mediawiki-extensions-SpamBl.../BaseBlacklist.php
Aaron Schulz 7a02693e9b Added local blacklist caching
* Also cleaned up the shared blacklist keys
* The cache keys now use getWithSetCallback(), which does
  things like preemptive re-caching to avoid cache slams

Change-Id: Ifda27edaf76770e84b4ece711d3c8bcb8e924674
2015-07-30 23:03:50 +00:00

410 lines
10 KiB
PHP
Executable file

<?php
/**
* Base class for different kinds of blacklists
*/
abstract class BaseBlacklist {
/**
* Array of blacklist sources
*
* @var array
*/
public $files = array();
/**
* Array containing regexes to test against
*
* @var bool|array
*/
protected $regexes = false;
/**
* Chance of receiving a warning when the filter is hit
*
* @var int
*/
public $warningChance = 100;
/**
* @var int
*/
public $warningTime = 600;
/**
* @var int
*/
public $expiryTime = 900;
/**
* Array containing blacklists that extend BaseBlacklist
*
* @var array
*/
private static $blacklistTypes = array(
'spam' => 'SpamBlacklist',
'email' => 'EmailBlacklist',
);
/**
* Array of blacklist instances
*
* @var array
*/
private static $instances = array();
/**
* Constructor
*
* @param array $settings
*/
function __construct( $settings = array() ) {
foreach ( $settings as $name => $value ) {
$this->$name = $value;
}
}
/**
* @param array $links
* @param Title $title
* @param bool $preventLog
* @return mixed
*/
abstract public function filter( array $links, Title $title, $preventLog = false );
/**
* Adds a blacklist class to the registry
*
* @param $type string
* @param $class string
*/
public static function addBlacklistType( $type, $class ) {
self::$blacklistTypes[$type] = $class;
}
/**
* Return the array of blacklist types currently defined
*
* @return array
*/
public static function getBlacklistTypes() {
return self::$blacklistTypes;
}
/**
* Returns an instance of the given blacklist
*
* @param $type string Code for the blacklist
* @return BaseBlacklist
* @throws Exception
*/
public static function getInstance( $type ) {
if ( !isset( self::$blacklistTypes[$type] ) ) {
throw new Exception( "Invalid blacklist type '$type' passed to " . __METHOD__ );
}
if ( !isset( self::$instances[$type] ) ) {
global $wgBlacklistSettings;
// Prevent notices
if ( !isset( $wgBlacklistSettings[$type] ) ) {
$wgBlacklistSettings[$type] = array();
}
self::$instances[$type] = new self::$blacklistTypes[$type]( $wgBlacklistSettings[$type] );
}
return self::$instances[$type];
}
/**
* Returns the code for the blacklist implementation
*
* @return string
*/
abstract protected function getBlacklistType();
/**
* Check if the given local page title is a spam regex source.
*
* @param Title $title
* @return bool
*/
public static function isLocalSource( Title $title ) {
global $wgDBname, $wgBlacklistSettings;
if( $title->getNamespace() == NS_MEDIAWIKI ) {
$sources = array();
foreach ( self::$blacklistTypes as $type => $class ) {
$type = ucfirst( $type );
$sources += array(
"$type-blacklist",
"$type-whitelist"
);
}
if( in_array( $title->getDBkey(), $sources ) ) {
return true;
}
}
$thisHttp = wfExpandUrl( $title->getFullUrl( 'action=raw' ), PROTO_HTTP );
$thisHttpRegex = '/^' . preg_quote( $thisHttp, '/' ) . '(?:&.*)?$/';
$files = array();
foreach ( self::$blacklistTypes as $type => $class ) {
if ( isset( $wgBlacklistSettings[$type]['files'] ) ) {
$files += $wgBlacklistSettings[$type]['files'];
}
}
foreach( $files as $fileName ) {
$matches = array();
if ( preg_match( '/^DB: (\w*) (.*)$/', $fileName, $matches ) ) {
if ( $wgDBname == $matches[1] ) {
if( $matches[2] == $title->getPrefixedDbKey() ) {
// Local DB fetch of this page...
return true;
}
}
} elseif( preg_match( $thisHttpRegex, $fileName ) ) {
// Raw view of this page
return true;
}
}
return false;
}
/**
* Returns the type of blacklist from the given title
*
* @param Title $title
* @return bool|string
*/
public static function getTypeFromTitle( Title $title ) {
$types = array_map( 'preg_quote', array_keys( self::$blacklistTypes ), array( '/' ) );
$regex = '/(' . implode( '|', $types ). ')-(?:Blacklist|Whitelist)/';
if ( preg_match( $regex, $title->getDBkey(), $m ) ) {
return strtolower( $m[1] );
}
return false;
}
/**
* Fetch local and (possibly cached) remote blacklists.
* Will be cached locally across multiple invocations.
* @return array set of regular expressions, potentially empty.
*/
function getBlacklists() {
if( $this->regexes === false ) {
$this->regexes = array_merge(
$this->getLocalBlacklists(),
$this->getSharedBlacklists() );
}
return $this->regexes;
}
/**
* Returns the local blacklist
*
* @return array Regular expressions
*/
public function getLocalBlacklists() {
$that = $this;
$type = $this->getBlacklistType();
return ObjectCache::getMainWANInstance()->getWithSetCallback(
wfMemcKey( 'spamblacklist', $type, 'blacklist-regex' ),
function () use ( $that, $type ) {
return SpamRegexBatch::regexesFromMessage( "{$type}-blacklist", $that );
},
$this->expiryTime
);
}
/**
* Returns the (local) whitelist
*
* @return array Regular expressions
*/
public function getWhitelists() {
$that = $this;
$type = $this->getBlacklistType();
