<?php
/**
* Localisation messages cache.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Cache
*/
/**
* MediaWiki message cache structure version.
* Bump this whenever the message cache format has changed.
*/
define( 'MSG_CACHE_VERSION', 1 );
/**
* Memcached timeout when loading a key.
* See MessageCache::load()
*/
define( 'MSG_LOAD_TIMEOUT', 60 );
/**
* Memcached timeout when locking a key for a writing operation.
* See MessageCache::lock()
*/
define( 'MSG_LOCK_TIMEOUT', 30 );
/**
* Number of times we will try to acquire a lock from Memcached.
* This comes in addition to MSG_LOCK_TIMEOUT.
*/
define( 'MSG_WAIT_TIMEOUT', 30 );
/**
* Message cache
* Performs various MediaWiki namespace-related functions
* @ingroup Cache
*/
class MessageCache {
/**
* Process local cache of loaded messages that are defined in
* MediaWiki namespace. First array level is a language code,
* second level is message key and the values are either message
* content prefixed with space, or !NONEXISTENT for negative
* caching.
*/
protected $mCache;
/**
* Should mean that database cannot be used, but check
* @var bool $mDisable
*/
protected $mDisable;
/**
* Lifetime for cache, used by object caching.
* Set on construction, see __construct().
*/
protected $mExpiry;
/**
* Message cache has it's own parser which it uses to transform
* messages.
*/
protected $mParserOptions, $mParser;
/**
* Variable for tracking which variables are already loaded
* @var array $mLoadedLanguages
*/
protected $mLoadedLanguages = array();
/**
* Singleton instance
*
* @var MessageCache $instance
*/
private static $instance;
/**
* @var bool $mInParser
*/
protected $mInParser = false;
/**
* Get the signleton instance of this class
*
* @since 1.18
* @return MessageCache
*/
public static function singleton() {
if ( is_null( self::$instance ) ) {
global $wgUseDatabaseMessages, $wgMsgCacheExpiry;
self::$instance = new self(
wfGetMessageCacheStorage(),
$wgUseDatabaseMessages,
$wgMsgCacheExpiry
);
}
return self::$instance;
}
/**
* Destroy the singleton instance
*
* @since 1.18
*/
public static function destroyInstance() {
self::$instance = null;
}
/**
* @param ObjectCache $memCached A cache instance. If none, fall back to CACHE_NONE.
* @param bool $useDB
* @param int $expiry Lifetime for cache. @see $mExpiry.
*/
function __construct( $memCached, $useDB, $expiry ) {
if ( !$memCached ) {
$memCached = wfGetCache( CACHE_NONE );
}
$this->mMemc = $memCached;
$this->mDisable = !$useDB;
$this->mExpiry = $expiry;
}
/**
* ParserOptions is lazy initialised.
*
* @return ParserOptions
*/
function getParserOptions() {
if ( !$this->mParserOptions ) {
$this->mParserOptions = new ParserOptions;
$this->mParserOptions->setEditSection( false );
}
return $this->mParserOptions;
}
/**
* Try to load the cache from a local file.
*
* @param string $hash the hash of contents, to check validity.
* @param Mixed $code Optional language code, see documenation of load().
* @return array The cache array
*/
function getLocalCache( $hash, $code ) {
global $wgCacheDirectory;
$filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
# Check file existence
wfSuppressWarnings();
$file = fopen( $filename, 'r' );
wfRestoreWarnings();
if ( !$file ) {
return false; // No cache file
}
// Check to see if the file has the hash specified
$localHash = fread( $file, 32 );
if ( $hash === $localHash ) {
// All good, get the rest of it
$serialized = '';
while ( !feof( $file ) ) {
$serialized .= fread( $file, 100000 );
}
fclose( $file );
return unserialize( $serialized );
} else {
fclose( $file );
return false; // Wrong hash
}
}
/**
* Save the cache to a local file.
