Ejemplo n.º 1
0
 public function execute()
 {
     $pages = $this->getOption('maxpages');
     $dbr = $this->getDB(DB_REPLICA);
     $totalsec = 0.0;
     $scanned = 0;
     $withcache = 0;
     $withdiff = 0;
     while ($pages-- > 0) {
         $row = $dbr->selectRow('page', '*', ['page_namespace' => $this->getOption('namespace'), 'page_is_redirect' => 0, 'page_random >= ' . wfRandom()], __METHOD__, ['ORDER BY' => 'page_random']);
         if (!$row) {
             continue;
         }
         ++$scanned;
         $title = Title::newFromRow($row);
         $page = WikiPage::factory($title);
         $revision = $page->getRevision();
         $content = $revision->getContent(Revision::RAW);
         $parserOptions = $page->makeParserOptions('canonical');
         $parserOutputOld = ParserCache::singleton()->get($page, $parserOptions);
         if ($parserOutputOld) {
             $t1 = microtime(true);
             $parserOutputNew = $content->getParserOutput($title, $revision->getId(), $parserOptions, false);
             $sec = microtime(true) - $t1;
             $totalsec += $sec;
             $this->output("Parsed '{$title->getPrefixedText()}' in {$sec} seconds.\n");
             $this->output("Found cache entry found for '{$title->getPrefixedText()}'...");
             $oldHtml = trim(preg_replace('#<!-- .+-->#Us', '', $parserOutputOld->getText()));
             $newHtml = trim(preg_replace('#<!-- .+-->#Us', '', $parserOutputNew->getText()));
             $diff = wfDiff($oldHtml, $newHtml);
             if (strlen($diff)) {
                 $this->output("differences found:\n\n{$diff}\n\n");
                 ++$withdiff;
             } else {
                 $this->output("No differences found.\n");
             }
             ++$withcache;
         } else {
             $this->output("No parser cache entry found for '{$title->getPrefixedText()}'.\n");
         }
     }
     $ave = $totalsec ? $totalsec / $scanned : 0;
     $this->output("Checked {$scanned} pages; {$withcache} had prior cache entries.\n");
     $this->output("Pages with differences found: {$withdiff}\n");
     $this->output("Average parse time: {$ave} sec\n");
 }
Ejemplo n.º 2
0
 /**
  * Get the set of add, subtract, and change operations required to transform leftText into rightText
  *
  * @param string $leftText The left, or old, revision of the text
  * @param string $rightText The right, or new, revision of the text
  * @return array Array of arrays containing changes to individual groups of lines within the text
  * Each change consists of:
  * An 'action', one of:
  * - add
  * - subtract
  * - change
  * 'content' that was added or removed, or in the case
  *     of a change, 'old_content' and 'new_content'
  * 'left_pos' and 'right_pos' (in 1-indexed lines) of the change.
  */
 public function getChangeSet($leftText, $rightText)
 {
     /**
      * The internal diff utility, which is used when GNU diff is not available
      * prefixes lines with 2 characters instead of 1.
      * For more info see bug 41689.
      */
     if (self::usingInternalDiff()) {
         $this->prefixLength = 2;
     } else {
         $this->prefixLength = 1;
     }
     $left = trim($leftText) . "\n";
     $right = trim($rightText) . "\n";
     $diff = wfDiff($left, $right, '-u -w');
     return $this->parse($diff, $left, $right);
 }
Ejemplo n.º 3
0
 function __call($name, $args)
 {
     $this->init();
     $results = array();
     $mismatch = false;
     $lastResult = null;
     $first = true;
     foreach ($this->parsers as $i => $parser) {
         $currentResult = call_user_func_array(array(&$this->parsers[$i], $name), $args);
         if ($first) {
             $first = false;
         } else {
             if (is_object($lastResult)) {
                 if ($lastResult != $currentResult) {
                     $mismatch = true;
                 }
             } else {
                 if ($lastResult !== $currentResult) {
                     $mismatch = true;
                 }
             }
         }
         $results[$i] = $currentResult;
         $lastResult = $currentResult;
     }
     if ($mismatch) {
         if (count($results) == 2) {
             $resultsList = array();
             foreach ($this->parsers as $i => $parser) {
