MediaWiki  master
MapCacheLRU.php
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1 <?php
24 
39  private $cache = [];
41  private $timestamps = [];
43  private $epoch;
44 
46  private $maxCacheKeys;
47 
50 
51  const RANK_TOP = 1.0;
52 
54  const SIMPLE = 0;
56  const FIELDS = 1;
57 
62  public function __construct( $maxKeys ) {
63  Assert::parameterType( 'integer', $maxKeys, '$maxKeys' );
64  Assert::parameter( $maxKeys > 0, '$maxKeys', 'must be above zero' );
65 
66  $this->maxCacheKeys = $maxKeys;
67  // Use the current time as the default "as of" timestamp of entries
68  $this->epoch = $this->getCurrentTime();
69  }
70 
77  public static function newFromArray( array $values, $maxKeys ) {
78  $mapCache = new self( $maxKeys );
79  $mapCache->cache = ( count( $values ) > $maxKeys )
80  ? array_slice( $values, -$maxKeys, null, true )
81  : $values;
82 
83  return $mapCache;
84  }
85 
90  public function toArray() {
91  return $this->cache;
92  }
93 
109  public function set( $key, $value, $rank = self::RANK_TOP ) {
110  if ( $this->has( $key ) ) {
111  $this->ping( $key );
112  } elseif ( count( $this->cache ) >= $this->maxCacheKeys ) {
113  reset( $this->cache );
114  $evictKey = key( $this->cache );
115  unset( $this->cache[$evictKey] );
116  unset( $this->timestamps[$evictKey] );
117  }
118 
119  if ( $rank < 1.0 && $rank > 0 ) {
120  $offset = intval( $rank * count( $this->cache ) );
121  $this->cache = array_slice( $this->cache, 0, $offset, true )
122  + [ $key => $value ]
123  + array_slice( $this->cache, $offset, null, true );
124  } else {
125  $this->cache[$key] = $value;
126  }
127 
128  $this->timestamps[$key] = [
129  self::SIMPLE => $this->getCurrentTime(),
130  self::FIELDS => []
131  ];
132  }
133 
141  public function has( $key, $maxAge = 0.0 ) {
142  if ( !is_int( $key ) && !is_string( $key ) ) {
143  throw new UnexpectedValueException(
144  __METHOD__ . ': invalid key; must be string or integer.' );
145  }
146 
147  if ( !array_key_exists( $key, $this->cache ) ) {
148  return false;
149  }
150 
151  return ( $maxAge <= 0 || $this->getAge( $key ) <= $maxAge );
152  }
153 
163  public function get( $key, $maxAge = 0.0 ) {
164  if ( !$this->has( $key, $maxAge ) ) {
165  return null;
166  }
167 
168  $this->ping( $key );
169 
170  return $this->cache[$key];
171  }
172 
179  public function setField( $key, $field, $value, $initRank = self::RANK_TOP ) {
180  if ( $this->has( $key ) ) {
181  $this->ping( $key );
182  } else {
183  $this->set( $key, [], $initRank );
184  }
185 
186  if ( !is_int( $field ) && !is_string( $field ) ) {
187  throw new UnexpectedValueException(
188  __METHOD__ . ": invalid field for '$key'; must be string or integer." );
189  }
190 
191  if ( !is_array( $this->cache[$key] ) ) {
192  $type = gettype( $this->cache[$key] );
193 
194  throw new UnexpectedValueException( "The value of '$key' ($type) is not an array." );
195  }
196 
197  $this->cache[$key][$field] = $value;
198  $this->timestamps[$key][self::FIELDS][$field] = $this->getCurrentTime();
199  }
200 
207  public function hasField( $key, $field, $maxAge = 0.0 ) {
208  $value = $this->get( $key );
209 
210  if ( !is_int( $field ) && !is_string( $field ) ) {
211  throw new UnexpectedValueException(
212  __METHOD__ . ": invalid field for '$key'; must be string or integer." );
213  }
214 
215  if ( !is_array( $value ) || !array_key_exists( $field, $value ) ) {
216  return false;
217  }
218 
219  return ( $maxAge <= 0 || $this->getAge( $key, $field ) <= $maxAge );
220  }
221 
228  public function getField( $key, $field, $maxAge = 0.0 ) {
229  if ( !$this->hasField( $key, $field, $maxAge ) ) {
230  return null;
231  }
232 
233  return $this->cache[$key][$field];
234  }
235 
240  public function getAllKeys() {
241  return array_keys( $this->cache );
242  }
243 
256  public function getWithSetCallback(
257  $key, callable $callback, $rank = self::RANK_TOP, $maxAge = 0.0
258  ) {
259  if ( $this->has( $key, $maxAge ) ) {
260  $value = $this->get( $key );
261  } else {
262  $value = call_user_func( $callback );
263  if ( $value !== false ) {
264  $this->set( $key, $value, $rank );
265  }
266  }
267 
268  return $value;
269  }
270 
