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Diffstat (limited to 'www/wiki/includes/diff/DifferenceEngine.php')
| -rw-r--r-- | www/wiki/includes/diff/DifferenceEngine.php | 1558 |
1 files changed, 1558 insertions, 0 deletions
diff --git a/www/wiki/includes/diff/DifferenceEngine.php b/www/wiki/includes/diff/DifferenceEngine.php new file mode 100644 index 00000000..8f57c578 --- /dev/null +++ b/www/wiki/includes/diff/DifferenceEngine.php @@ -0,0 +1,1558 @@ +<?php +/** + * User interface for the difference engine. + * + * 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 DifferenceEngine + */ +use MediaWiki\MediaWikiServices; +use MediaWiki\Shell\Shell; + +/** + * @todo document + * @ingroup DifferenceEngine + */ +class DifferenceEngine extends ContextSource { + /** + * Constant to indicate diff cache compatibility. + * Bump this when changing the diff formatting in a way that + * fixes important bugs or such to force cached diff views to + * clear. + */ + const DIFF_VERSION = '1.12'; + + /** @var int */ + public $mOldid; + + /** @var int */ + public $mNewid; + + private $mOldTags; + private $mNewTags; + + /** @var Content */ + public $mOldContent; + + /** @var Content */ + public $mNewContent; + + /** @var Language */ + protected $mDiffLang; + + /** @var Title */ + public $mOldPage; + + /** @var Title */ + public $mNewPage; + + /** @var Revision */ + public $mOldRev; + + /** @var Revision */ + public $mNewRev; + + /** @var bool Have the revisions IDs been loaded */ + private $mRevisionsIdsLoaded = false; + + /** @var bool Have the revisions been loaded */ + public $mRevisionsLoaded = false; + + /** @var int How many text blobs have been loaded, 0, 1 or 2? */ + public $mTextLoaded = 0; + + /** @var bool Was the diff fetched from cache? */ + public $mCacheHit = false; + + /** + * Set this to true to add debug info to the HTML output. + * Warning: this may cause RSS readers to spuriously mark articles as "new" + * (T22601) + */ + public $enableDebugComment = false; + + /** @var bool If true, line X is not displayed when X is 1, for example + * to increase readability and conserve space with many small diffs. + */ + protected $mReducedLineNumbers = false; + + /** @var string Link to action=markpatrolled */ + protected $mMarkPatrolledLink = null; + + /** @var bool Show rev_deleted content if allowed */ + protected $unhide = false; + + /** @var bool Refresh the diff cache */ + protected $mRefreshCache = false; + + /**#@-*/ + + /** + * @param IContextSource $context Context to use, anything else will be ignored + * @param int $old Old ID we want to show and diff with. + * @param string|int $new Either revision ID or 'prev' or 'next'. Default: 0. + * @param int $rcid Deprecated, no longer used! + * @param bool $refreshCache If set, refreshes the diff cache + * @param bool $unhide If set, allow viewing deleted revs + */ + public function __construct( $context = null, $old = 0, $new = 0, $rcid = 0, + $refreshCache = false, $unhide = false + ) { + if ( $context instanceof IContextSource ) { + $this->setContext( $context ); + } + + wfDebug( "DifferenceEngine old '$old' new '$new' rcid '$rcid'\n" ); + + $this->mOldid = $old; + $this->mNewid = $new; + $this->mRefreshCache = $refreshCache; + $this->unhide = $unhide; + } + + /** + * @param bool $value + */ + public function setReducedLineNumbers( $value = true ) { + $this->mReducedLineNumbers = $value; + } + + /** + * @return Language + */ + public function getDiffLang() { + if ( $this->mDiffLang === null ) { + # Default language in which the diff text is written. + $this->mDiffLang = $this->getTitle()->getPageLanguage(); + } + + return $this->mDiffLang; + } + + /** + * @return bool + */ + public function wasCacheHit() { + return $this->mCacheHit; + } + + /** + * @return int + */ + public function getOldid() { + $this->loadRevisionIds(); + + return $this->mOldid; + } + + /** + * @return bool|int + */ + public function getNewid() { + $this->loadRevisionIds(); + + return $this->mNewid; + } + + /** + * Look up a special:Undelete link to the given deleted revision id, + * as a workaround for being unable to load deleted diffs in currently. + * + * @param int $id Revision ID + * + * @return string|bool Link HTML or false + */ + public function deletedLink( $id ) { + if ( $this->getUser()->isAllowed( 'deletedhistory' ) ) { + $dbr = wfGetDB( DB_REPLICA ); + $arQuery = Revision::getArchiveQueryInfo(); + $row = $dbr->selectRow( + $arQuery['tables'], + array_merge( $arQuery['fields'], [ 'ar_namespace', 'ar_title' ] ), + [ 'ar_rev_id' => $id ], + __METHOD__, + [], + $arQuery['joins'] + ); + if ( $row ) { + $rev = Revision::newFromArchiveRow( $row ); + $title = Title::makeTitleSafe( $row->ar_namespace, $row->ar_title ); + + return SpecialPage::getTitleFor( 'Undelete' )->getFullURL( [ + 'target' => $title->getPrefixedText(), + 'timestamp' => $rev->getTimestamp() + ] ); + } + } + + return false; + } + + /** + * Build a wikitext link toward a deleted revision, if viewable. + * + * @param int $id Revision ID + * + * @return string Wikitext fragment + */ + public function deletedIdMarker( $id ) { + $link = $this->deletedLink( $id ); + if ( $link ) { + return "[$link $id]"; + } else { + return (string)$id; + } + } + + private function showMissingRevision() { + $out = $this->getOutput(); + + $missing = []; + if ( $this->mOldRev === null || + ( $this->mOldRev && $this->mOldContent === null ) + ) { + $missing[] = $this->deletedIdMarker( $this->mOldid ); + } + if ( $this->mNewRev === null || + ( $this->mNewRev && $this->mNewContent === null ) + ) { + $missing[] = $this->deletedIdMarker( $this->mNewid ); + } + + $out->setPageTitle( $this->msg( 'errorpagetitle' ) ); + $msg = $this->msg( 'difference-missing-revision' ) + ->params( $this->getLanguage()->listToText( $missing ) ) + ->numParams( count( $missing ) ) + ->parseAsBlock(); + $out->addHTML( $msg ); + } + + public function showDiffPage( $diffOnly = false ) { + # Allow frames except in certain special cases + $out = $this->getOutput(); + $out->allowClickjacking(); + $out->setRobotPolicy( 'noindex,nofollow' ); + + // Allow extensions to add any extra output here + Hooks::run( 'DifferenceEngineShowDiffPage', [ $out ] ); + + if ( !