*/
function saveToLocal( $serialized, $hash, $code ) {
global $wgCacheDirectory;
$filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
wfMkdirParents( $wgCacheDirectory, null, __METHOD__ ); // might fail
wfSuppressWarnings();
$file = fopen( $filename, 'w' );
wfRestoreWarnings();
if ( !$file ) {
wfDebug( "Unable to open local cache file for writing\n" );
return;
}
fwrite( $file, $hash . $serialized );
fclose( $file );
wfSuppressWarnings();
chmod( $filename, 0666 );
wfRestoreWarnings();
}
/**
* Loads messages from caches or from database in this order:
* (1) local message cache (if $wgUseLocalMessageCache is enabled)
* (2) memcached
* (3) from the database.
*
* When succesfully loading from (2) or (3), all higher level caches are
* updated for the newest version.
*
* Nothing is loaded if member variable mDisable is true, either manually
* set by calling code or if message loading fails (is this possible?).
*
* Returns true if cache is already populated or it was succesfully populated,
* or false if populating empty cache fails. Also returns true if MessageCache
* is disabled.
*
* @param bool|String $code Language to which load messages
* @throws MWException
* @return bool
*/
function load( $code = false ) {
global $wgUseLocalMessageCache;
if ( !is_string( $code ) ) {
# This isn't really nice, so at least make a note about it and try to
# fall back
wfDebug( __METHOD__ . " called without providing a language code\n" );
$code = 'en';
}
# Don't do double loading...
if ( isset( $this->mLoadedLanguages[$code] ) ) {
return true;
}
# 8 lines of code just to say (once) that message cache is disabled
if ( $this->mDisable ) {
static $shownDisabled = false;
if ( !$shownDisabled ) {
wfDebug( __METHOD__ . ": disabled\n" );
$shownDisabled = true;
}
return true;
}
# Loading code starts
wfProfileIn( __METHOD__ );
$success = false; # Keep track of success
$staleCache = false; # a cache array with expired data, or false if none has been loaded
$where = array(); # Debug info, delayed to avoid spamming debug log too much
$cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages
# Local cache
# Hash of the contents is stored in memcache, to detect if local cache goes
# out of date (e.g. due to replace() on some other server)
if ( $wgUseLocalMessageCache ) {
wfProfileIn( __METHOD__ . '-fromlocal' );
$hash = $this->mMemc->get( wfMemcKey( 'messages', $code, 'hash' ) );
if ( $hash ) {
$cache = $this->getLocalCache( $hash, $code );
if ( !$cache ) {
$where[] = 'local cache is empty or has the wrong hash';
} elseif ( $this->isCacheExpired( $cache ) ) {
$where[] = 'local cache is expired';
$staleCache = $cache;
} else {
$where[] = 'got from local cache';
$success = true;
$this->mCache[$code] = $cache;
}
}
wfProfileOut( __METHOD__ . '-fromlocal' );
}
if ( !$success ) {
# Try the global cache. If it is empty, try to acquire a lock. If
# the lock can't be acquired, wait for the other thread to finish
# and then try the global cache a second time.
for ( $failedAttempts = 0; $failedAttempts < 2; $failedAttempts++ ) {
wfProfileIn( __METHOD__ . '-fromcache' );
$cache = $this->mMemc->get( $cacheKey );
if ( !$cache ) {
$where[] = 'global cache is empty';
} elseif ( $this->isCacheExpired( $cache ) ) {
$where[] = 'global cache is expired';
$staleCache = $cache;
} else {
$where[] = 'got from global cache';
$this->mCache[$code] = $cache;
$this->saveToCaches( $cache, 'local-only', $code );
$success = true;
}
wfProfileOut( __METHOD__ . '-fromcache' );
if ( $success ) {
# Done, no need to retry
break;
