MediaWiki  master
LinkCache.php
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1 <?php
28 
34 class LinkCache {
36  private $goodLinks;
38  private $badLinks;
40  private $wanCache;
41 
43  private $mForUpdate = false;
44 
46  private $titleFormatter;
47 
49  private $nsInfo;
50 
55  private const MAX_SIZE = 10000;
56 
57  public function __construct(
60  NamespaceInfo $nsInfo = null
61  ) {
62  if ( !$nsInfo ) {
63  wfDeprecated( __METHOD__ . ' with no NamespaceInfo argument', '1.34' );
64  $nsInfo = MediaWikiServices::getInstance()->getNamespaceInfo();
65  }
66  $this->goodLinks = new MapCacheLRU( self::MAX_SIZE );
67  $this->badLinks = new MapCacheLRU( self::MAX_SIZE );
68  $this->wanCache = $cache;
69  $this->titleFormatter = $titleFormatter;
70  $this->nsInfo = $nsInfo;
71  }
72 
79  public static function singleton() {
80  return MediaWikiServices::getInstance()->getLinkCache();
81  }
82 
94  public function forUpdate( $update = null ) {
95  return wfSetVar( $this->mForUpdate, $update );
96  }
97 
102  public function getGoodLinkID( $title ) {
103  $info = $this->goodLinks->get( $title );
104  if ( !$info ) {
105  return 0;
106  }
107  return $info['id'];
108  }
109 
117  public function getGoodLinkFieldObj( LinkTarget $target, $field ) {
118  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
119  $info = $this->goodLinks->get( $dbkey );
120  if ( !$info ) {
121  return null;
122  }
123  return $info[$field];
124  }
125 
130  public function isBadLink( $title ) {
131  // Use get() to ensure it records as used for LRU.
132  return $this->badLinks->has( $title );
133  }
134 
146  public function addGoodLinkObj( $id, LinkTarget $target, $len = -1, $redir = null,
147  $revision = 0, $model = null, $lang = null
148  ) {
149  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
150  $this->goodLinks->set( $dbkey, [
151  'id' => (int)$id,
152  'length' => (int)$len,
153  'redirect' => (int)$redir,
154  'revision' => (int)$revision,
155  'model' => $model ? (string)$model : null,
156  'lang' => $lang ? (string)$lang : null,
157  'restrictions' => null
158  ] );
159  }
160 
168  public function addGoodLinkObjFromRow( LinkTarget $target, $row ) {
169  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
170  $this->goodLinks->set( $dbkey, [
171  'id' => intval( $row->page_id ),
172  'length' => intval( $row->page_len ),
173  'redirect' => intval( $row->page_is_redirect ),
174  'revision' => intval( $row->page_latest ),
175  'model' => !empty( $row->page_content_model )
176  ? strval( $row->page_content_model )
177  : null,
178  'lang' => !empty( $row->page_lang )
179  ? strval( $row->page_lang )
180  : null,
181  'restrictions' => !empty( $row->page_restrictions )
182  ? strval( $row->page_restrictions )
183  : null
184  ] );
185  }
186 
190  public function addBadLinkObj( LinkTarget $target ) {
191  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
192  if ( !$this->isBadLink( $dbkey ) ) {
193  $this->badLinks->set( $dbkey, 1 );
194  }
195  }
196 
200  public function clearBadLink( $title ) {
201  $this->badLinks->clear( $title );
202  }
203 
207  public function clearLink( LinkTarget $target ) {
208  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
209  $this->badLinks->clear( $dbkey );
210  $this->goodLinks->clear( $dbkey );
211  }
212 
219  public static function getSelectFields() {
220  global $wgPageLanguageUseDB;
221 
222  $fields = [
223  'page_id',
224  'page_len',
225  'page_is_redirect',
226  'page_latest',
227  'page_restrictions',
228  'page_content_model',
229  ];
230 
231  if ( $wgPageLanguageUseDB ) {
232  $fields[] = 'page_lang';
233  }
234 
235  return $fields;
236  }
237 
244  public function addLinkObj( LinkTarget $nt ) {
245  $key = $this->titleFormatter->getPrefixedDBkey( $nt );
246  if ( $this->isBadLink( $key ) || $nt->isExternal() || $nt->getNamespace() < 0 ) {
247  return 0;
248  }
249  $id = $this->getGoodLinkID( $key );
250  if ( $id != 0 ) {
251  return $id;
252  }
253 
254  if ( $key === '' ) {
