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+<?php
+/**
+ * See diff.doc
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+
+/** */
+define( 'MAX_DIFF_LINE', 10000 );
+define( 'MAX_DIFF_XREF_LENGTH', 10000 );
+
+/**
+ * @todo document
+ * @public
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class DifferenceEngine {
+ /**#@+
+ * @private
+ */
+ var $mOldid, $mNewid, $mTitle;
+ var $mOldtitle, $mNewtitle, $mPagetitle;
+ var $mOldtext, $mNewtext;
+ var $mOldPage, $mNewPage;
+ var $mRcidMarkPatrolled;
+ var $mOldRev, $mNewRev;
+ var $mRevisionsLoaded = false; // Have the revisions been loaded
+ var $mTextLoaded = 0; // How many text blobs have been loaded, 0, 1 or 2?
+ /**#@-*/
+
+ /**
+ * Constructor
+ * @param $titleObj Title object that the diff is associated with
+ * @param $old Integer: old ID we want to show and diff with.
+ * @param $new String: either 'prev' or 'next'.
+ * @param $rcid Integer: ??? FIXME (default 0)
+ */
+ function DifferenceEngine( $titleObj = null, $old = 0, $new = 0, $rcid = 0 ) {
+ $this->mTitle = $titleObj;
+ wfDebug("DifferenceEngine old '$old' new '$new' rcid '$rcid'\n");
+
+ if ( 'prev' === $new ) {
+ # Show diff between revision $old and the previous one.
+ # Get previous one from DB.
+ #
+ $this->mNewid = intval($old);
+
+ $this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid );
+
+ } elseif ( 'next' === $new ) {
+ # Show diff between revision $old and the previous one.
+ # Get previous one from DB.
+ #
+ $this->mOldid = intval($old);
+ $this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid );
+ if ( false === $this->mNewid ) {
+ # if no result, NewId points to the newest old revision. The only newer
+ # revision is cur, which is "0".
+ $this->mNewid = 0;
+ }
+
+ } else {
+ $this->mOldid = intval($old);
+ $this->mNewid = intval($new);
+ }
+ $this->mRcidMarkPatrolled = intval($rcid); # force it to be an integer
+ }
+
+ function showDiffPage() {
+ global $wgUser, $wgOut, $wgContLang, $wgUseExternalEditor, $wgUseRCPatrol;
+ $fname = 'DifferenceEngine::showDiffPage';
+ wfProfileIn( $fname );
+
+ # If external diffs are enabled both globally and for the user,
+ # we'll use the application/x-external-editor interface to call
+ # an external diff tool like kompare, kdiff3, etc.
+ if($wgUseExternalEditor && $wgUser->getOption('externaldiff')) {
+ global $wgInputEncoding,$wgServer,$wgScript,$wgLang;
+ $wgOut->disable();
+ header ( "Content-type: application/x-external-editor; charset=".$wgInputEncoding );
+ $url1=$this->mTitle->getFullURL("action=raw&oldid=".$this->mOldid);
+ $url2=$this->mTitle->getFullURL("action=raw&oldid=".$this->mNewid);
+ $special=$wgLang->getNsText(NS_SPECIAL);
+ $control=<<<CONTROL
+[Process]
+Type=Diff text
+Engine=MediaWiki
+Script={$wgServer}{$wgScript}
+Special namespace={$special}
+
+[File]
+Extension=wiki
+URL=$url1
+
+[File 2]
+Extension=wiki
+URL=$url2
+CONTROL;
+ echo($control);
+ return;
+ }
+
+ $t = $this->mTitle->getPrefixedText() . " (Diff: {$this->mOldid}, " .
+ "{$this->mNewid})";
+ $mtext = wfMsg( 'missingarticle', "<nowiki>$t</nowiki>" );
+
+ $wgOut->setArticleFlag( false );
+ if ( ! $this->loadRevisionData() ) {
+ $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
+ $wgOut->addWikitext( $mtext );
+ wfProfileOut( $fname );
+ return;
+ }
+
+ wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
+
+ if ( $this->mNewRev->isCurrent() ) {
+ $wgOut->setArticleFlag( true );
+ }
+
+ # mOldid 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->mOldid === false ) {
+ $this->showFirstRevision();
+ wfProfileOut( $fname );
+ return;
+ }
+
+ $wgOut->suppressQuickbar();
+
+ $oldTitle = $this->mOldPage->getPrefixedText();
+ $newTitle = $this->mNewPage->getPrefixedText();
+ if( $oldTitle == $newTitle ) {
+ $wgOut->setPageTitle( $newTitle );
+ } else {
+ $wgOut->setPageTitle( $oldTitle . ', ' . $newTitle );
+ }
+ $wgOut->setSubtitle( wfMsg( 'difference' ) );
+ $wgOut->setRobotpolicy( 'noindex,nofollow' );
+
+ if ( !( $this->mOldPage->userCanRead() && $this->mNewPage->userCanRead() ) ) {
+ $wgOut->loginToUse();
+ $wgOut->output();
+ wfProfileOut( $fname );
+ exit;
+ }
+
+ $sk = $wgUser->getSkin();
+ $talk = $wgContLang->getNsText( NS_TALK );
+ $contribs = wfMsg( 'contribslink' );
+
+ if ( $this->mNewRev->isCurrent() && $wgUser->isAllowed('rollback') ) {
+ $username = $this->mNewRev->getUserText();
+ $rollback = '&nbsp;&nbsp;&nbsp;<strong>[' . $sk->makeKnownLinkObj( $this->mTitle, wfMsg( 'rollbacklink' ),
+ 'action=rollback&from=' . urlencode( $username ) .
+ '&token=' . urlencode( $wgUser->editToken( array( $this->mTitle->getPrefixedText(), $username ) ) ) ) .
+ ']</strong>';
+ } else {
+ $rollback = '';
+ }
+ if( $wgUseRCPatrol && $this->mRcidMarkPatrolled != 0 && $wgUser->isAllowed( 'patrol' ) ) {
+ $patrol = ' [' . $sk->makeKnownLinkObj( $this->mTitle, wfMsg( 'markaspatrolleddiff' ), "action=markpatrolled&rcid={$this->mRcidMarkPatrolled}" ) . ']';
+ } else {
+ $patrol = '';
+ }
+
+ $prevlink = $sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'previousdiff' ),
+ 'diff=prev&oldid='.$this->mOldid, '', '', 'id="differences-prevlink"' );
+ if ( $this->mNewRev->isCurrent() ) {
+ $nextlink = '&nbsp;';
+ } else {
+ $nextlink = $sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'nextdiff' ),
+ 'diff=next&oldid='.$this->mNewid, '', '', 'id="differences-nextlink"' );
+ }
+
+ $oldHeader = "<strong>{$this->mOldtitle}</strong><br />" .
