IkiWiki/Plugin/search.pm

   1 #!/usr/bin/perl
   2 # xapian-omega search engine plugin
   3 package IkiWiki::Plugin::search;
   4
   5 use warnings;
   6 use strict;
   7 use IkiWiki 2.00;
   8
   9 sub import { #{{{
  10         hook(type => "checkconfig", id => "search", call => \&checkconfig);
  11         hook(type => "pagetemplate", id => "search", call => \&pagetemplate);
  12         hook(type => "sanitize", id => "search", call => \&index);
  13         hook(type => "delete", id => "search", call => \&delete);
  14         hook(type => "cgi", id => "search", call => \&cgi);
  15 } # }}}
  16
  17 sub checkconfig () { #{{{
  18         foreach my $required (qw(url cgiurl)) {
  19                 if (! length $config{$required}) {
  20                         error(sprintf(gettext("Must specify %s when using the search plugin"), $required));
  21                 }
  22         }
  23
  24         if (! exists $config{omega_cgi}) {
  25                 $config{omega_cgi}="/usr/lib/cgi-bin/omega/omega";
  26         }
  27 } #}}}
  28
  29 my $form;
  30 sub pagetemplate (@) { #{{{
  31         my %params=@_;
  32         my $page=$params{page};
  33         my $template=$params{template};
  34
  35         # Add search box to page header.
  36         if ($template->query(name => "searchform")) {
  37                 if (! defined $form) {
  38                         my $searchform = template("searchform.tmpl", blind_cache => 1);
  39                         $searchform->param(searchaction => $config{cgiurl});
  40                         $form=$searchform->output;
  41                 }
  42
  43                 $template->param(searchform => $form);
  44         }
  45 } #}}}
  46
  47 my $scrubber;
  48 my $stemmer;
  49 sub index (@) { #{{{
  50         my %params=@_;
  51
  52         return $params{content} if $IkiWiki::preprocessing{$params{destpage}};
  53
  54         setupfiles();
  55
  56         # A unique pageterm is used to identify the document for a page.
  57         my $pageterm=pageterm($params{page});
  58         return $params{content} unless defined $pageterm;
  59
  60         my $db=xapiandb();
  61         my $doc=Search::Xapian::Document->new();
  62         my $caption=IkiWiki::pagetitle($params{page});
  63         my $title;
  64         if (exists $pagestate{$params{page}}{meta} &&
  65                 exists $pagestate{$params{page}}{meta}{title}) {
  66                 $title=$pagestate{$params{page}}{meta}{title};
  67         }
  68         else {
  69                 $title=$caption;
  70         }
  71
  72         # Remove html from text to be indexed.
  73         if (! defined $scrubber) {
  74                 eval q{use HTML::Scrubber};
  75                 if (! $@) {
  76                         $scrubber=HTML::Scrubber->new(allow => []);
  77                 }
  78         }
  79         my $toindex = defined $scrubber ? $scrubber->scrub($params{content}) : $params{content};
  80
  81         # Take 512 characters for a sample, then extend it out
  82         # if it stopped in the middle of a word.
  83         my $size=512;
  84         my ($sample)=substr($toindex, 0, $size);
  85         if (length($sample) == $size) {
  86                 my $max=length($toindex);
  87                 my $next;
  88                 while ($size < $max &&
  89                        ($next=substr($toindex, $size++, 1)) !~ /\s/) {
  90                         $sample.=$next;
  91                 }
  92         }
  93         $sample=~s/\n/ /g;
  94
  95         # data used by omega
  96         # Decode html entities in it, since omega re-encodes them.
  97         eval q{use HTML::Entities};
  98         $doc->set_data(
  99                 "url=".urlto($params{page}, "")."\n".
 100                 "sample=".decode_entities($sample)."\n".
 101                 "caption=".decode_entities($caption)."\n".
 102                 "modtime=$IkiWiki::pagemtime{$params{page}}\n".
 103                 "size=".length($params{content})."\n"
 104         );
 105
 106         # Index document and add terms for other metadata.