}
# We need to call loadFromDB. Limit the concurrency to a single
# process. This prevents the site from going down when the cache
# expires.
$statusKey = wfMemcKey( 'messages', $code, 'status' );
$acquired = $this->mMemc->add( $statusKey, 'loading', MSG_LOAD_TIMEOUT );
if ( $acquired ) {
# Unlock the status key if there is an exception
$that = $this;
$statusUnlocker = new ScopedCallback( function () use ( $that, $statusKey ) {
$that->mMemc->delete( $statusKey );
} );
# Now let's regenerate
$where[] = 'loading from database';
# Lock the cache to prevent conflicting writes
# If this lock fails, it doesn't really matter, it just means the
# write is potentially non-atomic, e.g. the results of a replace()
# may be discarded.
if ( $this->lock( $cacheKey ) ) {
$mainUnlocker = new ScopedCallback( function () use ( $that, $cacheKey ) {
$that->unlock( $cacheKey );
} );
} else {
$mainUnlocker = null;
$where[] = 'could not acquire main lock';
}
$cache = $this->loadFromDB( $code );
$this->mCache[$code] = $cache;
$success = true;
$saveSuccess = $this->saveToCaches( $cache, 'all', $code );
# Unlock
ScopedCallback::consume( $mainUnlocker );
ScopedCallback::consume( $statusUnlocker );
if ( !$saveSuccess ) {
# Cache save has failed.
# There are two main scenarios where this could be a problem:
#
# - The cache is more than the maximum size (typically
# 1MB compressed).
#
# - Memcached has no space remaining in the relevant slab
# class. This is unlikely with recent versions of
# memcached.
#
# Either way, if there is a local cache, nothing bad will
# happen. If there is no local cache, disabling the message
# cache for all requests avoids incurring a loadFromDB()
# overhead on every request, and thus saves the wiki from
# complete downtime under moderate traffic conditions.
if ( !$wgUseLocalMessageCache ) {
$this->mMemc->set( $statusKey, 'error', 60 * 5 );
$where[] = 'could not save cache, disabled globally for 5 minutes';
} else {
$where[] = "could not save global cache";
}
}
# Load from DB complete, no need to retry
break;
} elseif ( $staleCache ) {
# Use the stale cache while some other thread constructs the new one
$where[] = 'using stale cache';
$this->mCache[$code] = $staleCache;
$success = true;
break;
} elseif ( $failedAttempts > 0 ) {
# Already retried once, still failed, so don't do another lock/unlock cycle
# This case will typically be hit if memcached is down, or if
# loadFromDB() takes longer than MSG_WAIT_TIMEOUT
$where[] = "could not acquire status key.";
break;
} else {
$status = $this->mMemc->get( $statusKey );
if ( $status === 'error' ) {
# Disable cache
break;
} else {
# Wait for the other thread to finish, then retry
$where[] = 'waited for other thread to complete';
$this->lock( $cacheKey );
$this->unlock( $cacheKey );
}
}
}
}
if ( !$success ) {
$where[] = 'loading FAILED - cache is disabled';
$this->mDisable = true;
$this->mCache = false;
# This used to throw an exception, but that led to nasty side effects like
# the whole wiki being instantly down if the memcached server died
} else {
# All good, just record the success
$this->mLoadedLanguages[$code] = true;
}
$info = implode( ', ', $where );
wfDebug( __METHOD__ . ": Loading $code... $info\n" );
wfProfileOut( __METHOD__ );
return $success;
}
/**
* Loads cacheable messages from the database. Messages bigger than
* $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
* on-demand from the database later.
*
* @param string $code Language code.
* @return array Loaded messages for storing in caches.
