summaryrefslogtreecommitdiff
path: root/includes/SearchPostgres.php
blob: 4862a44e57c346c852c7ba5c806871770466dfac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
<?php
# Copyright (C) 2006-2007 Greg Sabino Mullane <greg@turnstep.com>
# http://www.mediawiki.org/
#
# 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.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
# http://www.gnu.org/copyleft/gpl.html

/**
 * @file
 * @ingroup Search
 */

/**
 * Search engine hook base class for Postgres
 * @ingroup Search
 */
class SearchPostgres extends SearchEngine {

	function __construct( $db ) {
		$this->db = $db;
	}

	/**
	 * Perform a full text search query via tsearch2 and return a result set.
	 * Currently searches a page's current title (page.page_title) and
	 * latest revision article text (pagecontent.old_text)
	 *
	 * @param string $term - Raw search term
	 * @return PostgresSearchResultSet
	 * @access public
	 */
	function searchTitle( $term ) {
		$q = $this->searchQuery( $term , 'titlevector', 'page_title' );
		$olderror = error_reporting(E_ERROR);
		$resultSet = $this->db->resultObject( $this->db->query( $q, 'SearchPostgres', true ) );
		error_reporting($olderror);
		if (!$resultSet) {
			// Needed for "Query requires full scan, GIN doesn't support it"
			return new SearchResultTooMany();
		}
		return new PostgresSearchResultSet( $resultSet, $this->searchTerms );
	}
	function searchText( $term ) {
		$q = $this->searchQuery( $term, 'textvector', 'old_text' );
		$olderror = error_reporting(E_ERROR);
		$resultSet = $this->db->resultObject( $this->db->query( $q, 'SearchPostgres', true ) );
		error_reporting($olderror);
		if (!$resultSet) {
			return new SearchResultTooMany();
		}
		return new PostgresSearchResultSet( $resultSet, $this->searchTerms );
	}


	/*
	 * Transform the user's search string into a better form for tsearch2
	 * Returns an SQL fragment consisting of quoted text to search for.
	*/
	function parseQuery( $term ) {

		wfDebug( "parseQuery received: $term" );

		## No backslashes allowed
		$term = preg_replace('/\\\/', '', $term);

		## Collapse parens into nearby words:
		$term = preg_replace('/\s*\(\s*/', ' (', $term);
		$term = preg_replace('/\s*\)\s*/', ') ', $term);

		## Treat colons as word separators:
		$term = preg_replace('/:/', ' ', $term);

		$searchstring = '';
		$m = array();
		if( preg_match_all('/([-!]?)(\S+)\s*/', $term, $m, PREG_SET_ORDER ) ) {
			foreach( $m as $terms ) {
				if (strlen($terms[1])) {
					$searchstring .= ' & !';
				}
				if (strtolower($terms[2]) === 'and') {
					$searchstring .= ' & ';
				}
				else if (strtolower($terms[2]) === 'or' or $terms[2] === '|') {
					$searchstring .= ' | ';
				}
				else if (strtolower($terms[2]) === 'not') {
					$searchstring .= ' & !';
				}
				else {
					$searchstring .= " & $terms[2]";
				}
			}
		}

		## Strip out leading junk
		$searchstring = preg_replace('/^[\s\&\|]+/', '', $searchstring);

		## Remove any doubled-up operators
		$searchstring = preg_replace('/([\!\&\|]) +(?:[\&\|] +)+/', "$1 ", $searchstring);

		## Remove any non-spaced operators (e.g. "Zounds!")
		$searchstring = preg_replace('/([^ ])[\!\&\|]/', "$1", $searchstring);

		## Remove any trailing whitespace or operators
		$searchstring = preg_replace('/[\s\!\&\|]+$/', '', $searchstring);

		## Remove unnecessary quotes around everything
		$searchstring = preg_replace('/^[\'"](.*)[\'"]$/', "$1", $searchstring);

		## Quote the whole thing
		$searchstring = $this->db->addQuotes($searchstring);

		wfDebug( "parseQuery returned: $searchstring" );

		return $searchstring;

