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RedisLockManager.php
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1 <?php
42  protected $lockTypeMap = [
43  self::LOCK_SH => self::LOCK_SH,
44  self::LOCK_UW => self::LOCK_SH,
45  self::LOCK_EX => self::LOCK_EX
46  ];
47 
49  protected $redisPool;
50 
52  protected $lockServers = [];
53 
64  public function __construct( array $config ) {
65  parent::__construct( $config );
66 
67  $this->lockServers = $config['lockServers'];
68  // Sanitize srvsByBucket config to prevent PHP errors
69  $this->srvsByBucket = array_filter( $config['srvsByBucket'], 'is_array' );
70  $this->srvsByBucket = array_values( $this->srvsByBucket ); // consecutive
71 
72  $config['redisConfig']['serializer'] = 'none';
73  $this->redisPool = RedisConnectionPool::singleton( $config['redisConfig'] );
74  }
75 
76  protected function getLocksOnServer( $lockSrv, array $pathsByType ) {
78 
79  $pathList = array_merge( ...array_values( $pathsByType ) );
80 
81  $server = $this->lockServers[$lockSrv];
82  $conn = $this->redisPool->getConnection( $server, $this->logger );
83  if ( !$conn ) {
84  foreach ( $pathList as $path ) {
85  $status->fatal( 'lockmanager-fail-acquirelock', $path );
86  }
87 
88  return $status;
89  }
90 
91  $pathsByKey = []; // (type:hash => path) map
92  foreach ( $pathsByType as $type => $paths ) {
93  $typeString = ( $type == LockManager::LOCK_SH ) ? 'SH' : 'EX';
94  foreach ( $paths as $path ) {
95  $pathsByKey[$this->recordKeyForPath( $path, $typeString )] = $path;
96  }
97  }
98 
99  try {
100  static $script =
102 <<<LUA
103  local failed = {}
104  -- Load input params (e.g. session, ttl, time of request)
105  local rSession, rTTL, rMaxTTL, rTime = unpack(ARGV)
106  -- Check that all the locks can be acquired
107  for i,requestKey in ipairs(KEYS) do
108  local _, _, rType, resourceKey = string.find(requestKey,"(%w+):(%w+)$")
109  local keyIsFree = true
110  local currentLocks = redis.call('hKeys',resourceKey)
111  for i,lockKey in ipairs(currentLocks) do
112  -- Get the type and session of this lock
113  local _, _, type, session = string.find(lockKey,"(%w+):(%w+)")
114  -- Check any locks that are not owned by this session
115  if session ~= rSession then
116  local lockExpiry = redis.call('hGet',resourceKey,lockKey)
117  if 1*lockExpiry < 1*rTime then
118  -- Lock is stale, so just prune it out
119  redis.call('hDel',resourceKey,lockKey)
120  elseif rType == 'EX' or type == 'EX' then
121  keyIsFree = false
122  break
123  end
124  end
125  end
126  if not keyIsFree then
127  failed[#failed+1] = requestKey
128  end
129  end
130  -- If all locks could be acquired, then do so
131  if #failed == 0 then
132  for i,requestKey in ipairs(KEYS) do
133  local _, _, rType, resourceKey = string.find(requestKey,"(%w+):(%w+)$")
134  redis.call('hSet',resourceKey,rType .. ':' .. rSession,rTime + rTTL)
135  -- In addition to invalidation logic, be sure to garbage collect
136  redis.call('expire',resourceKey,rMaxTTL)
137  end
138  end
139  return failed
140 LUA;
141  $res = $conn->luaEval( $script,
142  array_merge(
143  array_keys( $pathsByKey ), // KEYS[0], KEYS[1],...,KEYS[N]
144  [
145  $this->session, // ARGV[1]
146  $this->lockTTL, // ARGV[2]
147  self::MAX_LOCK_TTL, // ARGV[3]
148  time() // ARGV[4]
149  ]
150  ),
151  count( $pathsByKey ) # number of first argument(s) that are keys
152  );
153  } catch ( RedisException $e ) {
154  $res = false;
155  $this->redisPool->handleError( $conn, $e );
156  }
157 
158  if ( $res === false ) {
159  foreach ( $pathList as $path ) {
160  $status->fatal( 'lockmanager-fail-acquirelock', $path );
161  }
162  } else {
163  foreach ( $res as $key ) {
164  $status->fatal( 'lockmanager-fail-acquirelock', $pathsByKey[$key] );
165  }
166  }
167 
168  return $status;
169  }
170 
171  protected function freeLocksOnServer( $lockSrv, array $pathsByType ) {
173 
174  $pathList = array_merge( ...array_values( $pathsByType ) );
175 
176  $server = $this->lockServers[$lockSrv];
177  $conn = $this->redisPool->getConnection( $server, $this->logger );
178  if ( !$conn ) {
179  foreach ( $pathList as $path ) {
180  $status->fatal( 'lockmanager-fail-releaselock', $path );
181  }
182 
183  return $status;
184  }
185 
186  $pathsByKey = []; // (type:hash => path) map
