wiki.techinc.nl/includes/MessageCache.php

774 lines
21 KiB
PHP

<?php
/**
* @file
* @ingroup Cache
*/
/**
*
*/
define( 'MSG_LOAD_TIMEOUT', 60);
define( 'MSG_LOCK_TIMEOUT', 10);
define( 'MSG_WAIT_TIMEOUT', 10);
define( 'MSG_CACHE_VERSION', 1 );
/**
* 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
protected $mDisable;
/// Lifetime for cache, used by object caching
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
protected $mLoadedLanguages = array();
function __construct( $memCached, $useDB, $expiry ) {
if ( !$memCached ) {
$memCached = wfGetCache( CACHE_NONE );
}
$this->mMemc = $memCached;
$this->mDisable = !$useDB;
$this->mExpiry = $expiry;
}
/**
* ParserOptions is lazy initialised.
*/
function getParserOptions() {
if ( !$this->mParserOptions ) {
$this->mParserOptions = new ParserOptions;
}
return $this->mParserOptions;
}
/**
* Try to load the cache from a local file.
* Actual format of the file depends on the $wgLocalMessageCacheSerialized
* setting.
*
* @param $hash String: the hash of contents, to check validity.
* @param $code Mixed: Optional language code, see documenation of load().
* @return false on failure.
*/
function loadFromLocal( $hash, $code ) {
global $wgCacheDirectory, $wgLocalMessageCacheSerialized;
$filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
# Check file existence
wfSuppressWarnings();
$file = fopen( $filename, 'r' );
wfRestoreWarnings();
if ( !$file ) {
return false; // No cache file
}
if ( $wgLocalMessageCacheSerialized ) {
// 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 $this->setCache( unserialize( $serialized ), $code );
} else {
fclose( $file );
return false; // Wrong hash
}
} else {
$localHash=substr(fread($file,40),8);
fclose($file);
if ($hash!=$localHash) {
return false; // Wrong hash
}
# Require overwrites the member variable or just shadows it?
require( $filename );
return $this->setCache( $this->mCache, $code );
}
}
/**
* Save the cache to a local file.
*/
function saveToLocal( $serialized, $hash, $code ) {
global $wgCacheDirectory;
$filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
wfMkdirParents( $wgCacheDirectory ); // 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 );
@chmod( $filename, 0666 );
}
function saveToScript( $array, $hash, $code ) {
global $wgCacheDirectory;
$filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
$tempFilename = $filename . '.tmp';
wfMkdirParents( $wgCacheDirectory ); // might fail
wfSuppressWarnings();
$file = fopen( $tempFilename, 'w');
wfRestoreWarnings();
if ( !$file ) {
wfDebug( "Unable to open local cache file for writing\n" );
return;
}
fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
foreach ($array as $key => $message) {
$key = $this->escapeForScript($key);
$messages = $this->escapeForScript($message);
fwrite($file, "'$key' => '$message',\n");
}
fwrite($file,");\n?>");
fclose($file);
rename($tempFilename, $filename);
}
function escapeForScript($string) {
$string = str_replace( '\\', '\\\\', $string );
$string = str_replace( '\'', '\\\'', $string );
return $string;
}
/**
* Set the cache to $cache, if it is valid. Otherwise set the cache to false.
*/
function setCache( $cache, $code ) {
if ( isset( $cache['VERSION'] ) && $cache['VERSION'] == MSG_CACHE_VERSION ) {
$this->mCache[$code] = $cache;
return true;
} else {
return false;
}
}
/**
* 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 $code String: language to which load messages