277  public function clear( $keys = null ) {
278  if ( func_num_args() == 0 ) {
279  $this->cache = [];
280  $this->timestamps = [];
281  } else {
282  foreach ( (array)$keys as $key ) {
283  unset( $this->cache[$key] );
284  unset( $this->timestamps[$key] );
285  }
286  }
287  }
288 
295  public function getMaxSize() {
296  return $this->maxCacheKeys;
297  }
298 
307  public function setMaxSize( $maxKeys ) {
308  Assert::parameterType( 'integer', $maxKeys, '$maxKeys' );
309  Assert::parameter( $maxKeys > 0, '$maxKeys', 'must be above zero' );
310 
311  $this->maxCacheKeys = $maxKeys;
312  while ( count( $this->cache ) > $this->maxCacheKeys ) {
313  reset( $this->cache );
314  $evictKey = key( $this->cache );
315  unset( $this->cache[$evictKey] );
316  unset( $this->timestamps[$evictKey] );
317  }
318  }
319 
325  private function ping( $key ) {
326  $item = $this->cache[$key];
327  unset( $this->cache[$key] );
328  $this->cache[$key] = $item;
329  }
330 
336  private function getAge( $key, $field = null ) {
337  if ( $field !== null ) {
338  $mtime = $this->timestamps[$key][self::FIELDS][$field] ?? $this->epoch;
339  } else {
340  $mtime = $this->timestamps[$key][self::SIMPLE] ?? $this->epoch;
341  }
342 
343  return ( $this->getCurrentTime() - $mtime );
344  }
345 
346  public function serialize() {
347  return serialize( [
348  'entries' => $this->cache,
349  'timestamps' => $this->timestamps
350  ] );
351  }
352 
353  public function unserialize( $serialized ) {
355  $this->cache = $data['entries'] ?? [];
356  $this->timestamps = $data['timestamps'] ?? [];
357  $this->epoch = $this->getCurrentTime();
358  }
359 
364  protected function getCurrentTime() {
365  return $this->wallClockOverride ?: microtime( true );
366  }
367 
372  public function setMockTime( &$time ) {
373  $this->wallClockOverride =& $time;
374  }
375 }
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))
clear( $keys=null)
Clear one or several cache entries, or all cache entries.
$data
Utility to generate mapping file used in mw.Title (phpCharToUpper.json)
__construct( $maxKeys)
Definition: MapCacheLRU.php:62
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
$value
either a unescaped string or a HtmlArmor object after in associative array form externallinks including delete and has completed for all link tables whether this was an auto creation use $formDescriptor instead default is conds Array Extra conditions for the No matching items in log is displayed if loglist is empty msgKey Array If you want a nice box with a set this to the key of the message First element is the message key
Definition: hooks.txt:2151
getWithSetCallback( $key, callable $callback, $rank=self::RANK_TOP, $maxAge=0.0)
Get an item with the given key, producing and setting it if not found.
see documentation in includes Linker php for Linker::makeImageLink & $time
Definition: hooks.txt:1799
array $timestamps
Map of (key => (UNIX timestamp, (field => UNIX timestamp)))
Definition: MapCacheLRU.php:41
hasField( $key, $field, $maxAge=0.0)
you have access to all of the normal MediaWiki so you can get a DB use the cache
Definition: maintenance.txt:52
ping( $key)
Push an entry to the top of the cache.
float null $wallClockOverride
Definition: MapCacheLRU.php:49
array $cache
Map of (key => value)
Definition: MapCacheLRU.php:39
getAge( $key, $field=null)
getField( $key, $field, $maxAge=0.0)
const RANK_TOP
Definition: MapCacheLRU.php:51
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
unserialize( $serialized)
int $maxCacheKeys
Max number of entries.
Definition: MapCacheLRU.php:46
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:9
setField( $key, $field, $value, $initRank=self::RANK_TOP)
static newFromArray(array $values, $maxKeys)
Definition: MapCacheLRU.php:77
setMaxSize( $maxKeys)
Resize the maximum number of cache entries, removing older entries as needed.
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 $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
getMaxSize()
Get the maximum number of keys allowed.
setMockTime(&$time)
foreach( $res as $row) $serialized
has( $key, $maxAge=0.0)
Check if a key exists.
float $epoch
Default entry timestamp if not specified.
Definition: MapCacheLRU.php:43