summaryrefslogtreecommitdiff
path: root/includes/cache/LinkBatch.php
blob: 48b60aa9788ba274344cc0e1df7aa99d694403dc (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
<?php
/**
 * Batch query to determine page existence.
 *
 * 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 Cache
 */

/**
 * Class representing a list of titles
 * The execute() method checks them all for existence and adds them to a LinkCache object
 *
 * @ingroup Cache
 */
class LinkBatch {
	/**
	 * 2-d array, first index namespace, second index dbkey, value arbitrary
	 */
	var $data = array();

	/**
	 * For debugging which method is using this class.
	 */
	protected $caller;

	function __construct( $arr = array() ) {
		foreach ( $arr as $item ) {
			$this->addObj( $item );
		}
	}

	/**
	 * Use ->setCaller( __METHOD__ ) to indicate which code is using this
	 * class. Only used in debugging output.
	 * @since 1.17
	 *
	 * @param $caller
	 */
	public function setCaller( $caller ) {
		$this->caller = $caller;
	}

	/**
	 * @param $title Title
	 */
	public function addObj( $title ) {
		if ( is_object( $title ) ) {
			$this->add( $title->getNamespace(), $title->getDBkey() );
		} else {
			wfDebug( "Warning: LinkBatch::addObj got invalid title object\n" );
		}
	}

	/**
	 * @param $ns int
	 * @param $dbkey string
	 * @return mixed
	 */
	public function add( $ns, $dbkey ) {
		if ( $ns < 0 ) {
			return;
		}
		if ( !array_key_exists( $ns, $this->data ) ) {
			$this->data[$ns] = array();
		}

		$this->data[$ns][str_replace( ' ', '_', $dbkey )] = 1;
	}

	/**
	 * Set the link list to a given 2-d array
	 * First key is the namespace, second is the DB key, value arbitrary
	 *
	 * @param $array array
	 */
	public function setArray( $array ) {
		$this->data = $array;
	}

	/**
	 * Returns true if no pages have been added, false otherwise.
	 *
	 * @return bool
	 */
	public function isEmpty() {
		return $this->getSize() == 0;
	}

	/**
	 * Returns the size of the batch.
	 *
	 * @return int
	 */
	public function getSize() {
		return count( $this->data );
	}

	/**
	 * Do the query and add the results to the LinkCache object
	 *
	 * @return Array mapping PDBK to ID
	 */
	public function execute() {
		$linkCache = LinkCache::singleton();
		return $this->executeInto( $linkCache );
	}

	/**
	 * Do the query and add the results to a given LinkCache object
	 * Return an array mapping PDBK to ID
	 *
	 * @param $cache LinkCache
	 * @return Array remaining IDs
	 */
	protected function executeInto( &$cache ) {
		wfProfileIn( __METHOD__ );
		$res = $this->doQuery();
		$this->doGenderQuery();
		$ids = $this->addResultToCache( $cache, $res );
		wfProfileOut( __METHOD__ );
		return $ids;
	}

	/**
	 * Add a ResultWrapper containing IDs and titles to a LinkCache object.
	 * As normal, titles will go into the static Title cache field.
	 * This function *also* stores extra fields of the title used for link
	 * parsing to avoid extra DB queries.
	 *
	 * @param $cache LinkCache
	 * @param $res
	 * @return Array of remaining titles
	 */
	public function addResultToCache( $cache, $res ) {
		if ( !$res ) {
			return array();
		}

		// For each returned entry, add it to the list of good links, and remove it from $remaining

		$ids = array();
		$remaining = $this->data;
		foreach ( $res as $row ) {
			$title = Title::makeTitle( $row->page_namespace, $row->page_title );
			$cache->addGoodLinkObjFromRow( $title, $row );
			$ids[$title->getPrefixedDBkey()] = $row->page_id;
			unset( $remaining[$row->page_namespace][$row->page_title] );
		}

		// The remaining links in $data are bad links, register them as such
		foreach ( $remaining as $ns => $dbkeys ) {
			foreach ( $dbkeys as $dbkey => $unused ) {
				$title = Title::makeTitle( $ns, $dbkey );
				$cache->addBadLinkObj( $title );
				$ids[$title->getPrefixedDBkey()] = 0;
			}
		}
		return $ids;
	}

	/**
	 * Perform the existence test query, return a ResultWrapper with page_id fields
	 * @return Bool|ResultWrapper
	 */
	public function doQuery() {
		if ( $this->isEmpty() ) {
			return false;
		}
		wfProfileIn( __METHOD__ );

		// This is similar to LinkHolderArray::replaceInternal
		$dbr = wfGetDB( DB_SLAVE );
		$table = 'page';
		$fields = array( 'page_id', 'page_namespace', 'page_title', 'page_len',
			'page_is_redirect', 'page_latest' );
		$conds = $this->constructSet( 'page', $dbr );

		// Do query
		$caller = __METHOD__;
		if ( strval( $this->caller ) !== '' ) {
			$caller .= " (for {$this->caller})";
		}
		$res = $dbr->select( $table, $fields, $conds, $caller );
		wfProfileOut( __METHOD__ );
		return $res;
	}

	/**
	 * Do (and cache) {{GENDER:...}} information for userpages in this LinkBatch
	 *
	 * @return bool whether the query was successful
	 */
	public function doGenderQuery() {
		if ( $this->isEmpty() ) {
			return false;
		}

		global $wgContLang;
		if ( !$wgContLang->needsGenderDistinction() ) {
			return false;
		}

		$genderCache = GenderCache::singleton();
		$genderCache->doLinkBatch( $this->data, $this->caller );
		return true;
	}

	/**
	 * Construct a WHERE clause which will match all the given titles.
	 *
	 * @param string $prefix the appropriate table's field name prefix ('page', 'pl', etc)
	 * @param $db DatabaseBase object to use
	 * @return mixed string with SQL where clause fragment, or false if no items.
	 */
	public function constructSet( $prefix, $db ) {
		return $db->makeWhereFrom2d( $this->data, "{$prefix}_namespace", "{$prefix}_title" );
	}
}