$this->loadRevisionData() ) { + if ( Hooks::run( 'DifferenceEngineShowDiffPageMaybeShowMissingRevision', [ $this ] ) ) { + $this->showMissingRevision(); + } + return; + } + + $user = $this->getUser(); + $permErrors = $this->mNewPage->getUserPermissionsErrors( 'read', $user ); + if ( $this->mOldPage ) { # mOldPage might not be set, see below. + $permErrors = wfMergeErrorArrays( $permErrors, + $this->mOldPage->getUserPermissionsErrors( 'read', $user ) ); + } + if ( count( $permErrors ) ) { + throw new PermissionsError( 'read', $permErrors ); + } + + $rollback = ''; + + $query = []; + # Carry over 'diffonly' param via navigation links + if ( $diffOnly != $user->getBoolOption( 'diffonly' ) ) { + $query['diffonly'] = $diffOnly; + } + # Cascade unhide param in links for easy deletion browsing + if ( $this->unhide ) { + $query['unhide'] = 1; + } + + # Check if one of the revisions is deleted/suppressed + $deleted = $suppressed = false; + $allowed = $this->mNewRev->userCan( Revision::DELETED_TEXT, $user ); + + $revisionTools = []; + + # mOldRev is false if the difference engine is called with a "vague" query for + # a diff between a version V and its previous version V' AND the version V + # is the first version of that article. In that case, V' does not exist. + if ( $this->mOldRev === false ) { + $out->setPageTitle( $this->msg( 'difference-title', $this->mNewPage->getPrefixedText() ) ); + $samePage = true; + $oldHeader = ''; + // Allow extensions to change the $oldHeader variable + Hooks::run( 'DifferenceEngineOldHeaderNoOldRev', [ &$oldHeader ] ); + } else { + Hooks::run( 'DiffViewHeader', [ $this, $this->mOldRev, $this->mNewRev ] ); + + if ( $this->mNewPage->equals( $this->mOldPage ) ) { + $out->setPageTitle( $this->msg( 'difference-title', $this->mNewPage->getPrefixedText() ) ); + $samePage = true; + } else { + $out->setPageTitle( $this->msg( 'difference-title-multipage', + $this->mOldPage->getPrefixedText(), $this->mNewPage->getPrefixedText() ) ); + $out->addSubtitle( $this->msg( 'difference-multipage' ) ); + $samePage = false; + } + + if ( $samePage && $this->mNewPage->quickUserCan( 'edit', $user ) ) { + if ( $this->mNewRev->isCurrent() && $this->mNewPage->userCan( 'rollback', $user ) ) { + $rollbackLink = Linker::generateRollback( $this->mNewRev, $this->getContext() ); + if ( $rollbackLink ) { + $out->preventClickjacking(); + $rollback = '   ' . $rollbackLink; + } + } + + if ( !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && + !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) + ) { + $undoLink = Html::element( 'a', [ + 'href' => $this->mNewPage->getLocalURL( [ + 'action' => 'edit', + 'undoafter' => $this->mOldid, + 'undo' => $this->mNewid + ] ), + 'title' => Linker::titleAttrib( 'undo' ), + ], + $this->msg( 'editundo' )->text() + ); + $revisionTools['mw-diff-undo'] = $undoLink; + } + } + + # Make "previous revision link" + if ( $samePage && $this->mOldRev->getPrevious() ) { + $prevlink = Linker::linkKnown( + $this->mOldPage, + $this->msg( 'previousdiff' )->escaped(), + [ 'id' => 'differences-prevlink' ], + [ 'diff' => 'prev', 'oldid' => $this->mOldid ] + $query + ); + } else { + $prevlink = ' '; + } + + if ( $this->mOldRev->isMinor() ) { + $oldminor = ChangesList::flag( 'minor' ); + } else { + $oldminor = ''; + } + + $ldel = $this->revisionDeleteLink( $this->mOldRev ); + $oldRevisionHeader = $this->getRevisionHeader( $this->mOldRev, 'complete' ); + $oldChangeTags = ChangeTags::formatSummaryRow( $this->mOldTags, 'diff', $this->getContext() ); + + $oldHeader = '<div id="mw-diff-otitle1"><strong>' . $oldRevisionHeader . '</strong></div>' . + '<div id="mw-diff-otitle2">' . + Linker::revUserTools( $this->mOldRev, !$this->unhide ) . '</div>' . + '<div id="mw-diff-otitle3">' . $oldminor . + Linker::revComment( $this->mOldRev, !$diffOnly, !$this->unhide ) . $ldel . '</div>' . + '<div id="mw-diff-otitle5">' . $oldChangeTags[0] . '</div>' . + '<div id="mw-diff-otitle4">' . $prevlink . '</div>'; + + // Allow extensions to change the $oldHeader variable + Hooks::run( 'DifferenceEngineOldHeader', [ $this, &$oldHeader, $prevlink, $oldminor, + $diffOnly, $ldel, $this->unhide ] ); + + if ( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) { + $deleted = true; // old revisions text is hidden + if ( $this->mOldRev->isDeleted( Revision::DELETED_RESTRICTED ) ) { + $suppressed = true; // also suppressed + } + } + + # Check if this user can see the revisions + if ( !$this->mOldRev->userCan( Revision::DELETED_TEXT, $user ) ) { + $allowed = false; + } + } + + $out->addJsConfigVars( [ + 'wgDiffOldId' => $this->mOldid, + 'wgDiffNewId' => $this->mNewid, + ] ); + + # Make "next revision link" + # Skip next link on the top revision + if ( $samePage && !