*/
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
$where = array(); # Debug info, delayed to avoid spamming debug log too much
$cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages
# (1) local cache
# Hash of the contents is stored in memcache, to detect if local cache goes
# out of date (due to update in other thread?)
if ( $wgUseLocalMessageCache ) {
wfProfileIn( __METHOD__ . '-fromlocal' );
$hash = $this->mMemc->get( wfMemcKey( 'messages', $code, 'hash' ) );
if ( $hash ) {
$success = $this->loadFromLocal( $hash, $code );
if ( $success ) $where[] = 'got from local cache';
}
wfProfileOut( __METHOD__ . '-fromlocal' );
}
# (2) memcache
# Fails if nothing in cache, or in the wrong version.
if ( !$success ) {
wfProfileIn( __METHOD__ . '-fromcache' );
$cache = $this->mMemc->get( $cacheKey );
$success = $this->setCache( $cache, $code );
if ( $success ) {
$where[] = 'got from global cache';
$this->saveToCaches( $cache, false, $code );
}
wfProfileOut( __METHOD__ . '-fromcache' );
}
# (3)
# Nothing in caches... so we need create one and store it in caches
if ( !$success ) {
$where[] = 'cache is empty';
$where[] = 'loading from database';
$this->lock($cacheKey);
# Limit the concurrency of loadFromDB to a single process
# This prevents the site from going down when the cache expires
$statusKey = wfMemcKey( 'messages', $code, 'status' );
$success = $this->mMemc->add( $statusKey, 'loading', MSG_LOAD_TIMEOUT );
if ( $success ) {
$cache = $this->loadFromDB( $code );
$success = $this->setCache( $cache, $code );
}
if ( $success ) {
$success = $this->saveToCaches( $cache, true, $code );
if ( $success ) {
$this->mMemc->delete( $statusKey );
} else {
$this->mMemc->set( $statusKey, 'error', 60*5 );
wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
}
}
$this->unlock($cacheKey);
}
if ( !$success ) {
# Bad luck... this should not happen
$where[] = 'loading FAILED - cache is disabled';
$info = implode( ', ', $where );
wfDebug( __METHOD__ . ": Loading $code... $info\n" );
$this->mDisable = true;
$this->mCache = false;
} else {
# All good, just record the success
$info = implode( ', ', $where );
wfDebug( __METHOD__ . ": Loading $code... $info\n" );
$this->mLoadedLanguages[$code] = true;
}
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 $code Optional language code, see documenation of load().
* @return Array: Loaded messages for storing in caches.
*/
function loadFromDB( $code = false ) {
wfProfileIn( __METHOD__ );
global $wgMaxMsgCacheEntrySize, $wgContLanguageCode;
$dbr = wfGetDB( DB_SLAVE );
$cache = array();
# Common conditions
$conds = array(
'page_is_redirect' => 0,
'page_namespace' => NS_MEDIAWIKI,
);
if ( $code ) {
# Is this fast enough. Should not matter if the filtering is done in the
# database or in code.
if ( $code !== $wgContLanguageCode ) {
# Messages for particular language
$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 ) {
$cache[$row->page_title] = ' ' . Revision::getRevisionText( $row );
}
$cache['VERSION'] = MSG_CACHE_VERSION;
wfProfileOut( __METHOD__ );
return $cache;
}
/**
* Updates cache as necessary when message page is changed
*
* @param $title String: name of the page changed.
* @param $text Mixed: new contents of the page.
*/
public function replace( $title, $text ) {
global $wgMaxMsgCacheEntrySize;
wfProfileIn( __METHOD__ );
if ( $this->mDisable ) {
return;
}
list( , $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], true, $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::getLanguageNames() );
}
global $parserMemc;
foreach ( $codes as $code ) {
$sidebarKey = wfMemcKey( 'sidebar', $code );
$parserMemc->delete( $sidebarKey );
}
wfRunHooks( "MessageCacheReplace", array( $title, $text ) );
wfProfileOut( __METHOD__ );
}
/**
* Shortcut to update caches.
*
* @param $cache Array: cached messages with a version.
* @param $memc Bool: Wether to update or not memcache.
* @param $code String: Language code.
* @return False on somekind of error.
