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 => "postscan", 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         setupfiles();
  53
  54         # A unique pageterm is used to identify the document for a page.
  55         my $pageterm=pageterm($params{page});
  56         return $params{content} unless defined $pageterm;
  57
  58         my $db=xapiandb();
  59         my $doc=Search::Xapian::Document->new();
  60         my $caption=IkiWiki::pagetitle($params{page});
  61         my $title;
  62         if (exists $pagestate{$params{page}}{meta} &&
  63                 exists $pagestate{$params{page}}{meta}{title}) {
  64                 $title=$pagestate{$params{page}}{meta}{title};
  65         }
  66         else {
  67                 $title=$caption;
  68         }
  69
  70         # Remove html from text to be indexed.
  71         if (! defined $scrubber) {
  72                 eval q{use HTML::Scrubber};
  73                 if (! $@) {
  74                         $scrubber=HTML::Scrubber->new(allow => []);
  75                 }
  76         }
  77         my $toindex = defined $scrubber ? $scrubber->scrub($params{content}) : $params{content};
  78
  79         # Take 512 characters for a sample, then extend it out
  80         # if it stopped in the middle of a word.
  81         my $size=512;
  82         my ($sample)=substr($toindex, 0, $size);
  83         if (length($sample) == $size) {
  84                 my $max=length($toindex);
  85                 my $next;
  86                 while ($size < $max &&
  87                        ($next=substr($toindex, $size++, 1)) !~ /\s/) {
  88                         $sample.=$next;
  89                 }
  90         }
  91         $sample=~s/\n/ /g;
  92
  93         # data used by omega
  94         # Decode html entities in it, since omega re-encodes them.
  95         eval q{use HTML::Entities};
  96         $doc->set_data(
  97                 "url=".urlto($params{page}, "")."\n".
  98                 "sample=".decode_entities($sample)."\n".
  99                 "caption=".decode_entities($caption)."\n".
 100                 "modtime=$IkiWiki::pagemtime{$params{page}}\n".
 101                 "size=".length($params{content})."\n"
 102         );
 103
 104         # Index document and add terms for other metadata.
 105         my $tg = Search::Xapian::TermGenerator->new();
 106         if (! $stemmer) {
 107                 my $langcode=$ENV{LANG} || "en";
 108                 $langcode=~s/_.*//;
 109
 110                 # This whitelist is here to work around a xapian bug (#486138)
 111                 my @whitelist=qw{da de en es fi fr hu it no pt ru ro sv tr};
 112
 113                 if (grep { $_ eq $langcode } @whitelist) {
 114                         $stemmer=Search::Xapian::Stem->new($langcode);
 115                 }
 116                 else {
 117                         $stemmer=Search::Xapian::Stem->new("english");
 118                 }
 119         }
 120         $tg->set_stemmer($stemmer);
 121         $tg->set_document($doc);
 122         $tg->index_text($params{page}, 2);
 123         $tg->index_text($caption, 2);
 124         $tg->index_text($title, 2) if $title ne $caption;
 125         $tg->index_text($toindex);
 126         $tg->index_text(lc($title), 1, "S"); # for title:foo
 127         foreach my $link (@{$links{$params{page}}}) {
 128                 $tg->index_text(lc($link), 1, "XLINK"); # for link:bar
 129         }
 130
 131         $doc->add_term($pageterm);
 132         $db->replace_document_by_term($pageterm, $doc);
 133 } #}}}
 134
 135 sub delete (@) { #{{{
 136         my $db=xapiandb();
 137         foreach my $page (@_) {
 138                 my $pageterm=pageterm(pagename($page));
 139                 $db->delete_document_by_term($pageterm) if defined $pageterm;
 140         }
 141 } #}}}
 142
 143 sub cgi ($) { #{{{
 144         my $cgi=shift;
 145
 146         if (defined $cgi->param('P')) {
 147                 # only works for GET requests
 148                 chdir("$config{wikistatedir}/xapian") || error("chdir: $!");
 149                 $ENV{OMEGA_CONFIG_FILE}="./omega.conf";
 150                 $ENV{CGIURL}=$config{cgiurl},
 151                 IkiWiki::loadindex();
 152                 $ENV{HELPLINK}=htmllink("", "", "ikiwiki/searching",
 153                         noimageinline => 1, linktext => "Help");
 154                 exec($config{omega_cgi}) || error("$config{omega_cgi} failed: $!");
 155         }
 156 } #}}}
 157
 158 sub pageterm ($) { #{{{
 159         my $page=shift;
 160
 161         # 240 is the number used by omindex to decide when to hash an
 162         # overlong term. This does not use a compatible hash method though.
 163         if (length $page > 240) {
 164                 eval q{use Digest::SHA1};
 165                 if ($@) {
 166                         debug("search: ".sprintf(gettext("need Digest::SHA1 to index %s"), $page)) if $@;
 167                         return undef;
 168                 }
 169
 170                 # Note no colon, therefore it's guaranteed to not overlap
 171                 # with a page with the same name as the hash..
 172                 return "U".lc(Digest::SHA1::sha1_hex($page));
 173         }
 174         else {
 175                 return "U:".$page;
 176         }
 177 } #}}}
 178
 179 my $db;
 180 sub xapiandb () { #{{{
 181         if (! defined $db) {
 182                 eval q{
 183                         use Search::Xapian;
 184                         use Search::Xapian::WritableDatabase;
 185                 };
 186                 error($@) if $@;
 187                 $db=Search::Xapian::WritableDatabase->new($config{wikistatedir}."/xapian/default",
 188                         Search::Xapian::DB_CREATE_OR_OPEN());
 189         }
 190         return $db;
 191 } #}}}
 192
 193 {
 194 my $setup=0;
 195 sub setupfiles () { #{{{
 196         if (! $setup and (! -e $config{wikistatedir}."/xapian" || $config{rebuild})) {
 197                 writefile("omega.conf", $config{wikistatedir}."/xapian",
 198                         "database_dir .\n".
 199                         "template_dir ./templates\n");
 200                 writefile("query", $config{wikistatedir}."/xapian/templates",
 201                         IkiWiki::misctemplate(gettext("search"),
 202                                 readfile(IkiWiki::template_file("searchquery.tmpl"))));
 203                 $setup=1;
 204         }
 205 } #}}}
 206 }
 207
 208 1