187  foreach ( $pathsByType as $type => $paths ) {
188  $typeString = ( $type == LockManager::LOCK_SH ) ? 'SH' : 'EX';
189  foreach ( $paths as $path ) {
190  $pathsByKey[$this->recordKeyForPath( $path, $typeString )] = $path;
191  }
192  }
193 
194  try {
195  static $script =
197 <<<LUA
198  local failed = {}
199  -- Load input params (e.g. session)
200  local rSession = unpack(ARGV)
201  for i,requestKey in ipairs(KEYS) do
202  local _, _, rType, resourceKey = string.find(requestKey,"(%w+):(%w+)$")
203  local released = redis.call('hDel',resourceKey,rType .. ':' .. rSession)
204  if released > 0 then
205  -- Remove the whole structure if it is now empty
206  if redis.call('hLen',resourceKey) == 0 then
207  redis.call('del',resourceKey)
208  end
209  else
210  failed[#failed+1] = requestKey
211  end
212  end
213  return failed
214 LUA;
215  $res = $conn->luaEval( $script,
216  array_merge(
217  array_keys( $pathsByKey ), // KEYS[0], KEYS[1],...,KEYS[N]
218  [
219  $this->session, // ARGV[1]
220  ]
221  ),
222  count( $pathsByKey ) # number of first argument(s) that are keys
223  );
224  } catch ( RedisException $e ) {
225  $res = false;
226  $this->redisPool->handleError( $conn, $e );
227  }
228 
229  if ( $res === false ) {
230  foreach ( $pathList as $path ) {
231  $status->fatal( 'lockmanager-fail-releaselock', $path );
232  }
233  } else {
234  foreach ( $res as $key ) {
235  $status->fatal( 'lockmanager-fail-releaselock', $pathsByKey[$key] );
236  }
237  }
238 
239  return $status;
240  }
241 
242  protected function releaseAllLocks() {
243  return StatusValue::newGood(); // not supported
244  }
245 
246  protected function isServerUp( $lockSrv ) {
247  $conn = $this->redisPool->getConnection( $this->lockServers[$lockSrv], $this->logger );
248 
249  return (bool)$conn;
250  }
251 
257  protected function recordKeyForPath( $path, $type ) {
258  return implode( ':',
259  [ __CLASS__, 'locks', "$type:" . $this->sha1Base36Absolute( $path ) ] );
260  }
261 
265  function __destruct() {
266  while ( count( $this->locksHeld ) ) {
267  $pathsByType = [];
268  foreach ( $this->locksHeld as $path => $locks ) {
269  foreach ( $locks as $type => $count ) {
270  $pathsByType[$type][] = $path;
271  }
272  }
273  $this->unlockByType( $pathsByType );
274  }
275  }
276 }
unlockByType(array $pathsByType)
Unlock the resources at the given abstract paths.
return true to allow those checks to and false if checking is done remove or add to the links of a group of changes in EnhancedChangesList Hook subscribers can return false to omit this line from recentchanges use this to change the tables headers change it to an object instance and return false override the list derivative used $groups Array of ChangesListFilterGroup objects(added in 1.34) 'FileDeleteComplete' null for the local wiki Added in
Definition: hooks.txt:1529
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global then executing the whole list after the page is displayed We don t do anything smart like collating updates to the same table or such because the list is almost always going to have just one item on if that
Definition: deferred.txt:11
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for and distribution as defined by Sections through of this document Licensor shall mean the copyright owner or entity authorized by the copyright owner that is granting the License Legal Entity shall mean the union of the acting entity and all other entities that control are controlled by or are under common control with that entity For the purposes of this definition control direct or to cause the direction or management of such whether by contract or including but not limited to software source documentation and configuration files Object form shall mean any form resulting from mechanical transformation or translation of a Source including but not limited to compiled object generated and conversions to other media types Work shall mean the work of whether in Source or Object made available under the as indicated by a copyright notice that is included in or attached to the whether in Source or Object that is based or other modifications as a whole
RedisConnectionPool $redisPool
__construct(array $config)
Construct a new instance from configuration.