$this->mNewRev->isCurrent() ) { + $nextlink = Linker::linkKnown( + $this->mNewPage, + $this->msg( 'nextdiff' )->escaped(), + [ 'id' => 'differences-nextlink' ], + [ 'diff' => 'next', 'oldid' => $this->mNewid ] + $query + ); + } else { + $nextlink = ' '; + } + + if ( $this->mNewRev->isMinor() ) { + $newminor = ChangesList::flag( 'minor' ); + } else { + $newminor = ''; + } + + # Handle RevisionDelete links... + $rdel = $this->revisionDeleteLink( $this->mNewRev ); + + # Allow extensions to define their own revision tools + Hooks::run( 'DiffRevisionTools', + [ $this->mNewRev, &$revisionTools, $this->mOldRev, $user ] ); + $formattedRevisionTools = []; + // Put each one in parentheses (poor man's button) + foreach ( $revisionTools as $key => $tool ) { + $toolClass = is_string( $key ) ? $key : 'mw-diff-tool'; + $element = Html::rawElement( + 'span', + [ 'class' => $toolClass ], + $this->msg( 'parentheses' )->rawParams( $tool )->escaped() + ); + $formattedRevisionTools[] = $element; + } + $newRevisionHeader = $this->getRevisionHeader( $this->mNewRev, 'complete' ) . + ' ' . implode( ' ', $formattedRevisionTools ); + $newChangeTags = ChangeTags::formatSummaryRow( $this->mNewTags, 'diff', $this->getContext() ); + + $newHeader = '<div id="mw-diff-ntitle1"><strong>' . $newRevisionHeader . '</strong></div>' . + '<div id="mw-diff-ntitle2">' . Linker::revUserTools( $this->mNewRev, !$this->unhide ) . + " $rollback</div>" . + '<div id="mw-diff-ntitle3">' . $newminor . + Linker::revComment( $this->mNewRev, !$diffOnly, !$this->unhide ) . $rdel . '</div>' . + '<div id="mw-diff-ntitle5">' . $newChangeTags[0] . '</div>' . + '<div id="mw-diff-ntitle4">' . $nextlink . $this->markPatrolledLink() . '</div>'; + + // Allow extensions to change the $newHeader variable + Hooks::run( 'DifferenceEngineNewHeader', [ $this, &$newHeader, $formattedRevisionTools, + $nextlink, $rollback, $newminor, $diffOnly, $rdel, $this->unhide ] ); + + if ( $this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) { + $deleted = true; // new revisions text is hidden + if ( $this->mNewRev->isDeleted( Revision::DELETED_RESTRICTED ) ) { + $suppressed = true; // also suppressed + } + } + + # If the diff cannot be shown due to a deleted revision, then output + # the diff header and links to unhide (if available)... + if ( $deleted && ( !$this->unhide || !$allowed ) ) { + $this->showDiffStyle(); + $multi = $this->getMultiNotice(); + $out->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) ); + if ( !$allowed ) { + $msg = $suppressed ? 'rev-suppressed-no-diff' : 'rev-deleted-no-diff'; + # Give explanation for why revision is not visible + $out->wrapWikiMsg( "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n", + [ $msg ] ); + } else { + # Give explanation and add a link to view the diff... + $query = $this->getRequest()->appendQueryValue( 'unhide', '1' ); + $link = $this->getTitle()->getFullURL( $query ); + $msg = $suppressed ? 'rev-suppressed-unhide-diff' : 'rev-deleted-unhide-diff'; + $out->wrapWikiMsg( + "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n", + [ $msg, $link ] + ); + } + # Otherwise, output a regular diff... + } else { + # Add deletion notice if the user is viewing deleted content + $notice = ''; + if ( $deleted ) { + $msg = $suppressed ? 'rev-suppressed-diff-view' : 'rev-deleted-diff-view'; + $notice = "<div id='mw-$msg' class='mw-warning plainlinks'>\n" . + $this->msg( $msg )->parse() . + "</div>\n"; + } + $this->showDiff( $oldHeader, $newHeader, $notice ); + if ( !$diffOnly ) { + $this->renderNewRevision(); + } + } + } + + /** + * Build a link to mark a change as patrolled. + * + * Returns empty string if there's either no revision to patrol or the user is not allowed to. + * Side effect: When the patrol link is build, this method will call + * OutputPage::preventClickjacking() and load mediawiki.page.patrol.ajax. + * + * @return string HTML or empty string + */ + public function markPatrolledLink() { + if ( $this->mMarkPatrolledLink === null ) { + $linkInfo = $this->getMarkPatrolledLinkInfo(); + // If false, there is no patrol link needed/allowed + if ( !$linkInfo ) { + $this->mMarkPatrolledLink = ''; + } else { + $this->mMarkPatrolledLink = ' <span class="patrollink" data-mw="interface">[' . + Linker::linkKnown( + $this->mNewPage, + $this->msg( 'markaspatrolleddiff' )->escaped(), + [], + [ + 'action' => 'markpatrolled', + 'rcid' => $linkInfo['rcid'], + ] + ) . ']</span>'; + // Allow extensions to change the markpatrolled link + Hooks::run( 'DifferenceEngineMarkPatrolledLink', [ $this, + &$this->mMarkPatrolledLink, $linkInfo['rcid'] ] ); + } + } + return $this->mMarkPatrolledLink; + } + + /** + * Returns an array of meta data needed to build a "mark as patrolled" link and + * adds the mediawiki.page.patrol.ajax to the output. + * + * @return array|false An array of meta data for a patrol link (rcid only) + * or false if no link is needed + */ + protected function getMarkPatrolledLinkInfo() { + global $wgUseRCPatrol, $wgEnableAPI, $wgEnableWriteAPI; + + $user = $this->getUser(); + + // Prepare a change patrol link, if applicable + if ( + // Is patrolling enabled and the user allowed to? + $wgUseRCPatrol && $this->mNewPage->quickUserCan( 'patrol', $user ) && + // Only do this if the revision isn't more than 6 hours older + // than the Max RC age (6h because the RC might not be cleaned out regularly) + RecentChange::isInRCLifespan( $this->mNewRev->getTimestamp(), 21600 ) + ) { + // Look for an unpatrolled change corresponding to this diff + $db = wfGetDB( DB_REPLICA ); + $change = RecentChange::newFromConds( + [ + 'rc_timestamp' => $db->timestamp( $this->mNewRev->getTimestamp() ), + 'rc_this_oldid' => $this->mNewid, + 'rc_patrolled' => RecentChange::PRC_UNPATROLLED + ], + __METHOD__ + ); + + if ( $change && !