                 $resultsList[] = var_export($results[$i], true);
             }
             $diff = wfDiff($resultsList[0], $resultsList[1]);
         } else {
             $diff = '[too many parsers]';
         }
         $msg = "Parser_DiffTest: results mismatch on call to {$name}\n";
         if (!$this->shortOutput) {
             $msg .= 'Arguments: ' . $this->formatArray($args) . "\n";
         }
         $msg .= 'Results: ' . $this->formatArray($results) . "\n" . "Diff: {$diff}\n";
         throw new MWException($msg);
     }
     return $lastResult;
 }
Ejemplo n.º 4
0
 function getDiffToMeasure($r)
 {
     $dbr = wfGetDB(DB_SLAVE);
     $result = array();
     // get the low, we compare this against the last edit
     // which was made by a different user
     $revlo = $dbr->selectField('revision', 'rev_id', array('rev_page' => $r->mTitle->getArticleID(), 'rev_user_text != ' . $dbr->addQuotes($r->mUserText), 'rev_id < ' . $r->mId), "RandomEdit::getDiffToMeasure", array("ORDER BY" => "rev_id desc", "LIMIT" => 1));
     // get the highest edit in this sequence of edits by this user
     $not_hi_row = $dbr->selectRow('revision', array('rev_id', 'rev_comment', 'rev_user_text'), array('rev_page' => $r->mTitle->getArticleID(), 'rev_user_text != ' . $dbr->addQuotes($r->mUserText), 'rev_id > ' . $r->mId));
     $revhi = null;
     if (!$not_hi_row) {
         $revhi = $r->mId;
     } else {
         $revhi = $dbr->selectField('revision', 'rev_id', array('rev_page' => $r->mTitle->getArticleID(), 'rev_id <  ' . $not_hi_row->rev_id), "RandomEdit::getDiffToMeasure", array("ORDER BY" => "rev_id desc", "LIMIT" => 1));
         $result['nextcomment'] = $not_hi_row->rev_comment;
         $result['nextuser'] = $not_hi_row->rev_user_text;
     }
     $hi = Revision::newFromID($revhi);
     $hitext = $hi->getText();
     $lotext = "";
     if ($revlo) {
         $lo = Revision::newFromID($revlo);
         $lotext = $lo->getText();
     }
     if ($lotext == "") {
         $result['newpage'] = 1;
     } else {
         $result['newpage'] = 0;
     }
     $opts = array('rev_page' => $r->mTitle->getArticleID(), 'rev_id <= ' . $revhi);
     if ($revlo) {
         $opts[] = 'rev_id >  ' . $revlo;
     }
     $result['numedits'] = $dbr->selectField('revision', 'count(*)', $opts);
     $result['diff'] = wfDiff($lotext, $hitext);
     $result['revhi'] = $hi;
     $result['revlo'] = $lo;
     return $result;
 }
 /**
  * @param $vars AbuseFilterVariableHolder
  * @return AFPData|array|int|mixed|null|string
  * @throws MWException
  * @throws AFPException
  */
 function compute($vars)
 {
     $parameters = $this->mParameters;
     $result = null;
     if (!wfRunHooks('AbuseFilter-interceptVariable', array($this->mMethod, $vars, $parameters, &$result))) {
         return $result instanceof AFPData ? $result : AFPData::newFromPHPVar($result);
     }
     switch ($this->mMethod) {
         case 'diff':
             $text1Var = $parameters['oldtext-var'];
             $text2Var = $parameters['newtext-var'];
             $text1 = $vars->getVar($text1Var)->toString() . "\n";
             $text2 = $vars->getVar($text2Var)->toString() . "\n";
             $result = wfDiff($text1, $text2);
             break;
         case 'diff-split':
             $diff = $vars->getVar($parameters['diff-var'])->toString();
             $line_prefix = $parameters['line-prefix'];
             $diff_lines = explode("\n", $diff);
             $interest_lines = array();
             foreach ($diff_lines as $line) {
                 if (substr($line, 0, 1) === $line_prefix) {
                     $interest_lines[] = substr($line, strlen($line_prefix));
                 }
             }
             $result = $interest_lines;
             break;
         case 'links-from-wikitext':
             // This should ONLY be used when sharing a parse operation with the edit.
             /* @var WikiPage $article */
             $article = $parameters['article'];
             if ($article !== null && (!defined('MW_SUPPORTS_CONTENTHANDLER') || $article->getContentModel() === CONTENT_MODEL_WIKITEXT)) {
                 $textVar = $parameters['text-var'];
                 // XXX: Use prepareContentForEdit. But we need a Content object for that.