div flags Integer display flags(NO_ACTION_LINK, NO_EXTRA_USER_LINKS) 'LogException' returning false will NOT prevent logging $e
Definition: hooks.txt:2147
globals txt Globals are evil The original MediaWiki code relied on globals for processing context far too often MediaWiki development since then has been a story of slowly moving context out of global variables and into objects Storing processing context in object member variables allows those objects to be reused in a much more flexible way Consider the elegance of
database rows
Definition: globals.txt:10
in this case you re responsible for computing and outputting the entire conflict i e
Definition: hooks.txt:1401
lock(array $paths, $type=self::LOCK_EX, $timeout=0)
Lock the resources at the given abstract paths.
This document provides an overview of the usage of PageUpdater and that is
Definition: pageupdater.txt:3
The ContentHandler facility adds support for arbitrary content types on wiki instead of relying on wikitext for everything It was introduced in MediaWiki Each kind of and so on Built in content types are
static singleton(array $options)
Status::newGood()` to allow deletion, and then `return false` from the hook function. Ensure you consume the 'ChangeTagAfterDelete' hook to carry out custom deletion actions. $tag:name of the tag $user:user initiating the action & $status:Status object. See above. 'ChangeTagsListActive':Allows you to nominate which of the tags your extension uses are in active use. & $tags:list of all active tags. Append to this array. 'ChangeTagsAfterUpdateTags':Called after tags have been updated with the ChangeTags::updateTags function. Params:$addedTags:tags effectively added in the update $removedTags:tags effectively removed in the update $prevTags:tags that were present prior to the update $rc_id:recentchanges table id $rev_id:revision table id $log_id:logging table id $params:tag params $rc:RecentChange being tagged when the tagging accompanies the action, or null $user:User who performed the tagging when the tagging is subsequent to the action, or null 'ChangeTagsAllowedAdd':Called when checking if a user can add tags to a change. & $allowedTags:List of all the tags the user is allowed to add. Any tags the user wants to add( $addTags) that are not in this array will cause it to fail. You may add or remove tags to this array as required. $addTags:List of tags user intends to add. $user:User who is adding the tags. 'ChangeUserGroups':Called before user groups are changed. $performer:The User who will perform the change $user:The User whose groups will be changed & $add:The groups that will be added & $remove:The groups that will be removed 'Collation::factory':Called if $wgCategoryCollation is an unknown collation. $collationName:Name of the collation in question & $collationObject:Null. Replace with a subclass of the Collation class that implements the collation given in $collationName. 'ConfirmEmailComplete':Called after a user 's email has been confirmed successfully. $user:user(object) whose email is being confirmed 'ContentAlterParserOutput':Modify parser output for a given content object. Called by Content::getParserOutput after parsing has finished. Can be used for changes that depend on the result of the parsing but have to be done before LinksUpdate is called(such as adding tracking categories based on the rendered HTML). $content:The Content to render $title:Title of the page, as context $parserOutput:ParserOutput to manipulate 'ContentGetParserOutput':Customize parser output for a given content object, called by AbstractContent::getParserOutput. May be used to override the normal model-specific rendering of page content. $content:The Content to render $title:Title of the page, as context $revId:The revision ID, as context $options:ParserOptions for rendering. To avoid confusing the parser cache, the output can only depend on parameters provided to this hook function, not on global state. $generateHtml:boolean, indicating whether full HTML should be generated. If false, generation of HTML may be skipped, but other information should still be present in the ParserOutput object. & $output:ParserOutput, to manipulate or replace 'ContentHandlerDefaultModelFor':Called when the default content model is determined for a given title. May be used to assign a different model for that title. $title:the Title in question & $model:the model name. Use with CONTENT_MODEL_XXX constants. 'ContentHandlerForModelID':Called when a ContentHandler is requested for a given content model name, but no entry for that model exists in $wgContentHandlers. Note:if your extension implements additional models via this hook, please use GetContentModels hook to make them known to core. $modeName:the requested content model name & $handler:set this to a ContentHandler object, if desired. 'ContentModelCanBeUsedOn':Called to determine whether that content model can be used on a given page. This is especially useful to prevent some content models to be used in some special location. $contentModel:ID of the content model in question $title:the Title in question. & $ok:Output parameter, whether it is OK to use $contentModel on $title. Handler functions that modify $ok should generally return false to prevent further hooks from further modifying $ok. 