MediaWiki  1.28.0
CacheHelper.php
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1 <?php
30 interface ICacheHelper {
37  function setCacheEnabled( $cacheEnabled );
38 
48  function startCache( $cacheExpiry = null, $cacheEnabled = null );
49 
64  function getCachedValue( $computeFunction, $args = [], $key = null );
65 
72  function saveCache();
73 
82  function setExpiry( $cacheExpiry );
83 }
84 
103 class CacheHelper implements ICacheHelper {
110  protected $cacheExpiry = 3600;
111 
120  protected $cachedChunks;
121 
129  protected $hasCached = null;
130 
137  protected $cacheEnabled = true;
138 
145  protected $onInitHandler = false;
146 
153  protected $cacheKey = [];
154 
161  public function setCacheEnabled( $cacheEnabled ) {
162  $this->cacheEnabled = $cacheEnabled;
163  }
164 
174  public function startCache( $cacheExpiry = null, $cacheEnabled = null ) {
175  if ( is_null( $this->hasCached ) ) {
176  if ( !is_null( $cacheExpiry ) ) {
177  $this->cacheExpiry = $cacheExpiry;
178  }
179 
180  if ( !is_null( $cacheEnabled ) ) {
181  $this->setCacheEnabled( $cacheEnabled );
182  }
183 
184  $this->initCaching();
185  }
186  }
187 
199  public function getCachedNotice( IContextSource $context, $includePurgeLink = true ) {
200  if ( $this->cacheExpiry < 86400 * 3650 ) {
201  $message = $context->msg(
202  'cachedspecial-viewing-cached-ttl',
203  $context->getLanguage()->formatDuration( $this->cacheExpiry )
204  )->escaped();
205  } else {
206  $message = $context->msg(
207  'cachedspecial-viewing-cached-ts'
208  )->escaped();
209  }
210 
211  if ( $includePurgeLink ) {
212  $refreshArgs = $context->getRequest()->getQueryValues();
213  unset( $refreshArgs['title'] );
214  $refreshArgs['action'] = 'purge';
215 
216  $subPage = $context->getTitle()->getFullText();
217  $subPage = explode( '/', $subPage, 2 );
218  $subPage = count( $subPage ) > 1 ? $subPage[1] : false;
219 
220  $message .= ' ' . Linker::link(
221  $context->getTitle( $subPage ),
222  $context->msg( 'cachedspecial-refresh-now' )->escaped(),
223  [],
224  $refreshArgs
225  );
226  }
227 
228  return $message;
229  }
230 
237  protected function initCaching() {
238  if ( $this->cacheEnabled && is_null( $this->hasCached ) ) {
240 
241  $this->hasCached = is_array( $cachedChunks );
242  $this->cachedChunks = $this->hasCached ? $cachedChunks : [];
243 
244  if ( $this->onInitHandler !== false ) {
245  call_user_func( $this->onInitHandler, $this->hasCached );
246  }
247  }
248  }
249 
264  public function getCachedValue( $computeFunction, $args = [], $key = null ) {
265  $this->initCaching();
266 
267  if ( $this->cacheEnabled && $this->hasCached ) {
268  $value = null;
269 
270  if ( is_null( $key ) ) {
271  $itemKey = array_keys( array_slice( $this->cachedChunks, 0, 1 ) );
272  $itemKey = array_shift( $itemKey );
273 
274  if ( !is_integer( $itemKey ) ) {
275  wfWarn( "Attempted to get item with non-numeric key while " .
