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 
52  const MAX_SIZE = 10000;
53 
55  $this->goodLinks = new MapCacheLRU( self::MAX_SIZE );
56  $this->badLinks = new MapCacheLRU( self::MAX_SIZE );
57  $this->wanCache = $cache;
58  $this->titleFormatter = $titleFormatter;
59  }
60 
67  public static function singleton() {
68  return MediaWikiServices::getInstance()->getLinkCache();
69  }
70 
81  public function forUpdate( $update = null ) {
82  return wfSetVar( $this->mForUpdate, $update );
83  }
84 
89  public function getGoodLinkID( $title ) {
90  $info = $this->goodLinks->get( $title );
91  if ( !$info ) {
92  return 0;
93  }
94  return $info['id'];
95  }
96 
104  public function getGoodLinkFieldObj( LinkTarget $target, $field ) {
105  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
106  $info = $this->goodLinks->get( $dbkey );
107  if ( !$info ) {
108  return null;
109  }
110  return $info[$field];
111  }
112 
117  public function isBadLink( $title ) {
118  // Use get() to ensure it records as used for LRU.
119  return $this->badLinks->has( $title );
120  }
121 
133  public function addGoodLinkObj( $id, LinkTarget $target, $len = -1, $redir = null,
134  $revision = 0, $model = null, $lang = null
135  ) {
136  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
137  $this->goodLinks->set( $dbkey, [
138  'id' => (int)$id,
139  'length' => (int)$len,
140  'redirect' => (int)$redir,
141  'revision' => (int)$revision,
142  'model' => $model ? (string)$model : null,
143  'lang' => $lang ? (string)$lang : null,
144  'restrictions' => null
145  ] );
146  }
147 
155  public function addGoodLinkObjFromRow( LinkTarget $target, $row ) {
156  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
157  $this->goodLinks->set( $dbkey, [
158  'id' => intval( $row->page_id ),
159  'length' => intval( $row->page_len ),
160  'redirect' => intval( $row->page_is_redirect ),
161  'revision' => intval( $row->page_latest ),
162  'model' => !empty( $row->page_content_model )
163  ? strval( $row->page_content_model )
164  : null,
165  'lang' => !empty( $row->page_lang )
166  ? strval( $row->page_lang )
167  : null,
168  'restrictions' => !empty( $row->page_restrictions )
169  ? strval( $row->page_restrictions )
170  : null
171  ] );
172  }
173 
177  public function addBadLinkObj( LinkTarget $target ) {
178  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
179  if ( !$this->isBadLink( $dbkey ) ) {
180  $this->badLinks->set( $dbkey, 1 );
181  }
182  }
183 
187  public function clearBadLink( $title ) {
188  $this->badLinks->clear( $title );
189  }
190 
194  public function clearLink( LinkTarget $target ) {
195  $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
196  $this->badLinks->clear( $dbkey );
197  $this->goodLinks->clear( $dbkey );
198  }
199 
206  public static function getSelectFields() {
208 
209  $fields = [
210  'page_id',
211  'page_len',
212  'page_is_redirect',
213  'page_latest',
214  'page_restrictions'
215  ];
216  if ( $wgContentHandlerUseDB ) {
217  $fields[] = 'page_content_model';
218  }
219  if ( $wgPageLanguageUseDB ) {
220  $fields[] = 'page_lang';
221  }
222 
223  return $fields;
224  }
225 
232  public function addLinkObj( LinkTarget $nt ) {
233  $key = $this->titleFormatter->getPrefixedDBkey( $nt );
234  if ( $this->isBadLink( $key ) || $nt->isExternal()
235  || $nt->inNamespace( NS_SPECIAL )
236  ) {
237  return 0;
238  }
239  $id = $this->getGoodLinkID( $key );
240  if ( $id != 0 ) {
241  return $id;
242  }
243 
244  if ( $key === '' ) {
245  return 0;
246  }
247 
248  // Cache template/file pages as they are less often viewed but heavily used
249  if ( $this->mForUpdate ) {
250  $row = $this->fetchPageRow( wfGetDB( DB_MASTER ), $nt );
251  } elseif ( $this->isCacheable( $nt ) ) {
252  // These pages are often transcluded heavily, so cache them
254  $row = $cache->getWithSetCallback(
255  $cache->makeKey( 'page', $nt->getNamespace(), sha1( $nt->getDBkey() ) ),
256  $cache::TTL_DAY,
257  function ( $curValue, &$ttl, array &$setOpts ) use ( $cache, $nt ) {
258  $dbr = wfGetDB( DB_REPLICA );
259  $setOpts += Database::getCacheSetOptions( $dbr );
260 
261  $row = $this->fetchPageRow( $dbr, $nt );
262  $mtime = $row ? wfTimestamp( TS_UNIX, $row->page_touched ) : false;
263  $ttl = $cache->adaptiveTTL( $mtime, $ttl );
264 
265  return $row;
266  }
267  );
268  } else {
269  $row = $this->fetchPageRow( wfGetDB( DB_REPLICA ), $nt );
270  }
271 
272  if ( $row ) {
273  $this->addGoodLinkObjFromRow( $nt, $row );
274  $id = intval( $row->page_id );
275  } else {
276  $this->addBadLinkObj( $nt );
277  $id = 0;
278  }
279 
280  return $id;
281  }
282 
290  if ( $this->isCacheable( $t ) ) {
291  return [ $cache->makeKey( 'page', $t->getNamespace(), sha1( $t->getDBkey() ) ) ];
292  }
293 
294  return [];
295  }
296 
297  private function isCacheable( LinkTarget $title ) {
298  $ns = $title->getNamespace();
299  if ( in_array( $ns, [ NS_TEMPLATE, NS_FILE, NS_CATEGORY ] ) ) {