$change->getPerformer()->equals( $user ) ) { + $rcid = $change->getAttribute( 'rc_id' ); + } else { + // None found or the page has been created by the current user. + // If the user could patrol this it already would be patrolled + $rcid = 0; + } + + // Allow extensions to possibly change the rcid here + // For example the rcid might be set to zero due to the user + // being the same as the performer of the change but an extension + // might still want to show it under certain conditions + Hooks::run( 'DifferenceEngineMarkPatrolledRCID', [ &$rcid, $this, $change, $user ] ); + + // Build the link + if ( $rcid ) { + $this->getOutput()->preventClickjacking(); + if ( $wgEnableAPI && $wgEnableWriteAPI + && $user->isAllowed( 'writeapi' ) + ) { + $this->getOutput()->addModules( 'mediawiki.page.patrol.ajax' ); + } + + return [ + 'rcid' => $rcid, + ]; + } + } + + // No mark as patrolled link applicable + return false; + } + + /** + * @param Revision $rev + * + * @return string + */ + protected function revisionDeleteLink( $rev ) { + $link = Linker::getRevDeleteLink( $this->getUser(), $rev, $rev->getTitle() ); + if ( $link !== '' ) { + $link = '   ' . $link . ' '; + } + + return $link; + } + + /** + * Show the new revision of the page. + */ + public function renderNewRevision() { + $out = $this->getOutput(); + $revHeader = $this->getRevisionHeader( $this->mNewRev ); + # Add "current version as of X" title + $out->addHTML( "<hr class='diff-hr' id='mw-oldid' /> + <h2 class='diff-currentversion-title'>{$revHeader}</h2>\n" ); + # Page content may be handled by a hooked call instead... + if ( Hooks::run( 'ArticleContentOnDiff', [ $this, $out ] ) ) { + $this->loadNewText(); + $out->setRevisionId( $this->mNewid ); + $out->setRevisionTimestamp( $this->mNewRev->getTimestamp() ); + $out->setArticleFlag( true ); + + if ( !Hooks::run( 'ArticleContentViewCustom', + [ $this->mNewContent, $this->mNewPage, $out ] ) + ) { + // Handled by extension + } else { + // Normal page + if ( $this->getTitle()->equals( $this->mNewPage ) ) { + // If the Title stored in the context is the same as the one + // of the new revision, we can use its associated WikiPage + // object. + $wikiPage = $this->getWikiPage(); + } else { + // Otherwise we need to create our own WikiPage object + $wikiPage = WikiPage::factory( $this->mNewPage ); + } + + $parserOutput = $this->getParserOutput( $wikiPage, $this->mNewRev ); + + # WikiPage::getParserOutput() should not return false, but just in case + if ( $parserOutput ) { + // Allow extensions to change parser output here + if ( Hooks::run( 'DifferenceEngineRenderRevisionAddParserOutput', + [ $this, $out, $parserOutput, $wikiPage ] ) + ) { + $out->addParserOutput( $parserOutput, [ + 'enableSectionEditLinks' => $this->mNewRev->isCurrent() + && $this->mNewRev->getTitle()->quickUserCan( 'edit', $this->getUser() ), + ] ); + } + } + } + } + + // Allow extensions to optionally not show the final patrolled link + if ( Hooks::run( 'DifferenceEngineRenderRevisionShowFinalPatrolLink' ) ) { + # Add redundant patrol link on bottom... + $out->addHTML( $this->markPatrolledLink() ); + } + } + + /** + * @param WikiPage $page + * @param Revision $rev + * + * @return ParserOutput|bool False if the revision was not found + */ + protected function getParserOutput( WikiPage $page, Revision $rev ) { + $parserOptions = $page->makeParserOptions( $this->getContext() ); + $parserOutput = $page->getParserOutput( $parserOptions, $rev->getId() ); + + return $parserOutput; + } + + /** + * Get the diff text, send it to the OutputPage object + * Returns false if the diff could not be generated, otherwise returns true + * + * @param string|bool $otitle Header for old text or false + * @param string|bool $ntitle Header for new text or false + * @param string $notice HTML between diff header and body + * + * @return bool + */ + public function showDiff( $otitle, $ntitle, $notice = '' ) { + // Allow extensions to affect the output here + Hooks::run( 'DifferenceEngineShowDiff', [ $this ] ); + + $diff = $this->getDiff( $otitle, $ntitle, $notice ); + if ( $diff === false ) { + $this->showMissingRevision(); + + return false; + } else { + $this->showDiffStyle(); + $this->getOutput()->addHTML( $diff ); + + return true; + } + } + + /** + * Add style sheets for diff display. + */ + public function showDiffStyle() { + $this->getOutput()->addModuleStyles( 'mediawiki.diff.styles' ); + } + + /** + * Get complete diff table, including header + * + * @param string|bool $otitle Header for old text or false + * @param string|bool $ntitle Header for new text or false + * @param string $notice HTML between diff header and body + * + * @return mixed + */ + public function getDiff( $otitle, $ntitle, $notice = '' ) { + $body = $this->getDiffBody(); + if ( $body === false ) { + return false; + } + + $multi = $this->getMultiNotice(); + // Display a message when the diff is empty + if ( $body === '' ) { + $notice .= '<div class="mw-diff-empty">' . + $this->msg( 'diff-empty' )->parse() . + "</div>\n"; + } + + return $this->addHeader( $body, $otitle, $ntitle, $multi, $notice ); + } + + /** + * Get the diff table body, without header + * + * @return mixed (string/false) + */ + public function getDiffBody() { + $this->mCacheHit = true; + // Check if the diff should be hidden from this user + if ( !$this->loadRevisionData() ) { + return false; + } elseif ( $this->mOldRev && + !$this->mOldRev->userCan( Revision::DELETED_TEXT, $this->getUser() ) + ) { + return false; + } elseif ( $this->mNewRev && + !