mediawiki-extensions-Echo/includes/ContainmentSet.php

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<?php
/**
* Interface providing list of contained values and an optional cache key to go along with it.
*/
interface EchoContainmentList {
/**
* @return array The values contained within this list.
*/
public function getValues();
/**
* @return string A string suitable for appending to the cache key prefix to facilitate
* cache busting when the underlying data changes, or a blank string if
* not relevant.
*/
public function getCacheKey();
}
/**
* Utilizes EchoContainmentList interface to provide a fluent interface to whitelist/blacklist
* from multiple sources like global variables, wiki pages, etc.
*
* Initialize:
* $cache = ObjectCache::getLocalClusterIntance();
* $set = new EchoContainmentSet;
* $set->addArray( $wgSomeGlobalParameter );
* $set->addOnWiki( NS_USER, 'Foo/bar-baz', $cache, 'some_user_specific_cache_key' );
*
* Usage:
* if ( $set->contains( 'SomeUser' ) ) {
* ...
* }
*/
class EchoContainmentSet {
/**
* @var EchoContainmentList[]
*/
protected $lists = array();
/**
* Add an EchoContainmentList to the set of lists checked by self::contains()
*
* @param $list EchoContainmentList
*/
public function add( EchoContainmentList $list ) {
$this->lists[] = $list;
}
/**
* Add a php array to the set of lists checked by self::contains()
*
* @param $list array
*/
public function addArray( array $list ) {
$this->add( new EchoArrayList( $list ) );
}
/**
* Add a list from a wiki page to the set of lists checked by self::contains(). Data
* from wiki pages is cached via the BagOStuff. Caching is disabled when passing a null
* $cache object.
*
* @param $namespace integer An NS_* constant representing the mediawiki namespace of the page containing the list.
* @param $title string The title of the page containing the list.
* @param $cache BagOStuff An object to cache the page with or null for no cache.
* @param $cacheKeyPrefix string A prefix to be combined with the pages latest revision id and used as a cache key.
*
* @throws MWException
*/
public function addOnWiki( $namespace, $title, BagOStuff $cache = null, $cacheKeyPrefix = '' ) {
$list = new EchoOnWikiList( $namespace, $title );
if ( $cache ) {
if ( $cacheKeyPrefix === '' ) {
throw new MWException( 'Cache requires providing a cache key prefix.' );
}
$list = new EchoCachedList( $cache, $cacheKeyPrefix, $list );
}
$this->add( $list );
}
/**
* Test the wrapped lists for existence of $value
*
* @param $value mixed The value to look for
* @return boolean True when the set contains the provided value
*/
public function contains( $value ) {
foreach ( $this->lists as $list ) {
if ( array_search( $value, $list->getValues() ) !== false ) {
return true;
}
}
return false;
}
}
/**
* Implements the EchoContainmentList interface for php arrays. Possible source
* of arrays includes $wg* global variables initialized from extensions or global
* wiki config.
*/
class EchoArrayList implements EchoContainmentList {
/**
* @var array
*/
protected $list;
/**
* @param $list array
*/
public function __construct( array $list ) {
$this->list = $list;
}
/**
* {@inheritDoc}
*/
public function getValues() {
return $this->list;
}
/**
* {@inheritDoc}
*/
public function getCacheKey() {
return '';
}
}
/**
* Implements EchoContainmentList interface for sourcing a list of items from a wiki
* page. Uses the pages latest revision ID as cache key.
*/
class EchoOnWikiList implements EchoContainmentList {
/**
* @var Title|null A title object representing the page to source the list from,
* or null if the page does not exist.
*/
protected $title;
/**
* @param $titleNs integer An NS_* constant representing the mediawiki namespace of the page
* @param $titleString string String portion of the wiki page title
*/
public function __construct( $titleNs, $titleString ) {
$title = Title::newFromText( $titleString, $titleNs );
if ( $title !== null && $title->getArticleId() ) {
$this->title = $title;
}
}
/**
* {@inheritDoc}
*/
public function getValues() {
if ( !$this->title ) {
return array();
}
$article = WikiPage::newFromID( $this->title->getArticleId() );
if ( $article === null || !$article->exists() ) {
return array();
}
return array_filter( array_map( 'trim', explode( "\n", $article->getText() ) ) );
}
/**
* {@inheritDoc}
*/
public function getCacheKey() {
if ( !$this->title ) {
return '';
}
return $this->title->getLatestRevID();
}
}
/**
* Caches an EchoContainmentList within a BagOStuff(memcache, etc) to prevent needing
* to load the nested list from a potentially slow source (mysql, etc).
*/
class EchoCachedList implements EchoContainmentList {
const ONE_WEEK = 4233600;
const ONE_DAY = 86400;
protected $cache;
protected $partialCacheKey;
protected $nestedList;
protected $timeout;
private $result;
/**
* @param $cache BagOStuff Bag to stored cached data in.
* @param $partialCacheKey string Partial cache key, $nestedList->getCacheKey() will be appended to this
* to construct the cache key used.
* @param $nestedList EchoContainmentList The nested EchoContainmentList to cache the result of.
* @param $timeout integer How long in seconds to cache the nested list, defaults to 1 week.
*/
public function __construct( BagOStuff $cache, $partialCacheKey, EchoContainmentList $nestedList, $timeout = self::ONE_WEEK ) {
$this->cache = $cache;
$this->partialCacheKey = $partialCacheKey;
$this->nestedList = $nestedList;
$this->timeout = $timeout;
}
/**
* {@inheritDoc}
*/
public function getValues() {
if ( $this->result ) {
return $this->result;
}
$cacheKey = $this->getCacheKey();
$fetched = $this->cache->get( $cacheKey );
if ( is_array( $fetched ) ) {
return $this->result = $fetched;
}
$result = $this->nestedList->getValues();
if ( !is_array( $result ) ) {
throw new MWException( sprintf(
"Expected array but received '%s' from '%s::getValues'",
is_object( $result ) ? get_class( $result ) : gettype( $result ),
get_class( $this->nestedList )
) );
}
$this->cache->set( $cacheKey, $result, $this->timeout );
return $this->result = $result;
}
/**
* {@inheritDoc}
*/
public function getCacheKey() {
return $this->partialCacheKey . '_' . $this->nestedList->getCacheKey();
}
}