+ $sk->revUserTools( $this->mOldRev ) . "<br />" .
+ $sk->revComment( $this->mOldRev ) . "<br />" .
+ $prevlink;
+ $newHeader = "<strong>{$this->mNewtitle}</strong><br />" .
+ $sk->revUserTools( $this->mNewRev ) . " $rollback<br />" .
+ $sk->revComment( $this->mNewRev ) . "<br />" .
+ $nextlink . $patrol;
+
+ $this->showDiff( $oldHeader, $newHeader );
+ $wgOut->addHTML( "<hr /><h2>{$this->mPagetitle}</h2>\n" );
+
+ if( !$this->mNewRev->isCurrent() ) {
+ $oldEditSectionSetting = $wgOut->mParserOptions->setEditSection( false );
+ }
+
+ $this->loadNewText();
+ if( is_object( $this->mNewRev ) ) {
+ $wgOut->setRevisionId( $this->mNewRev->getId() );
+ }
+ $wgOut->addSecondaryWikiText( $this->mNewtext );
+
+ if( !$this->mNewRev->isCurrent() ) {
+ $wgOut->mParserOptions->setEditSection( $oldEditSectionSetting );
+ }
+
+ wfProfileOut( $fname );
+ }
+
+ /**
+ * Show the first revision of an article. Uses normal diff headers in
+ * contrast to normal "old revision" display style.
+ */
+ function showFirstRevision() {
+ global $wgOut, $wgUser;
+
+ $fname = 'DifferenceEngine::showFirstRevision';
+ wfProfileIn( $fname );
+
+ # Get article text from the DB
+ #
+ if ( ! $this->loadNewText() ) {
+ $t = $this->mTitle->getPrefixedText() . " (Diff: {$this->mOldid}, " .
+ "{$this->mNewid})";
+ $mtext = wfMsg( 'missingarticle', "<nowiki>$t</nowiki>" );
+ $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
+ $wgOut->addWikitext( $mtext );
+ wfProfileOut( $fname );
+ return;
+ }
+ if ( $this->mNewRev->isCurrent() ) {
+ $wgOut->setArticleFlag( true );
+ }
+
+ # Check if user is allowed to look at this page. If not, bail out.
+ #
+ if ( !( $this->mTitle->userCanRead() ) ) {
+ $wgOut->loginToUse();
+ $wgOut->output();
+ wfProfileOut( $fname );
+ exit;
+ }
+
+ # Prepare the header box
+ #
+ $sk = $wgUser->getSkin();
+
+ $nextlink = $sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'nextdiff' ), 'diff=next&oldid='.$this->mNewid, '', '', 'id="differences-nextlink"' );
+ $header = "<div class=\"firstrevisionheader\" style=\"text-align: center\"><strong>{$this->mOldtitle}</strong><br />" .
+ $sk->revUserTools( $this->mNewRev ) . "<br />" .
+ $sk->revComment( $this->mNewRev ) . "<br />" .
+ $nextlink . "</div>\n";
+
+ $wgOut->addHTML( $header );
+
+ $wgOut->setSubtitle( wfMsg( 'difference' ) );
+ $wgOut->setRobotpolicy( 'noindex,nofollow' );
+
+
+ # Show current revision
+ #
+ $wgOut->addHTML( "<hr /><h2>{$this->mPagetitle}</h2>\n" );
+ if( is_object( $this->mNewRev ) ) {
+ $wgOut->setRevisionId( $this->mNewRev->getId() );
+ }
+ $wgOut->addSecondaryWikiText( $this->mNewtext );
+
+ wfProfileOut( $fname );
+ }
+
+ /**
+ * Get the diff text, send it to $wgOut
+ * Returns false if the diff could not be generated, otherwise returns true
+ */
+ function showDiff( $otitle, $ntitle ) {
+ global $wgOut;
+ $diff = $this->getDiff( $otitle, $ntitle );
+ if ( $diff === false ) {
+ $wgOut->addWikitext( wfMsg( 'missingarticle', "<nowiki>(fixme, bug)</nowiki>" ) );
+ return false;
+ } else {
+ $wgOut->addHTML( $diff );
+ return true;
+ }
+ }
+
+ /**
+ * Get diff table, including header
+ * Note that the interface has changed, it's no longer static.
+ * Returns false on error
+ */
+ function getDiff( $otitle, $ntitle ) {
+ $body = $this->getDiffBody();
+ if ( $body === false ) {
+ return false;
+ } else {
+ return $this->addHeader( $body, $otitle, $ntitle );
+ }
+ }
+
+ /**
+ * Get the diff table body, without header
+ * Results are cached
+ * Returns false on error
+ */
+ function getDiffBody() {
+ global $wgMemc, $wgDBname;
+ $fname = 'DifferenceEngine::getDiffBody';
+ wfProfileIn( $fname );
+
+ // Cacheable?