*/
function loadFromDB( $code ) {
wfProfileIn( __METHOD__ );
global $wgMaxMsgCacheEntrySize, $wgLanguageCode, $wgAdaptiveMessageCache;
$dbr = wfGetDB( DB_SLAVE );
$cache = array();
# Common conditions
$conds = array(
'page_is_redirect' => 0,
'page_namespace' => NS_MEDIAWIKI,
);
$mostused = array();
if ( $wgAdaptiveMessageCache && $code !== $wgLanguageCode ) {
if ( !isset( $this->mCache[$wgLanguageCode] ) ) {
$this->load( $wgLanguageCode );
}
$mostused = array_keys( $this->mCache[$wgLanguageCode] );
foreach ( $mostused as $key => $value ) {
$mostused[$key] = "$value/$code";
}
}
if ( count( $mostused ) ) {
$conds['page_title'] = $mostused;
} elseif ( $code !== $wgLanguageCode ) {
$conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), '/', $code );
} else {
# Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
# other than language code.
$conds[] = 'page_title NOT' . $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
}
# Conditions to fetch oversized pages to ignore them
$bigConds = $conds;
$bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );
# Load titles for all oversized pages in the MediaWiki namespace
$res = $dbr->select( 'page', 'page_title', $bigConds, __METHOD__ . "($code)-big" );
foreach ( $res as $row ) {
$cache[$row->page_title] = '!TOO BIG';
}
# Conditions to load the remaining pages with their contents
$smallConds = $conds;
$smallConds[] = 'page_latest=rev_id';
$smallConds[] = 'rev_text_id=old_id';
$smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );
$res = $dbr->select(
array( 'page', 'revision', 'text' ),
array( 'page_title', 'old_text', 'old_flags' ),
$smallConds,
__METHOD__ . "($code)-small"
);
foreach ( $res as $row ) {
$text = Revision::getRevisionText( $row );
if ( $text === false ) {
// Failed to fetch data; possible ES errors?
// Store a marker to fetch on-demand as a workaround...
$entry = '!TOO BIG';
wfDebugLog(
'MessageCache',
__METHOD__
. ": failed to load message page text for {$row->page_title} ($code)"
);
} else {
$entry = ' ' . $text;
}
$cache[$row->page_title] = $entry;
}
$cache['VERSION'] = MSG_CACHE_VERSION;
$cache['EXPIRY'] = wfTimestamp( TS_MW, time() + $this->mExpiry );
wfProfileOut( __METHOD__ );
return $cache;
}
/**
* Updates cache as necessary when message page is changed
*
* @param string $title Name of the page changed.
* @param mixed $text New contents of the page.
*/
public function replace( $title, $text ) {
global $wgMaxMsgCacheEntrySize;
wfProfileIn( __METHOD__ );
if ( $this->mDisable ) {
wfProfileOut( __METHOD__ );
return;
}
list( $msg, $code ) = $this->figureMessage( $title );
$cacheKey = wfMemcKey( 'messages', $code );
$this->load( $code );
$this->lock( $cacheKey );
$titleKey = wfMemcKey( 'messages', 'individual', $title );
if ( $text === false ) {
# Article was deleted
$this->mCache[$code][$title] = '!NONEXISTENT';
$this->mMemc->delete( $titleKey );
} elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
# Check for size
$this->mCache[$code][$title] = '!TOO BIG';
$this->mMemc->set( $titleKey, ' ' . $text, $this->mExpiry );
} else {
$this->mCache[$code][$title] = ' ' . $text;
$this->mMemc->delete( $titleKey );
}
# Update caches
$this->saveToCaches( $this->mCache[$code], 'all', $code );
$this->unlock( $cacheKey );
// Also delete cached sidebar... just in case it is affected
$codes = array( $code );
if ( $code === 'en' ) {
// Delete all sidebars, like for example on action=purge on the
// sidebar messages
$codes = array_keys( Language::fetchLanguageNames() );
}
global $wgMemc;
foreach ( $codes as $code ) {
$sidebarKey = wfMemcKey( 'sidebar', $code );
$wgMemc->delete( $sidebarKey );
}
// Update the message in the message blob store
global $wgContLang;
MessageBlobStore::updateMessage( $wgContLang->lcfirst( $msg ) );
wfRunHooks( 'MessageCacheReplace', array( $title, $text ) );
wfProfileOut( __METHOD__ );
}
/**
* Is the given cache array expired due to time passing or a version change?