*/
protected function saveToCaches( $cache, $memc = true, $code = false ) {
wfProfileIn( __METHOD__ );
global $wgUseLocalMessageCache, $wgLocalMessageCacheSerialized;
$cacheKey = wfMemcKey( 'messages', $code );
if ( $memc ) {
$success = $this->mMemc->set( $cacheKey, $cache, $this->mExpiry );
} else {
$success = true;
}
# Save to local cache
if ( $wgUseLocalMessageCache ) {
$serialized = serialize( $cache );
$hash = md5( $serialized );
$this->mMemc->set( wfMemcKey( 'messages', $code, 'hash' ), $hash, $this->mExpiry );
if ($wgLocalMessageCacheSerialized) {
$this->saveToLocal( $serialized, $hash, $code );
} else {
$this->saveToScript( $cache, $hash, $code );
}
}
wfProfileOut( __METHOD__ );
return $success;
}
/**
* Represents a write lock on the messages key
*
* @return Boolean: success
*/
function lock($key) {
$lockKey = $key . ':lock';
for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
sleep(1);
}
return $i >= MSG_WAIT_TIMEOUT;
}
function unlock($key) {
$lockKey = $key . ':lock';
$this->mMemc->delete( $lockKey );
}
/**
* Get a message from either the content language or the user language.
*
* @param $key String: the message cache key
* @param $useDB Boolean: get the message from the DB, false to use only
* the localisation
* @param $langcode String: code of the language to get the message for, if
* it is a valid code create a language for that language,
* if it is a string but not a valid code then make a basic
* language object, if it is a false boolean then use the
* current users language (as a fallback for the old
* parameter functionality), or if it is a true boolean
* then use the wikis content language (also as a
* fallback).
* @param $isFullKey Boolean: specifies whether $key is a two part key
* "msg/lang".
*/
function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
global $wgContLanguageCode, $wgContLang;
if ( !is_string( $key ) ) {
throw new MWException( "Non-string key given" );
}
if ( strval( $key ) === '' ) {
# Shortcut: the empty key is always missing
return false;
}
$lang = wfGetLangObj( $langcode );
$langcode = $lang->getCode();
$message = false;
# Normalise title-case input (with some inlining)
$lckey = str_replace( ' ', '_', $key );
if ( ord( $key ) < 128 ) {
$lckey[0] = strtolower( $lckey[0] );
$uckey = ucfirst( $lckey );
} else {
$lckey = $wgContLang->lcfirst( $lckey );
$uckey = $wgContLang->ucfirst( $lckey );
}
# Try the MediaWiki namespace
if( !$this->mDisable && $useDB ) {
$title = $uckey;
if(!$isFullKey && ( $langcode != $wgContLanguageCode ) ) {
$title .= '/' . $langcode;
}
$message = $this->getMsgFromNamespace( $title, $langcode );
}
# Try the array in the language object
if ( $message === false ) {
$message = $lang->getMessage( $lckey );
if ( is_null( $message ) ) {
$message = false;
}
}
# Try the array of another language
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 ( is_null( $message ) ) {
$message = false;
}
}
}
# Is this a custom message? Try the default language in the db...
if( ($message === false || $message === '-' ) &&
!$this->mDisable && $useDB &&
!$isFullKey && ($langcode != $wgContLanguageCode) ) {
$message = $this->getMsgFromNamespace( $uckey, $wgContLanguageCode );
}
# Final fallback
if( $message === false ) {
return false;
}
# Fix whitespace
$message = strtr( $message,
array(
# Fix for trailing whitespace, removed by textarea
'&#32;' => ' ',
# Fix for NBSP, converted to space by firefox
'&nbsp;' => "\xc2\xa0",
'&#160;' => "\xc2\xa0",
) );
return $message;
}
/**
* Get a message from the MediaWiki namespace, with caching. The key must
* first be converted to two-part lang/msg form if necessary.
*
* @param $title String: Message cache key with initial uppercase letter.
* @param $code String: code denoting the language to try.