'ContribsPager::getQueryInfo':Before the contributions query is about to run & $pager:Pager object for contributions & $queryInfo:The query for the contribs Pager 'ContribsPager::reallyDoQuery':Called before really executing the query for My Contributions & $data:an array of results of all contribs queries $pager:The ContribsPager object hooked into $offset:Index offset, inclusive $limit:Exact query limit $descending:Query direction, false for ascending, true for descending 'ContributionsLineEnding':Called before a contributions HTML line is finished $page:SpecialPage object for contributions & $ret:the HTML line $row:the DB row for this line & $classes:the classes to add to the surrounding< li > & $attribs:associative array of other HTML attributes for the< li > element. Currently only data attributes reserved to MediaWiki are allowed(see Sanitizer::isReservedDataAttribute). 'ContributionsToolLinks':Change tool links above Special:Contributions $id:User identifier $title:User page title & $tools:Array of tool links $specialPage:SpecialPage instance for context and services. Can be either SpecialContributions or DeletedContributionsPage. Extensions should type hint against a generic SpecialPage though. 'ConvertContent':Called by AbstractContent::convert when a conversion to another content model is requested. Handler functions that modify $result should generally return false to disable further attempts at conversion. $content:The Content object to be converted. $toModel:The ID of the content model to convert to. $lossy:boolean indicating whether lossy conversion is allowed. & $result:Output parameter, in case the handler function wants to provide a converted Content object. Note that $result->getContentModel() must return $toModel. 'ContentSecurityPolicyDefaultSource':Modify the allowed CSP load sources. This affects all directives except for the script directive. If you want to add a script source, see ContentSecurityPolicyScriptSource hook. & $defaultSrc:Array of Content-Security-Policy allowed sources $policyConfig:Current configuration for the Content-Security-Policy header $mode:ContentSecurityPolicy::REPORT_ONLY_MODE or ContentSecurityPolicy::FULL_MODE depending on type of header 'ContentSecurityPolicyDirectives':Modify the content security policy directives. Use this only if ContentSecurityPolicyDefaultSource and ContentSecurityPolicyScriptSource do not meet your needs. & $directives:Array of CSP directives $policyConfig:Current configuration for the CSP header $mode:ContentSecurityPolicy::REPORT_ONLY_MODE or ContentSecurityPolicy::FULL_MODE depending on type of header 'ContentSecurityPolicyScriptSource':Modify the allowed CSP script sources. Note that you also have to use ContentSecurityPolicyDefaultSource if you want non-script sources to be loaded from whatever you add. & $scriptSrc:Array of CSP directives $policyConfig:Current configuration for the CSP header $mode:ContentSecurityPolicy::REPORT_ONLY_MODE or ContentSecurityPolicy::FULL_MODE depending on type of header 'CustomEditor':When invoking the page editor Return true to allow the normal editor to be used, or false if implementing a custom editor, e.g. for a special namespace, etc. $article:Article being edited $user:User performing the edit 'DeletedContribsPager::reallyDoQuery':Called before really executing the query for Special:DeletedContributions Similar to ContribsPager::reallyDoQuery & $data:an array of results of all contribs queries $pager:The DeletedContribsPager object hooked into $offset:Index offset, inclusive $limit:Exact query limit $descending:Query direction, false for ascending, true for descending 'DeletedContributionsLineEnding':Called before a DeletedContributions HTML line is finished. Similar to ContributionsLineEnding $page:SpecialPage object for DeletedContributions & $ret:the HTML line $row:the DB row for this line & $classes:the classes to add to the surrounding< li > & $attribs:associative array of other HTML attributes for the< li > element. Currently only data attributes reserved to MediaWiki are allowed(see Sanitizer::isReservedDataAttribute). 'DeleteUnknownPreferences':Called by the cleanupPreferences.php maintenance script to build a WHERE clause with which to delete preferences that are not known about. This hook is used by extensions that have dynamically-named preferences that should not be deleted in the usual cleanup process. For example, the Gadgets extension creates preferences prefixed with 'gadget-', and so anything with that prefix is excluded from the deletion. &where:An array that will be passed as the $cond parameter to IDatabase::select() to determine what will be deleted from the user_properties table. $db:The IDatabase object, useful for accessing $db->buildLike() etc. 