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( $diffOnly = false ) { global $wgUser, $wgOut, $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=<<setArticleFlag( false ); if ( ! $this->loadRevisionData() ) { $t = $this->mTitle->getPrefixedText() . " (Diff: {$this->mOldid}, {$this->mNewid})"; $mtext = wfMsg( 'missingarticle', "$t" ); $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(); $this->renderNewRevision(); // should we respect $diffOnly here or not? 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(); if ( $this->mNewRev->isCurrent() && $wgUser->isAllowed('rollback') ) { $rollback = '   ' . $sk->generateRollback( $this->mNewRev ); } 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 = ' '; } else { $nextlink = $sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'nextdiff' ), 'diff=next&oldid='.$this->mNewid, '', '', 'id="differences-nextlink"' ); } $oldminor = ''; $newminor = ''; if ($this->mOldRev->mMinorEdit == 1) { $oldminor = wfElement( 'span', array( 'class' => 'minor' ), wfMsg( 'minoreditletter') ) . ' '; } if ($this->mNewRev->mMinorEdit == 1) { $newminor = wfElement( 'span', array( 'class' => 'minor' ), wfMsg( 'minoreditletter') ) . ' '; } $oldHeader = "{$this->mOldtitle}
" . $sk->revUserTools( $this->mOldRev ) . "
" . $oldminor . $sk->revComment( $this->mOldRev, !$diffOnly ) . "
" . $prevlink; $newHeader = "{$this->mNewtitle}
" . $sk->revUserTools( $this->mNewRev ) . " $rollback
" . $newminor . $sk->revComment( $this->mNewRev, !$diffOnly ) . "
" . $nextlink . $patrol; $this->showDiff( $oldHeader, $newHeader ); if ( !$diffOnly ) $this->renderNewRevision(); wfProfileOut( $fname ); } /** * Show the new revision of the page. */ function renderNewRevision() { global $wgOut; $fname = 'DifferenceEngine::renderNewRevision'; wfProfileIn( $fname ); $wgOut->addHTML( "

{$this->mPagetitle}

\n" ); #add deleted rev tag if needed if ( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) { $wgOut->addWikiText( wfMsg( 'rev-deleted-text-permission' ) ); } if( !$this->mNewRev->isCurrent() ) { $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false ); } $this->loadNewText(); if( is_object( $this->mNewRev ) ) { $wgOut->setRevisionId( $this->mNewRev->getId() ); } $wgOut->addWikiTextTidy( $this->mNewtext ); if( !$this->mNewRev->isCurrent() ) { $wgOut->parserOptions()->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})"; $mtext = wfMsg( 'missingarticle', "$t" ); $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"' ); $header = "
{$this->mOldtitle}
" . $sk->revUserTools( $this->mNewRev ) . "
" . $sk->revComment( $this->mNewRev ) . "
" . $nextlink . "
\n"; $wgOut->addHTML( $header ); $wgOut->setSubtitle( wfMsg( 'difference' ) ); $wgOut->setRobotpolicy( 'noindex,nofollow' ); 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', "(fixme, bug)" ) ); 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 { $multi = $this->getMultiNotice(); return $this->addHeader( $body, $otitle, $ntitle, $multi ); } } /** * Get the diff table body, without header * Results are cached * Returns false on error */ function getDiffBody() { global $wgMemc; $fname = 'DifferenceEngine::getDiffBody'; wfProfileIn( $fname ); // Cacheable? $key = false; if ( $this->mOldid && $this->mNewid ) { // Try cache $key = wfMemcKey( 'diff', 'oldid', $this->mOldid, 'newid', $this->mNewid ); $difftext = $wgMemc->get( $key ); if ( $difftext ) { wfIncrStats( 'diff_cache_hit' ); $difftext = $this->localiseLineNumbers( $difftext ); $difftext .= "\n\n"; wfProfileOut( $fname ); return $difftext; } } #loadtext is permission safe, this just clears out the diff if ( !$this->loadText() ) { wfProfileOut( $fname ); return false; } else if ( $this->mOldRev && !$this->mOldRev->userCan(Revision::DELETED_TEXT) ) { return ''; } else if ( $this->mNewRev && !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) { return ''; } $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( $text ) { return preg_replace_callback( '//', array( &$this, 'localiseLineNumbersCb' ), $text ); } function localiseLineNumbersCb( $matches ) { global $wgLang; return wfMsgExt( 'lineno', array('parseinline'), $wgLang->formatNum( $matches[1] ) ); } /** * If there are revisions between the ones being compared, return a note saying so. */ function getMultiNotice() { if ( !is_object($this->mOldRev) || !is_object($this->mNewRev) ) return ''; if( !$this->mOldPage->equals( $this->mNewPage ) ) { // Comparing two different pages? Count would be meaningless. return ''; } $oldid = $this->mOldRev->getId(); $newid = $this->mNewRev->getId(); if ( $oldid > $newid ) { $tmp = $oldid; $oldid = $newid; $newid = $tmp; } $n = $this->mTitle->countRevisionsBetween( $oldid, $newid ); if ( !$n ) return ''; return wfMsgExt( 'diff-multi', array( 'parseinline' ), $n ); } /** * Add the header to a diff body */ function addHeader( $diff, $otitle, $ntitle, $multi = '' ) { global $wgOut; if ( $this->mOldRev && $this->mOldRev->isDeleted(Revision::DELETED_TEXT) ) { $otitle = ''.$otitle.''; } if ( $this->mNewRev && $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) { $ntitle = ''.$ntitle.''; } $header = " "; if ( $multi != '' ) $header .= ""; return $header . $diff . "