$this->mNewRev->userCan( Revision::DELETED_TEXT, $this->getUser() ) + ) { + return false; + } + // Short-circuit + if ( $this->mOldRev === false || ( $this->mOldRev && $this->mNewRev + && $this->mOldRev->getId() == $this->mNewRev->getId() ) + ) { + if ( Hooks::run( 'DifferenceEngineShowEmptyOldContent', [ $this ] ) ) { + return ''; + } + } + // Cacheable? + $key = false; + $cache = ObjectCache::getMainWANInstance(); + if ( $this->mOldid && $this->mNewid ) { + // Check if subclass is still using the old way + // for backwards-compatibility + $key = $this->getDiffBodyCacheKey(); + if ( $key === null ) { + $key = call_user_func_array( + [ $cache, 'makeKey' ], + $this->getDiffBodyCacheKeyParams() + ); + } + + // Try cache + if ( !$this->mRefreshCache ) { + $difftext = $cache->get( $key ); + if ( $difftext ) { + wfIncrStats( 'diff_cache.hit' ); + $difftext = $this->localiseDiff( $difftext ); + $difftext .= "\n<!-- diff cache key $key -->\n"; + + return $difftext; + } + } // don't try to load but save the result + } + $this->mCacheHit = false; + + // Loadtext is permission safe, this just clears out the diff + if ( !$this->loadText() ) { + return false; + } + + $difftext = $this->generateContentDiffBody( $this->mOldContent, $this->mNewContent ); + + // Avoid PHP 7.1 warning from passing $this by reference + $diffEngine = $this; + + // Save to cache for 7 days + if ( !Hooks::run( 'AbortDiffCache', [ &$diffEngine ] ) ) { + wfIncrStats( 'diff_cache.uncacheable' ); + } elseif ( $key !== false && $difftext !== false ) { + wfIncrStats( 'diff_cache.miss' ); + $cache->set( $key, $difftext, 7 * 86400 ); + } else { + wfIncrStats( 'diff_cache.uncacheable' ); + } + // localise line numbers and title attribute text + if ( $difftext !== false ) { + $difftext = $this->localiseDiff( $difftext ); + } + + return $difftext; + } + + /** + * Returns the cache key for diff body text or content. + * + * @deprecated since 1.31, use getDiffBodyCacheKeyParams() instead + * @since 1.23 + * + * @throws MWException + * @return string|null + */ + protected function getDiffBodyCacheKey() { + return null; + } + + /** + * Get the cache key parameters + * + * Subclasses can replace the first element in the array to something + * more specific to the type of diff (e.g. "inline-diff"), or append + * if the cache should vary on more things. Overriding entirely should + * be avoided. + * + * @since 1.31 + * + * @return array + * @throws MWException + */ + protected function getDiffBodyCacheKeyParams() { + if ( !$this->mOldid || !$this->mNewid ) { + throw new MWException( 'mOldid and mNewid must be set to get diff cache key.' ); + } + + $engine = $this->getEngine(); + $params = [ + 'diff', + $engine, + self::DIFF_VERSION, + "old-{$this->mOldid}", + "rev-{$this->mNewid}" + ]; + + if ( $engine === 'wikidiff2' ) { + $params[] = phpversion( 'wikidiff2' ); + $params[] = $this->getConfig()->get( 'WikiDiff2MovedParagraphDetectionCutoff' ); + } + + return $params; + } + + /** + * Generate a diff, no caching. + * + * This implementation uses generateTextDiffBody() to generate a diff based on the default + * serialization of the given Content objects. This will fail if $old or $new are not + * instances of TextContent. + * + * Subclasses may override this to provide a different rendering for the diff, + * perhaps taking advantage of the content's native form. This is required for all content + * models that are not text based. + * + * @since 1.21 + * + * @param Content $old Old content + * @param Content $new New content + * + * @throws MWException If old or new content is not an instance of TextContent. + * @return bool|string + */ + public function generateContentDiffBody( Content $old, Content $new ) { + if ( !( $old instanceof TextContent ) ) { + throw new MWException( "Diff not implemented for " . get_class( $old ) . "; " . + "override generateContentDiffBody to fix this." ); + } + + if ( !( $new instanceof TextContent ) ) { + throw new MWException( "Diff not implemented for " . get_class( $new ) . "; " + . "override generateContentDiffBody to fix this." ); + } + + $otext = $old->serialize(); + $ntext = $new->serialize(); + + return $this->generateTextDiffBody( $otext, $ntext ); + } + + /** + * Generate a diff, no caching + * + * @todo move this to TextDifferenceEngine, make DifferenceEngine abstract. At some point. + * + * @param string $otext Old text, must be already segmented + * @param string $ntext New text, must be already segmented + * + * @return bool|string + */ + public function generateTextDiffBody( $otext, $ntext ) { + $diff = function () use ( $otext, $ntext ) { + $time = microtime( true ); + + $result = $this->textDiff( $otext, $ntext ); + + $time = intval( ( microtime( true ) - $time ) * 1000 ); + MediaWikiServices::getInstance()->getStatsdDataFactory()->timing( 'diff_time', $time ); + // Log requests slower than 99th percentile + if ( $time > 100 && $this->mOldPage && $this->mNewPage ) { + wfDebugLog( 'diff', + "$time ms diff: {$this->mOldid} -> {$this->mNewid} {$this->mNewPage}" ); + } + + return $result; + }; + + /** + * @param Status $status + * @throws FatalError + */ + $error = function ( $status ) { + throw new FatalError( $status->getWikiText() ); + }; + + // Use PoolCounter if the diff looks like it can be expensive + if ( strlen( $otext ) + strlen( $ntext ) > 20000 ) { + $work = new PoolCounterWorkViaCallback( 'diff', + md5( $otext ) . md5( $ntext ), + [ 'doWork' => $diff, 'error' => $error ] + ); + return $work->execute(); + } + + return $diff(); + } + + /** + * Process $wgExternalDiffEngine and get a sane, usable engine + * + * @return bool|string 'wikidiff2', path to an executable, or false + */ + private function getEngine() { + global $wgExternalDiffEngine; + // We use the global here instead of Config because we write to the value, + // and Config is not mutable. + if ( $wgExternalDiffEngine == 'wikidiff' || $wgExternalDiffEngine == 'wikidiff3' ) { + wfDeprecated( "\$wgExternalDiffEngine = '{$wgExternalDiffEngine}'", '1.27' ); + $wgExternalDiffEngine = false; + } elseif ( $wgExternalDiffEngine == 'wikidiff2' ) { + // Same as above, but with no deprecation warnings + $wgExternalDiffEngine = false; + } elseif ( !is_string( $wgExternalDiffEngine ) && $wgExternalDiffEngine !