+ $key = false;
+ if ( $this->mOldid && $this->mNewid ) {
+ // Try cache
+ $key = "$wgDBname:diff:oldid:{$this->mOldid}:newid:{$this->mNewid}";
+ $difftext = $wgMemc->get( $key );
+ if ( $difftext ) {
+ wfIncrStats( 'diff_cache_hit' );
+ $difftext = $this->localiseLineNumbers( $difftext );
+ $difftext .= "\n<!-- diff cache key $key -->\n";
+ wfProfileOut( $fname );
+ return $difftext;
+ }
+ }
+
+ if ( !$this->loadText() ) {
+ wfProfileOut( $fname );
+ return false;
+ }
+
+ $difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
+
+ // Save to cache for 7 days
+ if ( $key !== false && $difftext !== false ) {
+ wfIncrStats( 'diff_cache_miss' );
+ $wgMemc->set( $key, $difftext, 7*86400 );
+ } else {
+ wfIncrStats( 'diff_uncacheable' );
+ }
+ // Replace line numbers with the text in the user's language
+ if ( $difftext !== false ) {
+ $difftext = $this->localiseLineNumbers( $difftext );
+ }
+ wfProfileOut( $fname );
+ return $difftext;
+ }
+
+ /**
+ * Generate a diff, no caching
+ * $otext and $ntext must be already segmented
+ */
+ function generateDiffBody( $otext, $ntext ) {
+ global $wgExternalDiffEngine, $wgContLang;
+ $fname = 'DifferenceEngine::generateDiffBody';
+
+ $otext = str_replace( "\r\n", "\n", $otext );
+ $ntext = str_replace( "\r\n", "\n", $ntext );
+
+ if ( $wgExternalDiffEngine == 'wikidiff' ) {
+ # For historical reasons, external diff engine expects
+ # input text to be HTML-escaped already
+ $otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
+ $ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
+ if( !function_exists( 'wikidiff_do_diff' ) ) {
+ dl('php_wikidiff.so');
+ }
+ return $wgContLang->unsegementForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) );
+ }
+
+ if ( $wgExternalDiffEngine == 'wikidiff2' ) {
+ # Better external diff engine, the 2 may some day be dropped
+ # This one does the escaping and segmenting itself
+ if ( !function_exists( 'wikidiff2_do_diff' ) ) {
+ wfProfileIn( "$fname-dl" );
+ @dl('php_wikidiff2.so');
+ wfProfileOut( "$fname-dl" );
+ }
+ if ( function_exists( 'wikidiff2_do_diff' ) ) {
+ wfProfileIn( 'wikidiff2_do_diff' );
+ $text = wikidiff2_do_diff( $otext, $ntext, 2 );
+ wfProfileOut( 'wikidiff2_do_diff' );
+ return $text;
+ }
+ }
+ if ( $wgExternalDiffEngine !== false ) {
+ # Diff via the shell
+ global $wgTmpDirectory;
+ $tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
+ $tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
+
+ $tempFile1 = fopen( $tempName1, "w" );
+ if ( !$tempFile1 ) {
+ wfProfileOut( $fname );
+ return false;
+ }
+ $tempFile2 = fopen( $tempName2, "w" );
+ if ( !$tempFile2 ) {
+ wfProfileOut( $fname );
+ return false;
+ }
+ fwrite( $tempFile1, $otext );
+ fwrite( $tempFile2, $ntext );
+ fclose( $tempFile1 );
+ fclose( $tempFile2 );
+ $cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
+ wfProfileIn( "$fname-shellexec" );
+ $difftext = wfShellExec( $cmd );
+ wfProfileOut( "$fname-shellexec" );
+ 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();
+ return $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) );
+ }
+
+
+ /**
+ * Replace line numbers with the text in the user's language
+ */
+ function localiseLineNumbers( $text ) {
+ return preg_replace_callback( '/<!--LINE (\d+)-->/',
+ array( &$this, 'localiseLineNumbersCb' ), $text );
+ }
+
+ function localiseLineNumbersCb( $matches ) {
+ global $wgLang;
+ return wfMsgExt( 'lineno', array('parseinline'), $wgLang->formatNum( $matches[1] ) );
+ }
+
+ /**
+ * Add the header to a diff body
+ */
+ function addHeader( $diff, $otitle, $ntitle ) {
+ $out = "
+ <table border='0' width='98%' cellpadding='0' cellspacing='4' class='diff'>
+ <tr>
+ <td colspan='2' width='50%' align='center' class='diff-otitle'>{$otitle}</td>
+ <td colspan='2' width='50%' align='center' class='diff-ntitle'>{$ntitle}</td>
+ </tr>
+ $diff
+ </table>
+ ";
+ return $out;
+ }
+
+ /**
+ * Use specified text instead of loading from the database
+ */
+ function setText( $oldText, $newText ) {
+ $this->mOldtext = $oldText;
+ $this->mNewtext = $newText;
+ $this->mTextLoaded = 2;
+ }
+
+ /**
+ * 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.
+ */
+ function loadRevisionData() {
+ global $wgLang;
+ if ( $this->mRevisionsLoaded ) {
+ return true;
+ } else {
+ // Whether it succeeds or fails, we don't want to try again
+ $this->mRevisionsLoaded = true;
+ }
+
+ // Load the new revision object
+ if( $this->mNewid ) {
+ $this->mNewRev = Revision::newFromId( $this->mNewid );
+ } else {
+ $this->mNewRev = Revision::newFromTitle( $this->mTitle );
+ }
+
+ if( is_null( $this->mNewRev ) ) {
+ return false;
+ }
+
+ // Set assorted variables
+ $timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
+ $this->mNewPage = $this->mNewRev->getTitle();
+ if( $this->mNewRev->isCurrent() ) {
+ $newLink = $this->mNewPage->escapeLocalUrl();
+ $this->mPagetitle = htmlspecialchars( wfMsg( 'currentrev' ) );
+ $newEdit = $this->mNewPage->escapeLocalUrl( 'action=edit' );
+
+ $this->mNewtitle = "<strong><a href='$newLink'>{$this->mPagetitle}</a> ($timestamp)</strong>"
+ . " (<a href='$newEdit'>" . htmlspecialchars( wfMsg( 'editold' ) ) . "</a>)";
+
+ } else {
+ $newLink = $this->mNewPage->escapeLocalUrl( 'oldid=' . $this->mNewid );
+ $newEdit = $this->mNewPage->escapeLocalUrl( 'action=edit&oldid=' . $this->mNewid );
+ $this->mPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $timestamp ) );
+
+ $this->mNewtitle = "<strong><a href='$newLink'>{$this->mPagetitle}</a></strong>"
+ . " (<a href='$newEdit'>" . htmlspecialchars( wfMsg( 'editold' ) ) . "</a>)";
+ }
+
+ // 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();
+
+ $t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
+ $oldLink = $this->mOldPage->escapeLocalUrl( 'oldid=' . $this->mOldid );
+ $oldEdit = $this->mOldPage->escapeLocalUrl( 'action=edit&oldid=' . $this->mOldid );
+ $this->mOldtitle = "<strong><a href='$oldLink'>" . htmlspecialchars( wfMsg( 'revisionasof', $t ) )
+ . "</a></strong> (<a href='$oldEdit'>" . htmlspecialchars( wfMsg( 'editold' ) ) . "</a>)";
+ }
+
+ return true;
+ }
+
+ /**
+ * Load the text of the revisions, as well as revision data.
+ */
+ function loadText() {
+ if ( $this->mTextLoaded == 2 ) {
+ return true;
+ } else {
+ // Whether it succeeds or fails, we don't want to try again
+ $this->mTextLoaded = 2;
+ }
+
+ if ( !$this->loadRevisionData() ) {
+ return false;
+ }
+ if ( $this->mOldRev ) {
+ // FIXME: permission tests
+ $this->mOldtext = $this->mOldRev->getText();
+ if ( $this->mOldtext === false ) {
+ return false;
+ }
+ }
+ if ( $this->mNewRev ) {
+ $this->mNewtext = $this->mNewRev->getText();
+ if ( $this->mNewtext === false ) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Load the text of the new revision, not the old one
+ */
+ function loadNewText() {
+ if ( $this->mTextLoaded >= 1 ) {
+ return true;
+ } else {
+ $this->mTextLoaded = 1;
+ }
+ if ( !$this->loadRevisionData() ) {
+ return false;
+ }
+ $this->mNewtext = $this->mNewRev->getText();
+ return true;
+ }
+
+
+}
+
+// A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
+//
+// Copyright (C) 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org>
+// You may copy this code freely under the conditions of the GPL.
