value 2",
534			};
535
536			=cut
537
538			sub kdp_replace {
539			my ($self, $n, $k => $d) = @_;
540			if (defined $k) {
541			$self->[$KEYS][$n] = $k;
542			$self->[$DATA][$n] = $d;
543			}
544			[$self->[$KEYS][$n],
545			$self->[$DATA][$n]];
546			}
547
548	dpavlin	12	=head2 kdp_insert
549	dpavlin	1
550	dpavlin	12	Insert key/data pair in tree
551	dpavlin	1
552	dpavlin	12	$node->kdp_insert("key value" => "data value");
553
554			No return value.
555
556	dpavlin	1	=cut
557
558			sub kdp_insert {
559			my $self = shift;
560			my ($k => $d) = @_;
561			my ($there, $where) = $self->locate_key($k) unless $self->is_empty;
562
563			if ($there) { croak("Tried to insert `$k => $d' into node where `$k' was already present."); }
564
565			# undef fix
566			$where \|\|= 0;
567
568			splice(@{$self->[$KEYS]}, $where, 0, $k);
569			splice(@{$self->[$DATA]}, $where, 0, $d);
570			splice(@{$self->[$SUBNODES]}, $where, 0, undef);
571			}
572
573	dpavlin	12	=head2 kdp_append
574	dpavlin	1
575			Adds new data keys and values to C<$i>th element in node
576
577			$node->kdp_append($i, "key value" => {
578			"added data key" => "added data value",
579			};
580
581			=cut
582
583			sub kdp_append {
584			my ($self, $n, $k => $d) = @_;
585			if (defined $k) {
586			$self->[$KEYS][$n] = $k;
587			my ($kv,$dv) = %{$d};
588			$self->[$DATA][$n]->{$kv} = $dv;
589			}
590			[$self->[$KEYS][$n],
591			$self->[$DATA][$n]];
592			}
593
594	dpavlin	12	=head2 subnode
595	dpavlin	1
596			Set new or return existing subnode
597
598			# return 4th subnode
599			my $my_node = $node->subnode(4);
600
601			# create new subnode 5 from $my_node
602			$node->subnode(5, $my_node);
603
604			=cut
605
606			sub subnode {
607			my ($self, $n, $newnode) = @_;
608			$self->[$SUBNODES][$n] = $newnode if defined $newnode;
609			$self->[$SUBNODES][$n];
610			}
611
612	dpavlin	12	=head2 is_leaf
613	dpavlin	1
614			Test if node is leaf
615
616			if ($node->is_leaf) { something }
617
618			=cut
619
620			sub is_leaf {
621			my $self = shift;
622			! defined $self->[$SUBNODES][0]; # undefined subnode means leaf node.
623			}
624
625	dpavlin	12	=head2 size
626	dpavlin	1
627			Return number of keys in the node
628
629			my $nr = $node->size;
630
631			=cut
632
633			sub size {
634			my $self = shift;
635			return scalar(@{$self->[$KEYS]});
636			}
637
638	dpavlin	12	=head2 halves
639	dpavlin	1
640	dpavlin	12	Split node into two halves so that keys C<0 .. $n-1> are in one node
641			and keys C<$n+1 ... $size> are in the other.