== false ) { + // And prevent people from shooting themselves in the foot... + wfWarn( '$wgExternalDiffEngine is set to a non-string value, forcing it to false' ); + $wgExternalDiffEngine = false; + } + + if ( is_string( $wgExternalDiffEngine ) && is_executable( $wgExternalDiffEngine ) ) { + return $wgExternalDiffEngine; + } elseif ( $wgExternalDiffEngine === false && function_exists( 'wikidiff2_do_diff' ) ) { + return 'wikidiff2'; + } else { + // Native PHP + return false; + } + } + + /** + * Generates diff, to be wrapped internally in a logging/instrumentation + * + * @param string $otext Old text, must be already segmented + * @param string $ntext New text, must be already segmented + * @return bool|string + */ + protected function textDiff( $otext, $ntext ) { + global $wgContLang; + + $otext = str_replace( "\r\n", "\n", $otext ); + $ntext = str_replace( "\r\n", "\n", $ntext ); + + $engine = $this->getEngine(); + + // Better external diff engine, the 2 may some day be dropped + // This one does the escaping and segmenting itself + if ( $engine === 'wikidiff2' ) { + $wikidiff2Version = phpversion( 'wikidiff2' ); + if ( + $wikidiff2Version !== false && + version_compare( $wikidiff2Version, '1.5.0', '>=' ) + ) { + $text = wikidiff2_do_diff( + $otext, + $ntext, + 2, + $this->getConfig()->get( 'WikiDiff2MovedParagraphDetectionCutoff' ) + ); + } else { + // Don't pass the 4th parameter for compatibility with older versions of wikidiff2 + $text = wikidiff2_do_diff( + $otext, + $ntext, + 2 + ); + + // Log a warning in case the configuration value is set to not silently ignore it + if ( $this->getConfig()->get( 'WikiDiff2MovedParagraphDetectionCutoff' ) > 0 ) { + wfLogWarning( '$wgWikiDiff2MovedParagraphDetectionCutoff is set but has no + effect since the used version of WikiDiff2 does not support it.' ); + } + } + + $text .= $this->debug( 'wikidiff2' ); + + return $text; + } elseif ( $engine !== false ) { + # Diff via the shell + $tmpDir = wfTempDir(); + $tempName1 = tempnam( $tmpDir, 'diff_' ); + $tempName2 = tempnam( $tmpDir, 'diff_' ); + + $tempFile1 = fopen( $tempName1, "w" ); + if ( !$tempFile1 ) { + return false; + } + $tempFile2 = fopen( $tempName2, "w" ); + if ( !$tempFile2 ) { + return false; + } + fwrite( $tempFile1, $otext ); + fwrite( $tempFile2, $ntext ); + fclose( $tempFile1 ); + fclose( $tempFile2 ); + $cmd = [ $engine, $tempName1, $tempName2 ]; + $result = Shell::command( $cmd ) + ->execute(); + $exitCode = $result->getExitCode(); + if ( $exitCode !== 0 ) { + throw new Exception( "External diff command returned code {$exitCode}. Stderr: " + . wfEscapeWikiText( $result->getStderr() ) + ); + } + $difftext = $result->getStdout(); + $difftext .= $this->debug( "external $engine" ); + unlink( $tempName1 ); + unlink( $tempName2 ); + + return $difftext; + } + + # Native PHP diff + $ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) ); + $nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) ); + $diffs = new Diff( $ota, $nta ); + $formatter = new TableDiffFormatter(); + $difftext = $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ); + $difftext .= $this->debug( 'native PHP' ); + + return $difftext; + } + + /** + * Generate a debug comment indicating diff generating time, + * server node, and generator backend. + * + * @param string $generator : What diff engine was used + * + * @return string + */ + protected function debug( $generator = "internal" ) { + global $wgShowHostnames; + if ( !$this->enableDebugComment ) { + return ''; + } + $data = [ $generator ]; + if ( $wgShowHostnames ) { + $data[] = wfHostname(); + } + $data[] = wfTimestamp( TS_DB ); + + return "<!-- diff generator: " . + implode( " ", array_map( "htmlspecialchars", $data ) ) . + " -->\n"; + } + + /** + * Localise diff output + * + * @param string $text + * @return string + */ + private function localiseDiff( $text ) { + $text = $this->localiseLineNumbers( $text ); + if ( $this->getEngine() === 'wikidiff2' && + version_compare( phpversion( 'wikidiff2' ), '1.5.1', '>=' ) + ) { + $text = $this->addLocalisedTitleTooltips( $text ); + } + return $text; + } + + /** + * Replace line numbers with the text in the user's language + * + * @param string $text + * + * @return mixed + */ + public function localiseLineNumbers( $text ) { + return preg_replace_callback( + '/<!--LINE (\d+)-->/', + [ $this, 'localiseLineNumbersCb' ], + $text + ); + } + + public function localiseLineNumbersCb( $matches ) { + if ( $matches[1] === '1' && $this->mReducedLineNumbers ) { + return ''; + } + + return $this->msg( 'lineno' )->numParams( $matches[1] )->escaped(); + } + + /** + * Add title attributes for tooltips on moved paragraph indicators + * + * @param string $text + * @return string + */ + private function addLocalisedTitleTooltips( $text ) { + return preg_replace_callback( + '/class="mw-diff-movedpara-(left|right)"/', + [ $this, 'addLocalisedTitleTooltipsCb' ], + $text + ); + } + + /** + * @param array $matches + * @return string + */ + private function addLocalisedTitleTooltipsCb( array $matches ) { + $key = $matches[1] === 'right' ? + 'diff-paragraph-moved-toold' : + 'diff-paragraph-moved-tonew'; + return $matches[0] . ' title="' . $this->msg( $key )->escaped() . '"'; + } + + /** + * If there are revisions between the ones being compared, return a note saying so. + * + * @return string + */ + public function getMultiNotice() { + if ( !is_object( $this->mOldRev ) || !is_object( $this->mNewRev ) ) { + return ''; + } elseif ( !