+//
+
+define('USE_ASSERTS', function_exists('assert'));
+
+/**
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class _DiffOp {
+ var $type;
+ var $orig;
+ var $closing;
+
+ function reverse() {
+ trigger_error('pure virtual', E_USER_ERROR);
+ }
+
+ function norig() {
+ return $this->orig ? sizeof($this->orig) : 0;
+ }
+
+ function nclosing() {
+ return $this->closing ? sizeof($this->closing) : 0;
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class _DiffOp_Copy extends _DiffOp {
+ var $type = 'copy';
+
+ function _DiffOp_Copy ($orig, $closing = false) {
+ if (!is_array($closing))
+ $closing = $orig;
+ $this->orig = $orig;
+ $this->closing = $closing;
+ }
+
+ function reverse() {
+ return new _DiffOp_Copy($this->closing, $this->orig);
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class _DiffOp_Delete extends _DiffOp {
+ var $type = 'delete';
+
+ function _DiffOp_Delete ($lines) {
+ $this->orig = $lines;
+ $this->closing = false;
+ }
+
+ function reverse() {
+ return new _DiffOp_Add($this->orig);
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class _DiffOp_Add extends _DiffOp {
+ var $type = 'add';
+
+ function _DiffOp_Add ($lines) {
+ $this->closing = $lines;
+ $this->orig = false;
+ }
+
+ function reverse() {
+ return new _DiffOp_Delete($this->closing);
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class _DiffOp_Change extends _DiffOp {
+ var $type = 'change';
+
+ function _DiffOp_Change ($orig, $closing) {
+ $this->orig = $orig;
+ $this->closing = $closing;
+ }
+
+ function reverse() {
+ return new _DiffOp_Change($this->closing, $this->orig);
+ }
+}
+
+
+/**
+ * Class used internally by Diff to actually compute the diffs.
+ *
+ * The algorithm used here is mostly lifted from the perl module
+ * Algorithm::Diff (version 1.06) by Ned Konz, which is available at:
+ * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip
+ *
+ * More ideas are taken from:
+ * http://www.ics.uci.edu/~eppstein/161/960229.html
+ *
+ * Some ideas are (and a bit of code) are from from analyze.c, from GNU
+ * diffutils-2.7, which can be found at:
+ * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz
+ *
+ * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations)
+ * are my own.
+ *
+ * Line length limits for robustness added by Tim Starling, 2005-08-31
+ *
+ * @author Geoffrey T. Dairiki, Tim Starling
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class _DiffEngine
+{
+ function diff ($from_lines, $to_lines) {
+ $fname = '_DiffEngine::diff';
+ wfProfileIn( $fname );
+
+ $n_from = sizeof($from_lines);
+ $n_to = sizeof($to_lines);
+
+ $this->xchanged = $this->ychanged = array();
+ $this->xv = $this->yv = array();
+ $this->xind = $this->yind = array();
+ unset($this->seq);
+ unset($this->in_seq);
+ unset($this->lcs);
+
+ // Skip leading common lines.
+ for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) {
+ if ($from_lines[$skip] !== $to_lines[$skip])
+ break;
+ $this->xchanged[$skip] = $this->ychanged[$skip] = false;
+ }
+ // Skip trailing common lines.
+ $xi = $n_from; $yi = $n_to;
+ for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) {
+ if ($from_lines[$xi] !== $to_lines[$yi])
+ break;
+ $this->xchanged[$xi] = $this->ychanged[$yi] = false;
+ }
+
+ // Ignore lines which do not exist in both files.
+ for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
+ $xhash[$this->_line_hash($from_lines[$xi])] = 1;
+ }
+
+ for ($yi = $skip; $yi < $n_to - $endskip; $yi++) {
+ $line = $to_lines[$yi];
+ if ( ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) )
+ continue;
+ $yhash[$this->_line_hash($line)] = 1;
+ $this->yv[] = $line;
+ $this->yind[] = $yi;
+ }
+ for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
+ $line = $from_lines[$xi];
+ if ( ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) )
+ continue;
+ $this->xv[] = $line;
+ $this->xind[] = $xi;
+ }
+
+ // Find the LCS.
+ $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv));
+
+ // Merge edits when possible
+ $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged);
+ $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged);
+
+ // Compute the edit operations.
+ $edits = array();
+ $xi = $yi = 0;
+ while ($xi < $n_from || $yi < $n_to) {
+ USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]);
+ USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]);
+
+ // Skip matching "snake".
+ $copy = array();
+ while ( $xi < $n_from && $yi < $n_to
+ && !$this->xchanged[$xi] && !$this->ychanged[$yi]) {
+ $copy[] = $from_lines[$xi++];
+ ++$yi;
+ }
+ if ($copy)
+ $edits[] = new _DiffOp_Copy($copy);
+
+ // Find deletes & adds.
+ $delete = array();
+ while ($xi < $n_from && $this->xchanged[$xi])
+ $delete[] = $from_lines[$xi++];
+
+ $add = array();
+ while ($yi < $n_to && $this->ychanged[$yi])
+ $add[] = $to_lines[$yi++];
+
+ if ($delete && $add)
+ $edits[] = new _DiffOp_Change($delete, $add);
+ elseif ($delete)
+ $edits[] = new _DiffOp_Delete($delete);
+ elseif ($add)
+ $edits[] = new _DiffOp_Add($add);
+ }
+ wfProfileOut( $fname );
+ return $edits;
+ }
+
+ /**
+ * Returns the whole line if it's small enough, or the MD5 hash otherwise
+ */
+ function _line_hash( $line ) {
+ if ( strlen( $line ) > MAX_DIFF_XREF_LENGTH ) {
+ return md5( $line );
+ } else {
+ return $line;
+ }
+ }
+
+
+ /* Divide the Largest Common Subsequence (LCS) of the sequences
+ * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally
+ * sized segments.
+ *
+ * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an
+ * array of NCHUNKS+1 (X, Y) indexes giving the diving points between
+ * sub sequences. The first sub-sequence is contained in [X0, X1),
+ * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note
+ * that (X0, Y0) == (XOFF, YOFF) and
+ * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM).
+ *
+ * This function assumes that the first lines of the specified portions
+ * of the two files do not match, and likewise that the last lines do not
+ * match. The caller must trim matching lines from the beginning and end
+ * of the portions it is going to specify.
+ */
+ function _diag ($xoff, $xlim, $yoff, $ylim, $nchunks) {
+ $fname = '_DiffEngine::_diag';
+ wfProfileIn( $fname );
+ $flip = false;
+
+ if ($xlim - $xoff > $ylim - $yoff) {
+ // Things seems faster (I'm not sure I understand why)
+ // when the shortest sequence in X.