*
* @param $cache
* @return bool
*/
protected function isCacheExpired( $cache ) {
if ( !isset( $cache['VERSION'] ) || !isset( $cache['EXPIRY'] ) ) {
return true;
}
if ( $cache['VERSION'] != MSG_CACHE_VERSION ) {
return true;
}
if ( wfTimestampNow() >= $cache['EXPIRY'] ) {
return true;
}
return false;
}
/**
* Shortcut to update caches.
*
* @param array $cache Cached messages with a version.
* @param string $dest Either "local-only" to save to local caches only
* or "all" to save to all caches.
* @param string|bool $code Language code (default: false)
* @return bool
*/
protected function saveToCaches( $cache, $dest, $code = false ) {
wfProfileIn( __METHOD__ );
global $wgUseLocalMessageCache;
$cacheKey = wfMemcKey( 'messages', $code );
if ( $dest === 'all' ) {
$success = $this->mMemc->set( $cacheKey, $cache );
} else {
$success = true;
}
# Save to local cache
if ( $wgUseLocalMessageCache ) {
$serialized = serialize( $cache );
$hash = md5( $serialized );
$this->mMemc->set( wfMemcKey( 'messages', $code, 'hash' ), $hash );
$this->saveToLocal( $serialized, $hash, $code );
}
wfProfileOut( __METHOD__ );
return $success;
}
/**
* Represents a write lock on the messages key.
*
* Will retry MessageCache::MSG_WAIT_TIMEOUT times, each operations having
* a timeout of MessageCache::MSG_LOCK_TIMEOUT.
*
* @param string $key
* @return Boolean: success
*/
function lock( $key ) {
$lockKey = $key . ':lock';
$acquired = false;
$testDone = false;
for ( $i = 0; $i < MSG_WAIT_TIMEOUT && !$acquired; $i++ ) {
$acquired = $this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT );
if ( $acquired ) {
break;
}
# Fail fast if memcached is totally down
if ( !$testDone ) {
$testDone = true;
if ( !$this->mMemc->set( wfMemcKey( 'test' ), 'test', 1 ) ) {
break;
}
}
sleep( 1 );
}
return $acquired;
}
function unlock( $key ) {
$lockKey = $key . ':lock';
$this->mMemc->delete( $lockKey );
}
/**
* Get a message from either the content language or the user language.
*
* First, assemble a list of languages to attempt getting the message from. This
* chain begins with the requested language and its fallbacks and then continues with
* the content language and its fallbacks. For each language in the chain, the following
* process will occur (in this order):
* 1. If a language-specific override, i.e., [[MW:msg/lang]], is available, use that.
* Note: for the content language, there is no /lang subpage.
* 2. Fetch from the static CDB cache.
* 3. If available, check the database for fallback language overrides.
*
* This process provides a number of guarantees. When changing this code, make sure all
* of these guarantees are preserved.
* * If the requested language is *not* the content language, then the CDB cache for that
* specific language will take precedence over the root database page ([[MW:msg]]).
* * Fallbacks will be just that: fallbacks. A fallback language will never be reached if
* the message is available *anywhere* in the language for which it is a fallback.
*
* @param string $key the message key
* @param bool $useDB If true, look for the message in the DB, false
* to use only the compiled l10n cache.
* @param bool|string|object $langcode Code of the language to get the message for.
* - If string and a valid code, will create a standard language object
* - If string but not a valid code, will create a basic language object
* - If boolean and false, create object from the current users language
* - If boolean and true, create object from the wikis content language
* - If language object, use it as given
* @param bool $isFullKey specifies whether $key is a two part key
* "msg/lang".