$this->mOldPage->equals( $this->mNewPage ) ) { + // Comparing two different pages? Count would be meaningless. + return ''; + } + + if ( $this->mOldRev->getTimestamp() > $this->mNewRev->getTimestamp() ) { + $oldRev = $this->mNewRev; // flip + $newRev = $this->mOldRev; // flip + } else { // normal case + $oldRev = $this->mOldRev; + $newRev = $this->mNewRev; + } + + // Sanity: don't show the notice if too many rows must be scanned + // @todo show some special message for that case + $nEdits = $this->mNewPage->countRevisionsBetween( $oldRev, $newRev, 1000 ); + if ( $nEdits > 0 && $nEdits <= 1000 ) { + $limit = 100; // use diff-multi-manyusers if too many users + $users = $this->mNewPage->getAuthorsBetween( $oldRev, $newRev, $limit ); + $numUsers = count( $users ); + + if ( $numUsers == 1 && $users[0] == $newRev->getUserText( Revision::RAW ) ) { + $numUsers = 0; // special case to say "by the same user" instead of "by one other user" + } + + return self::intermediateEditsMsg( $nEdits, $numUsers, $limit ); + } + + return ''; // nothing + } + + /** + * Get a notice about how many intermediate edits and users there are + * + * @param int $numEdits + * @param int $numUsers + * @param int $limit + * + * @return string + */ + public static function intermediateEditsMsg( $numEdits, $numUsers, $limit ) { + if ( $numUsers === 0 ) { + $msg = 'diff-multi-sameuser'; + } elseif ( $numUsers > $limit ) { + $msg = 'diff-multi-manyusers'; + $numUsers = $limit; + } else { + $msg = 'diff-multi-otherusers'; + } + + return wfMessage( $msg )->numParams( $numEdits, $numUsers )->parse(); + } + + /** + * Get a header for a specified revision. + * + * @param Revision $rev + * @param string $complete 'complete' to get the header wrapped depending + * the visibility of the revision and a link to edit the page. + * + * @return string HTML fragment + */ + public function getRevisionHeader( Revision $rev, $complete = '' ) { + $lang = $this->getLanguage(); + $user = $this->getUser(); + $revtimestamp = $rev->getTimestamp(); + $timestamp = $lang->userTimeAndDate( $revtimestamp, $user ); + $dateofrev = $lang->userDate( $revtimestamp, $user ); + $timeofrev = $lang->userTime( $revtimestamp, $user ); + + $header = $this->msg( + $rev->isCurrent() ? 'currentrev-asof' : 'revisionasof', + $timestamp, + $dateofrev, + $timeofrev + )->escaped(); + + if ( $complete !== 'complete' ) { + return $header; + } + + $title = $rev->getTitle(); + + $header = Linker::linkKnown( $title, $header, [], + [ 'oldid' => $rev->getId() ] ); + + if ( $rev->userCan( Revision::DELETED_TEXT, $user ) ) { + $editQuery = [ 'action' => 'edit' ]; + if ( !$rev->isCurrent() ) { + $editQuery['oldid'] = $rev->getId(); + } + + $key = $title->quickUserCan( 'edit', $user ) ? 'editold' : 'viewsourceold'; + $msg = $this->msg( $key )->escaped(); + $editLink = $this->msg( 'parentheses' )->rawParams( + Linker::linkKnown( $title, $msg, [], $editQuery ) )->escaped(); + $header .= ' ' . Html::rawElement( + 'span', + [ 'class' => 'mw-diff-edit' ], + $editLink + ); + if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) { + $header = Html::rawElement( + 'span', + [ 'class' => 'history-deleted' ], + $header + ); + } + } else { + $header = Html::rawElement( 'span', [ 'class' => 'history-deleted' ], $header ); + } + + return $header; + } + + /** + * Add the header to a diff body + * + * @param string $diff Diff body + * @param string $otitle Old revision header + * @param string $ntitle New revision header + * @param string $multi Notice telling user that there are intermediate + * revisions between the ones being compared + * @param string $notice Other notices, e.g. that user is viewing deleted content + * + * @return string + */ + public function addHeader( $diff, $otitle, $ntitle, $multi = '', $notice = '' ) { + // shared.css sets diff in interface language/dir, but the actual content + // is often in a different language, mostly the page content language/dir + $header = Html::openElement( 'table', [ + 'class' => [ 'diff', 'diff-contentalign-' . $this->getDiffLang()->alignStart() ], + 'data-mw' => 'interface', + ] ); + $userLang = htmlspecialchars( $this->getLanguage()->getHtmlCode() ); + + if ( !$diff && !$otitle ) { + $header .= " + <tr class=\"diff-title\" lang=\"{$userLang}\"> + <td class=\"diff-ntitle\">{$ntitle}</td> + </tr>"; + $multiColspan = 1; + } else { + if ( $diff ) { // Safari/Chrome show broken output if cols not used + $header .= " + <col class=\"diff-marker\" /> + <col class=\"diff-content\" /> + <col class=\"diff-marker\" /> + <col class=\"diff-content\" />"; + $colspan = 2; + $multiColspan = 4; + } else { + $colspan = 1; + $multiColspan = 2; + } + if ( $otitle || $ntitle ) { + $header .= " + <tr class=\"diff-title\" lang=\"{$userLang}\"> + <td colspan=\"$colspan\" class=\"diff-otitle\">{$otitle}</td> + <td colspan=\"$colspan\" class=\"diff-ntitle\">{$ntitle}</td> + </tr>"; + } + } + + if ( $multi != '' ) { + $header .= "<tr><td colspan=\"{$multiColspan}\" " . + "class=\"diff-multi\" lang=\"{$userLang}\">{$multi}</td></tr>"; + } + if ( $notice != '' ) { + $header .