+ $flip = true;
+ list ($xoff, $xlim, $yoff, $ylim)
+ = array( $yoff, $ylim, $xoff, $xlim);
+ }
+
+ if ($flip)
+ for ($i = $ylim - 1; $i >= $yoff; $i--)
+ $ymatches[$this->xv[$i]][] = $i;
+ else
+ for ($i = $ylim - 1; $i >= $yoff; $i--)
+ $ymatches[$this->yv[$i]][] = $i;
+
+ $this->lcs = 0;
+ $this->seq[0]= $yoff - 1;
+ $this->in_seq = array();
+ $ymids[0] = array();
+
+ $numer = $xlim - $xoff + $nchunks - 1;
+ $x = $xoff;
+ for ($chunk = 0; $chunk < $nchunks; $chunk++) {
+ wfProfileIn( "$fname-chunk" );
+ if ($chunk > 0)
+ for ($i = 0; $i <= $this->lcs; $i++)
+ $ymids[$i][$chunk-1] = $this->seq[$i];
+
+ $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks);
+ for ( ; $x < $x1; $x++) {
+ $line = $flip ? $this->yv[$x] : $this->xv[$x];
+ if (empty($ymatches[$line]))
+ continue;
+ $matches = $ymatches[$line];
+ reset($matches);
+ while (list ($junk, $y) = each($matches))
+ if (empty($this->in_seq[$y])) {
+ $k = $this->_lcs_pos($y);
+ USE_ASSERTS && assert($k > 0);
+ $ymids[$k] = $ymids[$k-1];
+ break;
+ }
+ while (list ($junk, $y) = each($matches)) {
+ if ($y > $this->seq[$k-1]) {
+ USE_ASSERTS && assert($y < $this->seq[$k]);
+ // Optimization: this is a common case:
+ // next match is just replacing previous match.
+ $this->in_seq[$this->seq[$k]] = false;
+ $this->seq[$k] = $y;
+ $this->in_seq[$y] = 1;
+ } else if (empty($this->in_seq[$y])) {
+ $k = $this->_lcs_pos($y);
+ USE_ASSERTS && assert($k > 0);
+ $ymids[$k] = $ymids[$k-1];
+ }
+ }
+ }
+ wfProfileOut( "$fname-chunk" );
+ }
+
+ $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff);
+ $ymid = $ymids[$this->lcs];
+ for ($n = 0; $n < $nchunks - 1; $n++) {
+ $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks);
+ $y1 = $ymid[$n] + 1;
+ $seps[] = $flip ? array($y1, $x1) : array($x1, $y1);
+ }
+ $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim);
+
+ wfProfileOut( $fname );
+ return array($this->lcs, $seps);
+ }
+
+ function _lcs_pos ($ypos) {
+ $fname = '_DiffEngine::_lcs_pos';
+ wfProfileIn( $fname );
+
+ $end = $this->lcs;
+ if ($end == 0 || $ypos > $this->seq[$end]) {
+ $this->seq[++$this->lcs] = $ypos;
+ $this->in_seq[$ypos] = 1;
+ wfProfileOut( $fname );
+ return $this->lcs;
+ }
+
+ $beg = 1;
+ while ($beg < $end) {
+ $mid = (int)(($beg + $end) / 2);
+ if ( $ypos > $this->seq[$mid] )
+ $beg = $mid + 1;
+ else
+ $end = $mid;
+ }
+
+ USE_ASSERTS && assert($ypos != $this->seq[$end]);
+
+ $this->in_seq[$this->seq[$end]] = false;
+ $this->seq[$end] = $ypos;
+ $this->in_seq[$ypos] = 1;
+ wfProfileOut( $fname );
+ return $end;
+ }
+
+ /* Find LCS of two sequences.
+ *
+ * The results are recorded in the vectors $this->{x,y}changed[], by
+ * storing a 1 in the element for each line that is an insertion
+ * or deletion (ie. is not in the LCS).
+ *
+ * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.
+ *
+ * Note that XLIM, YLIM are exclusive bounds.
+ * All line numbers are origin-0 and discarded lines are not counted.
+ */
+ function _compareseq ($xoff, $xlim, $yoff, $ylim) {
+ $fname = '_DiffEngine::_compareseq';
+ wfProfileIn( $fname );
+
+ // Slide down the bottom initial diagonal.
+ while ($xoff < $xlim && $yoff < $ylim
+ && $this->xv[$xoff] == $this->yv[$yoff]) {
+ ++$xoff;
+ ++$yoff;
+ }
+
+ // Slide up the top initial diagonal.
+ while ($xlim > $xoff && $ylim > $yoff
+ && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) {
+ --$xlim;
+ --$ylim;
+ }
+
+ if ($xoff == $xlim || $yoff == $ylim)
+ $lcs = 0;
+ else {
+ // This is ad hoc but seems to work well.
+ //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5);
+ //$nchunks = max(2,min(8,(int)$nchunks));
+ $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1;
+ list ($lcs, $seps)
+ = $this->_diag($xoff,$xlim,$yoff, $ylim,$nchunks);
+ }
+
+ if ($lcs == 0) {
+ // X and Y sequences have no common subsequence:
+ // mark all changed.
+ while ($yoff < $ylim)
+ $this->ychanged[$this->yind[$yoff++]] = 1;
+ while ($xoff < $xlim)
+ $this->xchanged[$this->xind[$xoff++]] = 1;
+ } else {
+ // Use the partitions to split this problem into subproblems.
+ reset($seps);
+ $pt1 = $seps[0];
+ while ($pt2 = next($seps)) {
+ $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]);
+ $pt1 = $pt2;
+ }
+ }
+ wfProfileOut( $fname );
+ }
+
+ /* Adjust inserts/deletes of identical lines to join changes
+ * as much as possible.
+ *
+ * We do something when a run of changed lines include a
+ * line at one end and has an excluded, identical line at the other.
+ * We are free to choose which identical line is included.
+ * `compareseq' usually chooses the one at the beginning,
+ * but usually it is cleaner to consider the following identical line
+ * to be the "change".
+ *
+ * This is extracted verbatim from analyze.c (GNU diffutils-2.7).
+ */
+ function _shift_boundaries ($lines, &$changed, $other_changed) {
+ $fname = '_DiffEngine::_shift_boundaries';
+ wfProfileIn( $fname );
+ $i = 0;
+ $j = 0;
+
+ USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)');
+ $len = sizeof($lines);
+ $other_len = sizeof($other_changed);
+
+ while (1) {
+ /*
+ * Scan forwards to find beginning of another run of changes.