                 $new_text = $vars->getVar($textVar)->toString();
                 $content = ContentHandler::makeContent($new_text, $article->getTitle());
                 $editInfo = $article->prepareContentForEdit($content);
                 $links = array_keys($editInfo->output->getExternalLinks());
                 $result = $links;
                 break;
             }
             // Otherwise fall back to database
         // Otherwise fall back to database
         case 'links-from-wikitext-nonedit':
         case 'links-from-wikitext-or-database':
             // TODO: use Content object instead, if available! In any case, use WikiPage, not Article.
             $article = self::articleFromTitle($parameters['namespace'], $parameters['title']);
             if ($vars->getVar('context')->toString() == 'filter') {
                 $links = $this->getLinksFromDB($article);
                 wfDebug("AbuseFilter: loading old links from DB\n");
             } elseif (!defined('MW_SUPPORTS_CONTENTHANDLER') || $article->getContentModel() === CONTENT_MODEL_WIKITEXT) {
                 wfDebug("AbuseFilter: loading old links from Parser\n");
                 $textVar = $parameters['text-var'];
                 $wikitext = $vars->getVar($textVar)->toString();
                 $editInfo = $this->parseNonEditWikitext($wikitext, $article);
                 $links = array_keys($editInfo->output->getExternalLinks());
             } else {
                 // TODO: Get links from Content object. But we don't have the content object.
                 //      And for non-text content, $wikitext is usually not going to be a valid
                 //      serialization, but rather some dummy text for filtering.
                 $links = array();
             }
             $result = $links;
             break;
         case 'link-diff-added':
         case 'link-diff-removed':
             $oldLinkVar = $parameters['oldlink-var'];
             $newLinkVar = $parameters['newlink-var'];
             $oldLinks = $vars->getVar($oldLinkVar)->toString();
             $newLinks = $vars->getVar($newLinkVar)->toString();
             $oldLinks = explode("\n", $oldLinks);
             $newLinks = explode("\n", $newLinks);
             if ($this->mMethod == 'link-diff-added') {
                 $result = array_diff($newLinks, $oldLinks);
             }
             if ($this->mMethod == 'link-diff-removed') {
                 $result = array_diff($oldLinks, $newLinks);
             }
             break;
         case 'parse-wikitext':
             // Should ONLY be used when sharing a parse operation with the edit.
             $article = $parameters['article'];
             if ($article !== null && (!defined('MW_SUPPORTS_CONTENTHANDLER') || $article->getContentModel() === CONTENT_MODEL_WIKITEXT)) {
                 $textVar = $parameters['wikitext-var'];
                 // XXX: Use prepareContentForEdit. But we need a Content object for that.
                 $new_text = $vars->getVar($textVar)->toString();
                 $editInfo = $article->prepareTextForEdit($new_text);
                 if (isset($parameters['pst']) && $parameters['pst']) {
                     $result = $editInfo->pstContent->serialize($editInfo->format);
                 } else {
                     $newHTML = $editInfo->output->getText();
                     // Kill the PP limit comments. Ideally we'd just remove these by not setting the
                     // parser option, but then we can't share a parse operation with the edit, which is bad.
                     $result = preg_replace('/<!--\\s*NewPP limit report[^>]*-->\\s*$/si', '', $newHTML);
                 }
                 break;
             }
             // Otherwise fall back to database
         // Otherwise fall back to database
         case 'parse-wikitext-nonedit':
             // TODO: use Content object instead, if available! In any case, use WikiPage, not Article.
             $article = self::articleFromTitle($parameters['namespace'], $parameters['title']);
             $textVar = $parameters['wikitext-var'];
             if (!defined('MW_SUPPORTS_CONTENTHANDLER') || $article->getContentModel() === CONTENT_MODEL_WIKITEXT) {
                 if (isset($parameters['pst']) && $parameters['pst']) {
                     // $textVar is already PSTed when it's not loaded from an ongoing edit.
                     $result = $vars->getVar($textVar)->toString();
                 } else {
                     $text = $vars->getVar($textVar)->toString();
                     $editInfo = $this->parseNonEditWikitext($text, $article);
                     $result = $editInfo->output->getText();
                 }
             } else {
                 // TODO: Parser Output from Content object. But we don't have the content object.
                 //      And for non-text content, $wikitext is usually not going to be a valid
                 //      serialization, but rather some dummy text for filtering.