*
* @throws MWException when given an invalid key
* @return string|bool False if the message doesn't exist, otherwise the message (which can be empty)
*/
function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
global $wgContLang;
$section = new ProfileSection( __METHOD__ );
if ( is_int( $key ) ) {
// Fix numerical strings that somehow become ints
// on their way here
$key = (string)$key;
} elseif ( !is_string( $key ) ) {
throw new MWException( 'Non-string key given' );
} elseif ( $key === '' ) {
// Shortcut: the empty key is always missing
return false;
}
// For full keys, get the language code from the key
$pos = strrpos( $key, '/' );
if ( $isFullKey && $pos !== false ) {
$langcode = substr( $key, $pos + 1 );
$key = substr( $key, 0, $pos );
}
// Normalise title-case input (with some inlining)
$lckey = strtr( $key, ' ', '_' );
if ( ord( $key ) < 128 ) {
$lckey[0] = strtolower( $lckey[0] );
$uckey = ucfirst( $lckey );
} else {
$lckey = $wgContLang->lcfirst( $lckey );
$uckey = $wgContLang->ucfirst( $lckey );
}
// Loop through each language in the fallback list until we find something useful
$lang = wfGetLangObj( $langcode );
$message = $this->getMessageFromFallbackChain( $lang, $lckey, $uckey, !$this->mDisable && $useDB );
// If we still have no message, maybe the key was in fact a full key so try that
if ( $message === false ) {
$parts = explode( '/', $lckey );
// We may get calls for things that are http-urls from sidebar
// Let's not load nonexistent languages for those
// They usually have more than one slash.
if ( count( $parts ) == 2 && $parts[1] !== '' ) {
$message = Language::getMessageFor( $parts[0], $parts[1] );
if ( $message === null ) {
$message = false;
}
}
}
// Post-processing if the message exists
if ( $message !== false ) {
// Fix whitespace
$message = str_replace(
array(
# Fix for trailing whitespace, removed by textarea
' ',
# Fix for NBSP, converted to space by firefox
' ',
' ',
),
array(
' ',
"\xc2\xa0",
"\xc2\xa0"
),
$message
);
}
return $message;
}
/**
* Given a language, try and fetch a message from that language, then the
* fallbacks of that language, then the site language, then the fallbacks for the
* site language.
*
* @param Language $lang Requested language
* @param string $lckey Lowercase key for the message
* @param string $uckey Uppercase key for the message
* @param bool $useDB Whether to use the database
*
* @see MessageCache::get
* @return string|bool The message, or false if not found
*/
protected function getMessageFromFallbackChain( $lang, $lckey, $uckey, $useDB ) {
global $wgLanguageCode, $wgContLang;
$langcode = $lang->getCode();
$message = false;
// First try the requested language.
if ( $useDB ) {
if ( $langcode === $wgLanguageCode ) {
// Messages created in the content language will not have the /lang extension
$message = $this->getMsgFromNamespace( $uckey, $langcode );
} else {
$message = $this->getMsgFromNamespace( "$uckey/$langcode", $langcode );
}
}
if ( $message !== false ) {
return $message;
}
// Check the CDB cache
$message = $lang->getMessage( $lckey );
if ( $message !== null ) {
return $message;
}
list( $fallbackChain, $siteFallbackChain ) = Language::getFallbacksIncludingSiteLanguage( $langcode );
// Next try checking the database for all of the fallback languages of the requested language.
if ( $useDB ) {
foreach ( $fallbackChain as $code ) {
if ( $code === $wgLanguageCode ) {
// Messages created in the content language will not have the /lang extension
$message = $this->getMsgFromNamespace( $uckey, $code );
} else {
$message = $this->getMsgFromNamespace( "$uckey/$code", $code );
}
if ( $message !== false ) {
// Found the message.
return $message;
}
}
}
// Now try checking the site language.
if ( $useDB ) {
$message = $this->getMsgFromNamespace( $uckey, $wgLanguageCode );
if ( $message !== false ) {
return $message;
}
}
$message = $wgContLang->getMessage( $lckey );
if ( $message !== null ) {
return $message;
}
// Finally try the DB for the site language's fallbacks.
if ( $useDB ) {
foreach ( $siteFallbackChain as $code ) {
$message = $this->getMsgFromNamespace( "$uckey/$code", $code );
if ( $message === false && $code === $wgLanguageCode ) {
// Messages created in the content language will not have the /lang extension
$message = $this->getMsgFromNamespace( $uckey, $code );
}
if ( $message !== false ) {
// Found the message.
return $message;
}
}
}
return false;
}
/**
* Get a message from the MediaWiki namespace, with caching. The key must
* first be converted to two-part lang/msg form if necessary.