276  "the next item in the queue has a key ($itemKey) in " . __METHOD__ );
277  } elseif ( is_null( $itemKey ) ) {
278  wfWarn( "Attempted to get an item while the queue is empty in " . __METHOD__ );
279  } else {
280  $value = array_shift( $this->cachedChunks );
281  }
282  } else {
283  if ( array_key_exists( $key, $this->cachedChunks ) ) {
284  $value = $this->cachedChunks[$key];
285  unset( $this->cachedChunks[$key] );
286  } else {
287  wfWarn( "There is no item with key '$key' in this->cachedChunks in " . __METHOD__ );
288  }
289  }
290  } else {
291  if ( !is_array( $args ) ) {
292  $args = [ $args ];
293  }
294 
295  $value = call_user_func_array( $computeFunction, $args );
296 
297  if ( $this->cacheEnabled ) {
298  if ( is_null( $key ) ) {
299  $this->cachedChunks[] = $value;
300  } else {
301  $this->cachedChunks[$key] = $value;
302  }
303  }
304  }
305 
306  return $value;
307  }
308 
315  public function saveCache() {
316  if ( $this->cacheEnabled && $this->hasCached === false && !empty( $this->cachedChunks ) ) {
317  wfGetCache( CACHE_ANYTHING )->set(
318  $this->getCacheKeyString(),
319  $this->cachedChunks,
320  $this->cacheExpiry
321  );
322  }
323  }
324 
333  public function setExpiry( $cacheExpiry ) {
334  $this->cacheExpiry = $cacheExpiry;
335  }
336 
346  protected function getCacheKeyString() {
347  if ( $this->cacheKey === [] ) {
348  throw new MWException( 'No cache key set, so cannot obtain or save the CacheHelper values.' );
349  }
350 
351  return call_user_func_array( 'wfMemcKey', $this->cacheKey );
352  }
353 
361  public function setCacheKey( array $cacheKey ) {
362  $this->cacheKey = $cacheKey;
363  }
364 
372  public function rebuildOnDemand() {
373  $this->hasCached = false;
374  }
375 
383  public function setOnInitializedHandler( $handlerFunction ) {
384  $this->onInitHandler = $handlerFunction;
385  }
386 }
setExpiry($cacheExpiry)
Sets the time to live for the cache, in seconds or a unix timestamp indicating the point of expiry...
Interface for objects which can provide a MediaWiki context on request.
the array() calling protocol came about after MediaWiki 1.4rc1.
$context
Definition: load.php:50
setCacheEnabled($cacheEnabled)
Sets if the cache should be enabled or not.
msg()
Get a Message object with context set.
$value
int $cacheExpiry
The time to live for the cache, in seconds or a unix timestamp indicating the point of expiry...
Helper class for caching various elements in a single cache entry.
bool null $hasCached
Indicates if the to be cached content was already cached.
getCachedNotice(IContextSource $context, $includePurgeLink=true)
Returns a message that notifies the user he/she is looking at a cached version of the page...
if($line===false) $args
Definition: cdb.php:64
initCaching()
Initializes the caching if not already done so.
getCachedValue($computeFunction, $args=[], $key=null)
Get a cached value if available or compute it if not and then cache it if possible.
startCache($cacheExpiry=null, $cacheEnabled=null)
Initializes the caching.
callable $onInitHandler
Function that gets called when initialization is done.
array $cachedChunks
List of HTML chunks to be cached (if !hasCached) or that where cached (of hasCached).
setOnInitializedHandler($handlerFunction)
Sets a function that gets called when initialization of the cache is done.
startCache($cacheExpiry=null, $cacheEnabled=null)
Initializes the caching.
wfGetCache($cacheType)
Get a specific cache object.
wfWarn($msg, $callerOffset=1, $level=E_USER_NOTICE)
Send a warning either to the debug log or in a PHP error depending on $wgDevelopmentWarnings.
getLanguage()
Get the Language object.
setCacheEnabled($cacheEnabled)
Sets if the cache should be enabled or not.
static link($target, $html=null, $customAttribs=[], $query=[], $options=[])
This function returns an HTML link to the given target.
Definition: Linker.php:203
getCachedValue($computeFunction, $args=[], $key=null)
Get a cached value if available or compute it if not and then cache it if possible.
setCacheKey(array $cacheKey)
Sets the cache key that should be used.
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 $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
rebuildOnDemand()
Rebuild the content, even if it's already cached.
setExpiry($cacheExpiry)
Sets the time to live for the cache, in seconds or a unix timestamp indicating the point of expiry...
const CACHE_ANYTHING
Definition: Defines.php:93
bool $cacheEnabled
If the cache is enabled or not.
getTitle()
Get the Title object.
saveCache()
Saves the HTML to the cache in case it got recomputed.
getCacheKeyString()
Returns the cache key to use to cache this page's HTML output.
saveCache()
Saves the HTML to the cache in case it got recomputed.
array $cacheKey
Elements to build a cache key with.
getRequest()
Get the WebRequest object.
Interface for all classes implementing CacheHelper functionality.
Definition: CacheHelper.php:30