+ * Also keep track of the corresponding point in the other file.
+ *
+ * Throughout this code, $i and $j are adjusted together so that
+ * the first $i elements of $changed and the first $j elements
+ * of $other_changed both contain the same number of zeros
+ * (unchanged lines).
+ * Furthermore, $j is always kept so that $j == $other_len or
+ * $other_changed[$j] == false.
+ */
+ while ($j < $other_len && $other_changed[$j])
+ $j++;
+
+ while ($i < $len && ! $changed[$i]) {
+ USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]');
+ $i++; $j++;
+ while ($j < $other_len && $other_changed[$j])
+ $j++;
+ }
+
+ if ($i == $len)
+ break;
+
+ $start = $i;
+
+ // Find the end of this run of changes.
+ while (++$i < $len && $changed[$i])
+ continue;
+
+ do {
+ /*
+ * Record the length of this run of changes, so that
+ * we can later determine whether the run has grown.
+ */
+ $runlength = $i - $start;
+
+ /*
+ * Move the changed region back, so long as the
+ * previous unchanged line matches the last changed one.
+ * This merges with previous changed regions.
+ */
+ while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) {
+ $changed[--$start] = 1;
+ $changed[--$i] = false;
+ while ($start > 0 && $changed[$start - 1])
+ $start--;
+ USE_ASSERTS && assert('$j > 0');
+ while ($other_changed[--$j])
+ continue;
+ USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]');
+ }
+
+ /*
+ * Set CORRESPONDING to the end of the changed run, at the last
+ * point where it corresponds to a changed run in the other file.
+ * CORRESPONDING == LEN means no such point has been found.
+ */
+ $corresponding = $j < $other_len ? $i : $len;
+
+ /*
+ * Move the changed region forward, so long as the
+ * first changed line matches the following unchanged one.
+ * This merges with following changed regions.
+ * Do this second, so that if there are no merges,
+ * the changed region is moved forward as far as possible.
+ */
+ while ($i < $len && $lines[$start] == $lines[$i]) {
+ $changed[$start++] = false;
+ $changed[$i++] = 1;
+ while ($i < $len && $changed[$i])
+ $i++;
+
+ USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]');
+ $j++;
+ if ($j < $other_len && $other_changed[$j]) {
+ $corresponding = $i;
+ while ($j < $other_len && $other_changed[$j])
+ $j++;
+ }
+ }
+ } while ($runlength != $i - $start);
+
+ /*
+ * If possible, move the fully-merged run of changes
+ * back to a corresponding run in the other file.
+ */
+ while ($corresponding < $i) {
+ $changed[--$start] = 1;
+ $changed[--$i] = 0;
+ USE_ASSERTS && assert('$j > 0');
+ while ($other_changed[--$j])
+ continue;
+ USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]');
+ }
+ }
+ wfProfileOut( $fname );
+ }
+}
+
+/**
+ * Class representing a 'diff' between two sequences of strings.
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class Diff
+{
+ var $edits;
+
+ /**
+ * Constructor.
+ * Computes diff between sequences of strings.
+ *
+ * @param $from_lines array An array of strings.
+ * (Typically these are lines from a file.)
+ * @param $to_lines array An array of strings.
+ */
+ function Diff($from_lines, $to_lines) {
+ $eng = new _DiffEngine;
+ $this->edits = $eng->diff($from_lines, $to_lines);
+ //$this->_check($from_lines, $to_lines);
+ }
+
+ /**
+ * Compute reversed Diff.
+ *
+ * SYNOPSIS:
+ *
+ * $diff = new Diff($lines1, $lines2);
+ * $rev = $diff->reverse();
+ * @return object A Diff object representing the inverse of the
+ * original diff.
+ */
+ function reverse () {
+ $rev = $this;
+ $rev->edits = array();
+ foreach ($this->edits as $edit) {
+ $rev->edits[] = $edit->reverse();
+ }
+ return $rev;
+ }
+
+ /**
+ * Check for empty diff.
+ *
+ * @return bool True iff two sequences were identical.
+ */
+ function isEmpty () {
+ foreach ($this->edits as $edit) {
+ if ($edit->type != 'copy')
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Compute the length of the Longest Common Subsequence (LCS).
+ *
+ * This is mostly for diagnostic purposed.
+ *
+ * @return int The length of the LCS.
+ */
+ function lcs () {
+ $lcs = 0;
+ foreach ($this->edits as $edit) {
+ if ($edit->type == 'copy')
+ $lcs += sizeof($edit->orig);
+ }
+ return $lcs;
+ }
+
+ /**
+ * Get the original set of lines.
+ *
+ * This reconstructs the $from_lines parameter passed to the
+ * constructor.
+ *
+ * @return array The original sequence of strings.
+ */
+ function orig() {
+ $lines = array();
+
+ foreach ($this->edits as $edit) {
+ if ($edit->orig)
+ array_splice($lines, sizeof($lines), 0, $edit->orig);
+ }
+ return $lines;
+ }
+
+ /**
+ * Get the closing set of lines.
+ *
+ * This reconstructs the $to_lines parameter passed to the
+ * constructor.
+ *
+ * @return array The sequence of strings.
+ */
+ function closing() {
+ $lines = array();
+
+ foreach ($this->edits as $edit) {
+ if ($edit->closing)
+ array_splice($lines, sizeof($lines), 0, $edit->closing);
+ }
+ return $lines;
+ }
+
+ /**
+ * Check a Diff for validity.
+ *
+ * This is here only for debugging purposes.
+ */
+ function _check ($from_lines, $to_lines) {
+ $fname = 'Diff::_check';
+ wfProfileIn( $fname );
+ if (serialize($from_lines) != serialize($this->orig()))
+ trigger_error("Reconstructed original doesn't match", E_USER_ERROR);
+ if (serialize($to_lines) != serialize($this->closing()))
+ trigger_error("Reconstructed closing doesn't match", E_USER_ERROR);
+
+ $rev = $this->reverse();
+ if (serialize($to_lines) != serialize($rev->orig()))
+ trigger_error("Reversed original doesn't match", E_USER_ERROR);
+ if (serialize($from_lines) != serialize($rev->closing()))
+ trigger_error("Reversed closing doesn't match", E_USER_ERROR);
+
+
+ $prevtype = 'none';
+ foreach ($this->edits as $edit) {
+ if ( $prevtype == $edit->type )
+ trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
+ $prevtype = $edit->type;
+ }
+
+ $lcs = $this->lcs();
+ trigger_error('Diff okay: LCS = '.$lcs, E_USER_NOTICE);
+ wfProfileOut( $fname );
+ }
+}
+
+/**
+ * FIXME: bad name.