*
* Unlike self::get(), this function doesn't resolve fallback chains, and
* some callers require this behavior. LanguageConverter::parseCachedTable()
* and self::get() are some examples in core.
*
* @param string $title Message cache key with initial uppercase letter.
* @param string $code Code denoting the language to try.
* @return string|bool The message, or false if it does not exist or on error
*/
function getMsgFromNamespace( $title, $code ) {
$this->load( $code );
if ( isset( $this->mCache[$code][$title] ) ) {
$entry = $this->mCache[$code][$title];
if ( substr( $entry, 0, 1 ) === ' ' ) {
// The message exists, so make sure a string
// is returned.
return (string)substr( $entry, 1 );
} elseif ( $entry === '!NONEXISTENT' ) {
return false;
} elseif ( $entry === '!TOO BIG' ) {
// Fall through and try invididual message cache below
}
} else {
// XXX: This is not cached in process cache, should it?
$message = false;
wfRunHooks( 'MessagesPreLoad', array( $title, &$message ) );
if ( $message !== false ) {
return $message;
}
return false;
}
# Try the individual message cache
$titleKey = wfMemcKey( 'messages', 'individual', $title );
$entry = $this->mMemc->get( $titleKey );
if ( $entry ) {
if ( substr( $entry, 0, 1 ) === ' ' ) {
$this->mCache[$code][$title] = $entry;
// The message exists, so make sure a string
// is returned.
return (string)substr( $entry, 1 );
} elseif ( $entry === '!NONEXISTENT' ) {
$this->mCache[$code][$title] = '!NONEXISTENT';
return false;
} else {
# Corrupt/obsolete entry, delete it
$this->mMemc->delete( $titleKey );
}
}
# Try loading it from the database
$revision = Revision::newFromTitle(
Title::makeTitle( NS_MEDIAWIKI, $title ), false, Revision::READ_LATEST
);
if ( $revision ) {
$content = $revision->getContent();
if ( !$content ) {
// A possibly temporary loading failure.
wfDebugLog(
'MessageCache',
__METHOD__ . ": failed to load message page text for {$title} ($code)"
);
$message = null; // no negative caching
} else {
// XXX: Is this the right way to turn a Content object into a message?
// NOTE: $content is typically either WikitextContent, JavaScriptContent or
// CssContent. MessageContent is *not* used for storing messages, it's
// only used for wrapping them when needed.