'DifferenceEngineAfterLoadNewText':called in DifferenceEngine::loadNewText() after the new revision 's content has been loaded into the class member variable $differenceEngine->mNewContent but before returning true from this function. $differenceEngine:DifferenceEngine object 'DifferenceEngineLoadTextAfterNewContentIsLoaded':called in DifferenceEngine::loadText() after the new revision 's content has been loaded into the class member variable $differenceEngine->mNewContent but before checking if the variable 's value is null. This hook can be used to inject content into said class member variable. $differenceEngine:DifferenceEngine object 'DifferenceEngineMarkPatrolledLink':Allows extensions to change the "mark as patrolled" link which is shown both on the diff header as well as on the bottom of a page, usually wrapped in a span element which has class="patrollink". $differenceEngine:DifferenceEngine object & $markAsPatrolledLink:The "mark as patrolled" link HTML(string) $rcid:Recent change ID(rc_id) for this change(int) 'DifferenceEngineMarkPatrolledRCID':Allows extensions to possibly change the rcid parameter. For example the rcid might be set to zero due to the user being the same as the performer of the change but an extension might still want to show it under certain conditions. & $rcid:rc_id(int) of the change or 0 $differenceEngine:DifferenceEngine object $change:RecentChange object $user:User object representing the current user 'DifferenceEngineNewHeader':Allows extensions to change the $newHeader variable, which contains information about the new revision, such as the revision 's author, whether the revision was marked as a minor edit or not, etc. $differenceEngine:DifferenceEngine object & $newHeader:The string containing the various #mw-diff-otitle[1-5] divs, which include things like revision author info, revision comment, RevisionDelete link and more $formattedRevisionTools:Array containing revision tools, some of which may have been injected with the DiffRevisionTools hook $nextlink:String containing the link to the next revision(if any) $status
Definition: hooks.txt:1244
__destruct()
Make sure remaining locks get cleared for sanity.
$res
Definition: database.txt:21
static newGood( $value=null)
Factory function for good results.
Definition: StatusValue.php:81
and(b) You must cause any modified files to carry prominent notices stating that You changed the files
as see the revision history and available at free of to any person obtaining a copy of this software and associated documentation to deal in the Software without including without limitation the rights to and or sell copies of the and to permit persons to whom the Software is furnished to do so
Definition: LICENSE.txt:10
const LOCK_SH
Lock types; stronger locks have higher values.
Definition: LockManager.php:68
array $lockServers
Map server names to hostname/IP and port numbers.
div flags Integer display flags(NO_ACTION_LINK, NO_EXTRA_USER_LINKS) 'LogException' returning false will NOT prevent logging a wrapping ErrorException create2 Corresponds to logging log_action database field and which is displayed in the UI similar to $comment or false if none Defaults to false if not set multiOccurrence Can this option be passed multiple times Defaults to false if not set this hook should only be used to add variables that depend on the current page request
Definition: hooks.txt:2147
getLocksOnServer( $lockSrv, array $pathsByType)
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for and distribution as defined by Sections through of this document Licensor shall mean the copyright owner or entity authorized by the copyright owner that is granting the License Legal Entity shall mean the union of the acting entity and all other entities that control are controlled by or are under common control with that entity For the purposes of this definition control direct or to cause the direction or management of such whether by contract or including but not limited to software source documentation and configuration files Object form shall mean any form resulting from mechanical transformation or translation of a Source including but not limited to compiled object generated and conversions to other media types Work shall mean the work of whether in Source or Object made available under the as indicated by a copyright notice that is included in or attached to the whether in Source or Object that is based or other modifications as a an original work of authorship For the purposes of this Derivative Works shall not include works that remain separable or merely the Work and Derivative Works thereof Contribution shall mean any work of including the original version of the Work and any modifications or additions to that Work or Derivative Works that is intentionally submitted to Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner For the purposes of this submitted means any form of or written communication sent to the Licensor or its including but not limited to communication on electronic mailing source code control and issue tracking systems that are managed by
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
array $lockTypeMap
Mapping of lock types to the type actually used.
Manage locks using redis servers.