                 $result = '';
             }
             break;
         case 'strip-html':
             $htmlVar = $parameters['html-var'];
             $html = $vars->getVar($htmlVar)->toString();
             $result = StringUtils::delimiterReplace('<', '>', '', $html);
             break;
         case 'load-recent-authors':
             $cutOff = $parameters['cutoff'];
             $title = Title::makeTitle($parameters['namespace'], $parameters['title']);
             if (!$title->exists()) {
                 $result = '';
                 break;
             }
             $dbr = wfGetDB(DB_SLAVE);
             $res = $dbr->select('revision', 'DISTINCT rev_user_text', array('rev_page' => $title->getArticleID(), 'rev_timestamp<' . $dbr->addQuotes($dbr->timestamp($cutOff))), __METHOD__, array('ORDER BY' => 'rev_timestamp DESC', 'LIMIT' => 10));
             $users = array();
             foreach ($res as $row) {
                 $users[] = $row->rev_user_text;
             }
             $result = $users;
             break;
         case 'get-page-restrictions':
             $action = $parameters['action'];
             $title = Title::makeTitle($parameters['namespace'], $parameters['title']);
             $rights = $title->getRestrictions($action);
             $rights = count($rights) ? $rights : array();
             $result = $rights;
             break;
         case 'simple-user-accessor':
             $user = $parameters['user'];
             $method = $parameters['method'];
             if (!$user) {
                 throw new MWException('No user parameter given.');
             }
             $obj = self::getUserObject($user);
             if (!$obj) {
                 throw new MWException("Invalid username {$user}");
             }
             $result = call_user_func(array($obj, $method));
             break;
         case 'user-age':
             $user = $parameters['user'];
             $asOf = $parameters['asof'];
             $obj = self::getUserObject($user);
             if ($obj->getId() == 0) {
                 $result = 0;
                 break;
             }
             $registration = $obj->getRegistration();
             $result = wfTimestamp(TS_UNIX, $asOf) - wfTimestampOrNull(TS_UNIX, $registration);
             break;
         case 'user-groups':
             // Deprecated but needed by old log entries
             $user = $parameters['user'];
             $obj = self::getUserObject($user);
             $result = $obj->getEffectiveGroups();
             break;
         case 'length':
             $s = $vars->getVar($parameters['length-var'])->toString();
             $result = strlen($s);
             break;
         case 'subtract':
             $v1 = $vars->getVar($parameters['val1-var'])->toFloat();
             $v2 = $vars->getVar($parameters['val2-var'])->toFloat();
             $result = $v1 - $v2;
             break;
         case 'revision-text-by-id':
             $rev = Revision::newFromId($parameters['revid']);
             $result = AbuseFilter::revisionToString($rev);
             break;
         case 'revision-text-by-timestamp':
             $timestamp = $parameters['timestamp'];
             $title = Title::makeTitle($parameters['namespace'], $parameters['title']);
             $dbr = wfGetDB(DB_SLAVE);
             $rev = Revision::loadFromTimestamp($dbr, $title, $timestamp);
             $result = AbuseFilter::revisionToString($rev);
             break;
         default:
             if (wfRunHooks('AbuseFilter-computeVariable', array($this->mMethod, $vars, $parameters, &$result))) {
                 throw new AFPException('Unknown variable compute type ' . $this->mMethod);
             }
     }
     return $result instanceof AFPData ? $result : AFPData::newFromPHPVar($result);
 }
 /**
  * Callback function for each revision, parse with both parsers and compare
  * @param $rev Revision
  */
 public function processRevision($rev)
 {
     $title = $rev->getTitle();
     $parser1Name = $this->getOption('parser1');
     $parser2Name = $this->getOption('parser2');
     self::checkParserLocally($parser1Name);
     self::checkParserLocally($parser2Name);
     $parser1 = new $parser1Name();
     $parser2 = new $parser2Name();
     $content = $rev->getContent();
     if ($content->getModel() !== CONTENT_MODEL_WIKITEXT) {
         $this->error("Page {$title->getPrefixedText()} does not contain wikitext but {$content->getModel()}\n");
         return;
     }
     $text = strval($content->getNativeData());
     $output1 = $parser1->parse($text, $title, $this->options);
     $output2 = $parser2->parse($text, $title, $this->options);
     if ($output1->getText() != $output2->getText()) {
         $this->failed++;
         $this->error("Parsing for {$title->getPrefixedText()} differs\n");
         if ($this->saveFailed) {
             file_put_contents($this->saveFailed . '/' . rawurlencode($title->getPrefixedText()) . ".txt", $text);
         }
         if ($this->showDiff) {