255  return 0;
256  }
257 
258  // Cache template/file pages as they are less often viewed but heavily used
259  if ( $this->mForUpdate ) {
260  $row = $this->fetchPageRow( wfGetDB( DB_MASTER ), $nt );
261  } elseif ( $this->isCacheable( $nt ) ) {
262  // These pages are often transcluded heavily, so cache them
264  $row = $cache->getWithSetCallback(
265  $cache->makeKey( 'page', $nt->getNamespace(), sha1( $nt->getDBkey() ) ),
266  $cache::TTL_DAY,
267  function ( $curValue, &$ttl, array &$setOpts ) use ( $cache, $nt ) {
268  $dbr = wfGetDB( DB_REPLICA );
269  $setOpts += Database::getCacheSetOptions( $dbr );
270 
271  $row = $this->fetchPageRow( $dbr, $nt );
272  $mtime = $row ? wfTimestamp( TS_UNIX, $row->page_touched ) : false;
273  $ttl = $cache->adaptiveTTL( $mtime, $ttl );
274 
275  return $row;
276  }
277  );
278  } else {
279  $row = $this->fetchPageRow( wfGetDB( DB_REPLICA ), $nt );
280  }
281 
282  if ( $row ) {
283  $this->addGoodLinkObjFromRow( $nt, $row );
284  $id = intval( $row->page_id );
285  } else {
286  $this->addBadLinkObj( $nt );
287  $id = 0;
288  }
289 
290  return $id;
291  }
292 
300  if ( $this->isCacheable( $t ) ) {
301  return [ $cache->makeKey( 'page', $t->getNamespace(), sha1( $t->getDBkey() ) ) ];
302  }
303 
304  return [];
305  }
306 
307  private function isCacheable( LinkTarget $title ) {
308  $ns = $title->getNamespace();
309  if ( in_array( $ns, [ NS_TEMPLATE, NS_FILE, NS_CATEGORY, NS_MEDIAWIKI ] ) ) {
310  return true;
311  }
312  // Focus on transcluded pages more than the main content
313  if ( $this->nsInfo->isContent( $ns ) ) {
314  return false;
315  }
316  // Non-talk extension namespaces (e.g. NS_MODULE)
317  return ( $ns >= 100 && $this->nsInfo->isSubject( $ns ) );
318  }
319 
320  private function fetchPageRow( IDatabase $db, LinkTarget $nt ) {
321  $fields = self::getSelectFields();
322  if ( $this->isCacheable( $nt ) ) {
323  $fields[] = 'page_touched';
324  }
325 
326  return $db->selectRow(
327  'page',
328  $fields,
329  [ 'page_namespace' => $nt->getNamespace(), 'page_title' => $nt->getDBkey() ],
330  __METHOD__
331  );
332  }
333 
340  public function invalidateTitle( LinkTarget $title ) {
341  if ( $this->isCacheable( $title ) ) {
343  $cache->delete(
344  $cache->makeKey( 'page', $title->getNamespace(), sha1( $title->getDBkey() ) )
345  );
346  }
347  }
348 
352  public function clear() {
353  $this->goodLinks->clear();
354  $this->badLinks->clear();
355  }
356 }
LinkCache\__construct
__construct(TitleFormatter $titleFormatter, WANObjectCache $cache, NamespaceInfo $nsInfo=null)
Definition: LinkCache.php:57
LinkCache
Cache for article titles (prefixed DB keys) and ids linked from one source.
Definition: LinkCache.php:34
Wikimedia\Rdbms\Database
Relational database abstraction object.
Definition: Database.php:49
LinkCache\$goodLinks
MapCacheLRU $goodLinks
Definition: LinkCache.php:36
LinkCache\addGoodLinkObjFromRow
addGoodLinkObjFromRow(LinkTarget $target, $row)
Same as above with better interface.
Definition: LinkCache.php:168
MediaWiki\MediaWikiServices
MediaWikiServices is the service locator for the application scope of MediaWiki.
Definition: MediaWikiServices.php:146
$lang
if(!isset( $args[0])) $lang
Definition: testCompression.php:37
wfSetVar
wfSetVar(&$dest, $source, $force=false)
Sets dest to source and returns the original value of dest If source is NULL, it just returns the val...
Definition: GlobalFunctions.php:1541
LinkCache\fetchPageRow
fetchPageRow(IDatabase $db, LinkTarget $nt)
Definition: LinkCache.php:320
wfTimestamp
wfTimestamp( $outputtype=TS_UNIX, $ts=0)
Get a timestamp string in one of various formats.
Definition: GlobalFunctions.php:1806
LinkCache\getMutableCacheKeys
getMutableCacheKeys(WANObjectCache $cache, LinkTarget $t)
Definition: LinkCache.php:299
NS_FILE
const NS_FILE
Definition: Defines.php:75
NS_TEMPLATE
const NS_TEMPLATE
Definition: Defines.php:79
LinkCache\getGoodLinkFieldObj
getGoodLinkFieldObj(LinkTarget $target, $field)
Get a field of a title object from cache.