= "<tr><td colspan=\"{$multiColspan}\" " . + "class=\"diff-notice\" lang=\"{$userLang}\">{$notice}</td></tr>"; + } + + return $header . $diff . "</table>"; + } + + /** + * Use specified text instead of loading from the database + * @param Content $oldContent + * @param Content $newContent + * @since 1.21 + */ + public function setContent( Content $oldContent, Content $newContent ) { + $this->mOldContent = $oldContent; + $this->mNewContent = $newContent; + + $this->mTextLoaded = 2; + $this->mRevisionsLoaded = true; + } + + /** + * Set the language in which the diff text is written + * (Defaults to page content language). + * @param Language|string $lang + * @since 1.19 + */ + public function setTextLanguage( $lang ) { + $this->mDiffLang = wfGetLangObj( $lang ); + } + + /** + * Maps a revision pair definition as accepted by DifferenceEngine constructor + * to a pair of actual integers representing revision ids. + * + * @param int $old Revision id, e.g. from URL parameter 'oldid' + * @param int|string $new Revision id or strings 'next' or 'prev', e.g. from URL parameter 'diff' + * + * @return int[] List of two revision ids, older first, later second. + * Zero signifies invalid argument passed. + * false signifies that there is no previous/next revision ($old is the oldest/newest one). + */ + public function mapDiffPrevNext( $old, $new ) { + if ( $new === 'prev' ) { + // Show diff between revision $old and the previous one. Get previous one from DB. + $newid = intval( $old ); + $oldid = $this->getTitle()->getPreviousRevisionID( $newid ); + } elseif ( $new === 'next' ) { + // Show diff between revision $old and the next one. Get next one from DB. + $oldid = intval( $old ); + $newid = $this->getTitle()->getNextRevisionID( $oldid ); + } else { + $oldid = intval( $old ); + $newid = intval( $new ); + } + + return [ $oldid, $newid ]; + } + + /** + * Load revision IDs + */ + private function loadRevisionIds() { + if ( $this->mRevisionsIdsLoaded ) { + return; + } + + $this->mRevisionsIdsLoaded = true; + + $old = $this->mOldid; + $new = $this->mNewid; + + list( $this->mOldid, $this->mNewid ) = self::mapDiffPrevNext( $old, $new ); + if ( $new === 'next' && $this->mNewid === false ) { + # if no result, NewId points to the newest old revision. The only newer + # revision is cur, which is "0". + $this->mNewid = 0; + } + + Hooks::run( + 'NewDifferenceEngine', + [ $this->getTitle(), &$this->mOldid, &$this->mNewid, $old, $new ] + ); + } + + /** + * Load revision metadata for the specified articles. If newid is 0, then compare + * the old article in oldid to the current article; if oldid is 0, then + * compare the current article to the immediately previous one (ignoring the + * value of newid). + * + * If oldid is false, leave the corresponding revision object set + * to false. This is impossible via ordinary user input, and is provided for + * API convenience. + * + * @return bool + */ + public function loadRevisionData() { + if ( $this->mRevisionsLoaded ) { + return true; + } + + // Whether it succeeds or fails, we don't want to try again + $this->mRevisionsLoaded = true; + + $this->loadRevisionIds(); + + // Load the new revision object + if ( $this->mNewid ) { + $this->mNewRev = Revision::newFromId( $this->mNewid ); + } else { + $this->mNewRev = Revision::newFromTitle( + $this->getTitle(), + false, + Revision::READ_NORMAL + ); + } + + if ( !$this->mNewRev instanceof Revision ) { + return false; + } + + // Update the new revision ID in case it was 0 (makes life easier doing UI stuff) + $this->mNewid = $this->mNewRev->getId(); + $this->mNewPage = $this->mNewRev->getTitle(); + + // Load the old revision object + $this->mOldRev = false; + if ( $this->mOldid ) { + $this->mOldRev = Revision::newFromId( $this->mOldid ); + } elseif ( $this->mOldid === 0 ) { + $rev = $this->mNewRev->getPrevious(); + if ( $rev ) { + $this->mOldid = $rev->getId(); + $this->mOldRev = $rev; + } else { + // No previous revision; mark to show as first-version only. + $this->mOldid = false; + $this->mOldRev = false; + } + } /* elseif ( $this->mOldid === false ) leave mOldRev false; */ + + if ( is_null( $this->mOldRev ) ) { + return false; + } + + if ( $this->mOldRev ) { + $this->mOldPage = $this->mOldRev->getTitle(); + } + + // Load tags information for both revisions + $dbr = wfGetDB( DB_REPLICA ); + if ( $this->mOldid !== false ) { + $this->mOldTags = $dbr->selectField( + 'tag_summary', + 'ts_tags', + [ 'ts_rev_id' => $this->mOldid ], + __METHOD__ + ); + } else { + $this->mOldTags = false; + } + $this->mNewTags = $dbr->selectField( + 'tag_summary', + 'ts_tags', + [ 'ts_rev_id' => $this->mNewid ], + __METHOD__ + ); + + return true; + } + + /** + * Load the text of the revisions, as well as revision data. + * + * @return bool + */ + public function loadText() { + if ( $this->mTextLoaded == 2 ) { + return true; + } + + // Whether it succeeds or fails, we don't want to try again + $this->mTextLoaded = 2; + + if ( !$this->loadRevisionData() ) { + return false; + } + + if ( $this->mOldRev ) { + $this->mOldContent = $this->mOldRev->getContent( Revision::FOR_THIS_USER, $this->getUser() ); + if ( $this->mOldContent === null ) { + return false; + } + } + + if ( $this->mNewRev ) { + $this->mNewContent = $this->mNewRev->getContent( Revision::FOR_THIS_USER, $this->getUser() ); + Hooks::run( 'DifferenceEngineLoadTextAfterNewContentIsLoaded', [ $this ] ); + if ( $this->mNewContent === null ) { + return false; + } + } + + return true; + } + + /** + * Load the text of the new revision, not the old one + * + * @return bool + */ + public function loadNewText() { + if ( $this->mTextLoaded >= 1 ) { + return true; + } + + $this->mTextLoaded = 1; + + if ( !$this->loadRevisionData() ) { + return false; + } + + $this->mNewContent = $this->mNewRev->getContent( Revision::FOR_THIS_USER, $this->getUser() ); + + Hooks::run( 'DifferenceEngineAfterLoadNewText', [ $this ] ); + + return true; + } + +} |