             $this->output(wfDiff($this->stripParameters($output1->getText()), $this->stripParameters($output2->getText()), ''));
         }
     } else {
         $this->output($title->getPrefixedText() . "\tOK\n");
         if ($this->showParsedOutput) {
             $this->output($this->stripParameters($output1->getText()));
         }
     }
 }
Ejemplo n.º 7
0
 /**
  * Callback function for each revision, parse with both parsers and compare
  * @param $rev Revision
  */
 public function processRevision($rev)
 {
     $title = $rev->getTitle();
     $parser1Name = $this->getOption('parser1');
     $parser2Name = $this->getOption('parser2');
     self::checkParserLocally($parser1Name);
     self::checkParserLocally($parser2Name);
     $parser1 = new $parser1Name();
     $parser2 = new $parser2Name();
     $output1 = $parser1->parse($rev->getText(), $title, $this->options);
     $output2 = $parser2->parse($rev->getText(), $title, $this->options);
     if ($output1->getText() != $output2->getText()) {
         $this->failed++;
         $this->error("Parsing for {$title->getPrefixedText()} differs\n");
         if ($this->saveFailed) {
             file_put_contents($this->saveFailed . '/' . rawurlencode($title->getPrefixedText()) . ".txt", $rev->getText());
         }
         if ($this->showDiff) {
             $this->output(wfDiff($this->stripParameters($output1->getText()), $this->stripParameters($output2->getText()), ''));
         }
     } else {
         $this->output($title->getPrefixedText() . "\tOK\n");
         if ($this->showParsedOutput) {
             $this->output($this->stripParameters($output1->getText()));
         }
     }
 }
 function compute($vars)
 {
     $parameters = $this->mParameters;
     $result = null;
     switch ($this->mMethod) {
         case 'diff':
             $text1Var = $parameters['oldtext-var'];
             $text2Var = $parameters['newtext-var'];
             $text1 = $vars->getVar($text1Var)->toString();
             $text2 = $vars->getVar($text2Var)->toString();
             $result = wfDiff($text1, $text2);
             $result = trim(preg_replace("/^\\\\ No newline at end of file\n/m", '', $result));
             break;
         case 'diff-split':
             $diff = $vars->getVar($parameters['diff-var'])->toString();
             $line_prefix = $parameters['line-prefix'];
             $diff_lines = explode("\n", $diff);
             $interest_lines = array();
             foreach ($diff_lines as $line) {
                 if (substr($line, 0, 1) === $line_prefix) {
                     $interest_lines[] = substr($line, strlen($line_prefix));
                 }
             }
             $result = $interest_lines;
             break;
         case 'links-from-wikitext':
             // This should ONLY be used when sharing a parse operation with the edit.
             $article = $parameters['article'];
             if ($article) {
                 $textVar = $parameters['text-var'];
                 $new_text = $vars->getVar($textVar)->toString();
                 $editInfo = $article->prepareTextForEdit($new_text);
                 $links = array_keys($editInfo->output->getExternalLinks());
                 $result = $links;
                 break;
             }
             // Otherwise fall back to database
         // Otherwise fall back to database
         case 'links-from-wikitext-nonedit':
         case 'links-from-wikitext-or-database':
             $article = self::articleFromTitle($parameters['namespace'], $parameters['title']);
             if ($vars->getVar('context')->toString() == 'filter') {
                 $links = $this->getLinksFromDB($article);
                 wfDebug("AbuseFilter: loading old links from DB\n");
             } else {
                 wfDebug("AbuseFilter: loading old links from Parser\n");
                 $textVar = $parameters['text-var'];
                 $wikitext = $vars->getVar($textVar)->toString();
                 $editInfo = $this->parseNonEditWikitext($wikitext, $article);
                 $links = array_keys($editInfo->output->getExternalLinks());
             }
             $result = $links;
             break;
         case 'link-diff-added':
         case 'link-diff-removed':
             $oldLinkVar = $parameters['oldlink-var'];
             $newLinkVar = $parameters['newlink-var'];
             $oldLinks = $vars->getVar($oldLinkVar)->toString();
             $newLinks = $vars->getVar($newLinkVar)->toString();
             $oldLinks = explode("\n", $oldLinks);
             $newLinks = explode("\n", $newLinks);
             if ($this->mMethod == 'link-diff-added') {
                 $result = array_diff($newLinks, $oldLinks);
             }
             if ($this->mMethod == 'link-diff-removed') {
                 $result = array_diff($oldLinks, $newLinks);
             }
             break;
         case 'parse-wikitext':
             // Should ONLY be used when sharing a parse operation with the edit.