642	dpavlin	1
643	dpavlin	12	my ($left_node, $right_node, $kdp) = $node->halves($n);
644
645	dpavlin	1	=cut
646
647			sub halves {
648			my $self = shift;
649			my $n = shift;
650			my $s = $self->size;
651			my @right;
652			my @left;
653
654			$left[$KEYS] = [@{$self->[$KEYS]}[0 .. $n-1]];
655			$left[$DATA] = [@{$self->[$DATA]}[0 .. $n-1]];
656			$left[$SUBNODES] = [@{$self->[$SUBNODES]}[0 .. $n]];
657
658			$right[$KEYS] = [@{$self->[$KEYS]}[$n+1 .. $s-1]];
659			$right[$DATA] = [@{$self->[$DATA]}[$n+1 .. $s-1]];
660			$right[$SUBNODES] = [@{$self->[$SUBNODES]}[$n+1 .. $s]];
661
662			my @middle = ($self->[$KEYS][$n], $self->[$DATA][$n]);
663
664			($self->new(@left), $self->new(@right), \@middle);
665			}
666
667	dpavlin	12	=head2 to_string
668	dpavlin	1
669			Dumps tree as string
670
671			my $str = $root->to_string;
672
673			=cut
674
675			sub to_string {
676			my $self = shift;
677			my $indent = shift \|\| 0;
678			my $I = ' ' x $indent;
679			return '' if $self->is_empty;
680			my ($k, $d, $s) = @$self;
681			my $result = '';
682			$result .= defined($s->[0]) ? $s->[0]->to_string($indent+2) : '';
683			my $N = $self->size;
684			my $i;
685			for ($i = 0; $i < $N; $i++) {
686			# $result .= $I . "$k->[$i] => $d->[$i]\n";
687			$result .= $I . "$k->[$i]\n";
688			$result .= defined($s->[$i+1]) ? $s->[$i+1]->to_string($indent+2) : '';
689			}
690			$result;
691			}
692
693			=begin comment
694
695			use Data::Dumper;
696
697			sub to_string {
698			my $self = shift;
699			my $indent = shift \|\| 0;
700			my $path = shift \|\| '0';
701			return '' if $self->is_empty;
702			my ($k, $d, $s) = @$self;
703			my $result = '';
704			$result .= defined($s->[0]) ? $s->[0]->to_string($indent+1,"$path/0") : '';
705			my $N = $self->size;
706			for (my $i = 0; $i < $N; $i++) {
707			my $dump = Dumper($d->[$i]);
708			$dump =~ s/[\n\r\s]+/ /gs;
709			$dump =~ s/\$VAR1\s=\s//;
710			$result .= sprintf("%-5s [%2d] %2s: %s => %s\n", $path, $i, $indent, $k->[$i], $dump);
711			$result .= defined($s->[$i+1]) ? $s->[$i+1]->to_string($indent+1,"$path/$i") : '';
712			}
713			$result;
714			}
715
716			=end comment
717
718	dpavlin	12	=head2 to_dot
719	dpavlin	1
720			Recursivly walk nodes of tree
721
722			=cut
723
724			sub to_dot {
725			my $self = shift;
726			my $parent = shift;
727
728			return '' if $self->is_empty;
729
730			my $dot = '';
731
732			my ($k, $d, $s) = @$self;
733			my $N = $self->size;
734
735			my @dot_keys;
736
737			my $node_name = $parent \|\| '_';
738			$node_name =~ s/\W+//g;
739			$node_name .= " [$N]";
740
741			for (my $i = 0; $i <= $N; $i++) {
742			if (my $key = $k->[$i]) {
743			push @dot_keys, qq{<$i>$key};
744			}
745			$dot .= $s->[$i]->to_dot(qq{"$node_name":$i}) if ($s->[$i]);
746			}
747			push @dot_keys, qq{<$N>...} if (! $self->is_leaf);
748
749			my $label = join("\|",@dot_keys);
750			$dot .= qq{"$node_name" [ shape=record, label="$label" ];\n};
751
752			$dot .= qq{$parent -> "$node_name";\n} if ($parent);
753
754			$dot;
755			}
756
757	dpavlin	12	=head2 to_xml
758	dpavlin	11
759			Escape <, >, & and ", and to produce valid XML
760
761			=cut
762
763			my %escape = ('<'=>'<', '>'=>'>', '&'=>'&', '"'=>'"');