{$otitle} {$ntitle}
{$multi}
"; } /** * 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' ); $this->mNewtitle = "{$this->mPagetitle} ($timestamp)" . " (" . htmlspecialchars( wfMsg( 'editold' ) ) . ")"; } else { $newLink = $this->mNewPage->escapeLocalUrl( 'oldid=' . $this->mNewid ); $newEdit = $this->mNewPage->escapeLocalUrl( 'action=edit&oldid=' . $this->mNewid ); $this->mPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $timestamp ) ); $this->mNewtitle = "{$this->mPagetitle}" . " (" . htmlspecialchars( wfMsg( 'editold' ) ) . ")"; } // 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 = "" . htmlspecialchars( wfMsg( 'revisionasof', $t ) ) . " (" . htmlspecialchars( wfMsg( 'editold' ) ) . ")"; //now that we considered old rev, we can make undo link (bug 8133, multi-edit undo) $newUndo = $this->mNewPage->escapeLocalUrl( 'action=edit&undoafter=' . $this->mOldid . '&undo=' . $this->mNewid); $this->mNewtitle .= " (" . htmlspecialchars( wfMsg( 'editundo' ) ) . ")"; } 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->revText(); if ( $this->mOldtext === false ) { return false; } } if ( $this->mNewRev ) { $this->mNewtext = $this->mNewRev->revText(); 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 // You may copy this code freely under the conditions of the GPL. // define('USE_ASSERTS', function_exists('assert')); /** * @todo document * @private * @addtogroup 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 * @addtogroup 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 * @addtogroup 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 * @addtogroup 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 * @addtogroup 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, $this->orig); } } /** * Class used internally by Diff to actually compute the diffs. * * The algorithm used here is mostly lifted from the perl module * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip * * More ideas are taken from: * http://www.ics.uci.edu/~eppstein/161/960229.html * * Some ideas are (and a bit of code) are from from analyze.c, from GNU * diffutils-2.7, which can be found at: * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz * * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) * are my own. * * Line length limits for robustness added by Tim Starling, 2005-08-31 * * @author Geoffrey T. Dairiki, Tim Starling * @private * @addtogroup DifferenceEngine */ class _DiffEngine { const MAX_XREF_LENGTH = 10000; function diff ($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 ) > self::MAX_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 * @addtogroup 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 ); } } /** * @todo document, bad name. * @private * @addtogroup 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 * @addtogroup 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', ' '); // iso-8859-x non-breaking space. /** * @todo document * @private * @addtogroup 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 == 'ins') $this->_line .= '' . htmlspecialchars ( $this->_group ) . ''; elseif ($this->_tag == 'del') $this->_line .= '' . htmlspecialchars ( $this->_group ) . ''; 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 $this->_lines; } } /** * @todo document * @private * @addtogroup DifferenceEngine */ class WordLevelDiff extends MappedDiff { const MAX_LINE_LENGTH = 10000; function WordLevelDiff ($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 ) > self::MAX_LINE_LENGTH ) { $words[] = $line; $stripped[] = $line; } else { $m = array(); 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, 'del'); } $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, 'ins'); } $lines = $closing->getLines(); wfProfileOut( $fname ); return $lines; } } /** * Wikipedia Table style diff formatter. * @todo document * @private * @addtogroup 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 = '\n" . '\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( $line ) { return "+{$line}"; } # HTML-escape parameter before calling this function deletedLine( $line ) { return "-{$line}"; } # HTML-escape parameter before calling this function contextLine( $line ) { return " {$line}"; } function emptyLine() { return ' '; } function _added( $lines ) { foreach ($lines as $line) { echo '' . $this->emptyLine() . $this->addedLine( htmlspecialchars ( $line ) ) . "\n"; } } function _deleted($lines) { foreach ($lines as $line) { echo '' . $this->deletedLine( htmlspecialchars ( $line ) ) . $this->emptyLine() . "\n"; } } function _context( $lines ) { foreach ($lines as $line) { echo '' . $this->contextLine( htmlspecialchars ( $line ) ) . $this->contextLine( htmlspecialchars ( $line ) ) . "\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 '' . $this->deletedLine( $line ) . $this->addedLine( $aline ) . "\n"; } foreach ($add as $line) { # If any leftovers echo '' . $this->emptyLine() . $this->addedLine( $line ) . "\n"; } wfProfileOut( $fname ); } } ?>