return ObjectCache::getMainWANInstance()->getWithSetCallback(
wfMemcKey( 'spamblacklist', $type, 'whitelist-regex' ),
function () use ( $that, $type ) {
return SpamRegexBatch::regexesFromMessage( "{$type}-whitelist", $that );
},
$this->expiryTime
);
}
/**
* Fetch (possibly cached) remote blacklists.
* @return array
*/
function getSharedBlacklists() {
$listType = $this->getBlacklistType();
wfDebugLog( 'SpamBlacklist', "Loading $listType regex..." );
if ( count( $this->files ) == 0 ){
# No lists
wfDebugLog( 'SpamBlacklist', "no files specified\n" );
return array();
}
$miss = false;
$that = $this;
$regexes = ObjectCache::getMainWANInstance()->getWithSetCallback(
// This used to be cached per-site, but that could be bad on a shared
// server where not all wikis have the same configuration.
wfMemcKey( 'spamblacklist', $listType, 'shared-blacklist-regex' ),
function () use ( $that, &$miss ) {
$miss = true;
return $that->buildSharedBlacklists();
},
$this->expiryTime
);
if ( !$miss ) {
wfDebugLog( 'SpamBlacklist', "Got shared spam regexes from cache\n" );
}
return $regexes;
}
/**
* Clear all primary blacklist cache keys
*
* @note: this method is unused atm
*/
function clearCache() {
$listType = $this->getBlacklistType();
$cache = ObjectCache::getMainWANInstance();
$cache->delete( wfMemcKey( 'spamblacklist', $listType, 'shared-blacklist-regex' ) );
$cache->delete( wfMemcKey( 'spamblacklist', $listType, 'blacklist-regex' ) );
$cache->delete( wfMemcKey( 'spamblacklist', $listType, 'whitelist-regex' ) );
wfDebugLog( 'SpamBlacklist', "$listType blacklist local cache cleared.\n" );
}
function buildSharedBlacklists() {
$regexes = array();
$listType = $this->getBlacklistType();
# Load lists
wfDebugLog( 'SpamBlacklist', "Constructing $listType blacklist\n" );
foreach ( $this->files as $fileName ) {
$matches = array();
if ( preg_match( '/^DB: ([\w-]*) (.*)$/', $fileName, $matches ) ) {
$text = $this->getArticleText( $matches[1], $matches[2] );
} elseif ( preg_match( '/^(https?:)?\/\//', $fileName ) ) {
$text = $this->getHttpText( $fileName );
} else {
$text = file_get_contents( $fileName );
wfDebugLog( 'SpamBlacklist', "got from file $fileName\n" );
}
// Build a separate batch of regexes from each source.
// While in theory we could squeeze a little efficiency
// out of combining multiple sources in one regex, if
// there's a bad line in one of them we'll gain more
// from only having to break that set into smaller pieces.
$regexes = array_merge( $regexes,
SpamRegexBatch::regexesFromText( $text, $this, $fileName ) );
}
return $regexes;
}
function getHttpText( $fileName ) {
global $wgDBname, $messageMemc;
$listType = $this->getBlacklistType();
# HTTP request
# To keep requests to a minimum, we save results into $messageMemc, which is
# similar to $wgMemc except almost certain to exist. By default, it is stored
# in the database
#
# There are two keys, when the warning key expires, a random thread will refresh
# the real key. This reduces the chance of multiple requests under high traffic
# conditions.
$key = "{$listType}_blacklist_file:$fileName";
$warningKey = "$wgDBname:{$listType}filewarning:$fileName";
$httpText = $messageMemc->get( $key );
$warning = $messageMemc->get( $warningKey );
if ( !is_string( $httpText ) || ( !$warning && !mt_rand( 0, $this->warningChance ) ) ) {
wfDebugLog( 'SpamBlacklist', "Loading $listType blacklist from $fileName\n" );
$httpText = Http::get( $fileName );
if( $httpText === false ) {
wfDebugLog( 'SpamBlacklist', "Error loading $listType blacklist from $fileName\n" );
}
$messageMemc->set( $warningKey, 1, $this->warningTime );
$messageMemc->set( $key, $httpText, $this->expiryTime );
} else {
wfDebugLog( 'SpamBlacklist', "Got $listType blacklist from HTTP cache for $fileName\n" );
}
return $httpText;
}
/**
* Fetch an article from this or another local MediaWiki database.
* This is probably *very* fragile, and shouldn't be used perhaps.
*
* @param string $wiki
* @param string $article
* @return string
*/
function getArticleText( $wiki, $article ) {
wfDebugLog( 'SpamBlacklist',
"Fetching {$this->getBlacklistType()} blacklist from '$article' on '$wiki'...\n" );
$title = Title::newFromText( $article );
// Load all the relevant tables from the correct DB.
// This assumes that old_text is the actual text or
// that the external store system is at least unified.
$row = wfGetDB( DB_SLAVE, array(), $wiki )->selectRow(
array( 'page', 'revision', 'text' ),
array_merge(
Revision::selectFields(),
Revision::selectPageFields(),
Revision::selectTextFields()
),
array(
'page_namespace' => $title->getNamespace(), // assume NS IDs match
'page_title' => $title->getDBkey(), // assume same case rules
'rev_id=page_latest',
'old_id=rev_text_id'
),
__METHOD__
);
return $row ? Revision::newFromRow( $row )->getText() : false;
}
/**
* Returns the start of the regex for matches
*
* @return string
*/
public function getRegexStart() {
return '/[a-z0-9_\-.]*';
}
/**
* Returns the end of the regex for matches
*
* @param $batchSize
* @return string
*/
public function getRegexEnd( $batchSize ) {
return ($batchSize > 0 ) ? '/Sim' : '/im';
}
}