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class MappedDiff extends Diff
+{
+ /**
+ * Constructor.
+ *
+ * Computes diff between sequences of strings.
+ *
+ * This can be used to compute things like
+ * case-insensitve diffs, or diffs which ignore
+ * changes in white-space.
+ *
+ * @param $from_lines array An array of strings.
+ * (Typically these are lines from a file.)
+ *
+ * @param $to_lines array An array of strings.
+ *
+ * @param $mapped_from_lines array This array should
+ * have the same size number of elements as $from_lines.
+ * The elements in $mapped_from_lines and
+ * $mapped_to_lines are what is actually compared
+ * when computing the diff.
+ *
+ * @param $mapped_to_lines array This array should
+ * have the same number of elements as $to_lines.
+ */
+ function MappedDiff($from_lines, $to_lines,
+ $mapped_from_lines, $mapped_to_lines) {
+ $fname = 'MappedDiff::MappedDiff';
+ wfProfileIn( $fname );
+
+ assert(sizeof($from_lines) == sizeof($mapped_from_lines));
+ assert(sizeof($to_lines) == sizeof($mapped_to_lines));
+
+ $this->Diff($mapped_from_lines, $mapped_to_lines);
+
+ $xi = $yi = 0;
+ for ($i = 0; $i < sizeof($this->edits); $i++) {
+ $orig = &$this->edits[$i]->orig;
+ if (is_array($orig)) {
+ $orig = array_slice($from_lines, $xi, sizeof($orig));
+ $xi += sizeof($orig);
+ }
+
+ $closing = &$this->edits[$i]->closing;
+ if (is_array($closing)) {
+ $closing = array_slice($to_lines, $yi, sizeof($closing));
+ $yi += sizeof($closing);
+ }
+ }
+ wfProfileOut( $fname );
+ }
+}
+
+/**
+ * A class to format Diffs
+ *
+ * This class formats the diff in classic diff format.
+ * It is intended that this class be customized via inheritance,
+ * to obtain fancier outputs.
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class DiffFormatter
+{
+ /**
+ * Number of leading context "lines" to preserve.
+ *
+ * This should be left at zero for this class, but subclasses
+ * may want to set this to other values.
+ */
+ var $leading_context_lines = 0;
+
+ /**
+ * Number of trailing context "lines" to preserve.
+ *
+ * This should be left at zero for this class, but subclasses
+ * may want to set this to other values.
+ */
+ var $trailing_context_lines = 0;
+
+ /**
+ * Format a diff.
+ *
+ * @param $diff object A Diff object.
+ * @return string The formatted output.
+ */
+ function format($diff) {
+ $fname = 'DiffFormatter::format';
+ wfProfileIn( $fname );
+
+ $xi = $yi = 1;
+ $block = false;
+ $context = array();
+
+ $nlead = $this->leading_context_lines;
+ $ntrail = $this->trailing_context_lines;
+
+ $this->_start_diff();
+
+ foreach ($diff->edits as $edit) {
+ if ($edit->type == 'copy') {
+ if (is_array($block)) {
+ if (sizeof($edit->orig) <= $nlead + $ntrail) {
+ $block[] = $edit;
+ }
+ else{
+ if ($ntrail) {
+ $context = array_slice($edit->orig, 0, $ntrail);
+ $block[] = new _DiffOp_Copy($context);
+ }
+ $this->_block($x0, $ntrail + $xi - $x0,
+ $y0, $ntrail + $yi - $y0,
+ $block);
+ $block = false;
+ }
+ }
+ $context = $edit->orig;
+ }
+ else {
+ if (! is_array($block)) {
+ $context = array_slice($context, sizeof($context) - $nlead);
+ $x0 = $xi - sizeof($context);
+ $y0 = $yi - sizeof($context);
+ $block = array();
+ if ($context)
+ $block[] = new _DiffOp_Copy($context);
+ }
+ $block[] = $edit;
+ }
+
+ if ($edit->orig)
+ $xi += sizeof($edit->orig);
+ if ($edit->closing)
+ $yi += sizeof($edit->closing);
+ }
+
+ if (is_array($block))
+ $this->_block($x0, $xi - $x0,
+ $y0, $yi - $y0,
+ $block);
+
+ $end = $this->_end_diff();
+ wfProfileOut( $fname );
+ return $end;
+ }
+
+ function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) {
+ $fname = 'DiffFormatter::_block';
+ wfProfileIn( $fname );
+ $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen));
+ foreach ($edits as $edit) {
+ if ($edit->type == 'copy')
+ $this->_context($edit->orig);
+ elseif ($edit->type == 'add')
+ $this->_added($edit->closing);
+ elseif ($edit->type == 'delete')
+ $this->_deleted($edit->orig);
+ elseif ($edit->type == 'change')
+ $this->_changed($edit->orig, $edit->closing);
+ else
+ trigger_error('Unknown edit type', E_USER_ERROR);
+ }
+ $this->_end_block();
+ wfProfileOut( $fname );
+ }
+
+ function _start_diff() {
+ ob_start();
+ }
+
+ function _end_diff() {
+ $val = ob_get_contents();
+ ob_end_clean();
+ return $val;
+ }
+
+ function _block_header($xbeg, $xlen, $ybeg, $ylen) {
+ if ($xlen > 1)
+ $xbeg .= "," . ($xbeg + $xlen - 1);
+ if ($ylen > 1)
+ $ybeg .= "," . ($ybeg + $ylen - 1);
+
+ return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg;
+ }
+
+ function _start_block($header) {
+ echo $header;
+ }
+
+ function _end_block() {
+ }
+
+ function _lines($lines, $prefix = ' ') {
+ foreach ($lines as $line)
+ echo "$prefix $line\n";
+ }
+
+ function _context($lines) {
+ $this->_lines($lines);
+ }
+
+ function _added($lines) {
+ $this->_lines($lines, '>');
+ }
+ function _deleted($lines) {
+ $this->_lines($lines, '<');
+ }
+
+ function _changed($orig, $closing) {
+ $this->_deleted($orig);
+ echo "---\n";
+ $this->_added($closing);
+ }
+}
+
+
+/**
+ * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3
+ *
+ */
+
+define('NBSP', '&#160;'); // iso-8859-x non-breaking space.
+
+/**
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class _HWLDF_WordAccumulator {
+ function _HWLDF_WordAccumulator () {
+ $this->_lines = array();
+ $this->_line = '';
+ $this->_group = '';
+ $this->_tag = '';
+ }
+
+ function _flushGroup ($new_tag) {
+ if ($this->_group !== '') {
+ if ($this->_tag == 'mark')
+ $this->_line .= '<span class="diffchange">' .
