MediaWiki  1.27.2
MultiWriteBagOStuff.php
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1 <?php
33  protected $caches;
35  protected $asyncWrites = false;
36 
38  const ALL = INF;
39 
40  const UPGRADE_TTL = 3600; // TTL when a key is copied to a higher cache tier
41 
62  public function __construct( $params ) {
63  parent::__construct( $params );
64 
65  if ( empty( $params['caches'] ) || !is_array( $params['caches'] ) ) {
66  throw new InvalidArgumentException(
67  __METHOD__ . ': "caches" parameter must be an array of caches'
68  );
69  }
70 
71  $this->caches = [];
72  foreach ( $params['caches'] as $cacheInfo ) {
73  if ( $cacheInfo instanceof BagOStuff ) {
74  $this->caches[] = $cacheInfo;
75  } else {
76  if ( !isset( $cacheInfo['args'] ) ) {
77  // B/C for when $cacheInfo was for ObjectCache::newFromParams().
78  // Callers intenting this to be for ObjectFactory::getObjectFromSpec
79  // should have set "args" per the docs above. Doings so avoids extra
80  // (likely harmless) params (factory/class/calls) ending up in "args".
81  $cacheInfo['args'] = [ $cacheInfo ];
82  }
83  $this->caches[] = ObjectFactory::getObjectFromSpec( $cacheInfo );
84  }
85  }
86 
87  $this->asyncWrites = (
88  isset( $params['replication'] ) &&
89  $params['replication'] === 'async' &&
90  is_callable( $this->asyncHandler )
91  );
92  }
93 
94  public function setDebug( $debug ) {
95  foreach ( $this->caches as $cache ) {
96  $cache->setDebug( $debug );
97  }
98  }
99 
100  protected function doGet( $key, $flags = 0 ) {
101  if ( ( $flags & self::READ_LATEST ) == self::READ_LATEST ) {
102  // If the latest write was a delete(), we do NOT want to fallback
103  // to the other tiers and possibly see the old value. Also, this
104  // is used by mergeViaLock(), which only needs to hit the primary.
105  return $this->caches[0]->get( $key, $flags );
106  }
107 
108  $misses = 0; // number backends checked
109  $value = false;
110  foreach ( $this->caches as $cache ) {
111  $value = $cache->get( $key, $flags );
112  if ( $value !== false ) {
113  break;
114  }
115  ++$misses;
116  }
117 
118  if ( $value !== false
119  && $misses > 0
120  && ( $flags & self::READ_VERIFIED ) == self::READ_VERIFIED
121  ) {
122  $this->doWrite( $misses, $this->asyncWrites, 'set', $key, $value, self::UPGRADE_TTL );
123  }
124 
125  return $value;
126  }
127 
128  public function set( $key, $value, $exptime = 0, $flags = 0 ) {
129  $asyncWrites = ( ( $flags & self::WRITE_SYNC ) == self::WRITE_SYNC )
130  ? false
132 
133  return $this->doWrite( self::ALL, $asyncWrites, 'set', $key, $value, $exptime );
134  }
135 
136  public function delete( $key ) {
137  return $this->doWrite( self::ALL, $this->asyncWrites, 'delete', $key );
138  }
139 
140  public function add( $key, $value, $exptime = 0 ) {
141  return $this->doWrite( self::ALL, $this->asyncWrites, 'add', $key, $value, $exptime );
142  }
143 
144  public function incr( $key, $value = 1 ) {
145  return $this->doWrite( self::ALL, $this->asyncWrites, 'incr', $key, $value );
146  }
147 
148  public function decr( $key, $value = 1 ) {
149  return $this->doWrite( self::ALL, $this->asyncWrites, 'decr', $key, $value );
150  }
151 
152  public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
153  // Only need to lock the first cache; also avoids deadlocks
154  return $this->caches[0]->lock( $key, $timeout, $expiry, $rclass );
155  }
156 
157  public function unlock( $key ) {
158  // Only the first cache is locked
159  return $this->caches[0]->unlock( $key );
160  }
161 
162  public function getLastError() {
163  return $this->caches[0]->getLastError();
164  }
165 
166  public function clearLastError() {
167  $this->caches[0]->clearLastError();
168  }
169 
179  protected function doWrite( $count, $asyncWrites, $method /*, ... */ ) {
180  $ret = true;
181  $args = array_slice( func_get_args(), 3 );
182 
183  foreach ( $this->caches as $i => $cache ) {
184  if ( $i >= $count ) {
185  break; // ignore the lower tiers
186  }
187 
188  if ( $i == 0 || !$asyncWrites ) {
189  // First store or in sync mode: write now and get result
190  if ( !call_user_func_array( [ $cache, $method ], $args ) ) {
191  $ret = false;
192  }
193  } else {
194  // Secondary write in async mode: do not block this HTTP request
196  call_user_func(
197  $this->asyncHandler,
198  function () use ( $cache, $method, $args, $logger ) {
199  if ( !call_user_func_array( [ $cache, $method ], $args ) ) {
200  $logger->warning( "Async $method op failed" );
201  }
202  }
203  );
204  }
205  }
206 
207  return $ret;
208  }
209 
218  public function deleteObjectsExpiringBefore( $date, $progressCallback = false ) {
219  $ret = false;
220  foreach ( $this->caches as $cache ) {
221  if ( $cache->deleteObjectsExpiringBefore( $date, $progressCallback ) ) {
222  $ret = true;
223  }
224  }
225 
226  return $ret;
227  }
228 }
magic word the default is to use $key to get the and $key value or $key value text $key value html to format the value $key
Definition: hooks.txt:2321
static getObjectFromSpec($spec)
Instantiate an object based on a specification array.
doWrite($count, $asyncWrites, $method)
Apply a write method to the first $count backing caches.
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
null means default in associative array with keys and values unescaped Should be merged with default with a value of false meaning to suppress the attribute in associative array with keys and values unescaped noclasses & $ret
Definition: hooks.txt:1798
add($key, $value, $exptime=0)
$value
it s the revision text itself In either if gzip is the revision text is gzipped $flags
Definition: hooks.txt:2548
if($line===false) $args
Definition: cdb.php:64
const ALL
Idiom for "write to all backends".
__construct($params)
$params include:
A cache class that replicates all writes to multiple child caches.
bool $asyncWrites
Use async secondary writes.
lock($key, $timeout=6, $expiry=6, $rclass= '')
$cache
Definition: mcc.php:33
$params
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Definition: distributors.txt:9
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 $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
deleteObjectsExpiringBefore($date, $progressCallback=false)
Delete objects expiring before a certain date.
LoggerInterface $logger
Definition: BagOStuff.php:56
$count
set($key, $value, $exptime=0, $flags=0)
$debug
Definition: mcc.php:31