Definition: LinkCache.php:117
LinkCache\forUpdate
forUpdate( $update=null)
General accessor to get/set whether the master DB should be used.
Definition: LinkCache.php:94
MediaWiki\Linker\LinkTarget\isExternal
isExternal()
Whether this LinkTarget has an interwiki component.
LinkCache\getSelectFields
static getSelectFields()
Fields that LinkCache needs to select.
Definition: LinkCache.php:219
Wikimedia\Rdbms\IDatabase
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:38
LinkCache\$badLinks
MapCacheLRU $badLinks
Definition: LinkCache.php:38
$dbr
$dbr
Definition: testCompression.php:54
MediaWiki\Linker\LinkTarget\getNamespace
getNamespace()
Get the namespace index.
LinkCache\isBadLink
isBadLink( $title)
Definition: LinkCache.php:130
wfDeprecated
wfDeprecated( $function, $version=false, $component=false, $callerOffset=2)
Logs a warning that $function is deprecated.
Definition: GlobalFunctions.php:1030
LinkCache\$titleFormatter
TitleFormatter $titleFormatter
Definition: LinkCache.php:46
wfGetDB
wfGetDB( $db, $groups=[], $wiki=false)
Get a Database object.
Definition: GlobalFunctions.php:2463
LinkCache\addBadLinkObj
addBadLinkObj(LinkTarget $target)
Definition: LinkCache.php:190
MapCacheLRU
Handles a simple LRU key/value map with a maximum number of entries.
Definition: MapCacheLRU.php:38
$title
$title
Definition: testCompression.php:38
DB_REPLICA
const DB_REPLICA
Definition: defines.php:25
NS_CATEGORY
const NS_CATEGORY
Definition: Defines.php:83
LinkCache\MAX_SIZE
const MAX_SIZE
How many Titles to store.
Definition: LinkCache.php:55
DB_MASTER
const DB_MASTER
Definition: defines.php:26
$wgPageLanguageUseDB
bool $wgPageLanguageUseDB
Enable page language feature Allows setting page language in database.
Definition: DefaultSettings.php:9107
LinkCache\$nsInfo
NamespaceInfo $nsInfo
Definition: LinkCache.php:49
LinkCache\clearBadLink
clearBadLink( $title)
Definition: LinkCache.php:200
LinkCache\$mForUpdate
bool $mForUpdate
Definition: LinkCache.php:43
LinkCache\isCacheable
isCacheable(LinkTarget $title)
Definition: LinkCache.php:307
Wikimedia\Rdbms\IDatabase\selectRow
selectRow( $table, $vars, $conds, $fname=__METHOD__, $options=[], $join_conds=[])
Wrapper to IDatabase::select() that only fetches one row (via LIMIT)
WANObjectCache
Multi-datacenter aware caching interface.
Definition: WANObjectCache.php:120
MediaWiki\Linker\LinkTarget\getDBkey
getDBkey()
Get the main part with underscores.
LinkCache\getGoodLinkID
getGoodLinkID( $title)
Definition: LinkCache.php:102
LinkCache\invalidateTitle
invalidateTitle(LinkTarget $title)
Purge the link cache for a title.
Definition: LinkCache.php:340
$cache
$cache
Definition: mcc.php:33
LinkCache\clear
clear()
Clears cache.
Definition: LinkCache.php:352
LinkCache\singleton
static singleton()
Get an instance of this class.
Definition: LinkCache.php:79
TitleFormatter
A title formatter service for MediaWiki.
Definition: TitleFormatter.php:34
NamespaceInfo
This is a utility class for dealing with namespaces that encodes all the "magic" behaviors of them ba...
Definition: NamespaceInfo.php:35
NS_MEDIAWIKI
const NS_MEDIAWIKI
Definition: Defines.php:77
$t
$t
Definition: testCompression.php:74
MediaWiki\Linker\LinkTarget
Definition: LinkTarget.php:26
LinkCache\addLinkObj
addLinkObj(LinkTarget $nt)
Add a title to the link cache, return the page_id or zero if non-existent.
Definition: LinkCache.php:244
LinkCache\addGoodLinkObj
addGoodLinkObj( $id, LinkTarget $target, $len=-1, $redir=null, $revision=0, $model=null, $lang=null)
Add a link for the title to the link cache.
Definition: LinkCache.php:146
LinkCache\$wanCache
WANObjectCache $wanCache
Definition: LinkCache.php:40
LinkCache\clearLink
clearLink(LinkTarget $target)
Definition: LinkCache.php:207