764			my $escape_re = join '\|' => keys %escape;
765
766			sub to_xml {
767			my $self = shift \|\| confess "you should call to_xml as object!";
768
769			my $d = shift \|\| return;
770			$d = $self->SUPER::_recode($d);
771			confess "escape_re undefined!" unless ($escape_re);
772			$d =~ s/($escape_re)/$escape{$1}/g;
773			return $d;
774			}
775
776	dpavlin	12	=head2 to_jsfind
777	dpavlin	1
778			Create jsFind xml files
779
780	dpavlin	8	my $nr=$tree->to_jsfind('/path/to/index','0');
781	dpavlin	1
782			Returns number of elements created
783
784			=cut
785
786	dpavlin	11
787	dpavlin	1	sub to_jsfind {
788			my $self = shift;
789			my ($path,$file) = @_;
790
791			return 0 if $self->is_empty;
792
793	dpavlin	8	confess("path is undefined.") unless ($path);
794			confess("file is undefined. Did you call \$t->root->to_jsfind(..) instead of \$t->to_jsfind(..) ?") unless (defined($file));
795
796	dpavlin	1	my $nr_keys = 0;
797
798			my ($k, $d, $s) = @$self;
799			my $N = $self->size;
800
801			my ($key_xml, $data_xml) = ("<n>","<d>");
802
803			for (my $i = 0; $i <= $N; $i++) {
804			my $key = lc($k->[$i]);
805
806			if ($key) {
807	dpavlin	11	$key_xml .= '<k>'.$self->to_xml($key).'</k>';
808			$data_xml .= '<e>';
809	dpavlin	1	#use Data::Dumper;
810			#print Dumper($d->[$i]);
811			foreach my $path (keys %{$d->[$i]}) {
812	dpavlin	11	$data_xml .= '<l f="'.($d->[$i]->{$path}->{'f'} \|\| 1).'" t="'.$self->to_xml($d->[$i]->{$path}->{'t'} \|\| 'no title').'">'.$self->to_xml($path).'</l>';
813	dpavlin	1	$nr_keys++;
814			}
815	dpavlin	11	$data_xml .= '</e>';
816	dpavlin	1	}
817
818			$nr_keys += $s->[$i]->to_jsfind("$path/$file","$i") if ($s->[$i]);
819			}
820
821	dpavlin	11	$key_xml .= '</n>';
822			$data_xml .= '</d>';
823	dpavlin	1
824			if (! -e $path) {
825			mkpath($path) \|\| croak "can't create dir '$path': $!";
826			}
827
828			open(K, "> ${path}/${file}.xml") \|\| croak "can't open '$path/$file.xml': $!";
829			open(D, "> ${path}/_${file}.xml") \|\| croak "can't open '$path/_$file.xml': $!";
830
831	dpavlin	11	print K $key_xml;
832			print D $data_xml;
833	dpavlin	1
834			close(K);
835			close(D);
836
837			return $nr_keys;
838			}
839
840			1;
841			__END__
842
843			=head1 SEE ALSO
844
845			jsFind web site L<http://www.elucidsoft.net/projects/jsfind/>
846
847			B-Trees in perl web site L<http://perl.plover.com/BTree/>
848
849			=head1 AUTHORS
850
851			Mark-Jonson Dominus E<lt>mjd@pobox.comE<gt> wrote C<BTree.pm> which was
852			base for this module
853
854			Shawn P. Garbett E<lt>shawn@elucidsoft.netE<gt> wrote jsFind
855
856			Dobrica Pavlinusic E<lt>dpavlin@rot13.orgE<gt> wrote this module
857
858			=head1 COPYRIGHT AND LICENSE
859
860			Copyright (C) 2004 by Dobrica Pavlinusic
861
862			This program is free software; you can redistribute it and/or modify it
863			under the terms of the GNU General Public License as published by the Free
864			Software Foundation; either version 2 of the License, or (at your option)
865			any later version. This program is distributed in the hope that it will be
866			useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
867			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
868			Public License for more details.
869
870			=cut