Using a hook running we can avoid having all this option specific stuff in our mainline code Using the function We ve cleaned up the code here by removing clumps of infrequently used code and moving them off somewhere else It s much easier for someone working with this code to see what s _really_ going and make changes or fix bugs In addition
Definition: hooks.txt:77
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
This document describes the state of Postgres support in and is fairly well maintained The main code is very well while extensions are very hit and miss it is probably the most supported database after MySQL Much of the work in making MediaWiki database agnostic came about through the work of creating Postgres as and are nearing end of but without copying over all the usage comments General notes on the but these can almost always be programmed around *Although Postgres has a true BOOLEAN type
Definition: postgres.txt:22
this hook is for auditing only RecentChangesLinked and Watchlist Do not use this to implement individual filters if they are compatible with the ChangesListFilter and ChangesListFilterGroup structure use sub classes of those in conjunction with the ChangesListSpecialPageStructuredFilters hook This hook can be used to implement filters that do not implement that structure
Definition: hooks.txt:960
recordKeyForPath( $path, $type)
freeLocksOnServer( $lockSrv, array $pathsByType)
=Architecture==Two class hierarchies are used to provide the functionality associated with the different content models:*Content interface(and AbstractContent base class) define functionality that acts on the concrete content of a page, and *ContentHandler base class provides functionality specific to a content model, but not acting on concrete content. The most important function of ContentHandler is to act as a factory for the appropriate implementation of Content. These Content objects are to be used by MediaWiki everywhere, instead of passing page content around as text. All manipulation and analysis of page content must be done via the appropriate methods of the Content object. For each content model, a subclass of ContentHandler has to be registered with $wgContentHandlers. The ContentHandler object for a given content model can be obtained using ContentHandler::getForModelID($id). Also Title, WikiPage and Revision now have getContentHandler() methods for convenience. ContentHandler objects are singletons that provide functionality specific to the content type, but not directly acting on the content of some page. ContentHandler::makeEmptyContent() and ContentHandler::unserializeContent() can be used to create a Content object of the appropriate type. However, it is recommended to instead use WikiPage::getContent() resp. Revision::getContent() to get a page 's content as a Content object. These two methods should be the ONLY way in which page content is accessed. Another important function of ContentHandler objects is to define custom action handlers for a content model, see ContentHandler::getActionOverrides(). This is similar to what WikiPage::getActionOverrides() was already doing.==Serialization==With the ContentHandler facility, page content no longer has to be text based. Objects implementing the Content interface are used to represent and handle the content internally. For storage and data exchange, each content model supports at least one serialization format via ContentHandler::serializeContent($content). The list of supported formats for a given content model can be accessed using ContentHandler::getSupportedFormats(). Content serialization formats are identified using MIME type like strings. The following formats are built in:*text/x-wiki - wikitext *text/javascript - for js pages *text/css - for css pages *text/plain - for future use, e.g. with plain text messages. *text/html - for future use, e.g. with plain html messages. *application/vnd.php.serialized - for future use with the api and for extensions *application/json - for future use with the api, and for use by extensions *application/xml - for future use with the api, and for use by extensions In PHP, use the corresponding CONTENT_FORMAT_XXX constant. Note that when using the API to access page content, especially action=edit, action=parse and action=query &prop=revisions, the model and format of the content should always be handled explicitly. Without that information, interpretation of the provided content is not reliable. The same applies to XML dumps generated via maintenance/dumpBackup.php or Special:Export. Also note that the API will provide encapsulated, serialized content - so if the API was called with format=json, and contentformat is also json(or rather, application/json), the page content is represented as a string containing an escaped json structure. Extensions that use JSON to serialize some types of page content may provide specialized API modules that allow access to that content in a more natural form.==Compatibility==The ContentHandler facility is introduced in a way that should allow all existing code to keep functioning at least for pages that contain wikitext or other text based content. However, a number of functions and hooks have been deprecated in favor of new versions that are aware of the page 's content model, and will now generate warnings when used. Most importantly, the following functions have been deprecated:*Revisions::getText() is deprecated in favor Revisions::getContent() *WikiPage::getText() is deprecated in favor WikiPage::getContent() Also, the old Article::getContent()(which returns text) is superceded by Article::getContentObject(). However, both methods should be avoided since they do not provide clean access to the page 's actual content. For instance, they may return a system message for non-existing pages. Use WikiPage::getContent() instead. Code that relies on a textual representation of the page content should eventually be rewritten. However, ContentHandler::getContentText() provides a stop-gap that can be used to get text for a page. Its behavior is controlled by $wgContentHandlerTextFallback it
skin txt MediaWiki includes four core it has been set as the default in MediaWiki since the replacing Monobook it had been the default skin since then
Definition: skin.txt:10
Version of LockManager that uses a quorum from peer servers for locks.
sha1Base36Absolute( $path)
Get the base 36 SHA-1 of a string, padded to 31 digits.