 107         my $tg = Search::Xapian::TermGenerator->new();
 108         if (! $stemmer) {
 109                 my $langcode=$ENV{LANG} || "en";
 110                 $langcode=~s/_.*//;
 111                 eval { $stemmer=Search::Xapian::Stem->new($langcode) };
 112                 if ($@) {
 113                         $stemmer=Search::Xapian::Stem->new("english");
 114                 }
 115         }
 116         $tg->set_stemmer($stemmer);
 117         $tg->set_document($doc);
 118         $tg->index_text($params{page}, 2);
 119         $tg->index_text($caption, 2);
 120         $tg->index_text($title, 2) if $title ne $caption;
 121         $tg->index_text($toindex);
 122         $tg->index_text(lc($title), 1, "ZS"); # for title:foo
 123         foreach my $link (@{$links{$params{page}}}) {
 124                 $tg->index_text(lc($link), 1, "ZLINK"); # for link:bar
 125         }
 126
 127         $doc->add_term($pageterm);
 128         $db->replace_document_by_term($pageterm, $doc);
 129
 130         return $params{content};
 131 } #}}}
 132
 133 sub delete (@) { #{{{
 134         my $db=xapiandb();
 135         foreach my $page (@_) {
 136                 my $pageterm=pageterm(pagename($page));
 137                 $db->delete_document_by_term($pageterm) if defined $pageterm;
 138         }
 139 } #}}}
 140
 141 sub cgi ($) { #{{{
 142         my $cgi=shift;
 143
 144         if (defined $cgi->param('P')) {
 145                 # only works for GET requests
 146                 chdir("$config{wikistatedir}/xapian") || error("chdir: $!");
 147                 $ENV{OMEGA_CONFIG_FILE}="./omega.conf";
 148                 $ENV{CGIURL}=$config{cgiurl},
 149                 IkiWiki::loadindex();
 150                 $ENV{HELPLINK}=htmllink("", "", "ikiwiki/searching",
 151                         noimageinline => 1, linktext => "Help");
 152                 exec($config{omega_cgi}) || error("$config{omega_cgi} failed: $!");
 153         }
 154 } #}}}
 155
 156 sub pageterm ($) { #{{{
 157         my $page=shift;
 158
 159         # 240 is the number used by omindex to decide when to hash an
 160         # overlong term. This does not use a compatible hash method though.
 161         if (length $page > 240) {
 162                 eval q{use Digest::SHA1};
 163                 if ($@) {
 164                         debug("search: ".sprintf(gettext("need Digest::SHA1 to index %s"), $page)) if $@;
 165                         return undef;
 166                 }
 167
 168                 # Note no colon, therefore it's guaranteed to not overlap
 169                 # with a page with the same name as the hash..
 170                 return "U".lc(Digest::SHA1::sha1_hex($page));
 171         }
 172         else {
 173                 return "U:".$page;
 174         }
 175 } #}}}
 176
 177 my $db;
 178 sub xapiandb () { #{{{
 179         if (! defined $db) {
 180                 eval q{
 181                         use Search::Xapian;
 182                         use Search::Xapian::WritableDatabase;
 183                 };
 184                 error($@) if $@;
 185                 $db=Search::Xapian::WritableDatabase->new($config{wikistatedir}."/xapian/default",
 186                         Search::Xapian::DB_CREATE_OR_OPEN());
 187         }
 188         return $db;
 189 } #}}}
 190
 191 sub setupfiles () { #{{{
 192         if (! -e $config{wikistatedir}."/xapian" || $config{rebuild}) {
 193                 writefile("omega.conf", $config{wikistatedir}."/xapian",
 194                         "database_dir .\n".
 195                         "template_dir ./templates\n");
 196                 writefile("query", $config{wikistatedir}."/xapian/templates",
 197                         IkiWiki::misctemplate(gettext("search"),
 198                                 readfile(IkiWiki::template_file("searchquery.tmpl"))));
 199         }
 200 } #}}}
 201
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