$message = $content->getWikitextForTransclusion();
if ( $message === false || $message === null ) {
wfDebugLog(
'MessageCache',
__METHOD__ . ": message content doesn't provide wikitext "
. "(content model: " . $content->getContentHandler() . ")"
);
$message = false; // negative caching
} else {
$this->mCache[$code][$title] = ' ' . $message;
$this->mMemc->set( $titleKey, ' ' . $message, $this->mExpiry );
}
}
} else {
$message = false; // negative caching
}
if ( $message === false ) { // negative caching
$this->mCache[$code][$title] = '!NONEXISTENT';
$this->mMemc->set( $titleKey, '!NONEXISTENT', $this->mExpiry );
}
return $message;
}
/**
* @param string $message
* @param bool $interface
* @param string $language Language code
* @param Title $title
* @return string
*/
function transform( $message, $interface = false, $language = null, $title = null ) {
// Avoid creating parser if nothing to transform
if ( strpos( $message, '{{' ) === false ) {
return $message;
}
if ( $this->mInParser ) {
return $message;
}
$parser = $this->getParser();
if ( $parser ) {
$popts = $this->getParserOptions();
$popts->setInterfaceMessage( $interface );
$popts->setTargetLanguage( $language );
$userlang = $popts->setUserLang( $language );
$this->mInParser = true;
$message = $parser->transformMsg( $message, $popts, $title );
$this->mInParser = false;
$popts->setUserLang( $userlang );
}
return $message;
}
/**
* @return Parser
*/
function getParser() {
global $wgParser, $wgParserConf;
if ( !$this->mParser && isset( $wgParser ) ) {
# Do some initialisation so that we don't have to do it twice
$wgParser->firstCallInit();
# Clone it and store it
$class = $wgParserConf['class'];
if ( $class == 'Parser_DiffTest' ) {
# Uncloneable
$this->mParser = new $class( $wgParserConf );
} else {
$this->mParser = clone $wgParser;
}
}
return $this->mParser;
}
/**
* @param string $text
* @param Title $title
* @param bool $linestart Whether or not this is at the start of a line
* @param bool $interface Whether this is an interface message
* @param string $language Language code
* @return ParserOutput|string
*/
public function parse( $text, $title = null, $linestart = true,
$interface = false, $language = null
) {
if ( $this->mInParser ) {
return htmlspecialchars( $text );
}
$parser = $this->getParser();
$popts = $this->getParserOptions();
$popts->setInterfaceMessage( $interface );
$popts->setTargetLanguage( $language );
wfProfileIn( __METHOD__ );
if ( !$title || !$title instanceof Title ) {
global $wgTitle;
$title = $wgTitle;
}
// Sometimes $wgTitle isn't set either...
if ( !$title ) {
# It's not uncommon having a null $wgTitle in scripts. See r80898
# Create a ghost title in such case
$title = Title::newFromText( 'Dwimmerlaik' );
}
$this->mInParser = true;
$res = $parser->parse( $text, $title, $popts, $linestart );
$this->mInParser = false;
wfProfileOut( __METHOD__ );
return $res;
}
function disable() {
$this->mDisable = true;
}
function enable() {
$this->mDisable = false;
}
/**
* Clear all stored messages. Mainly used after a mass rebuild.
*/
function clear() {
$langs = Language::fetchLanguageNames( null, 'mw' );
foreach ( array_keys( $langs ) as $code ) {
# Global cache
$this->mMemc->delete( wfMemcKey( 'messages', $code ) );
# Invalidate all local caches
$this->mMemc->delete( wfMemcKey( 'messages', $code, 'hash' ) );
}
$this->mLoadedLanguages = array();
}
/**
* @param $key
* @return array
*/
public function figureMessage( $key ) {
global $wgLanguageCode;
$pieces = explode( '/', $key );
if ( count( $pieces ) < 2 ) {
return array( $key, $wgLanguageCode );
}
$lang = array_pop( $pieces );
if ( !Language::fetchLanguageName( $lang, null, 'mw' ) ) {
return array( $key, $wgLanguageCode );
}
$message = implode( '/', $pieces );
return array( $message, $lang );
}
/**
* Get all message keys stored in the message cache for a given language.
* If $code is the content language code, this will return all message keys
* for which MediaWiki:msgkey exists. If $code is another language code, this
* will ONLY return message keys for which MediaWiki:msgkey/$code exists.
* @param string $code Language code
* @return array of message keys (strings)
*/
public function getAllMessageKeys( $code ) {
global $wgContLang;
$this->load( $code );
if ( !isset( $this->mCache[$code] ) ) {
// Apparently load() failed
return null;
}
// Remove administrative keys
$cache = $this->mCache[$code];
unset( $cache['VERSION'] );
unset( $cache['EXPIRY'] );
// Remove any !NONEXISTENT keys
$cache = array_diff( $cache, array( '!NONEXISTENT' ) );
// Keys may appear with a capital first letter. lcfirst them.
return array_map( array( $wgContLang, 'lcfirst' ), array_keys( $cache ) );
}
}