*/
function getMsgFromNamespace( $title, $code ) {
$type = false;
$message = false;
$this->load( $code );
if ( isset( $this->mCache[$code][$title] ) ) {
$entry = $this->mCache[$code][$title];
if ( substr( $entry, 0, 1 ) === ' ' ) {
return substr( $entry, 1 );
} elseif ( $entry === '!NONEXISTENT' ) {
return false;
}
}
# Call message hooks, in case they are defined
wfRunHooks('MessagesPreLoad', array( $title, &$message ) );
if ( $message !== false ) {
return $message;
}
# 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;
return 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 ) );
if ( $revision ) {
$message = $revision->getText();
$this->mCache[$code][$title] = ' ' . $message;
$this->mMemc->set( $titleKey, ' ' . $message, $this->mExpiry );
} else {
$this->mCache[$code][$title] = '!NONEXISTENT';
$this->mMemc->set( $titleKey, '!NONEXISTENT', $this->mExpiry );
}
return $message;
}
function transform( $message, $interface = false, $language = null ) {
// Avoid creating parser if nothing to transform
if( strpos( $message, '{{' ) === false ) {
return $message;
}
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;
}
#wfDebug( __METHOD__ . ": following contents triggered transform: $message\n" );
}
if ( $this->mParser ) {
$popts = $this->getParserOptions();
$popts->setInterfaceMessage( $interface );
$popts->setTargetLanguage( $language );
$message = $this->mParser->transformMsg( $message, $popts );
}
return $message;
}
function disable() { $this->mDisable = true; }
function enable() { $this->mDisable = false; }
/** @deprecated */
function disableTransform(){
wfDeprecated( __METHOD__ );
}
function enableTransform() {
wfDeprecated( __METHOD__ );
}
function setTransform( $x ) {
wfDeprecated( __METHOD__ );
}
function getTransform() {
wfDeprecated( __METHOD__ );
return false;
}
/**
* Clear all stored messages. Mainly used after a mass rebuild.
*/
function clear() {
$langs = Language::getLanguageNames( false );
foreach ( array_keys($langs) as $code ) {
# Global cache
$this->mMemc->delete( wfMemcKey( 'messages', $code ) );
# Invalidate all local caches
$this->mMemc->delete( wfMemcKey( 'messages', $code, 'hash' ) );
}
}
/**
* Add a message to the cache
* @deprecated Use $wgExtensionMessagesFiles
*
* @param $key Mixed
* @param $value Mixed
* @param $lang String: the messages language, English by default
*/
function addMessage( $key, $value, $lang = 'en' ) {
wfDeprecated( __METHOD__ );
$lc = Language::getLocalisationCache();
$lc->addLegacyMessages( array( $lang => array( $key => $value ) ) );
}
/**
* Add an associative array of message to the cache
* @deprecated Use $wgExtensionMessagesFiles
*
* @param $messages Array: an associative array of key => values to be added
* @param $lang String: the messages language, English by default
*/
function addMessages( $messages, $lang = 'en' ) {
wfDeprecated( __METHOD__ );
$lc = Language::getLocalisationCache();
$lc->addLegacyMessages( array( $lang => $messages ) );
}
/**
* Add a 2-D array of messages by lang. Useful for extensions.
* @deprecated Use $wgExtensionMessagesFiles
*
* @param $messages Array: the array to be added
*/
function addMessagesByLang( $messages ) {
wfDeprecated( __METHOD__ );
$lc = Language::getLocalisationCache();
$lc->addLegacyMessages( $messages );
}
/**
* Set a hook for addMessagesByLang()
*/
function setExtensionMessagesHook( $callback ) {
$this->mAddMessagesHook = $callback;
}
/**
* @deprecated
*/
function loadAllMessages( $lang = false ) {
}
/**
* @deprecated
*/
function loadMessagesFile( $filename, $langcode = false ) {
}
public function figureMessage( $key ) {
global $wgContLanguageCode;
$pieces = explode( '/', $key );
if( count( $pieces ) < 2 )
return array( $key, $wgContLanguageCode );
$lang = array_pop( $pieces );
$validCodes = Language::getLanguageNames();
if( !array_key_exists( $lang, $validCodes ) )
return array( $key, $wgContLanguageCode );
$message = implode( '/', $pieces );
return array( $message, $lang );
}
}