+ htmlspecialchars ( $this->_group ) . '</span>';
+ else
+ $this->_line .= htmlspecialchars ( $this->_group );
+ }
+ $this->_group = '';
+ $this->_tag = $new_tag;
+ }
+
+ function _flushLine ($new_tag) {
+ $this->_flushGroup($new_tag);
+ if ($this->_line != '')
+ array_push ( $this->_lines, $this->_line );
+ else
+ # make empty lines visible by inserting an NBSP
+ array_push ( $this->_lines, NBSP );
+ $this->_line = '';
+ }
+
+ function addWords ($words, $tag = '') {
+ if ($tag != $this->_tag)
+ $this->_flushGroup($tag);
+
+ foreach ($words as $word) {
+ // new-line should only come as first char of word.
+ if ($word == '')
+ continue;
+ if ($word[0] == "\n") {
+ $this->_flushLine($tag);
+ $word = substr($word, 1);
+ }
+ assert(!strstr($word, "\n"));
+ $this->_group .= $word;
+ }
+ }
+
+ function getLines() {
+ $this->_flushLine('~done');
+ return $this->_lines;
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class WordLevelDiff extends MappedDiff
+{
+ function WordLevelDiff ($orig_lines, $closing_lines) {
+ $fname = 'WordLevelDiff::WordLevelDiff';
+ wfProfileIn( $fname );
+
+ list ($orig_words, $orig_stripped) = $this->_split($orig_lines);
+ list ($closing_words, $closing_stripped) = $this->_split($closing_lines);
+
+ $this->MappedDiff($orig_words, $closing_words,
+ $orig_stripped, $closing_stripped);
+ wfProfileOut( $fname );
+ }
+
+ function _split($lines) {
+ $fname = 'WordLevelDiff::_split';
+ wfProfileIn( $fname );
+
+ $words = array();
+ $stripped = array();
+ $first = true;
+ foreach ( $lines as $line ) {
+ # If the line is too long, just pretend the entire line is one big word
+ # This prevents resource exhaustion problems
+ if ( $first ) {
+ $first = false;
+ } else {
+ $words[] = "\n";
+ $stripped[] = "\n";
+ }
+ if ( strlen( $line ) > MAX_DIFF_LINE ) {
+ $words[] = $line;
+ $stripped[] = $line;
+ } else {
+ if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs',
+ $line, $m))
+ {
+ $words = array_merge( $words, $m[0] );
+ $stripped = array_merge( $stripped, $m[1] );
+ }
+ }
+ }
+ wfProfileOut( $fname );
+ return array($words, $stripped);
+ }
+
+ function orig () {
+ $fname = 'WordLevelDiff::orig';
+ wfProfileIn( $fname );
+ $orig = new _HWLDF_WordAccumulator;
+
+ foreach ($this->edits as $edit) {
+ if ($edit->type == 'copy')
+ $orig->addWords($edit->orig);
+ elseif ($edit->orig)
+ $orig->addWords($edit->orig, 'mark');
+ }
+ $lines = $orig->getLines();
+ wfProfileOut( $fname );
+ return $lines;
+ }
+
+ function closing () {
+ $fname = 'WordLevelDiff::closing';
+ wfProfileIn( $fname );
+ $closing = new _HWLDF_WordAccumulator;
+
+ foreach ($this->edits as $edit) {
+ if ($edit->type == 'copy')
+ $closing->addWords($edit->closing);
+ elseif ($edit->closing)
+ $closing->addWords($edit->closing, 'mark');
+ }
+ $lines = $closing->getLines();
+ wfProfileOut( $fname );
+ return $lines;
+ }
+}
+
+/**
+ * Wikipedia Table style diff formatter.
+ * @todo document
+ * @private
+ * @package MediaWiki
+ * @subpackage DifferenceEngine
+ */
+class TableDiffFormatter extends DiffFormatter
+{
+ function TableDiffFormatter() {
+ $this->leading_context_lines = 2;
+ $this->trailing_context_lines = 2;
+ }
+
+ function _block_header( $xbeg, $xlen, $ybeg, $ylen ) {
+ $r = '<tr><td colspan="2" align="left"><strong><!--LINE '.$xbeg."--></strong></td>\n" .
+ '<td colspan="2" align="left"><strong><!--LINE '.$ybeg."--></strong></td></tr>\n";
+ return $r;
+ }
+
+ function _start_block( $header ) {
+ echo $header;
+ }
+
+ function _end_block() {
+ }
+
+ function _lines( $lines, $prefix=' ', $color='white' ) {
+ }
+
+ # HTML-escape parameter before calling this
+ function addedLine( $line ) {
+ return "<td>+</td><td class='diff-addedline'>{$line}</td>";
+ }
+
+ # HTML-escape parameter before calling this
+ function deletedLine( $line ) {
+ return "<td>-</td><td class='diff-deletedline'>{$line}</td>";
+ }
+
+ # HTML-escape parameter before calling this
+ function contextLine( $line ) {
+ return "<td> </td><td class='diff-context'>{$line}</td>";
+ }
+
+ function emptyLine() {
+ return '<td colspan="2">&nbsp;</td>';
+ }
+
+ function _added( $lines ) {
+ foreach ($lines as $line) {
+ echo '<tr>' . $this->emptyLine() .
+ $this->addedLine( htmlspecialchars ( $line ) ) . "</tr>\n";
+ }
+ }
+
+ function _deleted($lines) {
+ foreach ($lines as $line) {
+ echo '<tr>' . $this->deletedLine( htmlspecialchars ( $line ) ) .
+ $this->emptyLine() . "</tr>\n";
+ }
+ }
+
+ function _context( $lines ) {
+ foreach ($lines as $line) {
+ echo '<tr>' .
+ $this->contextLine( htmlspecialchars ( $line ) ) .
+ $this->contextLine( htmlspecialchars ( $line ) ) . "</tr>\n";
+ }
+ }
+
+ function _changed( $orig, $closing ) {
+ $fname = 'TableDiffFormatter::_changed';
+ wfProfileIn( $fname );
+
+ $diff = new WordLevelDiff( $orig, $closing );
+ $del = $diff->orig();
+ $add = $diff->closing();
+
+ # Notice that WordLevelDiff returns HTML-escaped output.
+ # Hence, we will be calling addedLine/deletedLine without HTML-escaping.
+
+ while ( $line = array_shift( $del ) ) {
+ $aline = array_shift( $add );
+ echo '<tr>' . $this->deletedLine( $line ) .
+ $this->addedLine( $aline ) . "</tr>\n";
+ }
+ foreach ($add as $line) { # If any leftovers
+ echo '<tr>' . $this->emptyLine() .
+ $this->addedLine( $line ) . "</tr>\n";
+ }
+ wfProfileOut( $fname );
+ }
+}
+
+?>