300  return true;
301  }
302  // Focus on transcluded pages more than the main content
303  if ( MWNamespace::isContent( $ns ) ) {
304  return false;
305  }
306  // Non-talk extension namespaces (e.g. NS_MODULE)
307  return ( $ns >= 100 && MWNamespace::isSubject( $ns ) );
308  }
309 
310  private function fetchPageRow( IDatabase $db, LinkTarget $nt ) {
311  $fields = self::getSelectFields();
312  if ( $this->isCacheable( $nt ) ) {
313  $fields[] = 'page_touched';
314  }
315 
316  return $db->selectRow(
317  'page',
318  $fields,
319  [ 'page_namespace' => $nt->getNamespace(), 'page_title' => $nt->getDBkey() ],
320  __METHOD__
321  );
322  }
323 
330  public function invalidateTitle( LinkTarget $title ) {
331  if ( $this->isCacheable( $title ) ) {
333  $cache->delete(
334  $cache->makeKey( 'page', $title->getNamespace(), sha1( $title->getDBkey() ) )
335  );
336  }
337  }
338 
342  public function clear() {
343  $this->goodLinks->clear();
344  $this->badLinks->clear();
345  }
346 }
The wiki should then use memcached to cache various data To use multiple just add more items to the array To increase the weight of a make its entry a array("192.168.0.1:11211", 2))
addLinkObj(LinkTarget $nt)
Add a title to the link cache, return the page_id or zero if non-existent.
Definition: LinkCache.php:232
isBadLink( $title)
Definition: LinkCache.php:117
addBadLinkObj(LinkTarget $target)
Definition: LinkCache.php:177
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
if(!isset( $args[0])) $lang
wfGetDB( $db, $groups=[], $wiki=false)
Get a Database object.
inNamespace( $ns)
Convenience function to test if it is in the namespace.
const NS_SPECIAL
Definition: Defines.php:53
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency MediaWikiServices
Definition: injection.txt:23
const NS_TEMPLATE
Definition: Defines.php:74
clearBadLink( $title)
Definition: LinkCache.php:187
const DB_MASTER
Definition: defines.php:26
getNamespace()
Get the namespace index.
static isContent( $index)
Does this namespace contain content, for the purposes of calculating statistics, etc?
clearLink(LinkTarget $target)
Definition: LinkCache.php:194
isExternal()
Whether this LinkTarget has an interwiki component.
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:133
$wgContentHandlerUseDB
Set to false to disable use of the database fields introduced by the ContentHandler facility...
selectRow( $table, $vars, $conds, $fname=__METHOD__, $options=[], $join_conds=[])
Single row SELECT wrapper.
wfTimestamp( $outputtype=TS_UNIX, $ts=0)
Get a timestamp string in one of various formats.
forUpdate( $update=null)
General accessor to get/set whether the master DB should be used.
Definition: LinkCache.php:81
TitleFormatter $titleFormatter
Definition: LinkCache.php:46
fetchPageRow(IDatabase $db, LinkTarget $nt)
Definition: LinkCache.php:310
static singleton()
Get an instance of this class.
Definition: LinkCache.php:67
getMutableCacheKeys(WANObjectCache $cache, LinkTarget $t)
Definition: LinkCache.php:289
invalidateTitle(LinkTarget $title)
Purge the link cache for a title.
Definition: LinkCache.php:330
clear()
Clears cache.
Definition: LinkCache.php:342
MapCacheLRU $badLinks
Definition: LinkCache.php:38
getGoodLinkFieldObj(LinkTarget $target, $field)
Get a field of a title object from cache.
Definition: LinkCache.php:104
getDBkey()
Get the main part with underscores.
$cache
Definition: mcc.php:33
const NS_CATEGORY
Definition: Defines.php:78
this hook is for auditing only or null if authentication failed before getting that far or null if we can t even determine that When $user is not null
Definition: hooks.txt:780
isCacheable(LinkTarget $title)
Definition: LinkCache.php:297
namespace and then decline to actually register it file or subcat img or subcat $title
Definition: hooks.txt:925
const NS_FILE
Definition: Defines.php:70
const MAX_SIZE
How many Titles to store.
Definition: LinkCache.php:52
static getSelectFields()
Fields that LinkCache needs to select.
Definition: LinkCache.php:206
bool $wgPageLanguageUseDB
Enable page language feature Allows setting page language in database.
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
wfSetVar(&$dest, $source, $force=false)
Sets dest to source and returns the original value of dest If source is NULL, it just returns the val...
WANObjectCache $wanCache
Definition: LinkCache.php:40
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:38
__construct(TitleFormatter $titleFormatter, WANObjectCache $cache)
Definition: LinkCache.php:54
getGoodLinkID( $title)
Definition: LinkCache.php:89
static isSubject( $index)
Is the given namespace is a subject (non-talk) namespace?
Definition: MWNamespace.php:45
MapCacheLRU $goodLinks
Definition: LinkCache.php:36
const DB_REPLICA
Definition: defines.php:25
bool $mForUpdate
Definition: LinkCache.php:43
makeKey( $class, $component=null)
addGoodLinkObjFromRow(LinkTarget $target, $row)
Same as above with better interface.
Definition: LinkCache.php:155