	}

	/**
	 * Construct the full SQL query to do the search.
	 * @param string $filteredTerm
	 * @param string $fulltext
	 * @private
	 */
	function searchQuery( $term, $fulltext, $colname ) {
		global $wgDBversion;

		if ( !isset( $wgDBversion ) ) {
			$this->db->getServerVersion();
			$wgDBversion = $this->db->numeric_version;
		}
		$prefix = $wgDBversion < 8.3 ? "'default'," : '';

		# Get the SQL fragment for the given term
		$searchstring = $this->parseQuery( $term );

		## We need a separate query here so gin does not complain about empty searches
		$SQL = "SELECT to_tsquery($prefix $searchstring)";
		$res = $this->db->doQuery($SQL);
		if (!$res) {
			## TODO: Better output (example to catch: one 'two)
			die ("Sorry, that was not a valid search string. Please go back and try again");
		}
		$top = pg_fetch_result($res,0,0);

		if ($top === "") { ## e.g. if only stopwords are used XXX return something better
			$query = "SELECT page_id, page_namespace, page_title, 0 AS score ".
				"FROM page p, revision r, pagecontent c WHERE p.page_latest = r.rev_id " .
				"AND r.rev_text_id = c.old_id AND 1=0";
		}
		else {
			$m = array();
			if( preg_match_all("/'([^']+)'/", $top, $m, PREG_SET_ORDER ) ) {
				foreach( $m as $terms ) {
					$this->searchTerms[$terms[1]] = $terms[1];
				}
			}

			$rankscore = $wgDBversion > 8.2 ? 5 : 1;
			$rank = $wgDBversion < 8.3 ? 'rank' : 'ts_rank';
			$query = "SELECT page_id, page_namespace, page_title, ".
			"$rank($fulltext, to_tsquery($prefix $searchstring), $rankscore) AS score ".
			"FROM page p, revision r, pagecontent c WHERE p.page_latest = r.rev_id " .
			"AND r.rev_text_id = c.old_id AND $fulltext @@ to_tsquery($prefix $searchstring)";
		}

		## Redirects
		if (! $this->showRedirects)
			$query .= ' AND page_is_redirect = 0';

		## Namespaces - defaults to 0
		if( !is_null($this->namespaces) ){ // null -> search all
			if ( count($this->namespaces) < 1)
				$query .= ' AND page_namespace = 0';
			else {
				$namespaces = $this->db->makeList( $this->namespaces );
				$query .= " AND page_namespace IN ($namespaces)";
			}
		}

		$query .= " ORDER BY score DESC, page_id DESC";

		$query .= $this->db->limitResult( '', $this->limit, $this->offset );

		wfDebug( "searchQuery returned: $query" );

		return $query;
	}

	## Most of the work of these two functions are done automatically via triggers

	function update( $pageid, $title, $text ) {
		## We don't want to index older revisions
		$SQL = "UPDATE pagecontent SET textvector = NULL WHERE old_id IN ".
				"(SELECT rev_text_id FROM revision WHERE rev_page = " . intval( $pageid ) . 
				" ORDER BY rev_text_id DESC OFFSET 1)";
		$this->db->doQuery($SQL);
		return true;
	}

	function updateTitle( $id, $title ) {
		return true;
	}

} ## end of the SearchPostgres class

/**
 * @ingroup Search
 */
class PostgresSearchResult extends SearchResult {
	function __construct( $row ) {
		parent::__construct($row);
		$this->score = $row->score;
	}
	function getScore() {
		return $this->score;
	}
}

/**
 * @ingroup Search
 */
class PostgresSearchResultSet extends SearchResultSet {
	function __construct( $resultSet, $terms ) {
		$this->mResultSet = $resultSet;
		$this->mTerms = $terms;
	}

	function termMatches() {
		return $this->mTerms;
	}

	function numRows() {
		return $this->mResultSet->numRows();
	}

	function next() {
		$row = $this->mResultSet->fetchObject();
		if( $row === false ) {
			return false;
		} else {
			return new PostgresSearchResult( $row );
		}
	}
}