             $article = $parameters['article'];
             if ($article) {
                 $textVar = $parameters['wikitext-var'];
                 $new_text = $vars->getVar($textVar)->toString();
                 $editInfo = $article->prepareTextForEdit($new_text);
                 $newHTML = $editInfo->output->getText();
                 // Kill the PP limit comments. Ideally we'd just remove these by not setting the
                 // parser option, but then we can't share a parse operation with the edit, which is bad.
                 $result = preg_replace('/<!--\\s*NewPP limit report[^>]*-->\\s*$/si', '', $newHTML);
                 break;
             }
             // Otherwise fall back to database
         // Otherwise fall back to database
         case 'parse-wikitext-nonedit':
             $article = self::articleFromTitle($parameters['namespace'], $parameters['title']);
             $textVar = $parameters['wikitext-var'];
             $text = $vars->getVar($textVar)->toString();
             $editInfo = $this->parseNonEditWikitext($text, $article);
             $result = $editInfo->output->getText();
             break;
         case 'strip-html':
             $htmlVar = $parameters['html-var'];
             $html = $vars->getVar($htmlVar)->toString();
             $result = StringUtils::delimiterReplace('<', '>', '', $html);
             break;
         case 'load-recent-authors':
             $cutOff = $parameters['cutoff'];
             $title = Title::makeTitle($parameters['namespace'], $parameters['title']);
             if (!$title->exists()) {
                 $result = '';
                 break;
             }
             $dbr = wfGetDB(DB_SLAVE);
             $res = $dbr->select('revision', 'DISTINCT rev_user_text', array('rev_page' => $title->getArticleId(), 'rev_timestamp<' . $dbr->addQuotes($dbr->timestamp($cutOff))), __METHOD__, array('ORDER BY' => 'rev_timestamp DESC', 'LIMIT' => 10));
             $users = array();
             foreach ($res as $row) {
                 $users[] = $row->rev_user_text;
             }
             $result = $users;
             break;
         case 'get-page-restrictions':
             $action = $parameters['action'];
             $title = Title::makeTitle($parameters['namespace'], $parameters['title']);
             $rights = $title->getRestrictions($action);
             $rights = count($rights) ? $rights : array();
             $result = $rights;
             break;
         case 'simple-user-accessor':
             $user = $parameters['user'];
             $method = $parameters['method'];
             if (!$user) {
                 throw new MWException('No user parameter given.');
             }
             $obj = self::userObjectFromName($user);
             if (!$obj) {
                 throw new MWException("Invalid username {$user}");
             }
             $result = call_user_func(array($obj, $method));
             break;
         case 'user-age':
             $user = $parameters['user'];
             $asOf = $parameters['asof'];
             $obj = self::userObjectFromName($user);
             if ($obj->getId() == 0) {
                 $result = 0;
                 break;
             }
             $registration = $obj->getRegistration();
             $result = wfTimestamp(TS_UNIX, $asOf) - wfTimestampOrNull(TS_UNIX, $registration);
             break;
         case 'user-groups':
             $user = $parameters['user'];
             $obj = self::userObjectFromName($user);
             $result = $obj->getEffectiveGroups();
             break;
         case 'length':
             $s = $vars->getVar($parameters['length-var'])->toString();
             $result = strlen($s);
             break;
         case 'subtract':
             $v1 = $vars->getVar($parameters['val1-var'])->toFloat();
             $v2 = $vars->getVar($parameters['val2-var'])->toFloat();
             $result = $v1 - $v2;
             break;
         case 'revision-text-by-id':
             $rev = Revision::newFromId($parameters['revid']);
             $result = $rev->getText();
             break;
         case 'revision-text-by-timestamp':
             $timestamp = $parameters['timestamp'];
             $title = Title::makeTitle($parameters['namespace'], $parameters['title']);
             $dbr = wfGetDB(DB_SLAVE);
             $rev = Revision::loadFromTimestamp($dbr, $title, $timestamp);
             if ($rev) {
                 $result = $rev->getText();
             } else {
                 $result = '';
             }
             break;
         default:
             if (wfRunHooks('AbuseFilter-computeVariable', array($this->mMethod, $vars))) {
                 throw new AFPException('Unknown variable compute type ' . $this->mMethod);
             }
     }
     return $result instanceof AFPData ? $result : AFPData::newFromPHPVar($result);
 }