and let’s assume the following content of Bar.php:
// Bar.phpnamespaceOtherDir;useSomeDir\Foo;// This now conflicts the class OtherDir\Foo
If both files OtherDir/Foo.php and SomeDir/Foo.php are loaded in the
same runtime, you will see a PHP error such as the following:
PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.php
However, as OtherDir/Foo.php does not necessarily have to be loaded and the
error is only triggered if it is loaded before OtherDir/Bar.php, this problem
might go unnoticed for a while. In order to prevent this error from surfacing,
you must import the namespace with a different alias:
// Bar.phpnamespaceOtherDir;useSomeDir\FooasSomeDirFoo;// There is no conflict anymore.
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25
26
/**
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* MediaWiki message cache structure version.
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* Bump this whenever the message cache format has changed.
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*/
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define( 'MSG_CACHE_VERSION', 2 );
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/**
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* Message cache
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* Performs various MediaWiki namespace-related functions
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* @ingroup Cache
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*/
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class MessageCache {
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const FOR_UPDATE = 1; // force message reload
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/** How long to wait for memcached locks */
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const WAIT_SEC = 15;
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/** How long memcached locks last */
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const LOCK_TTL = 30;
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/**
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* Process local cache of loaded messages that are defined in
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* MediaWiki namespace. First array level is a language code,
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* second level is message key and the values are either message
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* content prefixed with space, or !NONEXISTENT for negative
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* caching.
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* @var array $mCache
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*/
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protected $mCache;
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/**
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* Should mean that database cannot be used, but check
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* @var bool $mDisable
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*/
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protected $mDisable;
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/**
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* Lifetime for cache, used by object caching.
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* Set on construction, see __construct().
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*/
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protected $mExpiry;
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/**
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* Message cache has its own parser which it uses to transform
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* messages.
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*/
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protected $mParserOptions, $mParser;
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/**
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* Variable for tracking which variables are already loaded
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* @var array $mLoadedLanguages
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*/
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protected $mLoadedLanguages = [];
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/**
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* @var bool $mInParser
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*/
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protected $mInParser = false;
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/** @var BagOStuff */
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protected $mMemc;
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/** @var WANObjectCache */
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protected $wanCache;
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/**
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* Singleton instance
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*
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* @var MessageCache $instance
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*/
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private static $instance;
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/**
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* Get the signleton instance of this class
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*
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* @since 1.18
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* @return MessageCache
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*/
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public static function singleton() {
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if ( self::$instance === null ) {
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global $wgUseDatabaseMessages, $wgMsgCacheExpiry;
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self::$instance = new self(
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wfGetMessageCacheStorage(),
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$wgUseDatabaseMessages,
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$wgMsgCacheExpiry
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);
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}
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return self::$instance;
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}
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/**
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* Destroy the singleton instance
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*
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* @since 1.18
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*/
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public static function destroyInstance() {
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self::$instance = null;
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}
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/**
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* Normalize message key input
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*
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* @param string $key Input message key to be normalized
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* @return string Normalized message key
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*/
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public static function normalizeKey( $key ) {
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global $wgContLang;
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$lckey = strtr( $key, ' ', '_' );
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if ( ord( $lckey ) < 128 ) {
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$lckey[0] = strtolower( $lckey[0] );
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} else {
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$lckey = $wgContLang->lcfirst( $lckey );
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}
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return $lckey;
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}
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/**
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* @param BagOStuff $memCached A cache instance. If none, fall back to CACHE_NONE.
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* @param bool $useDB
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* @param int $expiry Lifetime for cache. @see $mExpiry.
146
*/
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function __construct( $memCached, $useDB, $expiry ) {
wikimedia /
mediawiki
Kunal Mehta
Aaron Schulz
Tyler Romeo
Roan Kattouw
Niklas Laxström
Siebrand Mazeland
Tim Starling
Andrew Green
Let’s assume that you have a directory layout like this:
. |-- OtherDir | |-- Bar.php | `-- Foo.php `-- SomeDir `-- Foo.phpand let’s assume the following content of
Bar.php:If both files
OtherDir/Foo.phpandSomeDir/Foo.phpare loaded in the same runtime, you will see a PHP error such as the following:PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.phpHowever, as
OtherDir/Foo.phpdoes not necessarily have to be loaded and the error is only triggered if it is loaded beforeOtherDir/Bar.php, this problem might go unnoticed for a while. In order to prevent this error from surfacing, you must import the namespace with a different alias: